Cap Assisted Colonoscopy for the Detection of Colon Polyps

This simple technique of attaching a transparent cap to the tip of the colonoscope has been
evaluated in Japan for improving the detection of polyps and cecal intubation but has not
been formally evaluated in the US and other western countries. In one study (19), the polyp
detection rate was higher with the transparent cap compared to no cap (49% vs. 39%, p=0.04).
Also, the cecal intubation time was shorter with the cap (11.5 min vs 14 min, p=0.008). In a
recently published study, a variation of the cap called the transparent retractable
extension device was used (21). Overall, the number of adenomas detected were significantly
higher with the device compared to without it (205 vs. 150, p=0.04). In an earlier study by
Tada et al (22), use of a transparent cap improved the detection rate of lesions per patient
(0.86 vs. 0.58) but did not increase the cecal intubation time. Finally, Lee et al (20) used
cap assisted colonoscopy in patients with difficult colonoscopy procedure (defined as
failure to pass through sigmoid colon after 20 minutes or failure to reach cecum). Using the
cap, cecal intubation was achieved in 94% of patients and this proved to be an effective
rescue method for failed or difficult colonoscopy. The major appeal of this technique is
that it is inexpensive, very practical, and easy to use. Furthermore it is safe and there
are no reported complications from this. If found to be effective in increasing the polyp
yield it has the potential to being incorporated by busy gastroenterologists in their day to
day clinical practice. These features and the preliminary data from Japan merit the
evaluation of this promising technique in the US.