Acute development and rupture of a pancreaticoduodenal artery aneurysm after endovascular aneurysm repair in a patient with median arcuate ligament syndrome

An 80-year-old man underwent endovascular aneurysm repair at our institution. Preoperative imaging demonstrated celiac artery occlusion caused by median arcuate ligament syndrome and markedly developed pancreaticoduodenal arcades; however, a pancreaticoduodenal artery (PDA) aneurysm (PDAA) was not identified. On postoperative day 2, contrast-enhanced computed tomography (CT) showed no aneurysm, hematoma, or vascular injury involving the arcade vessels. On postoperative day 3, sudden abdominal pain developed. Contrast-enhanced CT revealed a retroperitoneal hematoma with active extravasation, and emergency angiography demonstrated a newly formed ruptured 4-mm aneurysm of the anterior inferior PDA. Coil embolization was successfully performed. This case demonstrates that PDAAs may form and rupture rapidly. Clinicians should explore this rare but potentially fatal condition even when recent imaging studies show no evidence of aneurysm formation.