A Novel Method to Localize Patency Capsule by Ileocolonoscopy Facilitates Endoscopic Assessment of the Small and Large Intestine in Patients with Crohn's Disease

Introduction: Patients with Crohn's disease (CD) require an assessment of small bowel lesions, while difficulties exist in performing small intestinal examinations, especially in small-sized medical offices. Small bowel capsule endoscopy (SBCE) is handy and can be performed in most clinical settings. The only drawback of SBCE is a requirement of patency testing prior to the exam because it sometimes requires CT scanning to localize the ingested patency capsule (PC), which may be a substantial burden for the patient. We have developed a novel PC detection system named PICS (patency capsule, ileocolonoscopy, and small bowel capsule endoscopy) method by which we can avoid CT scanning. In the PICS method, ileocolonoscopy (ICS) is performed after 30-33 h of PC ingestion and the PC can be localized by ICS in patients who have not excreted the PC, and the entire intestine can be examined in combination with subsequent SBCE without additional bowel preparation. The aim of this study was to assess the usefulness and safety of the PICS method for CD patients. Methods: CD patients who underwent PICS method from April 2021 to March 2023 were reviewed for clinical data, outcome of PICS method including the rates of PC detection by ICS, the number of patients underwent SBCE, and adverse events. Lewis score was used to assess SBCE results. Results: The PICS method was performed in 54 patients. The median age of patients was 28.5 years old, and 64.8% of them were ileocolic type. The median disease duration was 10.5 months and 24.1% had history of small bowel resection. Five cases (9.3%) confirmed gastrointestinal patency by ICS, and none of the cases required CT scanning. One patient who could not be confirmed patency by ICS, and the other patient who excreted PC but was found ileal stenosis by ICS did not undergo SBCE. Remaining 52 patients received SBCE, and the median Lewis score of them was 0 (IQR 0, 450). There were no adverse events including small bowel obstruction by PC and SBCE retention in this series. Conclusion: The PICS method is not only feasible and safe but also convenient to assess disease extent in patients with CD. By localizing PC with ICS, additional CT scanning could be unnecessary for SBCE, which benefits both physicians and CD patients.