Biflanged metal stents versus plastic stents in the endoscopic ultrasound-guided drainage of walled-off necrosis: a randomized controlled trial.

OBJECTIVE:Endoscopic ultrasound(EUS) guided drainage of walled off necrosis(WON) with either plastic stents or metal stents is the mainstay of WON management. This is a single center randomized controlled study evaluating the efficacy of bi-flanged metal stent(BFMS) and plastic stents for WON drainage. DESIGN:Patients with symptomatic WON amenable for EUS guided drainage were randomized to either BFMS or plastic stents. Primary outcome was reintervention free clinical success at 4 weeks. Secondary outcomes were overall clinical success(complete resolution of symptoms and significant reduction in size of WON (<50% of original size and <5 cm largest diameter size at 4-week follow-up)), number of re-interventions, adverse events, hospital stay for first admission and medium term outcomes at 6 months (recurrence, disconnected pancreatic duct, chronic pancreatitis and new onset diabetes mellitus). RESULTS:92 patients were randomized - 46 in each arm. The reintervention free clinical success was significantly higher in BFMS group(67.4% vs 43.5%; P: 0.021; ITT analysis). Overall clinical success at one month was similar in both groups. There were significantly lower number of reinterventions (median 0(IQR 0-1) vs 1(0-2) P:0.028)and hospital stay duration in BFMS group(7.04 ± 3.36 days vs 9.09 ± 5.53 days; P:0.035). There was no difference in procedure-related adverse events, mortality and medium-term outcomes. CONCLUSIONS:The BFMS provides higher reintervention free clinical success at 4 weeks with shorter hospital stay without increased risk of adverse events compared to plastic stents for EUS-guided drainage of WON. Medium term outcomes are however similar in both BFMS, and plastics stents.