Mo1639 POLYP DETECTION DURING INSERTION VS WITHDRAWAL PHASE OF COLONOSCOPY - IS THERE A DIFFERENCE? A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

Abstract

Colonoscopy is considered to be the preferred modality for colo-rectal cancer (CRC) screening because it has both diagnostic and therapeutic capabilities. Current consensus dictates that colonoscopy be performed with rapid passage of the instrument through the loops and bends of the colon to the cecum. The time taken for this is called cecal intubation time (CIT). This is then followed by thorough evaluation for and removal of all polyps during a slow deliberate withdrawal, the time taken for which is called withdrawal time. There have been reports suggesting that polyps that are seen but not removed during insertion phase are sometimes quite difficult to find during withdrawal phase and can be missed entirely. We performed a comprehensive literature search of several major databases (from inception to November 2019) to identify randomized controlled trials evaluating inspection and polypectomy during insertion and withdrawal phase compared to the traditional practice of inspection and polypectomy performed entirely during withdrawal phase. The outcomes compared were polyps detected per patient, cecal intubation time and total procedure time. Random-effects model was used to derive the pooled rates and heterogeneity was assessed by I2 statistics. Six randomized controlled trials, including 2535 patients, comparing polyp detection rates during insertion/withdrawal versus withdrawal only were included in our final analysis. Insertion/withdrawal cohort included 1282 patients, 322 of whom underwent a screening colonoscopy and 371 patients underwent surveillance colonoscopy (4 studies). Withdrawal only cohort included 1236 patients, 297 of whom underwent a screening colonoscopy and 342 underwent surveillance colonoscopy (4 studies). The pooled rate of number of polyps detected per patient was 1.5 (CI 1.3-1.7, I2=83) in insertion/withdrawal cohort and 1.7 (CI 1.5-1.9, I2=87) in the withdrawal only cohort. The difference between the two was not statistically significant (p=0.1). CIT in insertion/withdrawal cohort was 10.7 mins (CI 8.6-12.8, I2=99) and this was statistically significant when compared to withdrawal only cohort, where it was 7.3 mins (CI 5.3-9.4, I2=99) (p=0.03). We did not find any statistically significant difference in total procedure times in both cohorts, 27.7 mins (CI 23.4-32, I2=99) vs 28.2 mins (CI 23.9-32.5, I2=99), p=0.9 Polypectomy performed during insertion phase of colonoscopy adds to longer cecal intubation and total procedure time without statistically significant increase in number of polyps detected per patient.Forest Plot - Total Procedure TimeView Large Image Figure ViewerDownload Hi-res image Download (PPT)