PillCam Colon and ulcerative colitis: what do physicians need to know?

We read with interest the paper from Sung et al., reporting their first experience with colon capsule endoscopy (CCE) in the assessment of ulcerative colitis [1]. We agree with their conclusion that CCE is a promising tool, but we think that the results of the study are not generalizable and do not reflect possible clinical use of CCE. Our impression arises from our smaller experience with 20 patients with ulcerative colitis (severe acute relapse, 4; mild/moderate recurrence, 11; and clinical remission, 5) who underwent first-generation CCE and colonoscopy on the same day, similarly to the patients in the study of Sung et al. The colon was cleaned as described by Eliakim et al. [2], and mucosal changes were assessed using the Baron score.

Two patients were excluded because of technical failure of CCE. In the remaining 18 CCE procedures the whole colon was explored, but the time for complete exploration ranged widely from 3 h 35 min to 8 h 17 min, and the time to the first image of the cecum was also very variable (range 1 h 49 min to 4 h 52 min).

Preparation was judged to be adequate in eight patients. Complete agreement between CCE and colonoscopy in assessing mucosal activity was obtained in 10 patients, and partial agreement (1-point difference in Baron score) in a further four. Preparation was poor in the four patients in whom complete disagreement was recorded. Agreement in assessment of extent of colon involvement was good in 11 /18 patients and partial in three (1-segment difference). Four small polyps in four patients were identified by colonoscopy and one of these was observed by CCE.

The results of our study were worse than those reported by Sung et al., but our study attempted to reflect a routine use of CCE, adopting a scoring system for mucosal changes (active or inactive colitis is not likely to be a useful classification for physicians) and trying to assess the extent of colon involvement (another valuable piece of information). The main problem observed in our study was the unpredictable response of an inflamed gut to laxatives, which caused in turn the poor quality of preparation and the extremely variable CCE transit time. We think that these aspects should be stressed more heavily than in the paper of Sung et al., and should be considered in further studies with larger numbers of patients.

• References

• 1 Sung J, Ho KY, Chiu HM et al. The use of Pillcam Colon in assessing mucosal inflammation in ulcerative colitis: a multicenter study. Endoscopy 2012; 44: 754-758
• 2 Eliakim R, Fireman Z, Gralnek IM et al. Evaluation of the PillCam colon capsule in the detection of colonic pathology: results of the first multicenter, prospective, comparative study. Endoscopy 2006; 38: 963-970