Review Articles in 2007

Medical therapy for GERD has improved remarkably since the introduction of PPIs; however, despite twice-daily dosing of PPIs, reflux symptoms can persist, new symptoms can occur or be unmasked, and esophagitis can fail to heal. Management of such 'refractory' GERD can be a challenge. The author of this Review considers the diagnostic approach to refractory GERD and the diagnoses that are possible.

Minimal hepatic encephalopathy (MHE)—the mild cognitive impairment commonly seen in patients who have cirrhosis—has a significant impact on quality of life. Current understanding is that MHE forms part of the spectrum of hepatic encephalopathy, although this remains to be proven. This Review focuses on the pathogenesis and neuropsychological findings of MHE, the effect of MHE on quality of life and survival, and treatment options.

Improved knowledge of the complex pharmacology, metabolism, mechanism of action, and toxicity profile of thiopurines has guided the development of strategies to improve pharmacotherapy in patients with IBD. This Review discusses the clinical implications of these developments, such as reducing the risk of adverse events (e.g. myelodepression and hepatotoxicity) by genetic screening, metabolite level characterization, and dose reductions.

The local staging and management of rectal cancer has evolved in the past decade. Imaging modalities used for staging rectal cancer include computed tomography, endoscopic ultrasound, magnetic resonance imaging, and positron emission tomography. In this Review, the author discusses the strengths and limitation of these modalities, along with the management of rectal cancer.

Twenty years ago, hepatopulmonary syndrome (HPS) was an absolute contraindication to orthotopic liver transplantation (OLT). HPS patients are now included on the waiting list for OLT because of reports that indicated survival after OLT in patients with hypoxemia had improved, the discovery that HPS can resolve after OLT, and the lack of other effective treatments. This Review provides an overview of information pertinent to the diagnosis of HPS and its management in OLT candidates.

This Review discusses the most common causes of chronic cough, the clinical features of GER-related cough and the usefulness of an empiric therapy trial to identify and treat these patients. The authors also consider how to proceed when patients do not improve with an empiric therapy trial. Clinical outcomes, long-term GER therapy and potential pitfalls of the treatment of GER-related cough are also covered.

The authors of this Review provide an overview of the mechanisms by which HCV is currently understood and postulated to govern liver injury. These mechanisms include the regulation of apoptosis, steatosis, activation of hepatic stellate cells, and the cytotoxic lymphocyte response.

Colonoscopy is increasingly being used for colorectal cancer screening, which has resulted in a growing cohort of patients who have polyps and require postpolypectomy surveillance. In this Review, the authors present an overview of the new postpolypectomy surveillance guidelines, explain the rationale behind them, discuss barriers to their implementation, and examine strategies to overcome these barriers.

Rectal prolapse causes significant discomfort because of the sensation of the prolapse itself, the mucus that it secretes, and because it tends to stretch the anal sphincters and cause incontinence. Treatment is primarily surgical; however, there are different opinions about which type of surgical repair is best. The authors of this Review discuss the pathogenesis, clinical presentation, evaluation and surgical management of rectal prolapse.

Although the incidence of stress-induced gastrointestinal bleeding has decreased, such bleeding is associated with increased morbidity and mortality in critically ill patients. In this Review, the authors address some of the issues surrounding treatment for the prevention of stress-induced gastrointestinal bleeding, such as whether all patients need prophylaxis, and how long prophylaxis should be continued for.

Over the past 15 years, intestinal transplantation for the treatment of intestinal failure has changed from a desperate last-ditch effort into a standard therapy for which a good outcome is expected. In this Review, the author considers several issues surrounding intestinal transplantation, including patient selection, allograft type, outcomes, complications, post-transplant monitoring and cost.

The authors of this Review discuss the diagnosis, clinical features and genetics of the hamartomatous polyposis syndromes, as well as the risk of malignancy associated with each syndrome and appropriate surveillance recommendations. Other disorders associated with the presence of hamartomatous polyps are briefly discussed, along with the potential for targeted therapy of hamartomatous polyposis syndromes.

This Review considers the role of endoscopic submucosal dissection as a treatment for early-stage gastrointestinal neoplasms. The author focuses on what is required for endoscopic submucosal dissection to be successful, safe and reliable—early detection, accurate preoperative diagnosis, a thorough knowledge of appropriate indications and techniques, and appropriate training.

Pancreatic stellate cells are the main mediator of fibrogenesis during chronic pancreatitis, and chronic pancreatitis is a consistent risk factor for pancreatic ductal adenocarcinoma. In this Review, the authors discuss the idea that pancreatic stellate cells have a linking role in the development of pancreatic ductal adenocarcinoma via their ability to communicate with inflammatory cells, acinar cells and pancreatic cancer cells.

This Review summarizes current understanding of nonalcoholic fatty liver disease, which is now accepted as the hepatic manifestation of metabolic syndrome. The authors consider the evaluation of patients at risk of developing nonalcoholic fatty liver disease, including the assessment of risk factors, the application of imaging modalities and the role of liver biopsy, as well as potential treatment approaches.

Numerous drugs can damage the gastrointestinal tract, and improved recognition of drug-induced gastrointestinal tract pathology is needed to improve patient care. The authors of this Review discuss the most common and well-described drug-related clinicopathological conditions of the gastrointestinal tract. Much discussion is dedicated to NSAIDs—the most commonly prescribed drugs and consequently the drugs most commonly associated with gastrointestinal tract toxicity.

With the advent of natural orifice translumimal endoscopic surgery (NOTES), a new dimension has been added to minimally invasive surgery. The authors of this Review examine the current status of NOTES, analyze the associated hazards and potential benefits of the technique, and consider the implications of NOTES for future surgical endoscopy.

Our understanding of how proteases function and interact within the gastrointestinal tract has been largely restricted to their role in nutrient digestion; however, it has become clear that proteases are involved in regulating signaling processes that are important for intestinal epithelial cell function. In this Review, the authors discuss how proteases impact gastrointestinal pathophysiology, specifically mucosal permeability, immune defense mechanisms and pathogenic challenges.

The large-scale study of protein expression and protein function by using molecular technologies—proteomics—has become increasingly attractive, because the proteome reflects the intrinsic genetic program of the cell and the impact of its immediate environment. This Review describes conventional proteomic technologies currently being used and their limitations, and demonstrates their clinical applicability, with specific reference to published data of relevance to the gastroenterology field.

Autoimmune pancreatitis—a nonalcoholic, chronic lymphoplasmacytic pancreatitis that frequently results in the stenosis of the main pancreatic duct and distal common bile duct—has been accepted as a unique clinical entity that is present predominantly in the Asian population. In this Review, the authors discuss various issues surrounding autoimmune pancreatitis, including its definition, epidemiology, pathogenesis and etiology, clinical presentation, diagnosis and treatment.