Arc of Buhler Pseudoaneurysm Causing Fatal Retroperitoneal Hemorrhage; A Rare Case Report and Discussion of Relevant Literature.

Identification of any variant anatomy prior to surgery is as essential as having knowledge of normal anatomy. These surprises bring on many challenges along with as they can be fatal. We encountered a case of patient who succumbed down to an unrecognized rare mesenteric vasculature variant known as "Arc of Buhler" (AOB) which is a persistent embryonic ventral anastomosis between the Celiac trunk and the Superior mesenteric artery. It is usually asymptomatic and found incidentally after evaluation for other pathologies. We herein report a pseudoaneurysm of Arc of Buhler being surgically managed after massive retroperitoneal hemorrhage. Unfortunately, the patient did not survive the procedure and passed away. AOB aneurysms present formidable risks to patients and diagnostic and therapeutic challenges to physicians. They are rare and require high index of suspicion on radiographic imaging. Present case reports underscore the importance of identifying it and treating it regardless of the size.