Factors affecting insertion time for colonoscopy performed under intramuscular analgesia in patients with history of colorectal resection

Background: Colonoscopy can detect both early intraluminal recurrence and metachronous neoplasia after colorectal cancer resection. Because colon length and location change after colorectal resection, factors affecting insertion time during colonoscopy also might be altered. The goal of this study was to examine whether colonoscope insertion time differs between left-sided resection and right-sided resection and to identify factors that impact the performance of colonoscopy after colorectal resection. Methods: We included consecutive patients who underwent colonoscopy between November 2005 and November 2009 after colorectal resection for colorectal cancer. We classified surgical methods into left-sided resection (left hemicolectomy, low anterior resection, anterior resection, Hartman, and Mile's operation) or right-sided resection (right hemicolectomy) and retrospectively evaluated the colonoscope insertion time. Moreover, we analyzed factors that might affect the insertion time. Results: A total of 1,260 patients underwent colonoscopy after colorectal resection during the study period. Of these, 1,248 patients (771 men) who underwent complete colonoscopy were evaluated in this study. The colonoscopy completion rate was 99%, and the mean insertion time was 6.5 ± 5.1 min (median, 5 min; range, 0.3-61 min). Right-sided resection, female gender, poor quality of bowel preparation, lower endoscopist case volume, open laparotomy, and colonoscopy performed more than 1 year after colorectal resection were found to be independent factors associated with prolonged insertion time. Conclusions: This large study identified six factors that affect colonoscope insertion time after colorectal resection. These findings have implications for the practice and teaching of colonoscopy after colorectal resection.