Safety, Feasibility, and Efficacy of Pancolonic Retroflexed Viewing Using a Short-turn Radius Colonoscope

Abstract

Goals: The goal of this study was to evaluate the safety and feasibility of routine segmental retroflexed withdrawal viewing (RV) of the colon with the RetroView colonoscope. Materials and Methods: This was a prospective, single-center, 2-stage diagnostic trial. After cecal intubation, mucosal evaluation by forward viewing (FV) and RV was performed by segment (right, transverse, left, and sigmoid colon, and rectum). Lesions detected during FV were removed and/or marked before retroflexion. Safety and feasibility were measured through adverse event and technical success rates. All lesions detected and removed endoscopically were recorded. Results: Two hundred twenty-five patients underwent colonoscopy with the RetroView colonoscope. Retroflexion by segment was successful in the right, transverse, left, and sigmoid colon, and rectum in 98.9%, 100%, 100%, 82.6%, and 100% of cases, respectively. The mean total procedure time was 16.6 minutes. Ninety-four lesions were detected through retroflexion evaluation, for an increase in the lesions’ detection rate of 30.7%. The per-adenoma miss rate of standard colonoscopy (FV) was 35.71%. The adenoma detection rate (ADR) for FV was 16%, whereas, when performing FV and RV, the ADR increased to 24.9%. Adverse events were recorded in 0.4% of cases. Therapeutic procedures were performed successfully through the retroflexed position in 81/225 patients. Conclusions: Routine retroflexion evaluation of the colonic mucosa by segment using the RetroView colonoscope is safe and feasible. Retroflexion evaluation increases the detection rate of colonic lesions behind folds, including the number of adenomas per colonoscopy and ADR, offering a complete screening colonoscopy. All therapeutic procedures are feasible through retroflexion.