- General Medicine
On Being a Physician (SAGHE)
By Elizabeth G Nabel, MD, FACPPurchase PDF
On Being a Physician (SAGHE)Purchase PDF
The role of a physician as healer has grown more complex, and emphasis will increasingly be on patient and family-centric care. Physicians must provide compassionate, appropriate, and effective patient care by demonstrating competence in the attributes that are essential to successful medical practice. Beyond simply gaining medical knowledge, modern physicians embrace lifelong learning and need effective interpersonal and communication skills. Medical professionalism encompasses multiple attributes, and physicians are increasingly becoming part of a larger health care team. To ensure that physicians are trained in an environment that fosters innovation and alleviates administrative burdens, the Accreditation Council for Graduate Medical Education has recently revamped the standards of accreditation for today’s more than 130 specialties and subspecialties.
This review contains 6 references.
Ethical and Social Issues in Medicine (SAGHE)
By Roberta Springer Loewy, PhD (PHIL, ETHICS); Erich H. Loewy, MD, FACP (deceased); Faith T. Fitzgerald, MD, MACPPurchase PDF
Ethical and Social Issues in Medicine (SAGHE)Purchase PDF
So rapidly has the field of health care ethics continued to grow that, when recently “googled,” the term produced 28.2 million hits. The challenge is to address the ethical and social issues in medicine in this very limited article space. It remains an impossible task to present more than a superficial discussion of these complex issues and the complicated cases in which they are to be found. Like good medicine, good ethics cannot be practiced by algorithm. The authors have opted to provide an operational guide to help clinicians sort through the ethical and social quandaries they must face on a daily basis. To that end, the authors have chosen to divide this chapter into the following sections:
1. A brief description of the biopsychosocial nature of ethics and how it differs from personal morality
2. A method for identifying and dealing with ethical issues
3. A discussion of the role of bioethicists and ethics committees
4. The professional fiduciary role of clinicians
5. Listings of some of the common key bioethical and legal terms (online access only)
6. A very brief discussion of the terms cited in the above listings (online access only)
This review contains 2 tables (Common Bioethical Concepts and Legal Concepts), 1 sidebar, 6 references, an appendix (A List of Some Central Bioethical Concepts Helpful for Clarifying Discussion of Ethical Issues), and 24 additional readings.
Practicing Evidence-based Medicine (SAGHE)
By Niteesh Choudhry, MD, PhD; Michael Barnett, MDPurchase PDF
Practicing Evidence-based Medicine (SAGHE)Purchase PDF
Today, a plethora of resources for evidence-based medicine (EBM) are available via alert services, compendia, and more. In theory, a clinician researching a topic or looking for information regarding a clinical decision should easily find the literature or synopses needed. However, the real challenge lies in recognizing which resources (out of hundreds or possibly thousands) present the best and most reliable evidence. As well, evidence from research is only part of the decision calculus, and the clinician, not the evidence, makes the final decisions. Medical decision analysis attempts to formalize the process and reduce it to algebra, but it is difficult or impossible to represent all the components of a decision mathematically and validly let alone do so in “real time” for individual patients. This review discusses these challenges and more, including how to ask answerable questions, understand the hierarchy for evidence-based information resources, critically appraise evidence, and apply research results to patient care. Figures show the total number of new articles in Medline from 1965 to 2012, a “4S” hierarchy of preappraised medicine, percentage of physician and medical student respondents with a correct or incorrect answer to a question about calculating the positive predictive value of a hypothetical screening test, a nomogram for Bayes’s rule, an example of nomogram use for pulmonary embolism, and a model for evidence-informed clinical decisions. Tables list selected barriers to the implementation of EBM; Patient, Intervention, Comparison, and Outcome (PICO) framework for formulating clinical questions; guides for assessing medical texts for evidence-based features; clinically useful measures of disease frequency and statistical significance and precision; definitions of clinically useful measures of diagnostic test performance and interpretation; definitions of clinically useful measures of treatment effects from clinical trials; summary of results and derived calculations from the North American Symptomatic Carotid Endarterectomy Trial (NASCET); and selected number needed to treat values for common therapies.
This review contains 6 highly rendered figures, 9 tables, and 28 references.
Quality of Care: Performance Measurement and Quality Improvement in Clinical Practice
By Sonali P. Desai, MD, MPH; Allen Kachalia, MD, JDPurchase PDF
Quality of Care: Performance Measurement and Quality Improvement in Clinical PracticePurchase PDF
Attention to the quality of care within the United States health care system has grown tremendously over the past decade. We have witnessed a significant change in how quality improvement and clinical performance measurement are approached. The current focus on quality and safety stems in part from the increasingly clear realization that more services and technological advancement are not automatically equivalent to high-quality care. Much of the discussion about cost and quality in health care is shifting towards the concept of value. Value is defined as health outcomes achieved per dollar spent (in other words, an assessment of the quality of care per cost). This chapter reviews the current state of quality improvement in health care and, because improvement cannot be determined without measurement, reviews several aspects of effective clinical performance measurement. Since many measures are already in place, the chapter describes some of the organizations involved in quality measurement and improvement, as well the approaches they utilize. It looks at the multiple strategies in place to improve quality, from process management to collaboration, from financial incentives to transparency, and reviews newer models of care delivery that may materialize in the near future. Tables list types of quality measures, characteristics to consider when developing a quality measure, and organizations involved in quality improvement and performance measurement. A figure shows strategies used by the federal government to spur performance measurement and quality improvement.
This review contains 1 highly rendered figure, 3 tables, and 56 references.
Medical Evaluation of the Surgical Patient (SAGHE)
By Marie Gerhard-Herman, MD; Jonathan Gates, MDPurchase PDF
Medical Evaluation of the Surgical Patient (SAGHE)Purchase PDF
Medical evaluation prior to surgery includes risk assessment and the institution of therapies to decrease perioperative morbidity and mortality to improve patient outcomes. The most effective medical consultation for surgical patients begins with an assessment of the individual patient and knowledge of the planned surgery and anesthesia followed by clear communication of a concise and specific recommended plan of perioperative care to the surgical team. This chapter describes anesthetic, cardiac, pulmonary, hepatic, nutritional, and endocrine risk assessment. Perioperative thrombotic management and postoperative care and complications, including fluid management; pulmonary, cardiac, renal complications; and delirium are discussed. Tables outline the American Society of Anesthesiologists class and perioperative mortality risk, a comparison of the Revised Cardiac Risk Index and National Surgery Quality Improvement Program, Duke Activity Status Index, high-risk stress test findings, markers for increased perioperative risk in pulmonary hypertension, aortic stenosis and nonemergent noncardiac surgery, risk factors for pulmonary complications in noncardiac surgery, the Model for End-Stage Liver Disease score to predict postoperative mortality, venous thromboembolism risk factors and options for pharmacologic prophylactic regimens, perioperative management of warfarin, and Brigham and Women’s Hospital guidelines for postoperative blood product replacement. Figures include a care algorithm for noncardiac surgery, an illustration of types of myocardial infarction, and an algorithm for the treatment of postoperative delirium.
This review contains 3 highly rendered figures, 12 tables, and 68 references.
Complementary, Alternative, and Integrative Medicine
By Helene M. Langevin, MDPurchase PDF
Complementary, Alternative, and Integrative MedicinePurchase PDF
Complementary and alternative medicine (CAM) refers to a group of diverse medical and health care systems, practices, and products that are not considered to be part of conventional or allopathic medicine. Common CAM practices (e.g., acupuncture, meditation, and therapeutic massage) are gradually becoming incorporated into conventional care in response to patients looking to alternative sources for information and advice about health matters and increased understanding of various CAM methods through evidence-based testing. However, although the claims of some methods are supported with academic research, well-founded concerns remain in many popularized CAM practices regarding the lack of evidence and placebo effects. It is thus imperative for physicians to be comfortable in discussing CAM-related topics with patients and be able to appropriately and informatively guide them in a way that harnesses potential benefits and avoids potential harm. In this review, the major CAM therapies in the United States are examined, including the settings in which they are being used, evidence base status, and efficacy of some of the most commonly used modalities. Figures show percentages of use for various CAM approaches. Tables show major CAM health practices, CAM therapies with significant increases between 2002 and 2007, Internet sources for evidence-based information and tools for patient education, sources for health care provider information, and resources to assess dietary supplement–drug interactions.
This review contains 5 highly rendered figures, 5 tables, and 155 references.
Infectious Diseases of the Esophagus
By Wai-Kit Lo, MD, MPHPurchase PDF
Infectious Diseases of the EsophagusPurchase PDF
This review considers the three most common infectious diseases affecting the esophageal mucosa: Candida organisms (particularly Candida albicans), cytomegalovirus (CMV), and herpes simplex virus (HSV), including their epidemiologies, pathogeneses, diagnoses, differentials, managements, complications, and prognoses. Infection is often indicated by the symptom of odynophagia, although more general gastrointestinal complaints such as dysphagia and heartburn can also be present. Esophageal candidiasis caused by C. albicans is the most common esophageal infection, detected in immunocompetent patients, as well as those with HIV infection, hematologic malignancies, or other immunologic disorders. Treatment of these diseases should target the fungal or viral pathogens involved using systemically active antibiotic regimens. As infectious esophagitis is frequently seen in immunocompromised hosts, assessment for HIV and malignancy should be considered with a new diagnosis. Figures show endoscopic images of Candida esophagitis and HSV esophagitis. Tables list risk factors for infectious esophagitis, possible symptoms of infectious esophagitis, pathogens causing infectious esophagitis and distinguishing characteristics, the Kodsi classification of Candida esophagitis severity on endoscopy, and treatment regimens for esophageal candidiasis, CMV esophagitis in HIV/AIDS patients, and HSV esophagitis.
This review contains 2 highly rendered figures, 8 tables, 38 references.
Key words: Candida albicans, Cytomegalovirus (CMV), Herpes simplex virus (HSV), HIV Complications, Immunosuppression Treatment for Candida, CMV, and HSV, Infections of the esophagus
- Esophageal Disorders
Disorders Involving the Pharynx and Upper Esophagus
By Hiroshi MashimoPurchase PDF
Disorders Involving the Pharynx and Upper EsophagusPurchase PDF
A wide variety of disorders can affect the pharynx and upper esophagus, such as inherited or acquired structural abnormalities, malignancies, and inflammation secondary to a number of etiologies including bacterial, yeast and viral infections, irradiation, and gastroesophageal reflux disorder. Laryngoceles and peritonsillar abscess can also lead to pain and dysfunction. However, this review will focus on the main motility disorders that affect the pharynx and upper esophagus, namely oropharyngeal dysphagia, disorders associated with globus pharyngeus, and Zenker’s diverticulum. Figures show the anatomy of the three stages of normal swallow, various findings on functional endoscopic evaluation of swallowing, electromyography of the cricopharyngeal sphincter and submental muscles, and Zenker’s diverticulum. Tables list causes of oropharyngeal dysphagia, neuromuscular control of the pharyngeal phase (with identified cranial and cervical spinal nerve roots), pathophysiology of oropharyngeal dysplasia, diagnostic tests for oropharyngeal dysplasia, behavioral treatments to improve swallow and reduce aspiration, and potential overlapping causes of impaired upper esophageal sphincter relaxation.
This review contains 4 highly rendered figures, 6 tables, and 40 references
Key words: Oropharyngeal dysphagia; Globus; Upper esophageal sphincter dysfunction; Swallowing disorder; Dysphagia; Zenker’s diverticulum; Swallow assessment; Globus pharyngeus
Esophageal Motility DisordersPurchase PDF
Esophageal Motility DisordersPurchase PDF
By Vikrant S Jagadeesan, MD; Walter W Chan, MD, MPHPurchase PDF
Eosinophilic EsophagitisPurchase PDF
Eosinophilic esophagitis (EoE) is a chronic disorder characterized by eosinophil-predominant inflammation of the esophagus and clinical symptoms of esophageal dysfunction. It is believed to be immune/antigen-mediated, and its diagnosis requires recognition of specific clinical features with appropriate histologic findings on esophageal mucosal biopsies. Over the last 10 years, there has been an increase in the prevalence of EoE worldwide. A recent analysis estimated a prevalence of 56.7 per 100,000 persons, with males more often affected than females. This review covers the epidemiology, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, complications, and prognosis of EoE.
This review contains 3 figures, 2 tables, and 46 references.
Key words: dysphagia, eosinophilic esophagitis, eotaxin-3, esophageal dysfunction, esophageal eosinophilia, food impaction, inflammation of the esophagus
By Kunal Jajoo, MD; Sravanya Gavini, MDPurchase PDF
Barrett EsophagusPurchase PDF
Barrett esophagus is the condition in which normal stratified squamous epithelium of the esophagus is replaced by metaplastic columnar epithelium, which may predispose to development of malignancy. This metaplasia is thought to be a reparative mechanism to cope with reflex esophagitis induced by chronic gastroesophageal reflux disease. Barrett esophagus is associated with an increased risk of esophageal adenocarcinoma (EAC), although the more recent studies have shown that the risk of progression to malignancy is lower than was initially postulated. Endoscopic screening and surveillance are still warranted for early detection of dysplasia and neoplasia and prevention of EAC. This review looks at Barrett esophagus in detail, including its epidemiology and risk factors, etiology and pathogenesis, clinical presentation and symptoms, diagnosis, differential diagnosis, treatment, complications, and prognosis. Figures show images of Barret esophagus, endoscopic mucosal resection of nodule associated with Barrett esophagus, and focal radiofrequency ablation; a schematic of using Prague circumferential (C) and maximal extent (M) criteria to classify and report Barrett esophagus; and a proposed management algorithm for patients with Barrett esophagus. Tables list risk factors associated with Barrett esophagus and neoplastic progression to EAC, guidelines for screening and surveillance, and endoscopic eradication therapies. A list of useful Web sites relating to Barrett esophagus is also presented.
This review contains 5 highly rendered figures, 3 tables, and 33 references.
Gastroesophageal Reflux Disease
By R. Thomas Finn III, MD, MBA; Walter W Chan, MD, MPHPurchase PDF
Gastroesophageal Reflux DiseasePurchase PDF
Gastroesophageal reflux disease (GERD) is the most common gastrointestinal diagnosis made in outpatient clinics, responsible for over 5 million annual outpatient visits and likely hundreds of thousands of inpatient stays for noncardiac chest pain. GERD’s current definition, based on international consensus, is a “condition which develops when the reflux of stomach contents causes troublesome symptoms (i.e., at least two heartburn episodes per week) and/or complications.” Also defining GERD is the presence of erosive esophagitis on upper endoscopy (esophagogastroduodenoscopy [EGD]) with or without the presence of troublesome symptoms or the presence of troublesome symptoms without endoscopic evidence of erosive esophagitis (also known as nonerosive reflux disease). This review looks at GERD in detail, including its epidemiology and risk factors, genetics, pathogenesis and etiologic factors, clinical presentation and symptoms, differentials, diagnosis, and complications. Figures presented are an EGD image showing signs of erosive esophagitis, Barrett esophagus, and hiatal hernia and sample recordings from a 24-hour combined multichannel intraluminal impedance and pH testing. Tables list differential diagnoses for GERD, indications for performing EGD in patients with GERD symptoms, and a summary of GERD therapies.
This review contains 2 highly rendered figures, 3 tables, and 73 references.
By Elizabeth S. Won, MD; David H. Ilson, MD, PhDPurchase PDF
Esophageal CancerPurchase PDF
Esophageal cancers are malignancies that can arise along the entire length of the esophagus, from the cervical inlet to the gastroesophageal junction (GEJ). The most common histologic types are adenocarcinoma and squamous cell carcinoma, which account for almost 95% of esophageal cancers. The location of esophageal cancer varies by histology and strongly influences its behavior and treatment approach. The esophagus is divided into four distinct anatomic regions: the cervical, upper thoracic, midthoracic, and lower thoracic esophagus. Squamous cancers usually occur in the upper or middle esophagus. Adenocarcinomas are more commonly found in the lower third of the esophagus and in the GEJ of the stomach. This review of esophageal cancer addresses the epidemiology, etiology/genetics, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, complications, and prognosis. Figures show Siewert classification, age-standardized esophageal cancer incidence rates by sex and world area, endoscopic images of esophageal tumors, chemotherapy for metastatic esophageal cancer, and a management algorithm for localized esophageal cancer. Tables list hereditary cancer syndromes associated with esophageal cancer, differential diagnosis of dysphagia, physical examination findings in esophageal cancer, differential diagnosis of esophageal lesions seen on endoscopy, and prognosis by stage at diagnosis.
This review contains 5 highly rendered figures, 5 tables, and 42 references.
