Review Articles, News & Views, Perspectives, Hypotheses, Analyses and Review in 2009

Detection of polyps by colonoscopy is commonly performed during slow withdrawal of the colonoscope, after its rapid insertion. The authors of a new study found that considerably more polyps were identified during endoscope insertion, rather than withdrawal, and suggest that further investigation of polyp inspection during the insertion phase is warranted.

Severe infections are an established risk of immunosuppressive therapy; however, the risk of opportunistic infections in patients with IBD who receive immunosuppressive therapy has so far only been studied retrospectively. The increased incidence of herpes flares and development or worsening of viral warts in patients with IBD who receive azathioprine has now been demonstrated for the first time in a prospective study.

Two very different studies have recently been published, which indicate that use of intravenous PPIs as an adjunct to endoscopic hemostasis might effectively prevent recurrent ulcer bleeding. What do these studies add to our current knowledge, and what are their practical implications for gastroenterologists?

Two multicenter trials have evaluated the potential of capsule endoscopy as a diagnostic tool for screening and surveillance of esophageal varices in cirrhotic patients. Their results are similar and show that capsule endoscopy has good performance characteristics, although it is somewhat inferior to esophagogastroduodenoscopy.

The optimal timing of endoscopy after presentation with upper gastrointestinal bleeding is a matter for debate. Tsoi and colleagues examine the findings of randomized clinical trials and retrospective cohort studies, and conclude that endoscopy within 24 h of admission to hospital aids risk stratification of patients and reduces the need for hospitalization. However, very early endoscopy shows no evidence of benefit in terms of the risk of rebleeding or improved survival.

Barrett esophagus involves the replacement of normal esophageal squamous epithelium with metaplastic columnar epithelium and is a major precursor to adenocarcinoma of the esophagus. Histological evaluation of biopsy samples from the esophagus and gastroesophageal junction for the presence of goblet cells and extent of dysplasia is the mainstay of surveillance for Barrett esophagus. This Review discusses the histological features of Barrett esophagus and its neoplastic complications.

Replication of HBV occurs through reverse transcription, but inherent lack of proofreading causes a high rate of mutations. The most common naturally occurring HBV mutations are those in the precore and core promoter regions that abolish or decrease the production of hepatitis B e antigen. In this Review article, Chotiyaputta and Lok discuss these mutations and those that confer resistance to antiviral agents and/or facilitate escape from host immunity.

The late consequences of acute pancreatitis refer to the complications that can arise after the convalescence period of acute pancreatitis, that is, 3–6 months after the initial pancreatitis episode. The development of late complications correlates with disease recurrence. This Review discusses risk factors for the recurrence of acute pancreatitis and the late consequences associated with this disease.

The low success rates of standard triple-therapy regimens for eradication of Helicobacter pylori infection have led to development of alternative approaches. Findings from a new meta-analysis that compared the efficacy of concomitant quadruple therapy with that of standard triple therapy revealed the concomitant approach to be superior for eradication of H. pylori.

The routine use of diagnostic laparoscopy for young women who present with right iliac fossa pain reduces the rate of negative appendectomy, according to a new study. However, the implementation of laparoscopy as a routine approach for the diagnosis of suspected acute appendicitis would probably increase morbidity and mortality for these patients.

Selection of an optimum treatment regimen for patients with ulcerative colitis depends on several factors, including the natural history of the disease. A new study indicates that prognosis for patients with newly diagnosed ulcerative colitis might not be as bad as typically thought—an important finding that should be taken into account when the risks and benefits of future treatment strategies are discussed.

Current recommendations for the performance of laparoscopic sigmoidectomy in patients with diverticulitis reserve this procedure for individuals who have complications of the disease or have had numerous, severe disease episodes. Findings from a 2009 study challenge this dogma and suggest that patients' quality of life should also be considered.

Several novel antiviral treatments for HCV are in preclinical or clinical development, and most target viral enzymes and their functions. These new drugs all potentially select for resistant viral variants, both in vitro and in vivo; viral resistance is, therefore, likely to become an important issue in clinical practice.

Standard treatment with pegylated interferon and ribavirin only cures just over half of patients with HCV infection. Pereira and Jacobson review the evidence on the efficacy and promise of several specifically targeted antiviral therapies, which, most likely in combination with interferon and ribavirin, may improve the success rate of HCV therapy.

Pancreatic cancer is lethal and notoriously difficult to treat, therefore, there is an urgent need to develop new therapeutic and diagnostic modalities. This Review discusses the agents that have been developed to target the pathways and processes involved in pancreatic tumorigenesis, and reviews the results of laboratory and clinical trials of these agents. Future therapeutic targets are also discussed.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Treatment options for patients with advanced HCC are limited because of the lack of effective chemotherapeutic agents. This Review discusses the mechanisms of targeted therapies and describes clinical studies that have investigated the safety and efficacy of these therapies in patients with HCC. Perspectives for future developments are also provided.

Patients with Barrett esophagus and high-grade dysplasia or intramucosal carcinoma have traditionally been managed by esophagectomy. However, the development of endoscopic ablative therapies has changed this management approach. This Review discusses the different endoscopic ablative therapies currently available including tissue-acquiring and non-tissue-acquiring modalities. The success rates and complications of the different techniques are also addressed.

Approximately 50% of patients with chronic hepatitis C fail to achieve a sustained virological response to standard therapy with pegylated interferon and ribavirin. Progression to advanced liver disease (which may lead to hepatic decompensation, hepatocellular carcinoma, and death) is common in these patients, but can low-dose pegylated interferon maintenance therapy improve outcomes?

Many patients with chronic constipation have a poor quality of life and are dissatisfied with laxative treatment. Findings from a multicenter, randomized, placebo-controlled, phase III study have demonstrated the beneficial effects of the 5-hydroxytryptamine 4 receptor agonist, prucalopride, for chronic constipation and associated symptoms. This drug represents the newest addition to the medical armamentarium for this disorder.

The benefit of preoperative combined chemotherapy and radiotherapy to perform sphincter-preserving surgery for patients with locally advanced distal rectal cancer is not supported by findings from randomized, controlled trials. These findings have, however, now been questioned by a study that supports the prospect of a tailored surgical approach to rectal-cancer treatment on the basis of tumor behavior after neoadjuvant treatment.