Spontaneous Mesenteric Hematoma Secondary to a Pancreaticoduodenal Artery Aneurysm in Median Arcuate Ligament Syndrome: A Case Report.

We report the case of a 45-year-old heavy smoker (20 pack-years) presenting with acute abdominal pain. Physical examination revealed diffuse abdominal tenderness without hemodynamic instability. Contrast-enhanced abdominal CT angiography demonstrated a large mesenteric hematoma measuring 24 × 25 × 11 cm, associated with a ruptured inferior pancreaticoduodenal artery aneurysm. It also showed significant celiac axis stenosis secondary to extrinsic compression by the median arcuate ligament, with post-stenotic dilatation, consistent with a hemodynamic alteration of the pancreaticoduodenal arcade. Emergency selective angiography confirmed active hemorrhage arising from the pancreaticoduodenal arcade. Urgent superselective coil embolization was performed, achieving effective hemostasis without periprocedural complications. The clinical course was favorable, with rapid symptom resolution and uneventful recovery. This case highlights the critical role of CT angiography in identifying both the bleeding source and the underlying vascular abnormality, and demonstrates the effectiveness of superselective transarterial embolization as a first-line treatment in this setting of celiac axis compression-related hemodynamic disturbance.