Walled-off necrosis (WON) is a complex sequela of acute pancreatitis that often necessitates interventional management. Endoscopic transmural drainage has emerged as the preferred first-line approach, especially with the increasing availability and refinement of endoscopic ultrasonography (EUS) guidance. This study aimed to present endoscopic management of patients with WON and to identify factors associated with technical and clinical success.

Patients who underwent endoscopic transmural drainage for symptomatic WON at a tertiary referral center were analyzed retrospectively. Two different techniques—conventional and EUS-guided—were used as endoscopic drainage modalities. Data on demographics, etiology of pancreatitis, collection size, drainage indications, procedural details, and outcomes were collected. Clinical and technical success, complications, recurrence and reintervention rates, and the impact of anatomical features such as paracolic extension, disconnected pancreatic duct syndrome (DPDS), and colonic fistula were analysed and compared according to endoscopic modalities.

A total of 73 patients (mean age: 54.6 ± 13.9 years; 46.6% male) underwent a total of 76 transmural drainage procedures. The median size of WON collections was 14cm (IQR:11–17cm), and the most common indication was infection (62.5%). Colonic fistula and DPDS were identified in 5 (6.8%) and 38 (52.1%) patients, respectively. Technical success was assessed per procedure. Overall technical success was 97.4% (74/76), with 100% (36/36) success in the conventional group and 95.0% (38/40) in the EUS group. Clinical success was achieved in 84.9% (62/73) of patients, with similar outcomes between conventional (83.3%) and EUS-guided (86.5%) drainage(p=0.961). Reintervention was required in 67.1%, and direct endoscopic necrosectomy was performed in 31.5%. Total number of interventional sessions was 294 (mean 4.0 per patient). Complications occurred in 28.7% of patients, most commonly bleeding (15.1%), generally managed endoscopically.

Endoscopic transmural drainage is an effective and safe intervention for the management of WON, with high technical and clinical success. EUS-guided drainage offers significant advantages by allowing intervention in patients without luminal bulging and in those with smaller collections, thereby expanding treatment eligibility to a broader patient population.