Case Report: Delayed intra-abdominal hemorrhage in a patient with a duodenal stump tumor after Billroth II gastrectomy

We report a case of a patient with duodenal stump adenocarcinoma who had a 30-year history of subtotal gastrectomy with Billroth II anastomosis. The patient presented with chronic gastrointestinal bleeding and secondary anemia, prompting tumor resection and lymph node dissection. However, on postoperative day 11, she developed delayed intra-abdominal hemorrhage due to a pseudoaneurysm in a minor branch of the superior mesenteric artery. Despite aggressive management including DSA-guided arterial embolization, the patient ultimately had a poor prognosis due to subsequent ischemic colitis. The rarity of duodenal stump tumors and the uncommon occurrence of delayed postoperative pseudoaneurysm rupture make this case clinically notable, highlighting key challenges in diagnosis, surgical management, and complication mitigation. Findings: A 77-year-old female with a 3-month history of dizziness and fatigue was diagnosed with massive gastrointestinal hemorrhage and duodenal stump adenocarcinoma via multimodal evaluation. She underwent duodenal stump tumor resection. On postoperative day 11, she developed delayed intra-abdominal hemorrhage from a artery pseudoaneurysm. Abdominal CTA detected a pseudoaneurysm in a superior mesenteric artery branch with contrast extravasation; emergency DSA-guided embolization successfully stopped bleeding. However, on postoperative day 25, she developed severe rectal bleeding; colonoscopy showed extensive ischemic necrosis in the descending colon. Despite supportive care, the patient's family discontinued treatment due to persistent bleeding and septic shock, and she died 1 week after discharge. Interpretation: Duodenal stump tumors require a high index of suspicion for diagnosis, as their nonspecific symptoms are often misattributed to postsurgical sequelae. Multimodal imaging and gastroscopy with biopsy are critical for preoperative planning. Delayed postoperative pseudoaneurysm-related hemorrhage is extremely rare but life-threatening; CTA and DSA are essential for rapid diagnosis and intervention. While DSA-guided embolization effectively controls bleeding, it carries a risk of bowel ischemia that requires close monitoring. This case underscores the need for meticulous preoperative assessment, careful surgical technique to avoid vascular injury, and postoperative vigilance for rare complications-supporting the utility of integrated clinical-radiological management in complex cases.