Abstract
A 54-year-old man admitted for abdominal pain was found on abdominal computed tomography (CT) to have a retroperitoneal hemorrhage around a middle colic arterial aneurysm and stricture of the celiac artery. Angiography showed the stricture of the celiac artery to be due to constriction by median arcuate ligament syndrome (MALS), with abnormal retrograde flow from the superior mesenteric artery to the celiac artery. Furthermore, angiography showed beading and narrowing change of the transverse pancreatic artery and the middle colic arterial aneurysm. Rupture of the arterial aneurysm owing to segmental arterial mediolysis (SAM) caused retroperitoneal hemorrhage. Though the blood supply of the middle colic artery came from the superior mesenteric artery in one direction, considering the risk of colonic ischemia with interventional radiology, emergency laparotomy was performed.
Two aneurysms and the transverse colon were resected, along with partial resection of the median arcuate ligament. The abnormal blood flow by MALS may have caused rupture of the transverse pancreatic arterial aneurysm.