- Gastrointestinal Bleeding
Lower Gastrointestinal Bleeding
By Jennifer Nayor, MD; John R. Saltzman, MDPurchase PDF
Lower Gastrointestinal BleedingPurchase PDF
Of patients who present with major gastrointestinal (GI) bleeding, 20 to 30% will ultimately be diagnosed with bleeding originating from a lower GI source. Lower GI bleeding has traditionally been defined as bleeding originating from a source distal to the ligament of Treitz; however, with the advent of capsule endoscopy and deep enteroscopy allowing for visualization of the entire small bowel, the definition has been updated to GI bleeding originating from a source distal to the ileocecal valve. Lower GI bleeding can range from occult blood loss to massive bleeding with hemodynamic instability and predominantly affects older individuals, with a mean age at presentation of 63 to 77 years. Comorbid illness, which is a risk factor for mortality from GI bleeding, is also more common with increasing age. Most deaths related to GI bleeding are not due to uncontrolled hemorrhage but exacerbation of underlying comorbidities or nosocomial complications. This review covers the following areas: evaluation of lower GI bleeding (including physical examination and diagnostic tests), initial management, and differential diagnosis. Disorders addressed in the differential diagnosis include diverticulosis, arteriovenous malformations (AVMs), ischemic colitis, anorectal disorders, radiation proctitis, postpolypectomy bleeding, and colorectal neoplasms. Figures show an algorithm for management of patients with suspected lower GI bleeding, tagged red blood cell scans, diverticular bleeding, colonic AVM, ischemic colitis, bleeding hemorrhoid, chronic radiation proctitis, and ileocolonic valve polyp. Tables list descriptive terms for rectal bleeding and suggested location of bleeding, imaging modalities and differential diagnosis for lower GI bleeding, endoscopic techniques for hemostasis, and an internal hemorrhoids grading system.
This review contains 8 highly rendered figures, 5 tables, and 100 references.
Nonvariceal Upper Gastrointestinal Bleeding
By Wasif Abidi, MD, PhD; John R. Saltzman, MDPurchase PDF
Nonvariceal Upper Gastrointestinal BleedingPurchase PDF
Gastrointestinal (GI) bleeding that is proximal to the ligament of Treitz is considered upper GI bleeding (UGIB). UGIB can be further divided into variceal and nonvariceal, differentiated by etiology, presentation, management, and mortality. This review of nonvariceal UGIB addresses the epidemiology, diagnosis, treatment (including endoscopic therapy), prognosis, and differential diagnosis. Recommendations presented are evidence based and consistent with consensus statements and society guidelines. Figures show stigmata of recent hemorrhage, endoscopic therapy, peptic ulcer disease, Mallory-Weiss syndrome, angiodysplasia, Dieulafoy lesion, and arterioenteric fistula. Tables list the manifestation of GI bleeding and the presumed source of the bleeding, clues in the symptom and presentation of the patient that may suggest the diagnosis, medical history and physical examination findings that can suggest a specific diagnosis, a comparison of different prognostic scoring systems, differential diagnosis of UGIB, various etiologies of peptic ulcer disease, and treatment regimens for Helicobacter pylori.
This review contains 7 highly rendered figures, 8 tables, and 83 references.
- Peptic Ulcer Disease
Helicobacter Pylori and Nonsteroidal Antiinflammatory Drug Peptic Ulcers
By Edward A Lew, MD, MPHPurchase PDF
Helicobacter Pylori and Nonsteroidal Antiinflammatory Drug Peptic UlcersPurchase PDF
Peptic ulcers are defects or breaks in the gastric or small intestinal mucosa that have depth and extend through the muscularis mucosae. The pathogenesis of peptic ulcers is multifactorial and arises from an imbalance of protective and aggressive factors such as when gastrointestinal mucosal defence mechanisms are impaired in the presence of gastric acid and pepsin. Infection with Helicobacter pylori and the use of nonsteroidal anti-inflammatory drugs and acetylsalicylic acid are major risk factors associated with peptic ulcers. In general, these factors disrupt normal mucosal defenses and repair, making the mucosa more susceptible to acid. This review covers the epidemiology of peptic ulcers, diagnostic tests for H. pylori, and treatment of peptic ulcers and H. pylori. The figure shows gastric biopsy samples stained with hematoxylin and eosin demonstrating chronic active gastritis both with and without the presence of H. pylori organisms. The tables list diagnostic tests for H pylori, and common treatment regimens for H. pylori.
Key words: Helicobacter pylori,H. pylori, NSAID-related peptic ulcer, diagnosis of helicobacter pylori, H. pylori treatment, urea breath test, ASA after bleeding ulcer
This review contains 1 highly rendered figure, 2 tables, and 54 references
Peptic Ulcer Diseases
By Edward A Lew, MD, MPHPurchase PDF
Peptic Ulcer DiseasesPurchase PDF
The etiology of peptic ulcers is generally related to impaired mucosal defenses in the presence of aggressive factors (e.g., gastric acid and pepsin). Major risk factors include infection with Helicobacter pylori and the use of nonsteroidal antiinflammatory drugs; high rates of acid secretion can also predispose to ulcer formation. The prevalence of peptic ulcers in Western countries has declined since the 1950s, a phenomenon that is likely due to a corresponding decrease in H. pylori infections among the general population. This review summarizes the epidemiology, etiology, diagnosis, and treatment of peptic ulcers. Figures show the etiopathogenesis of peptic ulcers, the approach to a patient who has new and undiagnosed ulcerlike symptoms, and images of a gastrointestinal series in which double contrast (barium and air) was used, as well as an upright chest x-ray of a patient with an acute abdomen caused by a perforated duodenal ulcer. Tables list the differential diagnosis of peptic ulcer disease and commonly used regimens to eradicate H. pylori.
This review contains 3 highly rendered figures, 2 tables, and 35 references.
- Gastrointestinal Motility and Functional Disorders
By Nadim Mahmud, MD, MS, MPH; Walter W Chan, MD, MPHPurchase PDF
Functional DyspepsiaPurchase PDF
Functional dyspepsia(FD), formerly “nonulcer dyspepsia,” makes up approximately 50 to 75% of dyspepsia presentations. These presentations are defined by having no identifiable structural disease that would explain the symptoms. Recognizing the heterogeneity within the diagnosis of FD, the Rome III criteria further classify FD based on primary symptoms: postprandial distress syndrome and epigastric pain syndrome. The former term refers to bothersome fullness or early satiety with regular meals, whereas the latter is characterized by intermittent epigastric pain or burning that is not predictably meal associated. This review addresses FD, detailing the epidemiology, pathophysiology and pathogenesis, differential diagnosis, diagnosis, treatment, and prognosis. A figure shows the diagnostic algorithm for new-onset dyspepsia. Tables list the Rome III criteria for functional dyspepsia, alarm features in dyspepsia, and medications commonly associated with dyspepsia.
This review contains 1 highly rendered figure, 3 tables, and 27 references.
By Braden Kuo, MD; Laurence Guay, MD, FRCPPurchase PDF
The gastric phase of digestion requires a tightly coordinated neuromuscular apparatus to permit appropriate timing for each step. Dysregulations in this apparatus may be related to the Cajal cells, the intrinsic enteric nervous system, the extrinsic nervous system, the muscle cells, or any combination of structures and may lead to abnormal gastric emptying, referred to as gastroparesis. Gastroparesis is idiopathic in 35 to 49.4% of cases but may also be related to diabetes, autoimmune and inflammatory conditions, multiple sclerosis, use of certain medications, and infections, among other factors. This review describes the epidemiology, etiology, pathophysiology, clinical manifestations, diagnosis, treatment, and prognosis of gastroparesis. The figure shows symptom mechanisms related to gastric physiology in gastroparesis patients. Tables list the physiopathologic mechanisms and symptoms associated with defective gastric physiologic phenomena, the classification of gastroparesis according to affected structures, and pharmacologic treatments for gastrointestinal dysmotility.
This review contains 1 highly rendered figure, 3 tables, and 56 references.
Small Bowel Dysmotilities and Small Bowel Bacterial Overgrowth
By Laurence Guay, MD; Braden Kuo, MD, MSPurchase PDF
Small Bowel Dysmotilities and Small Bowel Bacterial OvergrowthPurchase PDF
The main role of the small bowel is nutrient absorption; its mucosa lined with villi increases the contact surface between chyme and intestinal cells. Although the small bowel is the longest segment of the gastrointestinal (GI) tract, its transit takes between 2 and 5 hours and is the shortest of the whole gut. It is the most resilient segment of the GI tract and is thus rarely affected by motility disorders. Small bowel dysmotilities comprise a group of rare disorders affecting the function of any structure of the contractile apparatus from the muscular cells, the intrinsic neurons, or the extrinsic neurons. This review covers the epidemiology, etiology, differential diagnosis, clinical manifestations, physical examination, diagnosis, and treatment of small bowel dysmotilities and bacterial overgrowth. The figure shows GI tract innervations and related pharmacologic treatments. Tables list etiologies of small bowel dysmotilities categorized as primary or secondary causes, treatment strategies related to physiologic abnormalities, and pharmacologic treatments for GI dysmotilities.
Key words: chronic intestinal pseudo-obstruction, gastrointestinal dysmotility, motility disorder, small bowel dysmotility, small intestinal bacterial overgrowth
This review contains 1 highly rendered figure, 3 tables, and 51 references.
Irritable Bowel Syndrome With Constipation
By Loni Tang, MD; Brooks D. Cash, MDPurchase PDF
Irritable Bowel Syndrome With ConstipationPurchase PDF
Irritable bowel syndrome (IBS) is characterized by recurrent abdominal pain or discomfort that has occurred at least 3 days per month in the 3 months prior to diagnosis. One of the subtypes of this disorder is IBS with constipation (IBS-C), where individuals experience hard or lumpy stools at least 25% of the time and loose or watery stools less than 25% of the time with defecation. This review addresses IBS-C, detailing the epidemiology, etiology, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, and prognosis. A figure shows the Bristol stool form scale. Tables list IBS subtypes, components of digital rectal examination, differential diagnoses for IBS and IBS-C, alarm features, and the American College of Gastroenterology Recommendations.
This review contains 1 highly rendered figure, 6 tables, and 71 references.
Irritable Bowel Syndrome With Diarrhea
By Judy Nee, MD; Jacqueline L. Wolf, MDPurchase PDF
Irritable Bowel Syndrome With DiarrheaPurchase PDF
Irritable bowel syndrome (IBS) is a complex, functional gastrointestinal condition characterized by abdominal pain and alteration in bowel habits without an organic cause. One of the subcategories of this disorder is IBS with diarrhea (IBS-D). Clinically, patients who present with more than 3 months of abdominal pain or discomfort associated with an increase in stool frequency and/or loose stool form are defined as having IBS-D. This review addresses IBS-D, detailing the epidemiology, etiology and genetics, pathophysiology and pathogenesis, diagnosis, clinical manifestations and physical examination findings, differential diagnosis, treatment, emerging therapies, complications, and prognosis. Figures show potential mechanisms and pathophysiology of IBS, IBS-D suspected by clinical assessment and Rome III criteria, pharmacologic and nonpharmacologic treatment options, potential mechanisms of action of probiotics, and potential treatment modalities. Tables list the Rome criteria for IBS, alarm signs and symptoms suggestive of alternative diagnoses, IBS criteria, differential diagnosis of IBS-D, dietary advice options for IBS-D, and alternative and emerging therapies in IBS-D.
This review contains 5 figures, 6 tables and 42 references
KEYWORDS: IBS-D, eluxadoline, rifaximin, probiotics, bloating, antidepressants, bile acid malabsorption, microscopic colitis, celiac
- Diseases of Malabsorption
Celiac Disease, Refractory Celiac Disease, and Tropical Sprue
By Jerry S. Trier, MDPurchase PDF
Celiac Disease, Refractory Celiac Disease, and Tropical SpruePurchase PDF
Celiac disease, often also termed celiac sprue, is an immune-mediated disorder triggered by ingestion of wheat, barley, rye, and triticale gluten proteins in genetically predisposed individuals. The offending glutens induce a characteristic but variable and nonspecific lesion of the small intestinal mucosa that improves following gluten withdrawal. Patients with refractory celiac disease (RCD) have persistent or recurrent symptomatic malabsorption together with biopsy-documented enteropathy that has not responded to 6 to 12 months of strict gluten withdrawal. Tropical sprue is an illness that occurs in individuals living in tropical countries; clinical features include anorexia, diarrhea, and intestinal malabsorption, leading to weight loss accompanied by a characteristic although nonspecific lesion of the mucosa of the small
intestine. This review addresses the epidemiology, etiology/genetics, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, complications, and prognosis of these related diseases. Figures show the celiac disease iceberg, duodenal mucosal surface seen at endoscopy, duodenal mucosal biopsies from a patient with celiac disease, higher magnification micrograph of the duodenal mucosal surface from a patient with untreated celiac disease, duodenal biopsies from a patient with refractory celiac disease, and duodenal biopsy obtained from an Indian expatriate with diarrhea, weight loss, and folate deficiency. Tables list selected extraintestinal manifestations of celiac disease, prevalence of celiac disease in selected conditions, disorders with duodenal lesions that may mimic those of celiac diseases, initial treatment for celiac disease, organizations that provide helpful information for gluten-intolerant patients, considerations in a patient not responding to a gluten-free diet, and features that help distinguish tropical sprue from celiac disease.
This review contains 6 highly rendered figures, 7 tables, and 96 references.
By Rachel Winter, MD; Robert Burakoff, MD, MPHPurchase PDF
Eosinophilic GastroenteritisPurchase PDF
Eosinophilic gastroenteritis (EG) is a rare condition characterized by eosinophilic infiltration of the gastrointestinal (GI) tract. This review addresses the epidemiology, etiology and genetics, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, complications, and prognosis of EG. A figure shows the histologic appearance of stomach and duodenal mucosa in patients with EG. Tables list symptoms of EG and differential diagnosis.
This review contains 1 highly rendered figure, 2 tables, and 27 references.
Short Bowel Syndrome
By Robert Burakoff, MD, MPH; Alison Goldin, MDPurchase PDF
Short Bowel SyndromePurchase PDF
Short bowel syndrome (SBS) is a state of malabsorption resulting from physical or functional loss of large portions of the small intestine, and is the most common cause of intestinal failure. The average length of a human’s small intestine is between 3 and 8 m, depending on the type of measurements made (surgical, radiologic, or autopsy); SBS occurs when less than 200 cm of small bowel remains. SBS may be congenital (intestinal atresia) or acquired. Physical losses usually occur from surgical resection for Crohn disease (CD), vascular insufficiency, radiation, malignancy, trauma, or volvulus. The site of intestinal resection helps to determine the degree of intestinal capacity. Functional losses, on the other hand, are less common and occur in the setting of a nonfunctioning, but intact, small intestine. Examples include radiation enteritis, congenital defects, and inflammatory bowel disease (IBD). This review addresses the epidemiology, pathophysiology and pathogenesis, clinical manifestations, treatment, complications, and prognosis of SBS. A figure shows sites of intestinal nutrient absorption. A table lists potential complications of SBS in patients receiving parenteral nutrition (PN).
This review contains 1 highly rendered figure, 1 table, and 67 references.
By Matthew J. Hamilton, MDPurchase PDF
Systemic MastocytosisPurchase PDF
Systemic mastocytosis (SM) is a disease characterized by an abnormal proliferation and accumulation of a clonal population of mast cells in the tissues including the bone marrow, gastrointestinal tract, and skin. In the most common form, indolent mastocytosis, the symptoms are most often due to the consequences of mast cell activation and include flushing, abdominal pain, and diarrhea. The diagnosis is made using a defined set of criteria based on a tissue biopsy, with special staining and a blood test for tryptase. Treatment is directed at the mast cell activation and specific symptoms such as nausea and abdominal bloating. Differential diagnosis includes the non-clonal form of mast cell activation syndrome and IgE-mediated allergy.
Keywords: mast cell, mast cell activation, mastocytosis, tryptase, flushing, urticaria pigmentosa, dermatographism
This review contains 5 highly rendered figures, 4 tables, and 35 references.
Nutritional Management of Celiac Disease
By Mariana Urquiaga, MD; Ciarán P Kelly, MD; Satya Kurada, MDPurchase PDF
Nutritional Management of Celiac DiseasePurchase PDF
Celiac disease (CD) is an autoimmune disorder characterized by an immune response to gluten peptides in wheat, barley, and rye. The diagnosis of celiac disease is confirmed by three important characteristics: consistent symptoms, positive celiac-specific serology, and small intestinal biopsy findings of inflammation, crypt hyperplasia, and villous atrophy. CD may present with overt gastrointestinal symptoms, including diarrhea (or constipation), weight loss, and abdominal bloating and discomfort, or covertly with micronutrient deficiencies such as iron deficiency with anemia. A gluten-free diet (GFD) remains the mainstay of treatment. The aim of this review is to highlight the pathogenesis of CD, concepts and challenges associated with a GFD, and nutritional management of CD applicable in clinical practice to internists, gastroenterologists, and dietitians. Patients should be referred to an expert celiac dietitian for education on adherence to a GFD to address gluten contamination in the diet, the psychosocial implications of following a GFD, and macro- and micronutrient disequilibria arising from celiac disease and the GFD. Several novel therapeutics are on the horizon in various stages of development, including glutenases, antigliadin antibodies, tight junction regulators, modulation of the immune response to gliadin, and efforts to engineer less toxic gluten-containing foodstuffs.
