Reply to van Malenstein et al.

We thank van Malenstein et al. for their interest and comments on our recently published article [1].

The authors have raised concern about removal of stents in unresolved walled-off necrosis (WON) after endoscopic drainage. It is agreed that large-caliber metal stents (LCMS) hasten the resolution of WON and reduce the reintervention rate [2] [3]. Studies have reported resolution of WON in 90 %–95 % within 4–6 weeks using a standard endoscopic “step-up approach” [4]. Adverse events associated with prolonged indwelling LCMS warrant early removal (i. e. within 4 weeks).

We agree that some patients can have unresolved WON after endoscopic drainage, especially those with a larger percentage of debris, and hence an additional intervention may be required. In our study, 3 % of patients had nonresolution of WON at 4 weeks and were intentionally excluded to maintain homogeneity [1].

The plausible reasons for nonresolving WON include: 1) remnant debris causing clogging of LCMS; 2) presence of multiple poorly or noncommunicating collections; 3) large WON extending deeper inside the abdomen warranting dual modality drainage or surgery; 4) ingested foods/liquids entering the cavity and preventing its collapse; 5) chronic collections with fibrotic wall taking a longer time to collapse.

Management of symptomatic unresolved WON includes one or more of the following options depending on the clinical status: 1) repeat direct endoscopic necrosectomy; 2) exchange of LCMS with plastic stents irrespective of pancreatic duct anatomy status; or 3) other modalities of drainage (percutaneous and/or surgery).

We agree that failure of exchange of LCMS with plastic stent deployment is mainly due to collapsed cavity. However, there was no recurrence seen in patients with failed stenting (Table2 s in the article), and conversely a successful replacement with plastic stents did not guarantee prevention of recurrence. The impact of disconnected pancreatic duct in unresolved WON and early replacement of LCMS with plastic stent before complete resolution requires further studies.

Publication History

Article published online:
29 March 2023

• References

• 1 Chavan R, Nabi Z, Lakhtakia S. et al. Impact of transmural plastic stent on recurrence of pancreatic fluid collection after metal stent removal in disconnected pancreatic duct: a randomized controlled trial. Endoscopy 2022; 54: 861-868
• 2 Bang JY, Navaneethan U, Hasan MK. et al. Non-superiority of lumen-apposing metal stents over plastic stents for drainage of walled-off necrosis in a randomised trial. Gut 2019; 68: 1200-1209
• 3 Bazerbachi F, Sawas T, Vargas EJ. et al. Metal stents versus plastic stents for the management of pancreatic walled-off necrosis: a systematic review and meta-analysis. Gastrointest Endosc 2018; 87: 30-42
• 4 Lakhtakia S, Basha J, Talukdar R. et al. Endoscopic “step-up approach” using a dedicated biflanged metal stent reduces the need for direct necrosectomy in walled-off necrosis (with videos). Gastrointest Endosc 2017; 85: 1243-1252