S2809 Detection and Management of an Intact Splenic Artery Branch Within a Pancreatic Pseudocyst During EUS-Guided Cystogastrostomy

Abstract

Introduction: Peripancreatic arteries are highly susceptible to pseudoaneurysm formation in chronic pancreatitis (CP) due to exposure to auto-digestive enzymes. Pseudoaneurysm incidence in CP is estimated between 10% - 17%, with rupture associated with a mortality rate of 40%.1 This case report describes the event of an endoscopic ultrasound (EUS) guided cystogastrostomy of a pancreatic pseudocyst within which an intact splenic artery branch was discovered after stent deployment, despite preceding EUS not revealing intervening vessels. Case Description/Methods: A 22-year-old man with a history of chronic pancreatitis presented for epigastric pain, nausea, and vomiting. CT abdomen and pelvis (CTAP) revealed a large necrotic area within the pancreas. Initial EUS demonstrated chronic pancreatitis along with an adjacent large fluid collection with surrounding collateral vessels. As flow doppler did not reveal internal vasculature, a lumen-apposing metal stent (LAMS) was placed. Insufflation of the now collapsed pseudocyst and repeat EUS revealed an 8mm vessel with notable pulsation. Following consultation with the hepatobiliary surgery service and repeat review of CTAP, the team determined that this vessel was a distal branch of the splenic artery. An 11 mm Conmed clip was then placed at the origin of the vessel for interventional radiological localization. The LAMS was removed, and the tract was closed to prevent the risk of catastrophic hemorrhage. Arterial embolization of the splenic artery branch with an 8 mm Amplatzer Family of Vascular Plug 4 and Azur coils was performed, with angiogram revealing occlusion of the artery. Subsequent EUS and gastroscopic visualization revealed negative flow on Doppler and no evidence of active bleeding, respectively. The LAMS and two double pigtail stents were replaced. The patient tolerated the procedure well and was transferred back to the referring facility. Discussion: Despite close inspection of the pseudocyst with doppler and B-mode evaluation prior to LAMS deployment an internal vessel was not seen and at risk of transection during LAMS placement. Careful review of CT imaging and detailed evaluation of cysts should be undertaken prior to therapeutic intervention. Multidisciplinary consultation with hepatobiliary surgery and interventional radiology is critical when high-risk anatomy is discovered to coordinate care. Prevention of hemorrhage should be the priority and once obtained, further therapy of fluid collections can be attempted. (Figure)Figure 1.: A. Flow doppler of pancreatic fluid collection without evidence of vasculature B. Placement of LAMS C. Visualization of arterial vessel within pseudocyst D. Placement of clip near origin of arterial vessel for IR localization.