To stent or not to stent: do we have an answer yet?

In the recent article published by Chavan et al. [1], the authors have evaluated, in a randomized controlled trial, whether keeping long-standing transmural plastic stents in situ in patients with a disconnected pancreatic duct (DPD) has any added benefit in preventing further recurrence of pancreatic fluid collections (PFCs). They found that there was no significant difference between the stent and no-stent arms at 3, 6, and 12 months in terms of PFC recurrence. However, there are certain caveats to this interpretation.

First, time is key to adequate judgement of PFC recurrence. Previous studies (Table 1 s, see online-only Supplementary material) have evaluated PFC recurrence with a median follow-up of 11–34 months; 92 % of the recurrences occurred within the first 2 years [2]. Even the current study showed an increasing trend toward recurrence in the no-stent group between 3 months (5.8 %) and 12 months (25 %). Therefore, a 3-month PFC recurrence does not seem to be a clinically meaningful primary outcome measure.

Second, the post-hoc power analysis, even for the 12-month outcome, shows that it is grossly underpowered (~32 %). Additionally, with a 20 % overall dropout rate and 19 % migration rate in the stent arm, the per-protocol analysis suffers from gross overall and differential attrition bias to support the intention-to-treat analysis. Therefore, it is statistically difficult to conclude non-superiority from the results of the current study.

Third, recurrence rates in previous stent arms have usually been reported to be < 2 % [3]; whereas, the current study reported a 13.5 % recurrence rate, which seems unusually high, although only one-third of these patients required re-intervention, which was akin to previous studies [4].

Interestingly, distal collection drained during the index procedure was found to have a higher tendency for future recurrence. Factors such as the site of initial collection, DPD site, and recurrence site might play additional roles, besides stent-in-situ, in determining the complex pathophysiology behind PFC recurrence in DPD. Further larger studies are needed to resolve this dilemma.

Publication History

Article published online:
28 June 2022

• 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; DOI: 10.1055/a-1747-3283.
• 2 Gkolfakis P, Bourguignon A, Arvanitakis M. et al. Indwelling double-pigtail plastic stents for treating disconnected pancreatic duct syndrome-associated peripancreatic fluid collections: long-term safety and efficacy. Endoscopy 2021; 53: 1141-1149
• 3 Bang JY, Wilcox CM, Arnoletti JP. et al. Importance of disconnected pancreatic duct syndrome in recurrence of pancreatic fluid collections initially drained using lumen-apposing metal stents. Clin Gastroenterol Hepatol 2021; 19: 1275-1281 e2
• 4 Dhir V, Adler DG, Dalal A. et al. Early removal of biflanged metal stents in the management of pancreatic walled-off necrosis: a prospective study. Endoscopy 2018; 50: 597-605