Digestive Disease Week 2008 Report: Part 1

Digestive Disease Week (DDW) is considered the largest and most prestigious meeting in the world for the gastrointestinal professional. Each year, DDW features leading researchers and clinicians in the field of gastrointestinal medicine discussing the latest research. Part 1 of a report based on a selection of key sessions in DDW 2008 has just been released.

Treating H. pylori: a long-term risk reduction strategy

Clinical Associate Professor Peter Katelaris reports on a study that carefully reviews patients who had been referred for gastroscopy for any indication. The group contained people who were not infected, those who were infected and treated successfully and those who remain infected, either because treatment was not given or failed. The investigators determined the long-term outcome of patients according to their H. pylori infection status.

In more than 400 evaluated patients with a mean duration of followup of 6.3 years (1-18 years), patients who remained H. pylori infected had worse outcomes for every parameter tested. Eradicating H. pylori irrespective of the symptom status of the patient therefore confers a meaningful risk reduction benefit, seen in a reduction of both major and less severe adverse outcomes.

Refractory ascites pathophysiology and treatment options: an update

Dr Andrew Keegan reports on an American Association for the Study of Liver Diseases clinical symposium that reviewed the underlying pathophysiology of refractory ascites together with current and future treatment options of this feature of end-stage liver disease.

The decompensation of cirrhosis reflects a poor prognosis and is often marked by the onset of ascites. 5-10% of patients with cirrhosis will develop ascites. There is a continuum from cirrhosis, to cirrhosis with ascites, to cirrhosis with ascites plus hyponatraemia, to refractory ascites, and finally, if there is not appropriate renal adaptation, the hepatorenal syndrome. The survival in ascitic patients is worse with increasing age, coexistent HCC, diabetes and ongoing alcohol consumption.

Liver transplantation is the definitive treatment for refractory ascites, but for those patients in whom transplantation is not an option, transjugular intrahepatic portosystemic shunt (TIPS) and large volume paracentesis (LVP) are alternatives.

The use of albumin improves survival in patients with diuretic responsive ascites, but it is not known whether the addition of albumin will impact upon the outcome of therapy for those with refractory ascites. The vasoconstrictor midodrine has been shown to improve systemic and renal haemodynamics and increase renal Na excretion in ascitic patients, but further investigation is required. The possible clinical role for Vaptans, vasopressin-2 receptor antagonists, is currently being assessed.

Clostridium difficile and IBD

Internationally, Clostridium difficile is becoming a growing concern. There are reports of increasing numbers of patients with significant Cl. difficile-related disease and the appearance of more virulent strains. Dr Keegan reports on two papers presented at an American Gastroenterological Association Institute Research Forum.

An Irish study of the carriage of Cl. difficile in outpatients with IBD in remission found that the carriage of Cl. difficile in IBD patients was significantly greater than in controls, as was the presence of toxin. There were no differences in the rates of Cl. difficile carriage or toxin production between patients with ulcerative colitis and those with Crohn’s disease.

An Italian study into the impact of Cl. difficile on paediatric IBD examined 284 patients admitted to hospital with gastrointestinal disease. Patients with active IBD were more likely to carry Cl. difficile than were those with inactive disease, with more than 80% of Cl. difficile infected IBD patients in relapse.

From these and other recent studies, the assessment of Cl. difficile status is likely to become increasingly important. Clearly, we need to be aware of the association of bacterial infection with IBD, especially during relapse.

Colonoscopy: optimising performance

Dr Sanjay Nandurkar reports on a meeting focused on the key determinants that may alter polyp yield at colonoscopy. Endoscopists are likely to be fresher at the start of the list. Therefore it is conceivable that the polyp pick up rate may be higher at the start of the list. One paper compared the outcomes (polyp yield) of patients who where first on the list versus those who had screening colonoscopy performed lower down. It was shown that polyp detection was 20% higher in those undergoing colonoscopy at the very start of the list.

Although large lesions are less likely to be missed with suboptimal preparation, small polyps and flat or depressed lesions can be overlooked. The merits of different bowel preps were discussed, and it was agreed that "split preps" gave the best results. Split preps were also thought to be associated with lesser degrees of electrolyte imbalance.

Irritable bowel syndrome: an update

A significant proportion of patients with irritable bowel syndrome (IBS) report bloating and flatulence as their main symptoms necessitating healthcare. Dr Sanjay Nandurkar reports on two studies regarding the use of rifaximin and mesalazine in IBS.

Rifaximin is a nonabsorbable oral antibiotic with a tolerable side effect profile and demonstrated efficacy in small intestinal bacterial overgrowth (SIBO) and Clostridium difficile colitis. A large study assessed the effects of rifaximin in diarrhoea predominant IBS. Patients on rifaximin tended to show improvement in global IBS symptoms compared to placebo, both during the treatment phase and at the end of therapy. Although rifaximin is well tolerated with very few side effects, the question of whether repeated exposure is safe remains to be studied.

Post-infectious IBS (PI-IBS) shows low grade inflammatory activity both at the mucosal and serological level. Inflammatory activity falls between that seen in a normal individual and that with typical inflammatory bowel disease. A preliminary study investigated the effect of mesalazine in 18 subjects with PI-IBS. In these patients, abdominal pain and distension improved significantly, along with stool frequency and consistency. This preliminary open-label study warrants a proper placebo-controlled design study with large numbers to determine whether the results remain valid.

Endoscopic therapy for reflux disease – has its time finally arrived?

Dr Richard Holloway reports on an experimental method for endoscopic anti-reflux therapy aimed at providing a simple and effective minimally invasive treatment. The technique of full-thickness plication offers the potential for effective longterm therapy.

The NDO Plicator^® was the first of these devices. In a sham-controlled trial, it was shown to be superior in controlling reflux symptoms, PPI use, and oesophageal acid exposure than a sham procedure. A new full-thickness plication technique has also emerged. The EsophyX^TM device deploys full-thickness polypropylene fasteners. Multiple fasteners can be placed circumferentially at the cardia to create a fundoplication with reconstruction of the gastrooesophageal flap valve.

Whilst the numbers of patients treated to date are relatively small, full-thickness plication appears to induce robust anatomic and structural changes at the gastric cardia that suggest a distinct possibility for effective long-term endoscopic therapy for reflux disease. More long-term studies in a large number of patients are required.

Wikipedia is a useful internet source for patients

The internet has become a major source of information for patients. The online encyclopedia Wikipedia is an open source and anyone can edit the information. Whilst this facilitates updating, it also makes its reliability open to criticism. Dr Richard Holloway reports on a study that assessed the comprehensiveness, reliability and readability of gastroenterological articles for knowledge transfer. The average readability score was equal to a grade slightly higher than high school, which is equivalent to most print materials. Wikipedia therefore should be regarded as a reasonable and potentially useful source of medical gastroenterological information for patients.