Can magnification endoscopy detect residual adenoma after piecemeal resection of large sessile colorectal lesions to guide subsequent treatment? A prospective single-center study.

PURPOSE

This study assesses the ability of magnification endoscopy to detect residual adenomatous tissue after endoscopic piecemeal resection of colorectal polyps and evaluates the impact of the technique on the incidence of recurrence.

METHODS

Patients who underwent endoscopic piecemeal resection for large (>2 cm) sessile colorectal polyps were included. After endoscopic piecemeal resection, both the outer resection margins and the central severed area were inspected with magnification endoscopy. Completeness of excision as determined from the magnified surface pattern was compared with that determined histologically. Areas of incomplete resection were treated with additional resection or argon plasma coagulation.

RESULTS

A total of 77 lesions were resected. Mean size of the resected lesions was 29 +/- 6 mm (range, 23-60). Complications of resection occurred in eight patients (seven had immediate bleeding that was successfully managed with hemoclip application, and one had delayed perforation that was treated surgically). The sensitivity of magnification endoscopy for predicting remnant adenoma at resection margins was 98% (95% confidence interval 90-100); specificity was 90% (95% confidence interval 79-100). Overall accuracy was 94.5% (95% confidence interval 87.2-98.6). On a mean follow-up of 32 months (range, 18-46) the recurrence rate was 2.6%.

CONCLUSIONS

Magnification endoscopy is accurate at predicting remnant tissue after endoscopic piecemeal resection of large sessile colorectal polypoid lesions. When applied on both outer margins and inner portions of the severed area, it is helpful as a guide to subsequent further treatment to decrease recurrence.