This review contains 3 figures, 5 tables, and 61 references.
Key words: celiac disease, genetic engineering, food engineering, gluten, glutenases, gluten-free diet, oats, IgY, nutrition, tight junction regulators, wheat
- Inflammatory Bowel Diseases
Epidemiology of Inflammatory Bowel Disease
By Edward L. Barnes, MD; Robert Burakoff, MD, MPHPurchase PDF
Epidemiology of Inflammatory Bowel DiseasePurchase PDF
Inflammatory bowel disease (IBD) comprises chronic disorders characterized by inflammation of the gastrointestinal tract. The two major identified subtypes of IBD are ulcerative colitis (UC) and Crohn disease (CD), and over many years, each can demonstrate periods of recurrence and remission. Although the presentation and clinical patterns of UC and CD have been well studied, many questions remain regarding the underlying disease pathogenesis. On an individual level, the development of clinically active IBD appears to occur on account of a complex set of interactions of distinct risk factors, including genetic predisposition, environmental exposures, and geographic location. On a global scale, the highest rates of IBD are found in Europe and North America, with worldwide prevalence of UC and CD increasing. Figures show the prevalence of UC and CD in the United States, stratified by region. Tables show the prevalence of IBD in North America as identified by various studies and environmental risk factors for inflammatory bowel disease.
This review contains 2 highly rendered figures, 2 tables, and 134 references.
Pathophysiology of Inflammatory Bowel Disease
By Matthew J. Hamilton, MD; Richard S Blumberg, MDPurchase PDF
Pathophysiology of Inflammatory Bowel DiseasePurchase PDF
The study of the pathogenesis of IBD has advanced tremendously in recent years, coinciding with novel scientific experimentation and computational analysis tools. Crohn disease (CD) and ulcerative colitis (UC) are the two major types, characterized by chronic relapsing and remitting intestinal inflammation, and their respective pathophysiologies are the focus of this review. Also examined are the genetic influences, environmental influences, immune defects, and clinical implications associated with IBD. Figures include presentations of UC and CD, the multidirectional relationship causing the pathogenesis of IBD, and functional programs identified through genetic associations in IBD. Table lists the current therapeutic strategies in IBD based on target.
This review contains 3 highly rendered figures, 1 table, and 131 references.
Pathology of Inflammatory Bowel Disease
By Deepa T. Patil, MD; Robert D. Odze, MDPurchase PDF
Pathology of Inflammatory Bowel DiseasePurchase PDF
Idiopathic inflammatory bowel disease (IBD) encompasses two major types: ulcerative colitis (UC) and Crohn disease (CD). The pathologic features of UC are typically restricted to the mucosa and superficial submucosa, whereas CD is characterized by patchy, segmental, mucosal, and mural inflammation. This review covers the classic pathologic features of IBD, differential diagnosis, dysplasia in IBD, and practical guidelines for clinicians who perform surveillance endoscopy. Figures show gross specimens of UC and CD variations and low- and high-grade dysplasia. Tables list the microscopic features of untreated UC and CD, the most common causes of uncertainty in IBD pathology that lead to a diagnosis of indeterminate colitis, a summary of inflammatory disorders of the colon that may mimic UC or CD on biopsy or resection, and diseases that can occur in patients with established UC or CD and result in changes to the type, pattern, and severity of inflammation.
This review contains 5 highly rendered figures, 4 tables, and 75 references.
Clinical Features and Differential Diagnosis of Ulcerative Colitis and Crohn Disease
By Edward L. Barnes, MD; Jonathan S. Levine, MDPurchase PDF
Clinical Features and Differential Diagnosis of Ulcerative Colitis and Crohn DiseasePurchase PDF
Inflammatory bowel disease (IBD) is composed of two major subtypes, ulcerative colitis (UC) and Crohn disease (CD). These chronic disorders, characterized by inflammation of the gastrointestinal tract, demonstrate a variety of clinical features, including intestinal and extraintestinal manifestations during periods of relapse and remission over many years. This review examines the clinical features of IBD, including the extraintestinal manifestations and diagnosis. Figures include examples of images conducted via computed tomography (CT), magnetic resonance imaging, and position emission tomography (PET)/CT. Tables list the location frequencies of UC and CD at the time of diagnosis, extraintestinal manifestations of IBD, differential diagnosis of UC and CD, and clinical utility of fecal calprotectin in the evaluation and management of IBD.
This review contains 4 highly rendered figures, 5 tables, and 48 references.
Update on Imaging Modalities for Inflammatory Bowel Diseases
By Koenraad J. Mortele, MD; Francesco Alessandrino, MDPurchase PDF
Update on Imaging Modalities for Inflammatory Bowel DiseasesPurchase PDF
Inflammatory bowel diseases (IBDs) are a group of chronic inflammatory disorders that are mainly represented by Crohn disease and ulcerative colitis. Over the last decade, conventional fluoroscopic barium studies used for the imaging of the gastrointestinal tract have been replaced with newer techniques, such as multidetector-row computed tomography (CT), dual-energy CT, and positron emission tomography (PET)/CT. Also increasingly seen is the use of magnetic resonance enterography, representing a robust, highly accurate, and radiation-free imaging method. This review covers these newer imaging modalities for IBD and more, as well as proposed techniques that could potentially help monitor and guide new antiinflammatory treatment strategies in the future. Figures include examples of images conducted via CT, magnetic resonance imaging, and PET/CT. Table compares different imaging modalities for the evaluation of IBD.
This review contains 13 highly rendered figures, 1 table, and 127 references.
Medical Therapy for Crohn Disease
By Jessica R Allegretti, MD; Joshua R. Korzenik, MDPurchase PDF
Medical Therapy for Crohn DiseasePurchase PDF
Crohn disease (CD) is an inflammatory condition that can affect any portion of the gastrointestinal tract from the mouth to the perianal area. The resulting transmural inflammation can lead to a spectrum of clinical presentations depending on disease location and severity. The treatment of CD depends on the severity of the disease, phenotype, presence of perianal disease, and response to previous therapies. This review examines the goals of therapy for CD, clinical symptoms and disease activity, treatment of disease based on mild to moderate to severe stages, treatment of refractory disease, perianal disease, postoperative CD, and noninflammatory treatment options. Figures show adalimumab injection-site reaction and perianal fistula with seton placement. Tables list the Crohn Disease Activity Index (CDAI), the Harvey Bradshaw Index, 5-aminosalicylic acid formulations, standard dosing of CD medications for moderate to severe disease, and rates of clinical response and remission in patients receiving anti–tumor necrosis factor agents versus placebo, by trial.
This review contains 2 highly rendered figures, 5 tables, and 85 references.
Medical Therapy of Ulcerative Colitis
By Kristin E. Burke, MD; Joseph D. Feuerstein, MD; Adam S. Cheifetz, MDPurchase PDF
Medical Therapy of Ulcerative ColitisPurchase PDF
Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disease (IBD) characterized by continuous colonic mucosal inflammation that extends proximally from the rectum. Most patients present with bloody diarrhea, abdominal pain, tenesmus, and urgency. The course of UC is characterized by periods of flares and remission, and can significantly impact quality of life. Most patients are successfully treated medically, though 15 to 25% of patients require total proctocolectomy.Treatment of UC depends on the extent and severity of the disease, and response to prior therapies. This review outlines the medical treatment of UC and the therapies available for the induction and maintenance of remission. Figures include endoscopic and histologic images of UC, and algorithms cover outpatient inductions for mild-to-moderate disease and moderate-to-severe-disease, outpatient management of known steroid-refractory/steroid-intolerant patient, and approach to inpatient management of acute severe UC. Tables list disease severity by Truelove and Witts criteria, IBD medication adverse effects and monitoring parameters, induction dosing of 5-aminosalicylates, and rates of clinical response, remission, and mucosal healing in patients receiving anti-tumor necrosis factor (TNF) agents versus placebo by trial.
This review contains 5 highly rendered figures, 4 tables, and 118 references.
Extraintestinal Manifestations of Inflammatory Bowel Disease
By Punyanganie de Silva, MBBS, MRCP (UK); Mital Patel, MDPurchase PDF
Extraintestinal Manifestations of Inflammatory Bowel DiseasePurchase PDF
The extraintestinal manifestations (EIMs) of inflammatory bowel disease (IBD) can be classified as the following: (a) true EIMs due to reactive IBD affecting organ systems, (b) complications secondary to IBD activity, (c) non–IBD-specific autoimmune disease which occurs in increased frequency in individuals with IBD. Overlap is frequent between EIMs and extraintestinal complications, and it is increasingly evident that multiple organ systems may be involved. This review covers EIMs through their epidemiology, etiology/genetics/pathogenesis, prognosis, complications, and treatment. Also detailed are the organ systems involved with reactive IBD, including musculoskeletal, pulmonary, dermatological, ophthalmic, and hepatobiliary manifestations. Figures show the classification, etiology, and pathogenesis of EIMs of IBD, musculoskeletal and pulmonary manifestations of IBD, metastatic Crohn disease of the intergluteal cleft, pyoderma gangrenosum, oral apthous ulcers, Sweet syndrome, leucocytoclastic vasculitis, anti-tumor necrosis factor–induced psoriasis, uveitis, episcleritis, and primary sclerosing cholangitis. Tables list the modified New York criteria for ankylosing spondylitis, pulmonary manifestations of IBD and IBD-related treatment, diagnostic techniques in lung disorders associated with IBD, dermatologic manifestations of IBD based on classifications, specific cutaneous manifestations or granulomatous cutaneous lesions with the same histological features as the underlying bowel disease, reactive cutaneous manifestation of IBD with immunological mechanisms triggered by common antigens shared by gut bacteria and skin, cutaneous disorders or dermatosis associated with IBD, secondary cutaneous manifestations due to complications of IBD and adverse effects of IBD treatment, treatment of dermatological manifestations of IBD, diagnosis of ophthalmological manifestations of IBD, and other hepatobiliary manifestations of IBD.
This review contains 13 highly rendered figures, 12 tables, and 79 references.
Fertility and Pregnancy in Inflammatory Bowel Disease
By Aoibhlinn M. O’Toole, MD; Sonia Friedman, MDPurchase PDF
Fertility and Pregnancy in Inflammatory Bowel DiseasePurchase PDF
Inflammatory bowel diseases (IBDs) commonly affect women in their reproductive years; 25% of women with IBD become pregnant after the diagnosis. The relation of IBD to reproductive function often manifests in issues concerning fertility, antepartum pregnancy management, mode of delivery, and lactation as these can be influenced by disease activity, medications, perianal disease, and previous ileoanal pouch surgery. As disease location, activity, and complications can vary between patients, an individualized approach with multidisciplinary management is recommended. Pregnancy outcomes, recommended medication, nursing, managing IBD flares during pregnancy, and immune pathways are also discussed. Figures show issues discussed in preconception counseling and pregnancy guidelines. Tables list medication recommendations, Food and Drug Administration categories for the use of medications in pregnancy, adverse pregnancy outcomes PIANO registry, pregnancy and biological recommendations, thiopurine recommendations, safety of biologics in pregnancy, biologic guidelines, and sick pregnant patient recommendations.
This review contains 2 highly rendered figures, 8 tables, and 29 references.
Adjuvant and Neoadjuvant Management of Colorectal Cancer
By Christina E Bailey, MD, MSCI; Eduardo Vilar, MD, PhD; Y. Nancy You, MD, MHScPurchase PDF
Adjuvant and Neoadjuvant Management of Colorectal CancerPurchase PDF
Colorectal cancer (CRC) is the third most common and lethal cancer in men and women in the United States. At presentation, a significant proportion of patients with CRC are able to undergo resection with curative intent, but up to 50% of these patients will develop recurrent disease. Fortunately, recurrence rates for both colon and rectal cancer have improved with the introduction of multimodality therapies, which include chemotherapy, chemoradiation therapy, and radiation therapy. These therapies are adjuncts to surgery and can be administered before (i.e. neoadjuvant) or after (i.e. adjuvant) surgery. This review summarizes the current evidence for the use of adjuvant and neoadjuvant therapies in colon and rectal cancer.
This review contains 2 figures, 5 tables, and 65 references.
By Anthony O’Connor, MD; Alan C. Moss, MDPurchase PDF
Microscopic ColitisPurchase PDF
Microscopic colitis (MC) is defined by the presence of specific histologic abnormalities in patients with diarrhea and a normal-appearing colon at endoscopy. MC can be categorized into two types: collagenous colitis (CC) and lymphocytic colitis (LC). CC is characterized by a thickened subepithelial collagen band in the colonic mucosa of at least 10 mm in thickness, whereas LC describes infiltration of the colonic epithelium with lymphocytes (intraepithelial lymphocytes), without excess collagen in the mucosa. This review of MC addresses the epidemiology, pathogenesis, etiology/genetics, diagnosis, differential diagnosis, treatment, complications, and prognosis between the two types. Tables list potential etiologic factors in MC, medications associated with MC, and treatments used for MC and evidence base.
This review contains 3 tables and 55 references.
Surgical Management of Ulcerative Colitis
By John H. Pemberton, MD; Amy Lightner, MD; Robert R. Cima, MD, MAPurchase PDF
Surgical Management of Ulcerative ColitisPurchase PDF
Inflammatory bowel disease is a chronic inflammatory disease of the intestine that can be divided into two main categories: Crohn disease and chronic ulcerative colitis (CUC). Although the role of medical therapy in CUC is directed at symptom control or the underlying inflammatory process, fortunately, the intestinal manifestations of CUC can be effectively cured by surgery. The operation of choice is an ileal pouch-anal anastomosis (IPAA), which can be performed open or laparoscopically, with a hand-sewn or stapled anastomosis, or in a one-, two-, or three-stage fashion. Although pouch function and quality of life remain good following IPAA, common complications include pouchitis, anal stricture, pouch fistulas, and small bowel obstructions. The most dreaded complication is an anastomotic leak resulting in pelvic sepsis and, often, eventual pouch excision. Less common complications include pouch dysplasia or cancer and de novo Crohn disease of the pouch. Overall, regardless of age, patient satisfaction following IPAA remains high, and more than 90% of patients retain their pouches for more than 20 years.
This review contains 11 highly rendered figures, and 83 references.
Complex Perianal Fistulas
By Amy L Halverson, MD; Massarat Zutshi, MDPurchase PDF
Complex Perianal FistulasPurchase PDF
Recurrent fistulas, fistulas with multiple external openings, those involving more than one third of the anal sphincter complex, and fistulas involving adjacent organs are considered complex. Fistulas occurring in the setting of perianal Crohn disease or following pelvic radiation are also considered complex. Evaluation of a fistula includes a detailed history and physical examination. Imaging with ultrasonography helps delineate the course of a fistula relative to adjacent structures as well as identify occult branching of the fistula tract. The initial step in treating fistulas is resolving associated inflammation. When treating fistulas with multiple branching tracts, the portion of the tracts outside the anal sphincter complex should be unroofed, with the goal of transforming the complex fistula into a simpler fistula with a single internal opening. The selection of the most appropriate treatment for a complex fistula depends on the etiology, anatomy, patient comorbidities, and condition of surrounding tissue.
Key Words: anal fistula, anovaginal fistula, Crohn disease, fistulotomy, rectourethral fistula
- Diseases of the Pancreas
By Robert A. Moran, MD; Manavi Solanki, MD; Vikesh K Singh, MD, MScPurchase PDF
Acute PancreatitisPurchase PDF
Acute pancreatitis (AP) is defined as the presence of two of the following findings: (1) upper abdominal pain; (2) serum amylase or lipase greater than three times the upper limit of normal; and/or (3) characteristic findings of AP on abdominal imaging (contrast-enhanced computed tomography, magnetic resonance imaging, or abdominal ultrasonography). This review addresses AP, detailing the subclassification, epidemiology, pathophysiology, etiology, diagnosis and differential diagnosis, treatment, complications, and prognosis. Figures include abdominal imaging of patients with AP, an algorithm depicting pancreatic collections, and an endoscopic image of the gastric portion of the cystogastrostomy. Tables list systemic inflammatory response syndrome; classification of the severity of AP; etiologies of AP, gallstones, biliary sludge, microlithiasis, and crystals; secondary causes of hypertriglyceridemia; common drugs and drug classes associated with AP; conditions mimicking AP; diagnostic criteria for infected necrosis; and prognostic scoring systems for AP.
This review contains 3 highly rendered figures, 9 tables, and 182 references.
