Colonoscope retraction technique and predicting adenoma detection rate: a multicenter study


Andreas Slot Vilmann, Morten Bo Søndergaard Svendsen, Christian Lachenmeier, Bo Søndergaard, Peter Vilmann, Yoon Soo Park, Lars Bo Svendsen, and Lars Konge. 2021. “Colonoscope retraction technique and predicting adenoma detection rate: a multicenter study.” Gastrointest Endosc.


BACKGROUND AND AIMS: The success of preventing colorectal cancer relies on the expertise of the colonoscopists. Studies suggest that the retraction technique is a powerful indicator of expertise in distinguishing endoscopists with various adenoma detection rates (ADRs). We aimed to develop a retraction technique score and explore the correlation between endoscopists' retraction technique and their ADR. METHODS: In a prospective, multicenter study, 8 colonoscopist nurses and physicians with various ADRs were included. Data from patients admitted for a colonoscopy, as part of the Danish Nationwide screening program, were gathered directly from the Olympus ScopeGuide system providing XYZ-coordinates from the coils along the length of the colonoscope. Motor skill measures were developed based on Tip Retraction, Retraction Efficiency, and Retraction Distance. The principal component analysis was used to study the association between the 3 measures and the historical ADR to create a combined score, the Colonoscopy Retraction Score (CoRS). RESULTS: A total of 333 recordings were analyzed. We demonstrated a significant and strong correlation between CoRS and ADR (0.90, p < 0.01). Contrary, withdrawal time did not correlate significantly with ADR (0.33, p=0.42). In procedures without polypectomies or biopsies, a significant and strong correlation was found between CoRS and ADR (0.88, p<0.01) and between withdrawal time and ADR (0.75, p=0.03). CONCLUSION: This study presents a novel, real-time computerized and unbiased assessment tool for colonoscopy withdrawal. CoRS strongly correlated with ADR with and without therapeutical interventions during withdrawal and could be used to ensure quality instead of minimal withdrawal time.