Do anchoring pigtail stents inserted within covered metal biliary stents reduce the likelihood of stent migration or occlusion?

Aims Endoscopic retrograde cholangiopancreatography (ERCP) with deployment of fully covered self-expanding metal biliary stents (FCSEMS) is a common treatment for hepato-biliary pathologies including biliary strictures (malignant or benign), post–sphincterotomy bleeding and bile leaks. Inward and outward stent migration post-ERCP is a recognised occurrence. An anchoring double-pigtail plastic stent can be deployed within the FCSEMS to reduce this risk, although evidence for this is limited. In the three similarly sized studies, two found anchoring stents significantly reduced migration [1] [2] and one did not [3]. Enhancing the evidence base in this area will help inform whether inserting anchoring pigtails is an effective strategy.

Methods We carried out a retrospective analysis of FCSEMS migration rates at our tertiary hepato-pancreato-biliary centre in the United Kingdom. All cases where FCSEMS were deployed between January 2019 and June 2023 were interrogated and divided into those with anchoring stents and those without. Complication rates, stent migration and stent occlusion were compared. Given the variety of indications for each ERCP procedure, cases were then subdivided between benign and malignant bile duct strictures. Statistical significance between groups was then calculated using the chi squared test.

Results 197 ERCPs were carried out with FCSEMS insertion; 67 with an additional anchoring pigtail within the FCSEMS and 130 without. Overall rate of stent migration was 9/67 (13.4%) in the pigtail group and 31/130 (23.8%) in the non-pigtail group (p=0.085). Overall rate of stent occlusion was 6/67 (9%) in the pigtail group and 15/130 (11.5%) in the non-pigtail group (p=0.58). Outcomes of patients with documented malignant or benign bile duct stricture were then analysed. For malignant strictures, there were 13 anchoring pigtails vs 79 without. 0/13 (0%) vs 13/79 (16.5%) had stent migration (p=0.11) and 3/13 (23.1%) vs 11/79 (13.9%) had stent occlusion (p=0.39). For benign strictures, there were 16 anchoring pigtails vs 29 without anchoring pigtails. 1/16 (6.25%) vs 8/29 (27.6%) had stent migration (p=0.09) and 2/16 (12.5%) vs 3/29 (10.3%) had stent occlusion (p=0.83).

Conclusions Inserting an anchoring pigtail stent appeared to lower the overall migration rate but statistical significance was not achieved. There were fewer instances of stent occlusion in the anchoring pigtail group, but with no significant difference between the groups. However, in the malignant strictures subgroup, occlusion rates were higher with anchoring pigtails but without statistical significance. A longer study period or future multi-centre analysis would help provide sufficient power to understand whether there is really a difference between the two groups. More data for specific ERCP indications with higher patient numbers will ascertain whether anchoring pigtails reduces the risk of stent migration or occlusion.

 

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Conflicts of Interest

Authors do not have any conflict of interest to disclose.

• References

• 1 Paik WH, Woo SM, Chun JW, Song BJ, Lee WJ, Ahn DW, Lee YS, Choi YH, Ryu JK, Kim YT, Lee SH.. Efficacy of an internal anchoring plastic stent to prevent migration of a fully covered metal stent in malignant distal biliary strictures: a randomized controlled study. Endoscopy 2021; 53 (6): 578-585
• 2 Chun JW, Woo SM, Han M, Lee MW, Choi JH, Cho IR, Paik WH, Lee WJ, Ryu JK, Kim YT, Lee SH.. Prolonged patency of fully covered self-expandable metal stents with an externally anchored plastic stent in distal malignant biliary obstruction. Endoscopy 2023; 55 (6): 563-568
• 3 Emhmed Ali S, Frandah WM, Su L, Fielding C, Mardini H.. Should a fully covered self-expandable biliary metal stent be anchored with a double-pigtail plastic stent? A retrospective study. World J Gastrointest Endosc 2019; 11 (5): 365-372

Publication History

Article published online:
27 March 2025