Lumen Apposing Metal Stents vs Double Pigtail Plastic Stents for the Drainage of Pancreatic Walled-Off Necrosis

BACKGROUND: Few studies compared lumen-apposing metal stents (LAMS) and standard double pigtail plastic stents (PS) for the endoscopic drainage of pancreatic walled-off necrosis (WON). Albeit sometimes large, previously described cohorts display considerable heterogeneity and often pooled together data from several centers, involving multiple operators and techniques. Moreover, they often lack a control group for the comparison of outcomes.Aim: to compare clinical efficacy and safety of PS versus LAMS for the endoscopic drainage of infected WON.METHODS: Single-centre, 1:1 case-control study. We compared patients undergoing endoscopic drainages of infected WON through LAMS (cases) or PS (controls). The primary endpoint was the clinical efficacy (resolution of the WON/sepsis), the secondary endpoint was safety (procedure-related complications).RESULTS: Thirty patients were enrolled between 2011 and 2017. Cases and controls were homogeneous in terms of etiology and clinical characteristics. 93% of cases and 86.7% of controls were clinically successfully treated, with no significant differences in rates of post-operative infections, bleedings and stent migrations (respectively 13.3% vs 21.4%; p=0.65; 13.3% vs 0%; p=0.48; 13.3% vs 7.1%; p=1.00). No difference was shown regarding the need for additional percutaneous or surgical treatments (33.3% vs 13.3%; p=0.39). Cases, however, displayed a significantly prolonged mean hospital stay (90.2 days vs 18.5 days; p<0.01) and a higher mean number of endoscopic procedures per patient (4.8 vs 1.5; p<0.01).CONCLUSIONS: PS might be not inferior to LAMS for the treatment WONs. Further prospective RCT is needed to compare clinical efficacy and safety in the two groups.