Objectives: Colorectal cancer (CRC) screening with colonoscopy was introduced into the National Cancer Prevention Program in Germany in 2002. As compliance for screening is low (around 3% per year), colon capsule endoscopy (CCE) could be an alternative approach. In this study, feasibility and performance of CCE were evaluated in comparison with colonoscopy in ambulatory patients with special attention to a short colon transit time.
Methods: CCE was prospectively tested in ambulatory patients enrolled for colonoscopy who presented for screening or with positive fecal occult blood test. Study subjects underwent colon preparation and ingested the capsule in the morning. Colonoscopy was performed after excretion of the capsule. Colonoscopy and CCE were performed by independent physicians who were blinded to the results.
Results: In total, 38 patients were included. One patient was excluded because the capsule remained in the stomach during the entire period of examination. Another patient had limited time and the procedure had to be stopped when the capsule was still in the transverse colon. We therefore report the results of 36 patients (30 men and 6 women; mean age 56 years, range 23-73 years) who successfully completed CCE and the conventional colonoscopy examination. The capsule was excreted within 6 h in 84% of the patients (median transit time 4.5 h). If oral sodium phosphate was excluded from the preparation, the colon transit time increased to a median of 8.25 h. In total, 7 of 11 small polyps (<6 mm) detected by colonoscopy were identified by CCE. One small polyp detected by CCE was not identified by colonoscopy. In this series, no large polyps were found. One CRC was detected by both methods. The mean rates of colon cleanliness (range from 1=excellent to 4=poor) in the cecum (2.1), transverse colon (1.6), and in the descending colon (1.5) were significantly better than in the rectosigmoid colon (2.6), and the overall mean rate during colonoscopy was significantly better than during CCE. No adverse effects occurred.
Conclusions: CCE appears to be a promising new modality for colonic evaluation and may increase compliance with CRC screening. To achieve a short colon transit time, sodium phosphate seems to be a necessary adjunct during preparation. The short transit time is a prerequisite to abandon the delay mode of the capsule. With an undelayed PillCam COLON capsule, a "pan-enteric" examination of the gastrointestinal tract would be possible. Further studies are needed to improve the cleanliness, especially in the rectum and to evaluate the method as a potential screening tool.