Pancreatitis in the Critical Care Setting
By Lisa M. Kodadek, MD; Pamela A. Lipsett, MD, MHPE, MCCMPurchase PDF
Pancreatitis in the Critical Care SettingPurchase PDF
Pancreatitis is a complex spectrum of disease including chronic pancreatitis, acute pancreatitis, and manifestations of severe acute pancreatitis such as sterile and infected necrotizing pancreatitis. Acute pancreatitis is the leading cause of hospitalization for gastrointestinal disorders in the United States. Pancreatitis is a dynamic condition, and severity may change and evolve during the course of the disease. Although most patients with acute pancreatitis have mild disease, 10 to 15% will run a fulminant course, leading to severe acute pancreatitis, pancreatic necrosis, and multisystem organ injury. The mortality for severe acute pancreatitis is 15 to 30%; however, the overall mortality for all patients with acute pancreatitis is less than 5%. Early management of acute pancreatitis includes fluid resuscitation, pain control, and enteral nutrition. There are no specific directed therapies proven to be effective for the early treatment of acute necrotizing pancreatitis; therapy is entirely supportive. Chronic pancreatitis is a challenging disease often marked by chronic pain. Surgical intervention may help improve quality of life and relieve pain in selected patients. International consensus guidelines provide definitions and classifications to aid clinicians with diagnosis and management of pancreatitis. This review covers advances related to pancreatitis, including literature pertaining to the step-up approach for necrotizing pancreatitis first published in 2010, discussion of the revised Atlanta Classification System for severity of acute pancreatitis published in 2013, review of the current spectrum of microbial pathogens implicated in infected necrotizing pancreatitis, and the international draft consensus proposal for a new mechanistic definition for chronic pancreatitis published in 2016.
Key words: acute pancreatitis, antibiotic prophylaxis, Atlanta Classification System, biliary pancreatitis, chronic pancreatitis, necrosectomy, pancreatic necrosis, pancreatitis, step-up approach, video-assisted retroperitoneal drainage (VARD)
Management of Chronic Pancreatitis
By Darwin L. Conwell, MD; Veeral M. Oza, MDPurchase PDF
Management of Chronic PancreatitisPurchase PDF
Chronic pancreatitis (CP) is a syndrome that is characterized by inflammation, irreversible fibrosis, and loss of acinar and islet cells. It has also been described as an “enigmatic process of uncertain pathogenesis, unpredictable clinical course, and unclear treatment.” This review describes the epidemiology, diagnosis, diagnostic challenges, differential diagnosis, treatment, complications, and clinical course and prognosis of CP, as well as future challenges. Figures show a computed tomographic (CT) scan of calcific CP, a secretin-enhanced magnetic resonance cholangiopancreatogram showing a dilated and tortuous main pancreatic duct, a CT scan of a large chronic pseudocyst compressing the stomach and pancreas, an endoscopic ultrasound (EUS) image of CP, a retrograde pancreatogram showing a dilated main pancreatic duct with stones and “blunted” side branches, sources of pain in CP, neuropathic pain mechanisms in CP, and an algorithm summarizing treatment of pain in CP. Tables list the TIGAR-O etiologic classification of CP, standard criteria for diagnosis of CP by EUS, Cambridge endoscopic retrograde cholangiopancreatography grading for CP, and a stepwise radiographic and endoscopic diagnostic approach to patients with suspected CP.
Key words: bile duct obstruction, chronic pancreatitis, pancreatic calcifications, TIGAR-O system
This review contains 8 highly rendered figures, 4 tables, and 54 references.
By Allison L Yang, MD; Julia McNabb-Baltar, MD, MPHPurchase PDF
Autoimmune PancreatitisPurchase PDF
Autoimmune pancreatitis (AIP) is a subcategory of chronic pancreatitis that is highly responsive to steroids. The term was first proposed in 1995 by Yoshida and colleagues, and since its discovery, the diagnosis of AIP has dramatically increased. AIP is a chronic fibroinflammatory disease characterized by lymphoplasmacytic infiltrates and fibrosis on histology. There are two distinct subtypes: type 1 AIP is the pancreatic manifestation of a systemic serum immunoglobulin G subtype 4–related disease (IgG4-RD) and type 2 AIP is described clinically as idiopathic duct-centric pancreatitis and has no association with IgG4. Clinically, AIP presents most commonly as obstructive jaundice in type 1 AIP and can present as acute pancreatitis in type 2 AIP. The diagnostic criteria include histology, imaging findings, and responsiveness to steroids as well as laboratory findings and other organ involvement. The mainstay of treatment is steroid therapy, with immunomodulators such as rituximab used for maintenance or relapsing disease. Long-term complications of AIP include pancreatic insufficiency and are often associated with relapsing disease.
This review contains 45 references, 1 figure, and 2 tables.
Key Words: autoimmune pancreatitis, chronic pancreatitis, EUS-guided biopsy, IgG4, immunomodulatory, obstructive jaundice, pancreas mass, steroid
Benign and Premalignant Lesions of the Pancreas
By Abdurrahman Kadayifci, MD; William R. Brugge, MDPurchase PDF
Benign and Premalignant Lesions of the PancreasPurchase PDF
Pancreatic cancer is among the most aggressive human cancers, with few symptoms and clinical findings until it is detected in an advanced stage. Today, the only favorable treatment is surgical resection before progression to an invasive stage. There are a variety of benign and premalignant conditions of the pancreas that may appear similar to malignant tumors; early detection and management of those premalignant pancreatic lesions may provide a significant improvement in patient outcome. This review covers cystic neoplasms of the pancreas, premalignant solid lesions of the pancreas, and inflammatory lesions of the pancreas. Figures show a 30 mm diameter hypoechoic lesion without septae in the pancreatic head, an oval 20 mm diameter pancreatic mass with mixed solid and cystic components, a 24 mm diameter hypoechoic mass with well-defined borders in the tail of the pancreas, a 22 × 18 mm cystic lesion with a thick wall and internal debris in the head of the pancreas, and an endoscopic cyst gastrostomy after balloon dilation. Tables list World Health Organization (WHO) 2010 classification of pancreatic tumors, classification of pancreatic cystic lesions, main characteristics of common pancreatic cystic lesions, high-risk stigmata and worrisome features of intraductal papillary mucinous neoplasm on cross-sectional imaging, and WHO classification of pancreatic neuroendocrine tumors.
This review contains 5 highly rendered figures, 5 tables and 55 references
Malignant Lesions of the Pancreas
By Omer Basar, MD; Abdurrahman Kadayifci, MD; William R. Brugge, MDPurchase PDF
Malignant Lesions of the PancreasPurchase PDF
Malignant lesions of pancreas are the fourth most common cause of cancer death in men and women. The majority of pancreatic cancer results from malignant transformation of the exocrine pancreas, and nearly 90% are ductal adenocarcinomas (pancreatic ductal adenocarcinoma, PDAC). Patients typically present at an advanced stage with a poor prognosis. PDAC is acquired through the accumulation of multiple genetic mutations. The major risk factors for PDAC include age, smoking, chronic pancreatitis, diabetes mellitus (DM), male gender, and African American race. Less commonly, hereditary syndromes may be implicated. The clinical presentation may involve weight loss, abdominal discomfort, and or jaundice. Painless jaundice, depression, and new-onset DM can suggest the diagnosis. Cross-sectional imaging has utility in diagnosis and staging. Endoscopic ultrasound (EUS) with fine needle aspiration (FNA) is a standard approach to tissue diagnosis. Endoscopic retrograde cholangiopancreaticography with palliative stenting can relieve obstructive jaundice. Surgical resection is the only potentially curative option in the management of PDAC but only a minority of patients are candidates for resection. The prognosis for most patients with pancreatic adenocarcinoma is poor. Less common pancreatic malignant lesions such as neuroendocrine tumors (NETs) have a much more favorable prognosis.
Key words: Pancreatic cancer; Pancreatic ductal adenocarcinoma; Pancreatic NETs (PNETs); Pancreatic neuroendocrine tumors
- Gallstones and Biliary Tract Diseases
By Robert J. Gianotti, MD; Michael D. Apstein, MDPurchase PDF
Gallstone DiseasePurchase PDF
Gallstone disease (cholelithiasis), very common in the United States, afflicts around 15% of the adult population and accounts for approximately 1.8 million ambulatory visits per year. Elective laparoscopic cholecystectomy for the removal of gallstones is currently the most commonly performed abdominal operation in the United States, with around 750,000 operations per year. Although the majority of patients with asymptomatic gallstones will never develop symptoms, approximately 25% of these initially asymptomatic patients will develop biliary pain and 3% will develop complications over a 10-year follow-up period. This review discusses the pertinent pathophysiology and treatment of gallstones and their complications. It is imperative for the primary care physician, gastroenterologist, and surgeon to rapidly identify those patients at risk for complications of gallstone disease and offer the best evidence-based therapies available. It is also important for the physician to understand when and if to offer treatment for those patients with asymptomatic gallstone disease. Figures show the mixed micelle, the anatomy of gallstones, radial endoscopic sonogram of a gallstone in common bile duct (CBD), an algorithm depicting the risk of CBD stone in patients with known cholelithiasis, and endoscopic retrograde cholangiography images of a large gallstone within CBD and stone fragments in duodenum following lithotripsy and extraction. Tables list risk factors for gallstone formation, common medications associated with gallstone formation, and uncommon complications of gallstone disease.
This review contains 5 highly rendered figures, 3 tables, and 53 references.
Primary Sclerosing Cholangitis
By Udayakumar Navaneethan, MD, FACP; Benjamin Tharian, MDPurchase PDF
Primary Sclerosing CholangitisPurchase PDF
Primary sclerosing cholangitis (PSC) is a chronic progressive cholestatic disease characterized by inflammation and fibrosis that may involve the entire biliary tree. The fibrosis causes diffuse narrowing of the intrahepatic and extrahepatic bile ducts, and the resulting biliary stasis leads to secondary biliary cirrhosis and associated complications. This review addresses PSC through its epidemiology, etiopathogenesis, diagnosis, differential diagnosis, management, complications, and prognosis. Figures show pouchoscopy, liver biopsy, and endoscopic retrograde cholangiopancreatography; direct peroral cholangioscopy visualization of cholangiocarcinoma; and algorithms depicting diagnosis of cholangiocarcinoma and screening for inflammatory bowel disease (IBD) in patients with PSC. Tables list characteristics of IBD in PSC, prevalence of antibodies in PSC, differential diagnosis of PSC, diagnostic approach in PSC, and risk of cancers in PSC.
This review contains 6 highly rendered figures, 5 tables, and 91 references.
Biliary Disease: Calculous and Acalculous Cholecystitis
By Kevin Y Pei, MD, FACS; Kimberly A Davis, MD, MBA, FACS, FCCMPurchase PDF
Biliary Disease: Calculous and Acalculous CholecystitisPurchase PDF
Cholelithiasis is extremely common in the United States, affecting approximately 10 to 15% of the population. The vast majority of patients remain asymptomatic. Elective cholecystectomy for symptomatic cholelithiasis is a well-established procedure with excellent outcomes. The diagnosis in critically ill patients may not be straightforward. Inflammation and infection of the gallbladder can lead to significant morbidity and mortality. Whether the gallbladder is the primary etiology of hemodynamic compromise (as in emphysematous or gangrenous cholecystitis) or is the victim of secondary insult (as in ischemia-related acalculous cholecystitis), the intensivist must consider cholecystitis in the differential of clinical deterioration.
This review contains 6 figures, 5 tables, and 53 references.
Key words: acalculous, biliary disease, cholangitis, cholecystitis, emphysematous cholecystitis
- Gastroenterology Miscellaneous
Diverticulosis and Diverticulitis
By Anna M. Duloy, MD; Frederick L Makrauer, MDPurchase PDF
Diverticulosis and DiverticulitisPurchase PDF
Diverticular disease has been considered a disease of the elderly, but recently, an increased incidence has been noted in younger patients. Diverticulosis is asymptomatic; however, when symptomatic, it is referred to as diverticular disease. When associated with any inflammation, it is diverticulitis. Diverticulitis is an acute illness, but symptoms may become chronic with recurrent episodes. When mucosal inflammation is present, segmental colitis associated with diverticula (SCAD) is identified. SCAD is a distinct, but uncommon, disorder sharing histological and clinical features of ulcerative colitis and Crohn disease. Only 1 to 2% of patients with diverticulosis will develop diverticulitis. This review covers the epidemiology, etiology and genetics, pathophysiology and pathogenesis, diagnosis, management, complications and prognosis of diverticulosis, and diverticulitis. Figures show diverticulosis, symptomatic uncomplicated diverticular disease, diverticulitis, computed tomography scan of acute diverticulitis, and a management algorithm. Tables list definitions, risk factors, pathophysiology, modified Hinchey classification, and acute diverticulitis differential diagnosis.
This review contains 5 highly rendered figures, 5 tables and 105 references
Colorectal Cancer Screening
By Jennifer A. Inra, MD; Molly Perencevich, MD; Ramona Lim, MDPurchase PDF
Colorectal Cancer ScreeningPurchase PDF
Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men and is the third leading cause of all cancer deaths in the United States. Due to screening examinations used to detect and remove premalignant colon polyps, as well as modification of risk factors and improvements in the treatment of CRC, the incidence and mortality due to CRC have declined over the last several decades. Regardless, CRC continues to account for about 9% of all cancer deaths in the United States. This review addresses CRC, including the epidemiology, pathophysiology and genetics, screening modalities, treatment, and complications associated with CRC screening. Figures show etiologies of CRC, multiple sessile adenomas, a pedunculated adenoma, a sessile polyp, a large polyp found on computed tomographic colonography, and a characteristic sessile serrated adenoma/polyp with a mucus cap in the proximal colon. Tables list oncogenes, tumor suppressor genes, and mismatch repair genes involved in CRC; surveillance recommendations based on a family history of CRC; CRC risk stratification; CRC screening recommendations by risk stratification; and CRC surveillance recommendations.
This review contains 6 highly rendered figures, 5 tables, and 82 references.
Familial Polyposis Syndromes
By Sahar Nissim, MD, PhD; Ramona M. Lim, MDPurchase PDF
Familial Polyposis SyndromesPurchase PDF
Although sporadic polyps in the gastrointestinal tract are common with increasing age, the finding of a large number of polyps raises suspicion for a hereditary polyposis syndrome associated with a germline genetic mutation. Because many of these hereditary polyposis syndromes also confer an increased risk of gastrointestinal and extraintestincal cancers, implicated in approximately 1% of all colorectal cancers, recognition of these syndromes is critical to offer preventive screening measures. A key distinguishing feature is polyp histologic type, ranging from adenomatous, to serrated, to hamartomatous. A clinical diagnosis can be confirmed by genetic testing for a germline mutation in known cancer susceptibility genes, although in many polyposis families, a genetic etiology has not yet been identified. This review covers familial adenomatous polyposis, MUTYH-associated polyposis, polyposis associated with polymerase proofreading, juvenile polyposis syndrome, PTEN hamartoma tumor syndromes, hereditary mixed polyposis syndrome, and serrated polyposis. The figures shows the spectrum of histologic types and genetic etiologies of hereditary polyposis syndromes. Tables list polyposis syndromes, American College of Gastroenterology surveillance guidelines for hereditary polyposis syndromes, diagnostic criteria for juvenile polyposis syndrome, diagnostic criteria for PTEN hamartoma tumor syndrome, and World Health Organization diagnostic criteria for serrated polyposis syndrome.
This review contains 1 highly rendered figure, 5 tables, and 172 references
Key words: Familial adenomatous polyposis; Polyposis syndromes; Gastrointestinal polyps; Hereditary polyposis syndromes
The Role of Enteral Nutritional Therapy in Inflammatory Bowel Disease
By Lindsey Albenberg, DO; Robert Baldassano, MDPurchase PDF
The Role of Enteral Nutritional Therapy in Inflammatory Bowel DiseasePurchase PDF
Enteral nutrition therapy is a dietary treatment regimen for inflammatory bowel disease that has the benefit of avoiding suppression of the immune system. Its mechanism of action has not been well characterized, but may be related to the elimination of dietary antigens or modulation of the gut microbiota. This treatment has shown success for induction of remission, and may also have a role in maintenance of remission. In the pediatric population, enteral nutrition therapy has the dual benefit of targeting both the inflammatory processes and the poor growth of these patients. This review details the administration and mechanism of action of enteral nutritional therapy, the induction and maintenance of remission, the impact of enteral nutritional therapy on growth and nutrition, and side effects and quality of life. A table summarizes studies investigating enteral nutritional therapy for induction of remission.
This review contains 1 table and 49 references.
By James Creswell Simpson, MD; Sarah Sebbag, MD, CM, CCFP(EM)Purchase PDF
Appendicitis is defined as inflammation of the vermiform appendix. It is the most common abdominal surgical emergency and occurs at an annual rate of approximately one in 10,000 in the United States. The lifetime risk of appendicitis is about 9% for males and 7% for females; approximately 80% of cases occur before 45 years of age. Appendicitis rarely occurs in infants; it increases in frequency between 2 and 4 years of age and reaches a peak between the ages of 10 and 19 years. However, clinicians must maintain a high index of suspicion in patients of all age groups. This review covers the pathophysiology, stabilization and assessment, and diagnosis and treatment of complicated and uncomplicated appendicitis. The disposition and outcomes are also reviewed. Figures show an image of appendicitis on a bedside sonogram, and a computed tomographic image of appendicitis. Tables list likelihood ratios of signs and symptoms of appendicitis, the sonographic appearance of appendicitis, the Alvarado scoring system, and the differential diagnosis of appendicitis.
