This Month in Gastroenterology

Article Outline

• Predictors of Disabling Crohn’s Disease
• Biofeedback Is Superior to Laxatives for Normal Transit Constipation Due to Pelvic Floor Dyssynergia
• Colonoscopy on Autopilot
• Level of Circulating Hepatitis B Viral Load Predicts Cirrhosis
• Copyright

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Predictors of Disabling Crohn’s Disease 

There are two general approaches to the treatment of Crohn’s disease, the first involving a step-up approach where the level of anti-inflammatory therapy is sequentially advanced to match the anatomic and clinical severity of disease; and the second, a top-down approach where intensive therapy (immunosuppressants and/or biologics) is used early in order to maintain a good quality of life and prevent potential irreversible consequences of the disease. Although the former is most frequently practiced, the choice of therapeutic approach would be benefited by knowing clinical criteria present at the time of diagnosis, which would be predictive of natural history.

The study by Beaugerie et al represents a large retrospective analysis of 1526 patients diagnosed with Crohn’s disease between 1985 and 1998 aimed at identifying predictive factors of a subsequent 5-year disabling course and to test prospectively the accuracy of these factors in an independent test-group seen at the same referral center. Patients operated on within the first month of the disease, inadequate data, and severe chronic nondigestive diseases were excluded. Among the remaining patients in the study, the rate of disabling disease was 85.2%. Initial requirement for steroid use, an age below 40, and the presence of perianal disease were independent initial predictive factors. In patients having 2 and 3 predictive factors of disabling disease, the predictive values were 0.91 and 0.93, respectively (Figure 1). When examined prospectively in an independent group of 302 consecutive patients, predictive values for having 2 and 3 factors were 0.84 and 0.91, respectively. Thus, factors predictive of a subsequent 5-year disabling course at the time of diagnosis are an age below 40, the presence of perianal disease, and the initial requirement for steroids.

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• Figure 1. 

  Distribution of the patients and predictive positive value of having a disabling Crohn’s disease course in the 5-year after diagnosis according to the value of the disabling Crohn’s disease predictive score.

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Biofeedback Is Superior to Laxatives for Normal Transit Constipation Due to Pelvic Floor Dyssynergia 

Pelvic floor dyssynergia (PFD) is one of the most common causes of constipation, characterized by inappropriate (paradoxical) contraction or failure to relax the pelvic floor muscles during attempts to defecate. While several uncontrolled studies suggest that patients with PFD can benefit from biofeedback, there have been no controlled trials in adults comparing biofeedback to laxatives. The study by Chiarioni et al reports the findings of a parallel group, randomized controlled trial that compared biofeedback with laxative treatment of PFD (polyethylene glycol or PEG 14.6 g/day). At 6 months, major improvement was reported by 43/54 (80%) of the biofeedback patients compared with 12/55 (22%) of the laxative-treated patients (P < .001). Biofeedback’s benefits were sustained at 12 and 24 months (Figure 2). Greater reductions in straining, sensations of incomplete evacuation and anorectal blockage, use of enemas and suppositories, and abdominal pain (all P < .01) were observed in the biofeedback group. Stool frequency increased in both groups. All biofeedback-treated patients were better able to relax the pelvic floor and defecate a 50 mL balloon at 6 and 12 months. Thus, biofeedback sessions proved more effective than continuous polyethylene glycol for treating PFD, with benefits lasting at least 2 years.

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• Figure 2. 

  Average number of bowel movements per week accompanied by straining in laxative-treated patients (gray bars) and biofeedback-treated patients (black bars). T-bars indicate standard errors; asterisk indicates significant difference (P < .01) between groups at 6 months or 12 months; and # indicates a significant (P < .01) change from pretreatment within the biofeedback group.

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Colonoscopy on Autopilot 

Colonoscopy is the standard of practice for effective colorectal cancer screening. However, colonoscopy requires considerable training and is associated with patient discomfort, high cost, and a risk of perforation. This study by Vucelic et al reports the first human use of a self-propelled, self-navigating, lower bowel endoscope (the Aer-O-Scope) that has the primary advantage of not requiring a highly skilled operator (Figure 3). The instrument was tested on a dozen healthy volunteers who underwent complete bowel preparation and a nonsedated examination. The cecum was successfully reached in 10 of 12 patients and, in the other 2 cases, the Aer-O-Scope made it to the hepatic flexure. The time required to reach the cecum averaged 14.0 ± 7 minutes and the driving pressures averaged 34 ± 2.3 mbar. Only 2 subjects requested analgesics during the procedures, 4 subjects experienced sweating and a bloating sensation that resolved spontaneously, and no complications were observed. While further studies are needed, these results are very encouraging.

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• Figure 3. 

  Work-station with disposable Aer-O-Scope (TM). A PC-based workstation with integrated interface for electronic medical record is operated via a control box at the patient side. The operator can choose various operation modes of advancement much as with a VCR viz forward, backwards, pause, and stop. The motion is generated via an algorithm derived pressure gradients across the balloon. The pressure in front of, inside, and behind the balloon is measured by pressure sensors and is automatically adjusted by a computerized algorithm. The high-resolution data from the digital camera within the capsule are received, processed, and displayed on the PC screen, as well as digitally recorded on a CD.

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Level of Circulating Hepatitis B Viral Load Predicts Cirrhosis 

Chronic HBV infection can lead to chronic and progressive liver disease and result in serious complications such as hepatocellular carcinoma, cirrhosis, and decompensated liver disease. The reported incidence rates of cirrhosis from chronic HBV infection range from 2%–7% annually, whereas, in a large cohort of asymptomatic HBV “carriers,” the cirrhosis incidence rate was 0.7%. Risk factors for chronic HBV-related cirrhosis include the presence of hepatitis B e-antigen (HBeAg), advanced age, elevated alanine aminotransferase level, coinfection with the hepatitis delta virus, and diabetes mellitus. What has become evident in the past several years is that effective suppression of viral replication in chronic hepatitis B patients can slow disease progression and improve patient outcomes. In the study by Iloeje et al, the HBV DNA level, a reflection of viral load, was assessed as a predictor of progression to cirrhosis in chronic hepatitis B infection.

HBV DNA levels from serum samples were prospectively assessed in 3582 untreated hepatitis B–infected subjects and followed for a mean of 11 years. Ultrasound was used to establish the development of cirrhosis. The study reports that that progression to cirrhosis in hepatitis B–infected persons is strongly correlated with the level of circulating virus (Figure 4). The risk of cirrhosis increases significantly with increasing HBV DNA levels and is independent of HBeAg status and serum ALT level.

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• Figure 4. 

  Cumulative incidence of liver cirrhosis (N = 3582). P value for log-rank test, < .001.