Standardized approach to removal of lumen apposing metal stents following endoscopic necrosectomy: one size does not fit all.

Abstract

Background: Walled-off necrosis (WON) is a sequela of acute necrotizing pancreatitis preferentially managed with lumen apposing metal stents (LAMS). Adverse events including buried stent syndrome and bleeding have been associated with a longer duration of LAMS placement.

Objectives: We attempt to examine our outcomes of a standardized approach to LAMS dwell time and hypothesize that LAMS removal based on imaging characteristics and patient symptoms improves outcomes.

Design: From November 2015 to May 2022, a prospectively maintained database on patients with symptomatic WON undergoing endoscopic drainage with LAMS was retrospectively reviewed and analyzed.

Methods: Patient characteristics, procedure details, and outcomes were recorded. Imaging was performed at 1, 3, and 6 weeks after LAMS placement and 1 week after each necrosectomy. Imaging findings and patient symptoms were used to determine the need for repeat necrosectomy. The timing of LAMS removal was guided by adequate endoscopic necrosectomy and resolution of the patient's symptoms. Subgroups were identified based on the duration of LAMS placement (less than 4 weeks and more than 4 weeks). Independent t-tests (continuous variables) and Fisher's exact tests (categorical outcomes) were used to analyze the two groups.

Results: In all, 104 patients underwent endoscopic necrosectomy during the study period. Of the two subgroups identified based on LAMS dwell time, 70 patients had a LAMS duration greater than 4 weeks and 34 patients had a LAMS duration less than 4 weeks. Collections with >50% necrosis were more commonly seen in patients with longer LAMS dwell time (<4 weeks (12%) vs >4 weeks (33%), p = 0.031). The median number of necrosectomies was fewer in the early LAMS removal group compared to the late LAMS removal cohort (p = 0.03). Clinical outcomes including technical success, clinical success, delayed adverse events, and 6-month mortality were similar in both groups.

Conclusion: A patient-specific customized approach to endoscopic drainage of WON improves outcomes. Patients with extensive necrosis may require a longer LAMS dwell time to achieve adequate debridement and clinical resolution. An increased risk of bleeding or adverse events related to prolonged duration of LAMS placement was not observed in our study. Future larger prospective studies are needed to confirm these conclusions.