The revised Atlanta Classification delineates the local complications of acute pancreatitis, categorizing them as acute (peri)pancreatic fluid collections (PFCs), acute necrotic collections, pancreatic pseudocysts, and walled-off pancreatic necrosis (WOPN). Various endoscopic interventions are employed for the management of WOPN, notably including direct transluminal endoscopic necrosectomy (DEN) following the placement of an endoscopic ultrasound-guided (EUS) lumen-apposing metal stent (LAMS). This study aims to assess the clinical outcomes and safety profile of DEN in patients diagnosed with pancreatic WOPN.

Between October 2021 and October 2025, we performed a total of 3337 endoscopic procedures, including 1705 EUS examinations. During this period, a total of 75 WOPN cases were identified, comprising 40 LAMS insertions, 11 conventional double pigtail plastic stent insertions, and 24 cases of spontaneous regression.This single-center retrospective analysis encompasses patients with pancreatic WOPN who underwent DEN at Semmelweis University between May 2022 and Oct 2025. The procedures were performed by three seasoned specialists in EUS. Comprehensive data on patient demographics, procedural specifics, and follow-up outcomes were collected, with adverse events classified according to the AGREE criteria.

We successfully placed LAMS in 40 patients (65,0% female, average age 55,9 years, SD 15,41). The primary indications for intervention included the dimensions of WOPN, exacerbation of gastric outlet obstruction, and signs of infection. The mean dimensions of WOPN were recorded as 104 mm in the anteroposterior direction (SD 54,0), 96,7 mm laterolateral (SD 46,6), and 104,9 mm craniocaudal (SD 53,0), with a predominant occurrence in the head of the pancreas (60%). Biliar reasons (42,3%) and alcohol consumption (38,5%) emerged as the leading etiological factors for WOPN in male patients and biliary causes were identified in 85,7% of female patients. In total, we conducted 111 DEN procedures across the 40 patients (26 males and 14 females). The average number of DEN sessions was three for both male and female groups (range: 0-7). The technical success rate achieved was 100%, accompanied by a clinical success rate of 97%. Six of the 40 patients required intensive care. Four of these six patients needed surgical intervention due to complications from endoscopic necrosectomy, including bleeding and perforation. Unfortunately, one patient succumbed to multiorgan failure. To enhance the resolution of infection between DEN sessions, we employed 7 Fr/250 cm nasocystic tubes for irrigation of the WOPN with a saline solution in 36 patients, with no adverse events reported as a result of this intervention.

DEN can be performed safely in experienced medical centers and demonstrates a high success rate in the treatment of infected WOPN, effectively alleviating symptoms and decreasing enzyme levels.