Splenic artery pseudoaneurysm and resultant haematosuccus pancreaticus

Abstract

Splenic artery pseudoaneurysm (SAP) is a rare and dangerous diagnosis with a high risk of rupture and death. It is the most common cause of main pancreatic duct haematoma-haematosuccus pancreaticus (HP). Neither SAP nor HP have specific clinical features that allow diagnosis without cross-sectional imaging. Upper gastrointestinal haemorrhage and a history of pancreatitis should raise clinical suspicion but ultimately endoscopy and CT are required. We report a case of a 51-year-old man without clinical symptoms in whom cross-sectional imaging was undertaken for incidental severe acute anaemia. This demonstrated stigmata of chronic pancreatitis and the main pancreatic duct was distended with dense material in keeping with haematoma. The diagnosis of a SAP bleeding into the main pancreatic duct was made radiologically. A subsequent oesophago-gastro-duodenoscopy confirmed the diagnosis. The imaging appearances, pathophysiology and management are discussed.

Keywords: GI bleeding; gastrointestinal system; general surgery; radiology.

Figure 1

(A) Non-contrast axial CT slice demonstrating dense material within and conforming to the shape of the dilated main pancreatic duct (arrow). Note the absence of pancreatic parenchyma secondary to atrophy and multiple calcific foci (open arrows), both stigmata of chronic pancreatitis. (B) Slightly more cranial axial CT slice, in portal venous phase showing multiple foci of calcification surrounding the dilated main pancreatic duct (open arrow). Dense material is visible toward the ampulla (arrow) which has not changed in density following administration of intravenous contrast. Note the presence of an incidental peri-pancreatic pseudocyst on both images (star).

Figure 2

Axial slices from a triple phase CT scan of the abdomen demonstrating an ovoid structure (arrow) which contains dense material on the non-contrast study (A) and which fills with iodinated contrast on the arterial phase scan (B), the same density as the luminal content of the abutting splenic artery (arrowhead). The contrast within the pseudoaneurysm matches the arterial contrast density on the portal venous phase study (C). Abutting the pseudoaneurysm anteriorly is a peri-pancreatic pseudocyst (open arrow) which contains dense material on the pre-contrast study (A) giving similar pre-contrast appearances. The administration of contrast allows differentiation of an uncomplicated pseudocyst from the splenic artery pseudoaneurysm.