Reflections on endoscopic ultrasound-guided drainage for infected walled-off necrosis

We read with great interest the article by Moon et al. [11], which compared novel electrocautery-enhanced lumen-apposing metal stents (LAMSs) and plastic stents in endoscopic ultrasound (EUS)-guided drainage of infected walled-off necrosis (WON). We appreciate the dedication of the authors to assessing the safety and efficacy of electrocautery-enhanced LAMSs for infected WON; however, we have some thoughts on this study.

First, this study found that the total number of direct endoscopic necrosectomy (DEN) procedures in the LAMS group was higher than that in the plastic stent group, although there was no statistical difference in the total number of DEN procedures between the two groups, which aligned with the conclusion of Karstensen et al. [22]. However, this result remains a subject of debate, as it contradicts the initial hypothesis that the LAMS group, owing to better drainage, would lower the number of DEN procedures [33]. The authors tried to explain this result, and finally attributed it to selection bias, with there being certain factors in the LAMS group that might have indicated a requirement for more DEN procedures; however, the underlying factors were not investigated. Therefore, we recommend that the authors perform a regression analysis using the number of DEN procedures as the dependent variable, which may yield further insights.

Additionally, the indications for the DEN procedures, including persistent symptoms and inadequate stent drainage, can result in variations in the number of DEN procedures performed [44], but the study did not clarify the specific indications for these procedures. LAMSs, with their larger diameter, facilitate easier endoscopic access through the lumen into the cyst for necrosectomy, which may lead to more aggressive DEN procedures for patients in the LAMS group [55]. These factors could potentially account for the higher number of DEN procedures in the LAMS group.

Second, it is often expected that there will be no statistical differences in the baseline characteristics between the two groups in a randomized controlled trial (RCT). Nevertheless, to ensure the study's methodologic rigor, the authors analyzed the baseline characteristics of the two groups. In our view, when dealing with multicategorical variables, such as the etiology of pancreatitis, it is more appropriate to use a chi-squared test for multiple independent proportions, which requires calculation of only a single chi-squared value and its corresponding P value.

Overall, despite certain limitations, this study is a well-designed RCT, providing valuable guidance for the treatment of infected WON with EUS.

Publication History

Article published online:
28 May 2025

• References

• 1 Moon JH, Park SW, Lee YN. et al. A comparison of novel electrocautery-enhanced lumen-apposing metal stents and plastic stents in endoscopic ultrasound-guided drainage of infected walled-off necrosis: a multicenter randomized study. Endoscopy 2024; 56: 926-937
• 2 Karstensen JG, Novovic S, Hansen EF. et al. EUS-guided drainage of large walled-off pancreatic necroses using plastic versus lumen-apposing metal stents: a single-centre randomised controlled trial. Gut 2023; 72: 1167-1173
• 3 Koduri KK, Jagtap N, Lakhtakia S. et al. Biflanged metal stents versus plastic stents for endoscopic ultrasound-guided drainage of walled-off necrosis: a randomized controlled trial. Endoscopy 2024; 56: 915-923
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• 5 Parsa N, Nieto JM, Powers P. et al. Endoscopic ultrasound-guided drainage of pancreatic walled-off necrosis using 20-mm versus 15-mm lumen-apposing metal stents: an international, multicenter, case-matched study. Endoscopy 2020; 52: 211-219