Immediate or On-Demand Endoscopic Necrosectomy for Necrotizing Pancreatitis: A Randomized Controlled Trial (WONDER-01)

The optimal timing for direct endoscopic necrosectomy (DEN) following endoscopic ultrasound (EUS)-guided transmural drainage of symptomatic necrotizing pancreatitis remains unknown. We hypothesized that immediate DEN following EUS-guided drainage might reduce the time to disease resolution compared with a drainage-oriented step-up approach. This study was a multicenter, open-label, superiority randomized trial (WONDER-01). Among patients who received EUS-guided treatment for symptomatic necrotizing pancreatitis, eligible patients were randomly assigned 1:1 to receive either immediate DEN or the drainage-oriented step-up approach. The primary endpoint was the time from randomization to clinical success, defined as a decrease in collection size to ≤3 cm and an improvement in inflammatory markers. Seventy patients were enrolled in this study: 33 in the immediate DEN arm and 37 in the step-up arm. Immediate DEN was associated with a shorter time to clinical success than the step-up approach ( P = .009), with median times (95% confidence interval) of 29 (19–34) and 44 (38–52) days, respectively. All patients in the immediate DEN arm received DEN compared to 46% in the step-up approach arm, but the rates of procedure-related adverse events were comparable (24% vs 22%, respectively; P = .79). No significant differences were noted between the treatment arms in terms of technical success (100% vs 97%, P > .99) and mortality (12% vs 5.4%, P = .41). Compared with the step-up approach, immediate DEN following EUS-guided drainage of necrotizing pancreatitis reduced time to clinical success without increasing adverse outcomes but required more DEN procedures ( ClinicalTrials.gov , Number: NCT05451901).