S5334 Life-Threatening Hemorrhage From a Gastroduodenal Artery Pseudoaneurysm Following LAMS Placement for a Pancreatic Pseudocyst

Introduction: Pancreatic pseudocysts are a common complication following acute or chronic pancreatitis. For symptomatic and persistent pseudocysts, endoscopic ultrasound (EUS)-guided drainage, typically via cystogastrostomy, is the first-line therapy. It involves the placement of a lumen-apposing metal stent (LAMS) to drain the fluid collection, and is usually removed after a few weeks. Bleeding is a known complication of LAMS placement, occurring in approximately 7-10% of cases. One potential source of bleeding is a visceral artery pseudoaneurysm. We present a case of a young woman who developed hematemesis from a gastroduodenal artery pseudoaneurysm one day after LAMS placement. Case Description: A 28-year-old woman with a history of trauma-induced pancreatitis and recurrent pancreatic pseudocysts was found unresponsive with hematemesis shortly after discharge from an outside hospital. She had recently undergone EUS-guided cystogastrostomy with LAMS placement for a recurrent pseudocyst. Her initial pancreatitis was months earlier after blunt abdominal trauma. A pseudocyst was previously drained with LAMS, which was removed after resolution. However, recurrence of symptoms led to a second stent placement. On arrival, she was somnolent and hypotensive (BP 62/31 mmHg, HR 130-140 bpm), with blood in the oropharynx. CT angiogram revealed active contrast extravasation into a pseudocyst and a bleeding gastroduodenal artery (GDA) pseudoaneurysm. She underwent emergent embolization of the GDA and supraduodenal artery. Post-procedure imaging confirmed successful embolization with no active bleeding. A 7.4 cm pseudocyst with hemorrhagic contents was identified in the pancreatic head. The patient was stabilized and transferred to the original treating hospital for hepatobiliary surgical evaluation. Discussion: With the increasing use of LAMS for pancreatic pseudocyst drainage, it is important to recognize rare but serious complications like delayed bleeding from a visceral artery pseudoaneurysm. In this case, a GDA pseudoaneurysm likely developed after the first cystogastrostomy, possibly due to stent-related erosion or local inflammation, and then ruptured following a second LAMS placement leading to life-threatening hematemesis. Prompt diagnosis with angiography and emergent embolization was key to manage the bleed. As LAMS use becomes more widespread, particularly in recurrent or complex cases, clinicians should be aware of potential vascular complications and act promptly at the first sign of bleeding.