A Pseudo to Pseudo Connection: Pseudoaneurysm Draining Into the Pseudocyst

Abstract

Pseudohemobilia or Hemosuccus Pancreaticus (HP) is a rare cause of gastrointestinal (GI) bleeding from an aneurysm of peripancreatic vessels that ruptures into a pancreatic pseudocyst, and blood travels through the pancreatic duct as a conduit entering the GI tract through the ampulla of Vater. We are highlighting a case of a 65-year-old female with past medical history of chronic pancreatitis who presented with multiple episodes of dark tarry stools for one day. Her vitals were stable and systemic examination was unremarkable. Laboratory evaluation was only significant for a hemoglobin of 6.7mg/dl and Doppler ultrasound of the abdomen revealed a 8.3 cm ovoid echogenic structure in the midline near the superior mesenteric artery with bidirectional flow suggesting a pseudoaneurysm raising suspicion for communication with pseudocysts. Contrast-enhanced CT showed multiple pancreatic pseudocysts connecting with a large 7.9 x 7.5 cm pseudoaneurysm close to the pancreatic head. (Figure 1) Emergent angiography was done revealing a large pseudoaneurysm arising from the middle part of the gastroduodenal artery with contrast extravasation into pseudocyst depicting active hemorrhage. (Figure 2) The pseudoaneurysm was embolized by microvascular plug (MVP) devices. Post-embolization angiogram showed preservation of hepatic arterial supply and patent portal vein with good flow towards the liver. (Figure 3) Sandblom first coined the name “hemosuccus pancreatitis” in 1970. (1) It's a rare and potentially lethal cause of GI bleed found mostly in men. (2) Most common cause of HP is the chronic recurrent pancreatitis resulting in pancreatic pseudocysts formation. (3) Pseudocyst induced pressure necrosis and autodigestion by pancreatic enzymes from repeated episodes of pancreatitis weaken the surrounding vessel walls and result in the formation of the pseudoaneurysms. (3) Rupture of these pseudoaneurysms into pseudocysts or sometimes directly into the pancreatic duct heralds GI bleed. This poses a diagnostic and management challenge due to the novelty of the condition and difficulty of diagnosing it with endoscopy because of the intermittent nature of the bleeding. Angiography is considered to be the gold standard as it not only serves a diagnostic role but also as a therapeutic modality. (4) Physicians should keep a high index of suspicion for HP in high-risk patients with a normal endoscopy.1359.tif Figure 1: Contrast-enhanced CT scan of the abdomen reveals a 7.9 x 7.5 cm mass adjacent to the pancreatic head. High-density area(arrow) corresponds to active hemorrhage in the pseudoaneurysm.