Visceral artery pseudoaneurysms in necrotizing pancreatitis: risk of early bleeding with lumen-apposing metal stents

Background and Aims: Visceral artery pseudoaneurysm (PSA) in necrotizing pancreatitis (NP) is associated with significant morbidity and mortality. This study aimed to evaluate the incidence, clinical presentation, management, and outcomes of PSA in NP. Methods: All NP patients managed at our institution between 2010 and 2020 were retrospectively reviewed from a prospectively maintained database for PSA. Demographics, clinical presentation, method of diagnosis, management, and outcomes were collected. Results: Thirty-nine of 607 patients (6.4%) with NP had a confirmed diagnosis of PSA. Demographics, presence of infected necrosis, development of organ failure(s), and severity of disease were similar between PSA and no PSA. Endoscopic and percutaneous drainages for walled-off necrosis (WON) were more common in the PSA group. Seven patients developed PSA without requiring any intervention for WON, and 17 patients (43.6%) had lumen-apposing metal stents (LAMSs) placed before PSA diagnosis. The time from NP diagnosis to PSA diagnosis was shorter in these patients (n = 17) compared with the remaining patients (n=22; 47 days [interquartile range {IQR}: 17-85] vs 109 days [IQR: 61-180.5, P=0.009]). In addition, 7 of 11 patients (63.6%) with early PSA (defined by <3 weeks from index cystgastrostomy/cystduodenostomy) had an indwelling LAMS at the time of the PSA diagnosis. Seventy-seven percent of patients presented with anemia, 74.3% with GI bleeding, and 30% with hemorrhagic shock. CT was diagnostic for PSA in 83.9% with a false-negative rate of 16.1%. Splenic (50%) and gastroduodenal (28%) arteries were the most common arteries involved by PSA. Angiography and embolization for PSA were successful in 33 of 35 patients. In-hospital mortality was observed in 9 patients (23.1%). Conclusions: Although visceral artery PSA affects a small percentage of NP patients, it is associated with significant morbidity and mortality. In addition, bleeding from PSA induced by erosion of LAMSs may occur in the first 2 weeks, prompting individualization of removal intervals.