Efficacy of cap-assisted colonoscopy according to lesion location and endoscopist training level

AIM: To evaluate the efficacy of cap-assisted colonoscopy(CAC) for detection of colorectal polyps and adenomas according to the lesion location and endoscopist training level.METHODS: Patients 20 years or older, who underwent their first screening colonoscopy in a single tertiary center from May 2011 to December 2012 were enrolled in this study. All patients underwent either CAC or standard colonoscopy(SC), and all of the procedures were performed by 11 endoscopists(8 trainees and 3 experts). All procedures were performed with highdefinition colonoscopes and narrow band imaging. The eight trainees had experiences of performing 150 to 500 colonoscopies, and the three experts had experiences of performing more than 3000 colonoscopies. A 4-mmlong transparent cap was attached to the end of a colonoscope in the CAC group. We retrospectively evaluated the number of polyps and adenomas, polyp detection rate(PDR), and the number of adenomas and adenoma detection rate(ADR) according to the lesion location and endoscopist training level between CAC and SC. We also evaluated the number of polyps and adenomas according to their size between CAC and SC.RESULTS: Overall, PDR and ADR using CAC were significantly higher than those using SC for both whole colon(48.5% vs 40.7%, P = 0.012; 35.7% vs 28.3%, P = 0.012) and right-side colon(35.3% vs 26.6%, P = 0.002; 27.0% vs 16.9%, P < 0.001). The number of polyps and adenomas per patient using CAC was significantly higher than that using SC for both the whole colon(1.07 ± 1.59 vs 0.82 ± 1.31, P = 0.008; 0.72 ± 1.32 vs 0.50 ± 1.01, P = 0.003) and right-side colon(0.66 ± 1.18 vs 0.41 ± 0.83, P < 0.001; 0.46 ± 0.97 vs 0.25 ± 0.67, P < 0.001). In the trainee group, the PDR and ADR using CAC were significantly higher than those using SC for both the whole colon(46.7% vs 39.7%, P = 0.040; 33.9% vs 26.0%, P =0.012) and right-side colon(34.2% vs 26.5%, P = 0.015; 25.3% vs 15.9%, P = 0.001). In the expert group, the PDR and ADR using CAC were significantly higher than those using SC only for the right-side colon(42.1% vs 27.0%, P =0.035; 36.8% vs 21.0%, P = 0.020).CONCLUSION: CAC is more effective than SC for detection of colorectal polyps and adenomas, especially when performed by trainees and when the lesions are located in the right-side colon.

Rectal tonsil:A case report and literature review

The rectal tonsil,a reactive proliferation of lymphoidtissue located in the rectum,is rare.Histologically,benign lymphoid hyperplasia of the rectum is usuallycharacterized by large lymphoid follicles with activegerminal centers and a narrow surrounding mantlezone and marginal zone.This lesion is benign,but must be differentiated from the polypoid type of mucosaassociated lymphoid tissue lymphomas.In the current paper,we present a case of rectal tonsil in a 59-yearold woman.We describe the endoscopic ultrasound imaging findings with literature review.