A Case of Intra-Abdominal Hemorrhage and Melena in a Middle Colic Aneurysm Rerupture by Segmental Arterial Mediolysis

Hisaharu Oya, Jiro Nagata, Yuki Morioka, Takahiro Mase, Masasi Hashimoto and Ichiro Honda

Department of Surgery, Ichinomiya Municipal Hospital

We report a case of rerupture of an aneurysm of the middle colic artery caused by segmental arterial mediolysis (SAM), a rare nonartherosclerotic nonimflammatory arteriopathy. A 56-year-old man admitted for abdominal pain was found in Abdominal computed tomografhy (CT) to have an intraabdominal hemorrhage, treated conservatively, and discharged. Three weeks later, he was readmitted for melena and loss of consciousness. Abdominal CT showed that the clearly bordered 95×64 mm tumor had come in contact with the transverse colon. We also found that contrast medium had extravasated to the tumor. Angiography showed that the left branch of the middle colic artery was bead-shaped and an aneurysm had formed there. We attributed these findings to SAM. Attempted arterial embolization was not successful, so we conducted emergency surgery, finding that the tumor, which was in diameter, 9 cm indeed contacted the transverse colon under the splenic flexure. We resected the colon and the tumor, which we concluded was a pseudoaneurysm, whose rupture toward the colonic lumen caused melena.

Key words
segmental arterial mediolysis (SAM), middle colic aneurysm, rerupture

Reprint requests
Hisaharu Oya Department of Surgery, Ichinomiya Municipal Hospital
2-2-22 Bunkyo, Ichinomiya, 491-8558 JAPAN

Accepted
July 22, 2009

To read the PDF file you will need Abobe Reader installed on your computer.