Endoscopic marginal assessment of fixed colorectal polyps accurately predicts complete resection after cold snare polypectomy:a prospective single-center observational study

Abstract

Objectives

This study aimed to ascertain the effectiveness of using fixed cold snare polypectomy (CSP) specimens, accompanied by endoscopic assessment, in predicting complete resection outcomes.

Methods

In this prospective, single-center, observational investigation, patients with colorectal polyps measuring 5–15 ​mm were enrolled, who underwent CSP between August 2018 and January 2020. Following resection, the specimens were procured and fixed. The primary focus was on evaluating the accuracy of endoscopic margin appraisal of the fixed specimens in forecasting complete resection. The generalized estimating equation model was employed to delve into the potential risk factors contributing to false-positive endoscopic margin assessments of these fixed specimens.

Results

A cohort of 150 patients, presenting with 260 polyps, were included in the analysis. The CSP procedure achieved a remarkable complete resection rate of 98.5 ​%. In assessing the accuracy of endoscopic evaluation for complete resection in fixed specimens with negative margins, we observed a sensitivity of 100.0 ​%, specificity of 87.1 ​%, an area under the curve (AUC) of 93.6 ​%, and an overall accuracy of 87.3 ​%. Crucial insights from the multivariate regression analysis unveiled sessile serrated lesions (SSL) as an independent risk factor for generating false-positive results during endoscopic margin assessments of fixed specimens, with an odds ratio of 3.5 (95 ​% CI: 1.3–9.3, P ​= ​0.011).

Conclusions

Endoscopic assessment's negative lateral margin could accurately predict complete resection in fixed specimens. The fixed specimens of SSL are not suitable for margin assessment by endoscopy after fixation.