Objective
Although the lumen-apposing metal stent (LAMS) has been increasingly used in the management of infected walled-off necrosis (WON), its advantages over plastic stent (PS) are not clear. Our objective was to investigate the safety and efficacy of a novel LAMS in the management of infected WON.
Design
All patients who underwent endoscopic ultrasound (EUS)-guided WON drainage were randomly assigned to either the LAMS or PS group. The primary outcome was the total number of direct endoscopic necrosectomy (DEN) procedures needed to achieve clinical success. Secondary outcomes included the technical success, clinical success, and the occurrence of adverse events.
Results
A total of 46 patients underwent LAMS (n=23) or PS (n=23) placement for EUS-guided WON drainage. The LAMS group demonstrated a significantly higher clinical success rate compared to the PS group, based on intention-to-treat analysis (100% vs. 73.9%, P=0.029) at eight weeks, despite no difference at the four-week assessment. The difference in the total number of DEN procedures needed to achieve clinical success did not reach statistical significance (PS vs LAMS group; median 4 interquartile range [IQR] [2.5-5.0] vs. median 9 IQR [8.0-9.0], P=0.072). Regarding significant bleeding, no events were reported in the LAMS group, while there was one case in the PS group.
Conclusion
A novel electrocautery-enhanced LAMS with simple one-step deployment and the ability to perform DEN with minimal migration proved to be safe and effective for the treatment of infected WON. Regarding the risk of bleeding during prolonged indwell times, LAMS can be considered a safe and reasonable option if sufficient treatment duration is required.

Figure 1. Illustration of the innovative lumen-apposing metal stent (LAMS) (Niti-S HOT SPAXUSTM, Taewoong Medical, Gyeonggi-do, Korea).
Figure 2. Study flow diagram
EUS, endoscopic ultrasound; WON, walled-off necrosis; LAMS, lumen-apposing metal stents; DPPS, double pigtail plastic stent