Question: A 66-year-old man presented acutely with fresh and altered blood per rectum. This was preceded by the sudden onset of dull epigastric pain. The patient was a former smoker with a past history of peptic ulcer disease, but was otherwise fit and well. He denied any use of nonsteroidal anti-inflammatory drugs, but did admit to an alcohol intake of approximately 40 units per week. He was hemodynamically stable and, other than fresh red blood on digital rectal examination, there were no clinical findings of note. Laboratory tests on admission revealed a hemoglobin concentration of 11.5 g/dL (normal, 13–18 g/dL), with normal liver function tests. The level of serum amylase was mildly raised at 257 IU/L (normal, <110 IU/L). Urgent upper gastrointestinal (GI) endoscopy was undertaken as the first-line investigation. Although this showed a small amount of blood in the duodenum, it failed to identify an obvious source of bleeding. The patient had 3 further episodes of bleeding over the next month. No abnormality was detected at colonoscopy or on technetium Tc99m–pertechnetate scintography (Meckel’s scan). Dual-phase computed tomography (CT) of the abdomen showed coarse calcification of the pancreas, in keeping with a diagnosis of chronic pancreatitis (Image A, labeled 1). Endoscopic ultrasonography was reported as normal. Six weeks after the initial presentation, he presented again with hematochezia associated with a fall in hemoglobin concentration to 7.3 g/dL. Repeat upper GI endoscopy with a side-viewing endoscope demonstrated fresh blood in the distal duodenum with a blood clot at the ampulla of Vater (Image B). An urgent mesenteric angiogram was requested (Image C), and revealed a vascular malformation (labeled 2). What is the most likely diagnosis?View Large Image Figure ViewerDownload Hi-res image Download (PPT) Hemosuccus pancreaticus (HP), defined as the loss of blood into the GI tract via the main pancreatic duct, is an important, although rare, cause of upper GI hemorrhage.1Wagner W.H. Cossman D.V. Treiman R.L. et al.Hemosuccus pancreaticus from intraductal rupture of a primary splenic artery.J Vasc Surg. 1994; 19: 58-64Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar In this case, the source was a saccular aneurysm of the splenic artery, most probably a pseudoaneurysm secondary to previous acute pancreatitis (labeled 2 on Image C). First described by Lower and Farrell in 1931, HP, alternatively termed wirsungorrhea, is most commonly observed on a background of chronic calcific pancreatitis.2Camishion R.C. Pello M.J. Spence R.K. et al.Hemoductal pancreatitis.Surgery. 1992; 111: 86-89PubMed Google Scholar The principal presenting feature is epigastric pain, which immediately precedes the onset of overt GI bleeding. Intermittent bleeding is characteristic due to clot formation within the pancreatic duct.1Wagner W.H. Cossman D.V. Treiman R.L. et al.Hemosuccus pancreaticus from intraductal rupture of a primary splenic artery.J Vasc Surg. 1994; 19: 58-64Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar, 2Camishion R.C. Pello M.J. Spence R.K. et al.Hemoductal pancreatitis.Surgery. 1992; 111: 86-89PubMed Google Scholar In most cases, bleeding occurs secondary to rupture of an arterial pseudoaneurysm,3Negi S.S. Sachdev A.K. Bhojwani R. et al.Experience of surgical management of pseudo-aneurysms of branches of the coeliac axis in a North Indian Hospital.Trop Gastroenterol. 2002; 23: 97-100PubMed Google Scholar although it may also originate from true aneurysmal vessels or from hemorrhage within the pancreas itself.1Wagner W.H. Cossman D.V. Treiman R.L. et al.Hemosuccus pancreaticus from intraductal rupture of a primary splenic artery.J Vasc Surg. 1994; 19: 58-64Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar The diagnosis of HP usually requires several investigations, including endoscopic retrograde cholangiopancreatography, abdominal CT, and angiography.1Wagner W.H. Cossman D.V. Treiman R.L. et al.Hemosuccus pancreaticus from intraductal rupture of a primary splenic artery.J Vasc Surg. 1994; 19: 58-64Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar In this patient, mesenteric angiography (Image D) identified an eccentric aneurysm of the distal splenic artery with active bleeding into the pancreatic duct (labeled 3). The splenic artery saccular aneurysm was occluded by coil embolization of the splenic artery distal and proximal to the aneurysm (Image E).1Wagner W.H. Cossman D.V. Treiman R.L. et al.Hemosuccus pancreaticus from intraductal rupture of a primary splenic artery.J Vasc Surg. 1994; 19: 58-64Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar Coils in the proximal splenic artery alone would have been ineffective as the aneurysm would continue to fill via collaterals and retrograde flow. The same collaterals maintain splenic viability. The patient went on to make an uneventful recovery, and has not experienced any further episodes of acute upper GI bleeding.View Large Image Figure ViewerDownload Hi-res image Download (PPT)