Key words: appendicitis, obstructed appendiceal lumen, rebound abdomen, right lower quadrant pain, ruptured appendix
This review contains 2 highly rendered figures, 4 tables, and 33 references.
By Megan Fix, MD; Steven Glerum, MDPurchase PDF
Anorectal DisordersPurchase PDF
Anorectal disorders can generate considerable patient discomfort and disability. Although mortality due to such complaints is very low, it is important for the clinician to maintain a high index of suspicion for systemic illness caused by an anorectal source. A detailed history and physical examination should be performed, and the need for imaging or procedures should be assessed. This review examines the pathophysiology, stabilization and assessment, diagnosis and treatment, and disposition and outcomes for patients with anorectal disorders. Figures show the important structures of the anal canal; differences in the anatomy of the origin of internal and external hemorrhoid venous supplies; depictions of a typical anodermal linear tear; Foley catheter–assisted rectal foreign body removal technique; and pertinent anatomy related to a prolapsed rectum through the anus; and types and locations of anorectal abscesses and fistulas. Tables list common painful and painless anorectal disorders; key differences in anal canal structures above and below the pectinate line; anal symptoms mistakenly attributed to hemorrhoids; internal hemorrhoidal grading, description, and recommended treatment; Rome III criteria for the diagnosis of constipation; and a summary of anorectal conditions.
This review contains 6 highly rendered figures, 6 tables, and 80 references.
Keywords: functional constipation; PEG; abdominal radiographs; pediatric constipation
Gastrointestinal Tract Infections
By Molly Paras, MD; Marcia B Goldberg, MDPurchase PDF
Gastrointestinal Tract InfectionsPurchase PDF
Gastrointestinal infections, which present with acute diarrhea, sometimes accompanied by vomiting, are an extremely common medical complaint, with an annual incidence of 0.6 illnesses per person. Transmission can occur from animals to person, from person to person, or by the ingestion of contaminated foodstuffs. In the United States, more than 90% of cases are caused by viruses, with norovirus being by far the most common. Common among bacterial causes of acute gastrointestinal infection are Salmonella, Campylobacter, Shigella, Shiga toxin–producing Escherichia coli, Vibrio,Yersinia, and Clostridium difficile. These infections are typically self-limited, but depending on the etiologic agent and characteristics of the host, antibiotic therapy may be indicated. Certain gastrointestinal infections are associated with significant complications, including reactive arthritis, Guillain-Barré syndrome, or septicemia.
This review contains 4 figures, 7 tables, and 60 references.
Key words: Campylobacter, Escherichia coli, Guillain-Barré syndrome,reactive arthritis, Shiga toxin, Shigella, Vibrio, Yersinia
By Andrew S. Liteplo, MD, FACEPPurchase PDF
Bowel ObstructionPurchase PDF
Small bowel obstruction can be a surgical emergency, and may be the ultimate diagnosis in 2 to 15% of patients presenting to the emergency department with abdominal pain. Bowel obstruction can be either mechanical (caused by extrinsic compression, twisting of the bowel, or intrinsic obstruction) or functional (caused by an impaired ability of the bowel to propel contents distally). The most common cause of small bowel obstruction in the developed world is postoperative adhesions.This review examines the pathophysiology, stabilization and assessment, diagnosis and treatment, and outcomes for patients with bowel obstruction.Figures show sonograms of small bowel obstruction, pneumatosis, and an abdominal wall hernia; and a computed tomographic scan of small bowel obstruction. Videos show ultrasonography of fluid-filled, dilated loops of bowel with decreased peristalsis; pendulous peristalsis; a ventral hernia with protruding bowel; normal peristalsis; and absent peristalsis in ileus. Tables list the differential diagnosis for smallbowel obstruction, and a summary of performance of imaging modalities in diagnosing small bowel obstruction.
This review contains 4 highly rendered figures, 5 videos, 2 tables, and 26 references.
Keywords: Bowel obstruction; Small bowel obstruction; Bowel peristalsis; Small intestinal peristalsis; Obstipation; Postoperative adhesions; Pendulous peristalsis; Decreased peristalsis
Hernias in the Emergency Department
By Daniel Berhanu, MD; Ciara J. Barclay-Buchanan, MD, FACEP; Mary C. Westergaard, MD, FACEPPurchase PDF
Hernias in the Emergency DepartmentPurchase PDF
Hernia is defined as an abnormal protrusion of an organ or tissue through a pathologic defect in its surrounding wall. Overall, hernia is common and is generally believed to be a benign condition associated with some morbidity, although it is not thought to be associated with significant mortality. Between 2001 and 2010, 2.3 million inpatient abdominal hernia repairs were performed in the United States, of which 567,000 were performed emergently. In some cases, a hernia can be a deadly condition. In 2002, hernia was listed as the cause of death for 1,595 US citizens. This review covers the pathophysiology, stabilization and assessment, diagnosis and treatment, and disposition and outcomes of hernia. Figures show anatomic locations of the various abdominal wall, groin, lumbar, and pelvic floor hernias; a direct inguinal hernia; an indirect inguinal hernia; point-of-care sonograms showing a ventral wall hernia and an abdominal wall hernia; and the differential diagnosis of an abdominal mass based on anatomic location. Tables list risk factors for the development of inguinal hernia, sex-based differences in inguinal hernia development, risk factors for the development of incisional hernia, factors to consider when assessing the patient for a hernia, and factors associated with the highest rates of incarceration in patients with groin hernia.
Key words: emergent hernia, hernia incarceration, incisional hernia, inguinal hernia, strangulated hernia
This review contains 6 highly rendered figures, 5 tables, and 66 references.
By Martin D Zielinski, MD, FACSPurchase PDF
Appendicitis became recognized as a surgical disease during a presentation by pathologist R. H. Fitz at the 1886 meeting of the Association of American Physicians. In 1894, Charles McBurney first described the surgical technique that was to become the gold standard for appendectomy. Although the appendectomy has traditionally been performed as an open procedure, laparoscopy holds several advantages, such as a lower risk of wound infection, the ability to thoroughly explore the abdominal cavity, and improved outcomes in women of childbearing age, obese patients, and patients with unclear diagnoses. This review covers operative technique, special considerations, and complications and outcome evaluation associated with appendectomy. Figures show an algorithm for choosing among treatment options for patients with suspected acute appendicitis, an open appendectomy demonstrating landmarks, exposure of the abdominal cavity, and mobilization of the appendix, laparoscopic appendectomy showing positioning and placement of the operative ports, division of the mesoappendix, and removal of the appendix through the infraumbilical port, a single-incision laparoscopic appendectomy, an algorithm for the management of an appendiceal mass encountered during exploration for clinically suspected acute appendicitis, and trocar placement for the gravid uterus. Tables list results of 31 prospective, randomized trials comparing laparoscopic appendectomy with open appendectomy, and results of prospective, randomized clinical trials comparing medical versus surgical management of acute appendicitis.
This review contains 12 highly rendered figures, 2 tables, and 92 references
Surgical Management of Benign and Malignant Colorectal Disease in the Immunocompromised Patient
By Cindy Kin, MD; Amy Lightner, MD; Mark Welton, MD, MHCMPurchase PDF
Surgical Management of Benign and Malignant Colorectal Disease in the Immunocompromised PatientPurchase PDF
Patients who are immunosuppressed either due to an underlying disease process or medications to treat a disease require important perioperative considerations. Preoperative evaluation mandates a higher index of suspicion for pathology given that peritoneal and systemic markers of illness may be masked. Intraoperatively, consideration should be given for diversion more frequently than in a nonimmunosuppressed patient. Postoperatively, patients should be managed in a multidisciplinary fashion. This review largely focuses on the immunosuppressive mediations used for the treatment of inflammatory bowel disease, benign colorectal disease in an immunosuppressed patient, and colorectal malignancies in immunosuppressed patients to highlight important considerations for this patient population.
This review contains 4 figures, 5 tables, and 78 references.
Key words: anal squamous cell carcinoma, appendicitis versus typhlitis, biologic therapy, corticosteroids, human papillomavirus, immunosuppression, neutropenic enterocolitis
Overview of Enteral Nutrition
By Erin Sisk, MS, RD, LDN, CNSC; Rebecca Lynch, MS, RD, LDN, CNSCPurchase PDF
Overview of Enteral NutritionPurchase PDF
Enteral nutrition (EN) is recognized as a medical nutrition therapy for patients with a functional gastrointestinal tract who are unable to maintain their weight and health by oral intake alone either due to a highly catabolic medical condition or a functional limitation. EN support provides calories and protein to help improve or maintain adequate weight, lean body mass, and overall nutritional status. EN also provides nonnutritive benefits such as maintaining intestinal integrity, supporting the immune system, and preventing infection. EN support can be tailored to a patient’s nutrient needs, and there are various formulas that vary in composition of macronutrients, concentration, and electrolytes for specific disease processes or conditions that may help with tolerance and absorption. EN support complications include issues with access, diarrhea, constipation, electrolyte abnormalities, hyperglycemia, and dehydration/overhydration. Generally, EN is well tolerated. While a patient is on this type of nutrition support, it is important to closely monitor tolerance, weight, laboratory values if indicated, and overall clinical progress, with adjustment to the regimen as needed.
This review contains 1 figure, 4 tables, and 48 references.
Key words: enteral access, enteral formula, enteral nutrition support, gastric residuals, gastrointestinal tract, immunonutrition, malnutrition, medical nutrition therapy, tube feed formula, tube feed tolerance, tube feeding, volume-based feeding
Liver Disease in Pregnancy
By Matthew S Chang, MD; Anna E. Rutherford, MD, MPHPurchase PDF
Liver Disease in PregnancyPurchase PDF
Liver disease in pregnancy can be unique to pregnancy or coincidental to pregnancy, or pregnancy can occur in women with chronic liver disease, cirrhosis, or portal hypertension. The gestational age of the pregnancy can help determine the diagnosis. Liver disease occurring during pregnancy has the potential to be life threatening to mother and fetus, and any elevation in liver tests should be investigated. Disorders unique to pregnancy include hyperemesis gravidarum; intrahepatic cholestasis of pregnancy; preeclampsia/eclampsia; hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome; and acute fatty liver of pregnancy. Liver diseases coincidental to pregnancy include acute viral hepatitis, gallstones/biliary disease, and thrombosis such as Budd-Chiari syndrome/hepatic vein thrombosis. Pregnant women may have chronic liver disease or cirrhosis from all of the same etiologies as nonpregnant women, most commonly chronic viral hepatitis. Treatment options may differ during pregnancy because of the potential risks to the fetus. Women who have cirrhosis or portal hypertension or who are post liver transplantation should be managed in conjunction with a hepatologist.
This review contains 4 figures, 6 tables and 40 references
Key words: acute liver failure, delivery, trimester
An Approach to the Patient With Abnormal Liver Tests and Jaundice
By Adrian Reuben, BSc, MBBS, FRCP, FACG, FAASLDPurchase PDF
An Approach to the Patient With Abnormal Liver Tests and JaundicePurchase PDF
Patients who present with abnormal liver test results and jaundice are generally suffering from an affliction of the liver and/or biliary tree; however, extrahepatic disorders can affect hepatobiliary function and even microscopic structure when there is no intrinsic primary liver or biliary abnormality. Extrahepatic disease may impinge directly on the liver and/or biliary system, and remote extrahepatic conditions, such as sepsis, systemic and localized inflammatory processes, and malignancy, can interfere with liver function without direct contact. This review covers history of the patient with abnormal liver tests and jaundice, physical findings in the patient with abnormal liver tests and jaundice, abnormal liver tests and elevated bilirubin, and recommended approaches to the patient with abnormal liver tests and jaundice. Figures show a case of renal cell cancer (hypernephroma) in a 69-year-old man, potential sites of interference with hepatobiliary metabolism and transport of bilirubin from hepatocyte to duodenum (with examples), a decision tree to evaluate suspected idiosyncratic drug-induced liver injury, physical signs in liver disease, a decision tree for investigation of the patient with aminotransferase-predominant abnormal liver tests and jaundice, and a decision tree for investigation of the patient with alkaline phosphatase elevation with or without abnormal liver tests with or without jaundice. Tables list symptom and risk factor evaluation in patients with abnormal liver tests and jaundice, comparison of features scored in two causality assessment methods, physical signs in liver disease, and disease-specific laboratory investigations, imaging, and tissue analysis.
This review contains 6 highly rendered figures, 4 tables, and 18 references
The Risk of Surgery in Patients With Liver Disease 1: Epidemiology, Pathophysiology, and Pre-operative Evaluation
By Adrian Reuben, BSc, MBBS, FRCP, FACG, FAASLDPurchase PDF
The Risk of Surgery in Patients With Liver Disease 1: Epidemiology, Pathophysiology, and Pre-operative EvaluationPurchase PDF
The results of retrospective large scale registry and cohort studies, and small case series, substantiate the common perception that operating on a liver disease patient is risky. The preexisting physiological derangements of liver disease may be exacerbated by the trauma of surgery and its complications, which contributes strongly to the aforementioned surgical risks, especially (but not exclusively) in cirrhotics. Perturbations in liver blood flow and oxygenation may be exaggerated by anesthesia, surgery itself, blood loss, and other operative complications. Cirrhotics are especially susceptible to acute and chronic kidney injury. Malnutrition is common in cirrhosis, which compromises wound healing and recovery from surgery. In cirrhosis, elimination of infection is impaired and its systemic effects are deleterious. The metabolic and immunological stresses of surgery may lead to liver function deterioration, even in stable cirrhotics. Presented here is the pre-operative evaluation of liver disease patients, including the use of predictive indices, new dynamic tests of liver function, and modestly invasive assessment of portal hypertension.
This review contains 9 figures, 6 tables and 52 references
Keywords: acute-on-chronic liver failure, Child-Turcotte-Pugh, cirrhosis, coagulopathy, infection, hepatic venous pressure gradient, liver blood flow, model for end-stage liver disease, systemic inflammatory response syndrome, thrombocytopenia
Liver Failure in the Critical Care Setting
By Jeffrey DellaVolpe, MD, MPH; Ali Al Khafaji, MD, MPHPurchase PDF
Liver Failure in the Critical Care SettingPurchase PDF
Acute liver failure (ALF) can be challenging to manage due to the effect of liver failure on other organs and the severity of illness that ensues. Both the practicing surgeon and the intensivist should be aware of the manifestations, workup, and management implications as ALF is not uncommon to many intensive care settings. ALF precipitates a severe multiorgan dysfunction syndrome in a majority of cases, with high rates of complications and an elevated risk of death. Management requires a systemic approach in addition to the collaboration of a multidisciplinary team with an emphasis on early recognition, prompt management of complications, and timely transfer to a transplant center. In the absence of spontaneous recovery, transplantation is the only definitive management option and may not always be feasible or immediately available. The continuing search to develop alternatives is essential.
Key words: acetaminophen, acute liver failure, cerebral edema, coagulopathy, hepatitis, jaundice, N-acetylcysteine, transplantation
The Risk of Surgery in Patients With Liver Disease 2
By Adrian Reuben, BSc, MBBS, FRCP, FACG, FAASLDPurchase PDF
The Risk of Surgery in Patients With Liver Disease 2Purchase PDF
The results of retrospective largescale registry and cohort studies and small case series, substantiate the common perception that operating on a liver disease patient is risky. The preexisting physiological derangements of liver disease may be exacerbated by the trauma of surgery and its complications, which contributes strongly to the aforementioned surgical risks, especially but not exclusively in cirrhotics. The risks of operating on patients with non-cirrhotic liver disease are reviewed with particular emphasis on the poor outcomes in acute hepatitis—especially alcoholic hepatitis—severe fatty liver disease, and obstructive jaundice. The outcomes of a broad spectrum of surgical procedures in cirrhotics (abdominal, cardiothoracic, orthopedic, vascular, etc.) are reviewed, with particular reference to common predictors of survival and morbidity, such as the Child-Turcotte-Pugh (CTP) score/class and the model for end-stage liver disease (MELD) score. The concept is proposed that the height of portal pressure may be a predictive factor of surgical outcome, which derives from experience with hepatic resection and suggests that measurement of hepatic venous pressures may be worthwhile in selected cases. New, non-invasive estimates of liver function are presented. A simple practical pre-operative decision tree is provided.
