Isolated ileal blind loop inflammation after intestinal resection with ileocolonic anastomosis in Crohn's disease: an often neglected endoscopic finding with an unfavorable outcome

Objective Postoperative endoscopic recurrence in patients with Crohn's disease (CD) is commonly classified using the Rutgeerts score. Ulcerations in the ileal blind loop are not taken into account in the Rutgeerts score, and the clinical relevance of these lesions is unknown. This study aimed to assess the outcome of isolated ileal blind loop inflammation (IBLI) in postoperative CD patients. Methods Adult CD patients who underwent intestinal surgery with ileocolonic anastomosis between 1997 and 2017 were included and postoperative endoscopy reports were retrospectively reviewed. IBLI was defined as isolated inflammation of the ileal blind loop with or without ulcera confined to the anastomosis. Outcome was assessed using endoscopic recurrence (Rutgeerts >i2) and surgical recurrence (re-resection). Results A total of 341 CD patients were included. In 125 out of 341 (37%) patients, the ileal blind loop was described in the endoscopy reports. IBLI was reported in 43 of 341 (13%) patients. Start or step-up drug therapy was initiated in 10 of 32 (31%) IBLI patients with abdominal symptoms within a median of 0.9 months [interquartile range (IQR) 0.7-1.4] after ileocolonoscopy. Endoscopic recurrence occurred in 4 out of 38 (11%) IBLI patients without re-resection, within a median of 12.4 months (IQR 6.8-13.3). Intestinal re-resection was performed in 5 out of 43 (16%) IBLI patients within a median of 3.7 months (IQR 3.5-10.8). Conclusion IBLI is associated with symptoms and an unfavorable outcome, with a high risk of endoscopic recurrence in the neoterminal ileum and intestinal re-resection during short-term follow-up. Therefore, the blind ileal loop needs to be assessed during endoscopy in postoperative CD patients.