Not all post-Whipple hemorrhage is Whipple-related: inferior rectal artery aneurysm rupture masquerading as delayed bleeding after pancreatoduodenectomy

Abstract

Delayed haemorrhage following pancreatoduodenectomy is a rare but life‑threatening complication that is usually attributed to peri‑pancreatic vessel erosion or anastomotic bleeding. We describe an extraordinary case of massive lower gastrointestinal bleeding caused by rupture of an inferior rectal artery aneurysm in a patient who had undergone pylorus‑resecting pancreatoduodenectomy for moderately differentiated ampullary adenocarcinoma. Despite successful endovascular embolization, persistent haemodynamic instability mandated surgical re‑exploration. We highlight diagnostic challenges, the pivotal role of cross‑sectional imaging and interventional radiology, and key principles for managing obscure postoperative haemorrhage. This case underscores a key diagnostic pitfall: not all delayed haemorrhage after pancreatoduodenectomy originates from the pancreatic bed. Clinicians should deliberately search for extra‑pancreatic sources—extending imaging to the pelvis and engaging interventional radiology early—to avoid misdirected interventions and delays in haemostasis. To our knowledge, this is the first report linking an inferior rectal artery aneurysm to post‑Whipple bleeding. Awareness of distant vascular sources and a structured multidisciplinary approach can improve outcomes when conventional causes are excluded.