This review contains 5 figures, 3 tables and 91 references
Keywords: cirrhosis, fatty liver, hepatic venous pressure gradient, hepatitis, model for end-stage liver disease, operative mortality, portal hypertension, Child-Turcotte-Pugh
Viral Hepatitis E
By Kenrad E Nelson, MD; Brittany L Kmush, PhDPurchase PDF
Viral Hepatitis EPurchase PDF
Hepatitis E Virus (HEV) infections are among the most frequent causes of viral hepatitis globally. They are especially common in southern Asia where large epidemics of waterborne hepatitis, primarily affect adults with increased mortality in pregnant women, occur frequently during and after monsoon rains when there is contamination of the drinking water supply. These epidemics have been recognized throughout modern history. Similar epidemics have been reported from Sub-Saharan Africa during humanitarian crises, when the water supply is compromised. The causal virus, HEV, was discovered in 1983. About a decade later, similar HEV viruses were found to be transmitted as a foodborne infection from infected pigs, deer, wild boar, and other zoonotic reservoirs. There are 4 genotypes of HEV that infect humans: genotypes 1 and 2 are strictly human pathogens, and genotypes 3 and 4 have zoonotic reservoirs and are transmitted as a foodborne infection or from contact with the zoonotic reservoir. Although most HEV infections cause asymptomatic infections or acute selflimited hepatitis in humans, in recent years, chronic infections among immunocompromised patients after solid organ transplants or other immunocompromising conditions have been reported among persons with genotype 3 infections.
This review contains 4 figues, 4 tables and 162 references
Key Words: epidemiology, global impact, Hepatitis E Vaccine, HEV, prevention, reservoirs, risk factors, treatment
- Viral Hepatitis
Hepatitis B Virus
By April Wall, MD; Ming V. Lin, MDPurchase PDF
Hepatitis B VirusPurchase PDF
Chronic hepatitis B virus (HBV) infection is a major health burden worldwide, with approximately 257 million people with chronic infection. HBV is a small partially double-stranded DNA virus that replicates within the nucleus of the hepatocyte and commonly leads to chronic infection. Chronic HBV infection can cause cirrhosis, hepatocellular carcinoma, and extrahepatic manifestations such as glomerulonephritis or vasculitis. The latter is due to deposition of circulating immune complex in the different tissues. The natural history of HBV infection can be conceptualized as a spectrum encompassing different phases, including immune tolerance, immune clearance, inactive carrier, and reactivation and resolution. The diagnosis of the different phases of chronic HBV infection relies on various HBV serologies, liver enzyme levels, and histology findings. There are currently eight therapies approved for the treatment of HBV. Tenofovir alafenamide was the most recently approved therapy with a better side effect profile compared with tenofovir disoproxil fumarate. With the recent advances in the basic research in hepatitis B, new treatment options may become available in the near-future.
This review contains 9 figures, 8 tables and 78 references
Key words: cirrhosis, entecavir, Hepadnaviridae, hepatitis B virus, hepatocellular carcinoma, precore mutation, tenofovir
Viral Hepatitis Other Than A, B, or C
By Kenneth E. Sherman, MD, PhD ; Nadeem Anwar, MDPurchase PDF
Viral Hepatitis Other Than A, B, or CPurchase PDF
Viral hepatitis is a global, although variably distributed, health problem associated with significant morbidity and mortality. Infection with a hepatitis virus leads to acute inflammation and liver cell damage (hepatocyte injury). Such infection may be symptomatic or subclinical and may result in disease resolution, death from fulminant hepatic failure, or development of a chronic disease state. Whereas the chronic infection with hepatitis B and C accounts for a global burden of more than 500,000,000 cases, the global death rate from all types of hepatitis is approximately 1 million people annually. This review focuses on the virology, epidemiology, clinical features, diagnosis, treatment, and prevention of hepatitis D and hepatitis E, as well as other viruses associated with hepatitis. Figures show the global distribution of hepatitis D infection, elevation of anti–hepatitis D virus antibodies in hepatitis B/hepatitis D virus coinfection, geographic distribution of hepatitis E virus by genotype, factors significant in the pathogenesis of hepatitis E, and pattern of antibody elevation in hepatitis E. The table lists proposed diagnostic criteria for hepatitis E virus.
This review contains 5 highly rendered figures, 1 table, and 42 references.
Key words: hepatitis D, hepatitis D virus, hepatitis E, hepatitis E virus, non-A hepatitis, non-B hepatitis, non-C hepatitis, viral hepatitis
Viral Hepatitis C: Epidemiology, pathogenesis, Transmission, and natural History
By Anna Lidofsky, BS; Raymond T. Chung, MD; Jacinta A Holmes, MBBS, PhDPurchase PDF
Viral Hepatitis C: Epidemiology, pathogenesis, Transmission, and natural HistoryPurchase PDF
Chronic infection with the hepatitis C virus (HCV) remains a significant global health issue, with more than 71 million infected worldwide and accounting for over 720,000 deaths annually in the United States alone. It can be associated with significant liver-related morbidity and mortality owing to complications from cirrhosis and end-stage liver disease. The aging HCV population, together with changing patterns of drug use, has seen an increase in these complications of HCV and an increase in the number of acute HCV infections. Screening and managing complications of chronic hepatitis C are an important consideration. The changing epidemiology, risk factors, transmission, diagnosis, natural history (including complications) and patient evaluation and education are discussed.
This review contains 4 figures and 68 references
Key words: epidemiology, hepatitis C virus, transmission, risk factors, natural history, patient education, evaluation
Viral Hepatitis C: Treatment
By Anna Lidofsky, BS; Raymond T. Chung, MD; Jay Luther, MD; Jacinta A Holmes, MBBS, PhD; Stephanie M Rutledge, MBBCh BAO MRCPIPurchase PDF
Viral Hepatitis C: TreatmentPurchase PDF
Infection with the hepatitis C virus (HCV) leads to chronic infection in the majority, and is associated with the development of complications including cirrhosis, end-stage liver failure, hepatocellular carcinoma and death. HCV is curable, and successful viral eradication is associated with a reduction in cirrhosis and liver-related mortality. However, previous HCV therapy, consisting of pegylated interferon plus ribavirin, was associated with poor cure rates and significant adverse events. The development of direct-acting antiviral agents (DAAs) that specifically target HCV replication has revolutionized the treatment of HCV. Current regimens are now highly potent, all-oral, interferon-free combinations of these DAAs. The Food and Drug Administration has now approved many of these regimens. The changing management of HCV infection, including recent advances in HCV therapy, are discussed.
This review contains 1 figure, 5 tables and 59 references
Key words: direct-acting antiviral agents, hepatitis C virus, interferon-free therapy, management, treatment
Viral Hepatitis A
By Kenrad E Nelson, MD; Brittany L Kmush, PhDPurchase PDF
Viral Hepatitis APurchase PDF
Epidemics of infectious jaundice have been reported throughout recorded history. However, the proof that many of these outbreaks and individual cases of acute hepatitis were caused by a viral infection, the hepatitis A virus (HAV), did not appear until the 1960s. After the transmission of infection to marmosets and humans, the epidemiologic and virologic characteristics that differed between hepatitis A and hepatitis B virus infections were defined more clearly. After the development and licensure of hepatitis A vaccines in the 1990s, it became possible to implement an effective prevention program involving routine immunization of young children in the United States and several other Western countries. However, despite the dramatic efficacy of the childhood immunization program in reducing the incidence of acute hepatitis from HAV in the population, older children and adults remained susceptible. Significant morbidity continues to occur in the United States among international travelers, injection drug users, persons with underlying liver disease, and other high-risk populations. Since HAV is a global pathogen, the prevention of increasing morbidity from hepatitis A attributable to the incidence of clinically more severe disease increases in countries transitioning from high to intermediate or low endemic status is a major public health challenge. In this review, we discuss the epidemiology, virology, clinical characteristics, and prevention of hepatitis A infections.
This review contains 8 figures, 2 tables and 88 references
Key words: epidemiology, global impact, hepatitis A vaccine, hepatitis A virus, prevention, reservoirs, risk factors, treatment
- Specific Liver Disorders
Metabolic Liver Diseases: Wilson Disease and Alpha 1-antitrypsin Deficiency
By Uri Avissar, MDPurchase PDF
Metabolic Liver Diseases: Wilson Disease and Alpha 1-antitrypsin DeficiencyPurchase PDF
Two significant metabolic diseases of the liver are Wilson disease (WD) and α1-antitrypsin deficiency (AATD). WD is defined as an autosomal recessive disorder caused by mutations in the ATP7B gene of copper metabolism, leading to copper accumulation in multiple organs, notably the liver and brain, with ensuing injury giving way to hepatic and neuropsychiatric symptoms. AATD is also a genetic disorder but is distinguished by the production of a defective protease inhibitor, which leads to hepatic and pulmonary injury. This review of WD and AATD addresses their respective epidemiologies, genetics, pathophysiologies, diagnoses, differential diagnoses, managements, complications, and prognoses. Figures show the pathophysiology, clinical presentation, and liver histology of WD; suggested approaches to the diagnosis of WD, suspected WD, and family screening of first-degree relatives of WD patients; monitoring therapy in WD disease; schematic representation of the α1-antitrypsin (AAT) mechanism of action and polymerization of the Z mutation variant; pathophysiology and clinical presentation of AATD; periodic acid–Schiff–positive diastase-resistant globules in AATD; and suggested approach to AAT diagnosis and management. Tables list the causes of low ceruloplasmin, medications used in WD, and AAT variants and risk of disease.
This review contains 12 highly rendered figures, 3 tables, and 167 references.
Alcoholic Liver Disease
By Tibor Krisko, MD; György Baffy, MD, PhDPurchase PDF
Alcoholic Liver DiseasePurchase PDF
Alcoholic liver disease encompasses all forms of liver injury related to the consumption of alcohol (ethyl alcohol, ethanol, CH3CH2OH), one of the most common hepatotoxic agents in the world. The spectrum of this disease ranges from steatosis, which is present in everyone who drinks alcohol in excess, to cirrhosis, which occurs in approximately 10 to 15% of individuals with alcohol abuse and conveys an annual risk of 1 to 2% for the development of hepatocellular carcinoma. Despite the prevalence of alcoholic liver disease and its profound impact on health, questions remain surrounding its pathogenesis and management. This review of alcoholic liver disease addresses the epidemiology, etiology and genetics, pathophysiology and pathogenesis, diagnosis, differential diagnosis and comorbidities, treatment, complications, measures of quality of care, and prognosis and outcome measurements. Figures show common patterns, pathogenesis, and natural history of alcoholic liver disease; visual approximations of “a standard drink” based on type of alcohol (e.g., beer, wine); alcoholic liver disease and comorbidities; and treatment of alcoholic hepatitis. Tables list major health conditions related to the harmful use of alcohol, alcohol use disorders, genes and gene variants implicated in predisposition to alcoholic liver disease, commonly used questionnaires in diagnosing alcohol use disorders, differential diagnosis of alcoholic liver disease, and prognostic models to predict severity of alcoholic hepatitis.
This review contains 6 highly rendered figures, 6 tables, and 93 references.
By Jennifer Y Chen, MD; Karin L. Andersson, MD, MPHPurchase PDF
Autoimmune HepatitisPurchase PDF
Autoimmune hepatitis (AIH) is defined by elevated serum transaminases along with the presence of one or more characteristic serum autoantibodies, including antinuclear antibody (ANA), anti–smooth muscle antibody (ASMA), and anti–liver-kidney microsomal type 1 antibody (anti-LKM-1); elevated levels of serum immunoglobulin G (IgG); interface hepatitis on histology; and responsiveness to immunosuppressive therapy. AIH has been classified into two disease subtypes based on serologic markers: type 1, which is characterized by the presence of either ANA or ASMA, and type 2, which is characterized by the presence of either anti-LKM-1 or anti–liver-cytosol antibody type 1 (anti-LC-1). This review addresses the epidemiology, natural history, pathogenesis, and management of AIH, as well as ongoing challenges. Several recent advances are highlighted, including the creation of a simplified diagnostic scoring system and the use of budesonide for AIH treatment. Figures show the pathology of AIH, treatment approach of moderate to severe AIH with combination therapy, azathioprine metabolism, and management of treatment outcomes. Tables list a comparison of type 1 and type 2 AIH, antibodies in AIH, the revised diagnostic scoring system (including a simplified version), indications for treatment in AIH, recommended treatment regimens for AIH by the American Association for the Study of Liver Diseases, and adverse effects associated with therapy for AIH.
This review contains 4 highly rendered figures, 7 tables, and 146 references.
By Matthew S Chang, MD; Benjamin N Smith, MDPurchase PDF
Hereditary HemochromatosisPurchase PDF
Hereditary hemochromatosis is an inherited iron overload disorder that can result in liver and other end-organ involvement and injury. The phenotypic expression ranges from asymptomatic to end-stage liver disease and can be separated into three stages. This review covers the epidemiology, etiology and genetics, pathophysiology and pathogenesis, diagnosis, treatment, complications, and prognosis of hereditary hemochromatosis. Figures show the fraction of patients with mutations for hemochromatosis and clinical manifestations, the regulation of iron by hepcidin, physical examination findings in hemochromatosis, a diagnostic algorithm for hemochromatosis, and a treatment algorithm for hemochromatosis. Tables list hemochromatosis disease stage according to the European Association for the Study of the Liver, genetic mutations in hemochromatosis, secondary (non-hemochromatosis-related) causes of iron overload, indications for liver biopsy in patients with hemochromatosis, and clinical manifestations in hemochromatosis.
This review contains 5 highly rendered figures, 5 tables, and 32 references
Key words: Hemochromatosis; Hereditary hemochromatosis; Iron overload; Iron regulatory pathways; Hepatic iron; Hepcidin
Nonalcoholic Fatty Liver Disease
By Puneet Puri, MD; Michael Fuchs, MD, PhDPurchase PDF
Nonalcoholic Fatty Liver DiseasePurchase PDF
Nonalcoholic fatty liver disease (NAFLD) is defined by the pathologic accumulation of fat in more than 5% of hepatocytes in the absence of significant alcohol consumption (daily intake < 20 g in women and < 30 g in men) and by excluding secondary causes of hepatic steatosis. NAFLD can be categorized into two principal phenotypes: nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH). NAFL is defined by the presence of macrovesicular steatosis without inflammation, whereas NASH sees inflammation and hepatocyte ballooning injury, is associated with varying degrees of fibrosis, and can progress to cirrhosis and end-stage liver disease. This review addresses the epidemiology, etiology, pathophysiology, diagnosis, treatment, and prognosis of NAFLD. Figures show the spectrum of fatty liver disease, hepatic consequences of insulin resistance, role of liver biopsy in evaluation of NAFLD, histologic features of NASH, and principles of NAFLD. Tables list risk factors and clinical manifestations for NAFLD, physical examination findings in NAFLD, comparison of imaging modalities, and noninvasive fibrosis markers.
This review contains 6 figures, 5 tables and 166 references
Key words: Nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, non-invasive assessment, vibration controlled transient elastography, magnetic resonance elastography, diet and lifestyle treatment
Drug-induced Liver Injury
By Thanh Tran, MD; William M. Lee, MDPurchase PDF
Drug-induced Liver InjuryPurchase PDF
Drug-induced liver injury (DILI) refers to liver damage caused by over-the-counter and prescription drugs as well as herbal and dietary supplements. Hepatocytes, the main factory cells of the liver, are the primary targets of drug-related injury. During hepatocyte injury, loss of cell integrity results in a leak of liver contents, including a variety of enzymes, into the circulation. Currently, more than 1,000 drugs and herbal products have recognized hepatotoxic properties, with acetaminophen (APAP) being the most common cause of acute liver failure in the United States and amoxicillin-clavulanate the most common cause of severe liver injury worldwide. This review of DILI addresses the epidemiology, classification, pathophysiology, clinical manifestations, diagnosis, common idiosyncratic drug reactions, unusual drug reactions, treatment, and prognosis, with special sections on APAP hepatotoxicity and the approval of prescription drugs by the Food and Drug Administration. Figures show histologic features of DILI, mechanisms of liver injury, genome-wide association study results for lumiracoxib, APAP metabolism, and the Rumack-Matthew nomogram. Tables list classification of DILI, features of idiosyncratic drug reactions, histologic patterns of DILI, haplotypes associated with specific drug-related disorders, and the Roussel-Uclaf causality assessment method.
This review contains 5 highly rendered figures, 5 tables, and 54 references.
Primary Biliary Cirrhosis
By Lindsay Y. King, MD, MPH; Daniel S. Pratt, MDPurchase PDF
Primary Biliary CirrhosisPurchase PDF
Primary biliary cirrhosis (PBC) is a progressive autoimmune disease of the liver. It is the most common cause of chronic intrahepatic cholestatic liver disease in adults. This review addresses the epidemiology, etiology and genetics, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, complications, and prognosis of PBC. Figures show the pathogenesis and natural history of PBC and histologic features of the four stages of PBC. Tables list diagnostic criteria for PBC via the American Association for the Study of Liver Diseases, differential diagnosis for PBC, medications used to treat PBC, secondary therapy for PBC, and follow-up of patients with PBC.
This review contains 2 highly rendered figures, 5 tables, and 45 references.
