Clinical impact of ultrathin colonoscopy for Crohn's disease patients with strictures

Background and Aim: Mucosal healing is now the ideal treatment goal for patients with Crohn's disease (CD) and endoscopy is suitable for both visualizing the intestinal mucosa and optimizing treatment according to the objective endoscopic findings; however, passing through strictures with a conventional colonoscope is sometimes difficult. An ultrathin colonoscope (outer diameter 9.2mm) has been developed for superior insertion performance. Methods: CD patients with strictures that could not be passed with a conventional colonoscope were eligible for entry into the study. We investigated the rate of passage of the ultrathin colonoscope beyond strictures. We also investigated the clinical impact of optimizing the treatment strategy according to the endoscopic findings beyond the stricture. Results: Of 49 patients, the ultrathin colonoscope could pass the stricture in 59.2% (29/49). The main reason for failure compared with the "pass" group was anal stricture (P=0.005). When including finger bougie for severe anal stricture, passage of the stricture was achieved in 83.7% (41/49) of cases and the oral mucosa beyond the stricture was visualized. In these cases, 56.1% (23/41) had treatment efficacy confirmed and 43.9% (18/41) required a change of treatment. Importantly, half (9/18) of them were in clinical remission. There were no complications of the study. Conclusion: The ultrathin colonoscope could provide optimized treatment based on objective findings of the activity of the oral-side mucosa in CD patients complicated with stricture. Selection of the appropriate endoscope to visualize the responsible lesion is essential to optimize the treatment strategy in each case of CD.