Superior Mesenteric Artery Syndrome Following Laparoscopic-Assisted Proctocolectomy and Ileal J-pouch-Anal Anastomosis in a Pediatric Patient.

Superior mesenteric artery syndrome (SMAS) is a rare cause of proximal bowel obstruction that results from extrinsic compression of the third portion of the duodenum by the superior mesenteric artery against the aorta. It is most commonly seen in the setting of severe weight loss or extreme physical malpositioning. We present the case of a 16-year-old girl who underwent laparoscopic-assisted proctocolectomy and ileal J-pouch-anal anastomosis. Postoperatively she developed symptoms of a proximal bowel obstruction. Computed tomography of the abdomen revealed a large fluid-filled stomach and a very dilated first and second portion of the duodenum [Images 1& 2]. The retroperitoneal portion of the duodenum was abruptly compressed at the level of the superior mesenteric artery and the distal bowel was small in caliber. She was treated with enteral nutrition via a nasojejunal feeding tube and her symptoms gradually resolved. We believe patients who undergo ileo-anal obstruction are at higher risk for SMAS because of the tension that is placed on the mesenteric vessels as the ileum is brought down to reach the anus.