Autoimmune Hepatitis/overlap Syndromes
By Albert J Czaja, MDPurchase PDF
Autoimmune Hepatitis/overlap SyndromesPurchase PDF
When autoimmune hepatitis has features of primary biliary cholangitis or primary sclerosing cholangitis, these mixed clinical phenotypes constitute overlap syndromes. Diagnostic criteria have been promulgated, but clinical judgement and liver tissue examination remain cornerstones of diagnosis. Cholestatic laboratory and histological findings, concurrent inflammatory bowel disease, or non-response to conventional corticosteroid therapy compel practitioners to consider overlap in patients with autoimmune hepatitis. Laboratory indices of marked liver inflammation and histological findings of moderate to severe interface hepatitis, especially with lymphoplasmacytic infiltration, also warrant consideration of overlap in patients with primary biliary cholangitis or primary sclerosing cholangitits. Treatment recommendations to date have been based on weak clinical evidence, and disease management should be individualized and guided by the predominant disease component. Prednisone or prednisolone in combination with azathioprine has been used in patients with predominantly autoimmune hepatitis, whereas low dose ursodeoxycholic acid in conjunction with corticosteroid-based regimens has been recommended in syndromes with predominately cholestatic disease. All treatments have been variably effective, especially in patients with overlapping features of primary sclerosing cholangitis. Mycophenolate mofetil and calcineurin inhibitors have been used as salvage therapies in limited experiences, and liver transplantation has been associated with graft and overall survivals similar to those of the classical unmixed diseases.
This review contains 6 figures, 7 tables and 50 references
Keywords: autoimmune hepatitis, primary biliary cholangitis, primary sclerosing cholangitis, overlap, cholestatic laboratory and histological features
Acute Liver Failure
By Constantine J Karvellas, MD, SM, FRCPC; R. Todd Stravitz, MD, FACP, FACG, FAASLDPurchase PDF
Acute Liver FailurePurchase PDF
Acute liver failure (ALF) remains one of the most dramatic and highly mortal syndromes in modern medicine, with a poor outcome (death or need for emergency liver transplantation) in more than 50% of affected patients. However, prevention of specific etiologies of ALF, general improvements in intensive care medicine, and specific improvements in the management of the systemic complications of ALF, have markedly reduced mortality over the last 40 years. Specific ALF etiologies, including hepatitis A and B, appear to have decreased in developed nations along with improvements in sanitation and widespread vaccination. The management of specific complications—cerebral edema in particular—has lowered the proportion of ALF deaths due to intracranial hypertension, which was once the most dreaded systemic manifestation of ALF. A recent randomized, multicenter trial has documented the efficacy of high-volume plasma exchange in improving transplant-free and overall in-hospital survival. These and other advances have led to a speculation that ALF will be a “curable” clinical condition by the year 2024. Challenges persist, however, as acetaminophen (APAP) overdose continues to account for ~50% of cases of ALF in many developed nations. In the United Kingdom, legislation to limit access to the drug has led to a marked decrease in the incidence of ALF due to acetaminophen overdose: an important lesson for other governments to consider as they work to meet the goal of rendering ALF a “curable” condition.
This review contains 6 figures, 10 tables and 53 references
Key Words: acetaminophen, acute liver failure, cerebral edema, drug-induced liver injury, extracorporeal liver assist device, fulminant liver failure, hepatic encephalopathy, intracranial hypertension, liver transplantation
- Complications of Chronic Liver Disease
Portal Hypertension and Variceal Hemorrhage
By Amir Qamar, MDPurchase PDF
Portal Hypertension and Variceal HemorrhagePurchase PDF
Gastrointestinal bleeding in patients with cirrhosis can occur from a number of different causes, including portal hypertension, gastric antral vascular ectasia, and acute variceal hemorrhage. The management of these conditions involves a combined medical and endoscopic approach, with radiologic and surgical therapies restricted to refractory cases. This review covers the natural history of gastroesophageal varices, portal hypertensive gastropathy, and gastric antral vascular ectasia; diagnostic principles; primary and secondary prophylaxis relating to esophageal variceal hemorrhage; and treatment overviews for gastric variceal hemorrhage, portal hypertensive gastropathy, and gastric antral vascular ectasia. Figures show the pathophysiology of complications of cirrhosis, esophageal varices as seen during an upper endoscopic procedure, natural history of esophageal varices in patients with cirrhosis, portal hypertensive gastropathy, gastric antral vascular ectasia, and management principles for acute variceal hemorrhage, esophageal variceal ligation, and gastric varices. Tables list the prevalence of various etiologies of hemorrhage in patients with cirrhosis, current recommendations for follow-up screening and surveillance of varices, sensitivities and specificities of some noninvasive markers, and principles of initial management of acute variceal hemorrhage.
This review contains 8 highly rendered figures, 4 tables, and 44 references.
By Allison R Schulman, MD; Nikroo Hashemi, MD, MPHPurchase PDF
Hepatic EncephalopathyPurchase PDF
Hepatic encephalopathy (HE) is one of the most debilitating manifestations of acute or chronic liver disease and/or portosystemic shunting. The clinical manifestations of HE span a wide spectrum of neurologic or psychiatric abnormalities, ranging from subclinical neuropsychological disturbances to coma. HE severely affects the lives of patients and their caregivers and results in the use of more health care resources in adults than other manifestations of hepatic dysfunction. To date, there are insufficient clinical studies and standardized definitions, making the diagnosis, classification, and treatment of HE challenging. This review covers the epidemiology, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, and follow-up of HE. Figures show the numerous processes and mechanisms involved in the pathogenesis of HE and ammonia trafficking and metabolism within the body. Tables list the four factors that dictate categorization and grading of HE, differential diagnosis of HE, summary of testing used for minimal HE and covert HE with associated advantages and/or disadvantages, and precipitating causes of HE in patients with cirrhosis.
This review contains 2 highly rendered figures, 4 tables, and 77 references.
Key words: chronic liver disease; covert hepatic encephalopathy; hepatic encephalopathy; minimal hepatic encephalopathy; overt hepatic encephalopathy; transjugular intrahepatic portosystemic shunt
Ascites, Spontaneous Bacterial Peritonitis, and Hepatorenal Syndrome
By Fredric D. Gordon, MDPurchase PDF
Ascites, Spontaneous Bacterial Peritonitis, and Hepatorenal SyndromePurchase PDF
Ascites, a common occurrence in cirrhotic patients with portal hypertension, is the pathologic accumulation of fluid in the peritoneum. Associated conditions are spontaneous bacterial peritonitis (SBP) and hepatorenal syndrome (HRS). SBP occurs in 30% of patients with ascites and carries a 20% mortality, most often due to the severity of the underlying cirrhosis. HRS involves life-threatening sequela of refractory ascites with limited treatment options; a review that focuses exclusively on this disease can be found elsewhere in this section. The development of these diseases is a poor prognostic feature, and referral for liver transplantation should be a consideration. This review examines ascites, SBP, and HRS and their relation to each other. The primary focus is ascites, addressing its epidemiology, pathophysiology, diagnosis, differential diagnosis, and management. Figures show theories of ascites formation and pathophysiology of HPS. Tables list screening tests on ascitic fluid, serum ascites–albumin gradient, drugs and agents to avoid in patients with ascites, diagnostic criteria for HPS, and clinical features of type 1 HPS. Also included are two recommended, pertinent Web sites for those who wish to learn more about ascites, SBP, and HPS.
This review contains 2 highly rendered figures, 5 tables, and 73 references.
By Stephen C Wright, MDPurchase PDF
Hepatorenal SyndromePurchase PDF
Hepatorenal syndrome (HRS) is a form of functional renal failure that develops as a consequence of portal hypertension in cirrhosis of the liver or other processes that acutely raise portal pressure, such as fulminant liver failure or severe alcoholic hepatitis. Its development is an independent risk factor for a poor post–liver transplantation outcome. This review addresses the epidemiology, pathophysiology, classification of subtypes of HRS, incidence, evaluation of the cirrhotic patient with renal insufficiency, prevention of HRS, and management. A figure shows the sequence of circulatory abnormalities in HRS, and a table lists the summary of the diagnostic criteria for HRS as established by the International Ascites Club.
This review contains 1 highly rendered figure, 1 table, and 28 references.
- Hepatology Miscellaneous
Liver Transplantation for the Gastroenterologist
By Andreea M. Catana, MD; Michael P. Curry, MDPurchase PDF
Liver Transplantation for the GastroenterologistPurchase PDF
The first liver transplantation (LT) was performed in 1963, and currently more than 65,000 people in the United States are living with a transplanted liver. In 2012, the number of adults who registered on the LT waiting list decreased for the first time since 2002; 10,143 candidates were added compared with 10,359 in 2011. LT offers long-term survival for complications of end-stage liver disease and prolongs life in properly selected patients, but problems such as donor deficit, geographic disparities, and long waiting lists remain. This overview of LT for the gastroenterologist details the indications for LT and patient selection, evaluation, liver organ allocation, prioritization for transplantation, transplantation benefit by the Model for End-Stage Liver Disease (MELD), MELD limitations, sources of liver graft, strategies employed to decrease the donor deficit, complications, and outcomes. Figures include indications for LT in Europe and the United States, Organ Procurement and Transplantation Network regions in the United States, the number of transplants and size of active waiting lists, mortality by MELD, regional disparity, patient survival rates with and without hepatitis C virus, and unadjusted patient and graft survival. Tables list LT milestones, indications for LT, contraindications for LT, minimal listing criteria for LT, criteria for LT in acute liver failure, LT evaluation process, adult recipient listing status 1A, and early posttransplantation complications.
This review contains 7 highly rendered figures, 8 tables, and 46 references.
Parenteral Nutrition Associated Liver Toxicity: Prevention, Diagnosis and Management
By Meredith A. Baker, MD; Lorenzo Anez-Bustillos, MD; Duy T. Dao, MD; Gillian L. Fell, MD; Kathleen M. Gura, PharmD; Mark Puder, MD, PhDPurchase PDF
Parenteral Nutrition Associated Liver Toxicity: Prevention, Diagnosis and ManagementPurchase PDF
Long-term parenteral nutrition (PN) treatment is limited by parenteral nutrition–associated liver disease (PNALD), which is characterized initially by intrahepatic cholestasis, typically defined as a direct bilirubin greater than 2 mg/dL in the absence of other causes of liver disease. PNALD is typically less common and less severe and progresses more slowly in older children and adults than in infants. The etiology of PNALD is multifactorial. Key factors include immature liver function, sepsis, and a lack of enteral nutrition. Additionally, nearly every component of PN has been attributed to or exacerbated hepatotoxicity. PN preparations must be carefully individualized and monitored to minimize hepatotoxicity from its various components. Although many hepatotoxic components or imbalances have been recognized, soybean oil–based lipid emulsions continue to be widely used as they are the only lipid emulsions currently approved for PN by the Food and Drug Administration. Fish oil–based lipid emulsions have been shown to reverse PNALD, with an associated decrease in mortality. As such, fish oil therapy should be considered early once biochemical cholestasis is detected in PN-dependent patients. Studies investigating the use of novel lipid emulsions for prevention and treatment of PNALD are ongoing.
This review contains 5 figures, 5 tables, and 114 references.
- Viral Liver Disease
By Justin Chan, MD; Arthur Yu-Shin Kim, MDPurchase PDF
HIV CoinfectionPurchase PDF
Improved screening of the blood supply and safer injection practice have led to a decreased prevalence of hepatitis C virus (HCV) worldwide over the past decade. However, those who are coinfected with HIV and HCV experience synergistic interaction between the viruses, leading to accelerated liver fibrosis and possibly increased HIV progression. Left untreated, these coinfected patients experience higher mortality compared with monoinfected individuals. The recent availability of highly efficacious direct-acting antivirals (DAAs) provides opportunity to prioritize coinfected patients for curing HCV, which can improve liver-related and overall mortality. This review summarizes the epidemiology, virology, and natural history of coinfection. Major clinical trials involving coinfected patients are summarized, and drug-drug interactions between HIV antiretroviral therapy and HCV DAA therapy are discussed. Given the numbers of people at risk for primary infection and reinfection after cure, we also discuss important strategies of harm reduction and treatment as prevention. The revolution in DAAs provides the prospect of reducing the burden of liver disease, which remains one of the leading causes of death in people living with HIV.
Key words: HIV-HCV coinfection; Epidemiology; Natural history; Viral interaction; Direct-acting antiviral; Drug-drug interaction
Foreign Body Ingestion
By Kunal Jajoo, MD; Allison R Schulman, MDPurchase PDF
Foreign Body IngestionPurchase PDF
Foreign-body ingestion and food bolus impaction are common causes of esophageal obstruction, with an annual incidence of 13 cases per 100,000, and represent approximately 4% of all emergency endoscopies. Although the majority of foreign bodies that travel to the gastrointestinal (GI) tract will pass spontaneously, 10 to 20% must be removed endoscopically, and 1 to 5% will require surgery. Key diagnostic and therapeutic decisions are based on common factors, including the type of ingested object, number of objects, timing between ingestion and presentation, anatomic location of the object, and presence or absence of symptoms. Complications relating to foreign-body ingestion are typically uncommon; however, the associated morbidity may be severe and occasionally life threatening, and despite the fact that overall mortality has been extremely low, it has been estimated that up to 1,500 deaths occur annually in the United States as a result of foreign-body ingestion. The initial and follow-up management strategies are crucial to preventing morbidity. This review details the epidemiology, etiology and pathophysiology, diagnosis, management, and complications of foreign-body ingestion. Figures show examples of foreign bodies in the esophagus and stomach, three esophageal areas where a foreign body is likely to be impacted, examples of a meat bolus in the esophagus, radiograph of a patient who swallowed one nail and three batteries, and examples of linear erosions of the esophagus and stomach. Tables list the most common GI pathology predisposing individuals to esophageal foreign-body impaction, timing and management of food bolus impaction and foreign-body ingestion, endoscopic management strategies for food bolus impaction and ingested foreign bodies, and radiographic and surgical management strategies for monitoring progress of foreign-body passage through the GI tract.
This review contains 5 highly rendered figures, 4 tables, and 78 references.
By Marvin Ryou, MD; Nitkin Kumar, MDPurchase PDF
Endoscopic UltrasonographyPurchase PDF
Endoscopic ultrasonography (EUS) is a versatile tool that can be used to perform a variety of diagnostic and therapeutic procedures in the upper or lower gastrointestinal tract. The proximity of the echoendoscope to the pancreas, liver, and other thoracic and abdominal organs allows detailed examination or minimally invasive intervention that would not be feasible by surgical or percutaneous approaches. EUS is available with radial or linear scanning arrays and is capable of guiding fine-needle aspiration to acquire tissue for cytologic analysis. This review covers the role of EUS in chronic pancreatitis; pancreatic cysts; submucosal tumors; suspected choledocholithiasis; fecal incontinence; staging of malignancy in esophageal, pancreatic, gastric, and rectal cancer; celiac plexus block/neurolysis; fiducial placement; pseudocyst drainage and cystogastrostomy/cystoduodenostomy; endoscopic necrosectomy; and biliary drainage. Figures show peripancreatic cysts, gastrointestinal stromal tumor, common bile duct stone, esophageal adenocarcinoma, pancreatic head mass causing biliary obstruction and invading portal confluence, fine-needle aspiration of a pancreatic head mass, rectal adenocarcinoma, abdominal aorta with celiac artery and superior mesenteric artery, celiac plexus neurolysis, necrosectomy, and EUS-guided choledochoduodenostomy for failed endoscopic retrograde cholangiopancreatography. Tables list the Rosemont criteria for chronic pancreatitis and pancreatic cystic lesions.
Key words: bile duct stone, biliary drainage, echoendoscope, endoscopic ultrasonography, fine-needle aspiration, pancreatic cyst
This review contains 12 highly rendered figures, 2 tables, and 62 references.
Video Capsule Endoscopy and Deep Enteroscopy
By Neil Marya, MD; Veronica Baptista, MD; Anupam Singh, MD; Joseph Charpentier, DO; David Cave, MD, PhDPurchase PDF
Video Capsule Endoscopy and Deep EnteroscopyPurchase PDF
Until 2001, the nonsurgical evaluation of the small intestine was largely limited to the use of radiologic imaging (e.g., small bowel follow-through or enteroclysis). With the now widespread availability of video capsule endoscopy and deep enteroscopy since 2001, we are now able to visualize the length and most of the mucosa of the small intestine and manage small bowel lesions that were previously inaccessible except by surgical intervention. This review serves as an overview for these two procedures, detailing the indications and contraindications, proper timing of the procedure, technical aspects of the devices themselves, possible complications, and outcomes. Figures show endoscopic images that demonstrate multiple angioectasias, bleeding during capsule endoscopy, active Crohn disease of the small bowel, severe mucosal scalloping, small bowel carcinoid tumor, small bowel polyp associated with Peutz-Jeghers syndrome, and nonsteroidal antiinflammatory drug enteropathy; serial x-rays of a patient with a patency capsule retained inside the small intestine; a computer image showing the distribution of small bowel tumors; and a pie chart displaying the breakdown of the distribution of benign and malignant tumors that can be found in the small intestine. Videos show multiple angioectasias, bleeding during capsule endoscopy, active Crohn disease of the small bowel, small bowel carcinoid tumor, and small bowel polyp associated with Peutz-Jeghers syndrome.
