EP-593 Blind loop mucocele of a side-to-end colorectal anastomosis as a rare cause of large bowel obstruction

Abstract

Background Large bowel obstruction (LBO) after colorectal surgery draws wide differentials. Very few reports of LBO secondary to closed loop mucocele have been published. To our knowledge, LBO due to mucocele of the blind colonic limb of a side-to-end colorectal anastomosis has not been described. Case Details A 57-year-old man presented with pain, gradual abdominal distension and one week history of constipation. He had extensive surgical history – colo-vesical fistula takedown, sigmoid resection and Hartmann type end colostomy followed by reversal, and mesh repair of incisional ventral hernia among others. Notably, a side-to-end configuration was fashioned as a descending colo-rectal anastomosis. CT, followed by MRI scans, of the abdomen and pelvis respectively suggested a mucus-filled short blind colonic bowel segment compressing the anastomotic site as the cause of large bowel obstruction proximal to the site. On flexible sigmoidoscopy under general anaesthesia, external compression of the rectum with narrowing of the lumen was noted. Transrectal needle aspiration of the blind colonic segment yielded 145 mL of mucoid fluid and allowed proximal examination. Anastomotic site was of normal calibre. The patient's symptoms improved and he was discharged with scheduled outpatient follow-up. Gastrografin enema post-discharge demonstrated an end-to-side rectosigmoid anastomosis with local rectal stenosis and showed the blind loop had emptied. Conclusion This case highlights that blind colonic loop mucoceles in colorectal anastomosis can rarely cause obstruction and endoscopic management is feasible when accurate diagnosis is confirmed on imaging.