This review contains 10 highly rendered figures, 5 videos, and 50 references.
Endoscopic Retrograde Cholangiopancreatography
By Wasif Abidi, MD, PhD; Linda S. Lee, MDPurchase PDF
Endoscopic Retrograde CholangiopancreatographyPurchase PDF
Endoscopic retrograde cholangiopancreatography (ERCP) is a specialized endoscopic procedure to view the biliary and pancreatic ducts fluoroscopically. First introduced in the 1970s as a diagnostic tool, ERCP has since evolved primarily into a therapeutic modality and is today regarded as the premier tool for performing therapeutic interventions involving the biliary and pancreatic ductal systems. Relatively complex, ERCP requires advanced training. Although generally considered safe, it does carry a risk of significant complications, including pancreatitis; thus, the most important factor to mitigate complications is to ensure the presence of an appropriate indication for the procedure. This review addresses the indications (e.g., disorders of the major duodenal papilla, biliary diseases, and pancreatic diseases), contraindications, protocol, and complications of ERCP, as well as an overview of the tools available for ERCP procedures. Figures show ampullary adenomas, choledocholithiasis, Mirizzi syndrome, benign common bile duct stricture, primary sclerosing cholangitis, malignant biliary stricture, bile leak, type I and III choledochal cysts, chronic pancreatitis, pancreatic ductal disruption, classic fish-mouth appearance of the papilla in a patient with main duct intraductal papillary mucinous neoplasm, pancreas divisum, side-viewing duodenoscope used for ERCP, and selected tools of ERCP. Tables list the Rome III criteria, risk-stratifying patients for choledocholithiasis, diagnostic criteria for acute cholangitis, choledochal cyst classification, and the Cambridge classification system for chronic pancreatitis.
This review contains 15 highly rendered figures, 5 tables, and 77 references.
Endoscopic Management of Postbariatric Fistulae and Leaks
By Yana Cavanagh, MD; Sohail N. Shaikh, MDPurchase PDF
Endoscopic Management of Postbariatric Fistulae and LeaksPurchase PDF
The number of bariatric procedures performed annually is increasing along with the number of complications. Gastrointestinal leak after bariatric surgery generally portends high morbidity and mortality, and its management depends on clinical and radiographic presentation. A leak is defined as an enteric defect with extravasation of luminal contents. Fistulae are abnormal connections between two epithelialized surfaces, are usually chronic, and may develop from long-standing leaks. Endoscopic therapies may offer an attenuated risk profile compared with surgical intervention and play a growing role in the management of postbariatric complications. Leak resolution may require multiple endoscopic sessions and modalities (e.g., stents, adhesives, plugs, clips, suturing, and VAC-assisted closure); therefore, it is critical to have appropriate follow-up and surveillance after therapeutic endoscopic intervention. This review discusses endoscopic leak and fistula management through endoscopic procedures, addressing indications and candidates for procedure, contraindications, recipient evaluation, and aspects of procedure, including proper timing, equipment, and types. Figures show Roux-en-Y gastric bypass, sleeve gastrectomy, management options for leaks after bariatric surgery, a diagnostic algorithm for leaks, upper gastrointestinal series performed with Gastrografin, and computed tomographic scans that demonstrate extraluminal air extending along the diaphragmatic surface of the spleen and a perisplenic gas and fluid-filled collection on the lateral margin. Tables list complications that follow bariatric surgery; an excerpt from the 2008 American Society for Gastrointestinal Endoscopy Guidelines; recommended equipment for endoscopic defect management; classification system based on duration after bariatric surgery; classification and approach to management based on clinical presentation and radiographic findings; summary of recommendations for pre-endoscopy, index endoscopy, therapeutic endoscopy, and posttherapeutic endoscopy; and early and late complications of stent placement.
This review contains 7 highly rendered figures, 7 tables, and 104 references.
New Endoscopic Techniques
By Phillip S Ge, MD; Christopher C Thompson, MD, MHESPurchase PDF
New Endoscopic TechniquesPurchase PDF
Major advancements in endoscopic techniques have allowed for the minimally invasive endoscopic management of many diseases that previously required surgical intervention. This review briefly describes major advances in endoscopic resection, including endoscopic mucosal resection and endoscopic submucosal dissection; endoscopic ablation, including radiofrequency ablation and cryotherapy; submucosal endoscopy, including peroral endoscopic myotomy and submucosal tunneling endoscopic resection; endoscopic access, including biliary access, pseudocyst drainage and direct endoscopic necrosectomy, and endoscopic gastrojejunostomy; endoscopic management of gastroesophageal reflux disease; and endoscopic management of obesity. Owing to the broad range of topics covered, extensive primary literature is provided for further reference for the interested reader.
This review contains 8 figures and 55 references
Key words: bariatric endoscopy, direct biliary access, endoscopic mucosal resection, endoscopic submucosal dissection, gastroesophageal reflux disease, gastrojejunostomy, peroral endoscopic myotomy, pseudocyst drainage, radiofrequency ablation, submucosal tumors
Endoscopic Techniques for Obtaining Enteral Access
By Sanjay Salgado, MD; Marvin Ryou, MDPurchase PDF
Endoscopic Techniques for Obtaining Enteral AccessPurchase PDF
In the absence of contraindications, enteral feeding is recommended for patients who are expected to be intolerant of oral feedings beyond 7 days. Enteral access can be accomplished by a variety of means, including surgical, endoscopic, or radiographic methods. This review focuses on endoscopy-guided options for enteral access. These methods include gastric feeding, which can be accomplished by orogastric, nasogastric, or percutaneous endoscopic gastrostomy tube placement, and postpyloric feeding, accessed through oral or nasal jejunal tubes, percutaneous gastrostomy with a jejunal extension, or direct percutaneous jejunostomy. The indications, techniques, complications, and comparative data of these placement options are outlined, and special clinical considerations (including establishing access in patients with dementia or cirrhosis and those on anticoagulation) are discussed.
This review contains 5 figures, 1 table, and 33 references.
Key words: direct percutaneous jejunostomy, endoscopy, enteral access in cirrhosis, enteral access in dementia, enteral feeding, enteric access, nasogastric feeding tubes, percutaneous endoscopic gastrojejunostomy tubes, percutaneous endoscopic gastrostomy tubes
Enteral Stenting: an Overview of Gastrointestinal Luminal Endoprostheses
By Vaishali Patel, MD, MHS; Field Willingham, MD, MPH, FASGEPurchase PDF
Enteral Stenting: an Overview of Gastrointestinal Luminal EndoprosthesesPurchase PDF
Enteral stents are tubular devices that can reestablish the patency of the gastrointestinal (GI) lumen in the setting of high-grade obstruction. Although they have been more commonly used in the palliation of malignant obstruction, they now have expanding roles for benign luminal strictures and stenoses. Familiarity with the indications and contraindications for enteral stent placement can enable consideration of a less invasive and morbid therapeutic option for many patients with symptomatic obstructions. The development of self-expandable metal stents and the subsequent emergence of lumen-apposing coaxial metal stents have expanded the role of enteral stents in the management of various GI disorders.
This review contains 49 references, 5 figures, and 5 tables.
Key Words: coaxial, enteral, gastrointestinal malignancy, lumen-apposing, obstruction, palliation, stent
Endoscopic Therapy for Dysplastic Barrett Esophagus and Intramucosal Cancer
By Aymeric Becq, MD; Tyler M Berzin, MD, MS, FASGEPurchase PDF
Endoscopic Therapy for Dysplastic Barrett Esophagus and Intramucosal CancerPurchase PDF
Barrett esophagus (BE) is a common premalignant condition that may evolve from nondysplastic intestinal metaplasia to low-grade dysplasia (LGD), high-grade dysplasia (HGD), and ultimately to esophageal adenocarcinoma (EAC). This review addresses the range of endoscopic approaches for treating dysplastic BE and early EAC. Endoscopic treatment is favored for most patients with LGD, although endoscopic surveillance continues to be an alternative. Endoscopic eradication is definitively recommended for patients with HGD. Radiofrequency ablation is the preferred technique for ablation of dysplastic BE, although there is also strong support for endoscopic mucosal resection as a first-line therapy. Cryotherapy is emerging as a valid alternative ablative approach. Endoscopic resection by endoscopic mucosal resection or endoscopic submucosal dissection is recommended as the first-line therapy for nodular BE and T1a EAC. Post-eradication endoscopic surveillance is indicated at intervals that depend on the category of pretreatment dysplasia. Because of advances in endoscopic therapy, surgery is now indicated only when endoscopic ablation or resection has failed or in the setting of more advanced EAC.
This review contains 8 figures, 2 tables, and 55 references.
Key Words: cryotherapy, endoscopic mucosal resection, esophageal adenocarcinoma, esophagectomy, high-grade dysplasia, low-grade dysplasia, nodular Barrett esophagus, radiofrequency ablation
Failure to Thrive in Infants and Toddlers
By Madhura Y Phadke, MD; Anthony F Porto, MD, MPHPurchase PDF
Failure to Thrive in Infants and ToddlersPurchase PDF
Failure to thrive (FTT) is a broad term that is used to document an abnormal pattern of weight gain over time. There is no single definition for FTT, but all proposed definitions use anthropometric parameters such as weight gain or weight for length. The term FTT has been falling out of favor, and the term weight/growth faltering is becoming more common to describe this clinical entity. The underlying problem in FTT is inadequate usable calories. The primary mechanisms leading to FTT are impaired absorption, increased metabolic demands, and inadequate caloric intake. Inadequate caloric intake is the most common of these mechanisms, although FTT is often a combination of the three. The diagnostic evaluation of FTT must take into account the multifactorial nature of this clinical sign. A comprehensive history is essential for diagnosis and should include specific questions about the child’s living situation and feeding habits. The physical examination must include accurate weight and length measurements. Clinicians should look for signs of abuse or neglect, dysmorphic features, abnormal skin or nail findings, digital clubbing, or other signs of chronic disease. Laboratory investigations are rarely revealing in FTT but should be considered if there is a high index of suspicion for underlying disease. Treatment in FTT favors a multidisciplinary approach. The primary goal of treatment is restoration of normal growth velocity. Children with FTT are at increased risk for growth and cognitive problems in later childhood, although the clinical significance of these findings is not well understood. The mainstay of treatment is increasing calories in the diet. Enteral feeding, orally or via a tube, is always preferred over parenteral feeding due to a better safety profile, ease of feeding, and lower cost. Parenteral nutrition is an acceptable way to meet caloric needs in infants and children when enteral nutrition is not possible. Children with FTT and malnutrition should be monitored closely for refeeding syndrome, which results from fluid and electrolyte shifts in malnourished children. In general, FTT can be treated on an outpatient basis with close follow-up. Indications for hospitalization include severe malnutrition/dehydration and concern for child endangerment.
Key words: enteral feeding, failure to thrive, growth charts, nutrition, parenteral nutrition, poor weight gain, tube feeding, weight loss
Eosinophilic Esophagitis in Children and Adolescents
By Elizabeth J Hait, MD, MPHPurchase PDF
Eosinophilic Esophagitis in Children and AdolescentsPurchase PDF
Eosinophilic esophagitis (EoE) is an inflammatory disorder of the esophagus characterized by symptoms of esophageal dysfunction in association with histologic evidence of eosinophilic infiltration of the esophageal mucosa. The diagnosis is based on esophageal biopsies showing more than 15 eosinophils per high-power field in the absence of pathologic gastroesophageal reflux. It can present with a wide array of upper gastrointestinal tract symptoms. Babies and toddlers typically present with feeding intolerance or refusal, vomiting, and failure to thrive. Older children often present with abdominal pain and reflux symptoms, whereas adolescents and adults typically present with solid-food dysphagia and/or food impaction. Diagnosis is also supported by a family history of EoE and other allergy-based disorders, such as asthma, seasonal allergies, and atopy. Topical corticosteroids and dietary elimination are acceptable first-line treatment approaches.
This review contains 7 figures, 5 tables, and 51 references.
Key words: dysphagia, elimination diets, endoscopic dilation, eosinophilic esophagitis, eotaxin-3, feeding dysfunction, interleukin-5, proton pump inhibitor–responsive esophageal eosinophilia, swallowed fluticasone, viscous budesonide
Cystic Fibrosis in Childhood and Adolescence
By Sabina Sabharwal, MD, MPHPurchase PDF
Cystic Fibrosis in Childhood and AdolescencePurchase PDF
Although cystic fibrosis (CF) has historically been considered a pulmonary disease, with the increasing life expectancy of these patients, gastrointestinal manifestations are becoming more important. Moreover, nutritional status is closely linked to pulmonary function and, thus, overall mortality. This review discusses gastrointestinal (including nutritional, pancreatic, and hepatobiliary) manifestations of CF and their management. It also discusses studies that have been critical to our understanding of these manifestations of CF.
This review contains 1 figure, 1 table, and 36 references.
Key words: body mass index, constipation, cystic fibrosis transmembrane regulator, distal intestinal obstruction syndrome, pancreatic insufficiency
Evaluation of Elevated Transaminases in Children
By Pamela L Valentino, MD, MSc, FRCPC; Udeme D Ekong, MD, MPHPurchase PDF
Evaluation of Elevated Transaminases in ChildrenPurchase PDF
The approach to elevated liver transaminases presented here includes an understanding of the biochemical testing, as well as a sequential pathway of investigations. In the pediatric patient who is not in acute liver failure, we discuss the differential diagnoses that should be considered, categorized in a systems-based approach. Infectious, autoimmune, genetic/metabolic, and cholestatic disease; drug-induced liver injury; and nonalcoholic fatty liver disease are among the categories that should be considered. Following a thorough history and physical examination, the patient should be referred to a pediatric specialist with expertise in the diagnosis and treatment of liver disease. Appropriate investigations by a pediatric gastroenterologist/hepatologist initially include blood tests and abdominal Doppler ultrasonography.
This review contains 4 figures, 3 tables and 42 references
Key words: acute liver failure, alanine aminotransferase, aspartate aminotransferase, cholestasis, chronic hepatitis, cirrhosis, elevated liver enzymes, end-stage liver disease, γ-glutamyl transaminase, portal hypertension
Evaluation and Treatment of Pediatric Obesity
By Nirav K Desai; Samir SofticPurchase PDF
Evaluation and Treatment of Pediatric ObesityPurchase PDF
Obesity is one of the most significant health problems facing children and adolescents. The definition of overweight in children is a body mass index between the 85th and less than 95th percentile, whereas obesity is greater than or equal to the 95thpercentile for age and sex. There are multiple comorbidities associated with obesity, including dyslipidemia, hypertension, type 2 diabetes, sleep apnea, and nonalcoholic fatty liver disease, as well as psychosocial issues. Contributors to obesity are multifactorial, including genetic and environmental factors. Environmental factors associated with obesity include increased availability of inexpensive fast food, sugar-sweetened beverages, and high-fat and -sugar convenience foods; decreased exercise; and increased screen time. Treatment begins with behavioral interventions focusing on dietary modifications and increasing physical activity. Although medications to treat obesity are an area of increased interest, options in the pediatric population are limited. Currently, orlistat is the only FDA-approved option. For the treatment of severe obesity, bariatric surgery should be considered, based on age, weight, and associated comorbidities. Weight loss associated with surgery is robust and long-lasting and results in improvement in/resolution of multiple comorbidities. However, benefits should also be weighed against the long-term risks of vitamin deficiency.
This review contains 73 references, 3 figures, and 3 tables.
Key words: bariatric surgery,metabolic syndrome, obesity treatment, pediatric obesity, weight loss surgery
Crohn Disease in Childhood and Adolescence
By Lori ZimmermanPurchase PDF
Crohn Disease in Childhood and AdolescencePurchase PDF
Crohn disease (CD) is a chronic inflammatory condition that can occur throughout the gastrointestinal tract (the mouth to the anus). CD is classified by location within the gastrointestinal tract and behavior of the disease (inflammatory, penetrating, and/or stricturing). It can also affect the extraintestinal tissue and cause perianal disease. It occurs from a complex interplay of genetic predisposition, altered gut microbiota, immunologic dysregulation, and likely environmental triggers. Children with CD often present with signs and symptoms related to the inflammation within their gastrointestinal tract. Most children with CD will present with diarrhea and abdominal pain, whereas some will present with rectal bleeding, fevers, weight loss, perianal disease, or joint disease. There is no single test to confidently diagnose a patient with CD. Instead, clinicians rely on a combination of biomarkers in the serum and stool, imaging studies, and endoscopic evaluation to make the diagnosis. The general aims of treatment of children with CD are to induce and maintain clinical remission of disease, optimize nutrition and growth, minimize adverse effects of therapies, and ultimately target mucosal healing.
This review contains 3 figures, 3 tables and 34 references.
Key Words: biologics, child, chronic diarrhea, Crohn disease, hematochezia, inflammatory bowel disease, immunodeficiency, pediatric, weight loss