Distal Biliary Stent Migration in Patients with Irretrievable Bile Duct Stones: Long-Term Comparison Between Straight and Double-Pigtail Stents

Background: Prolonged biliary stenting may be considered in high-risk patients with irretrievable bile duct stones (IBDS). Distal stent migration (DSM) is a known complication, although data beyond the recommended interval of temporary stenting (3-6 months) are lacking. We compared the long-term incidence of DSM between straight and double-pigtail stents in patients with IBDS.

Methods: Consecutive patients with IBDS undergoing plastic biliary stenting (1/2009-12/2019) were retrospectively reviewed. DSM was confirmed on follow-up examination when the stent was no longer present at the papillary orifice nor fluoroscopically visible in the bile duct. Kaplan-Meier and Cox regression analyses were used to determine estimates and predictors of DSM.

Results: Overall, 618 biliary stenting procedures (410 patients) were included: 289 with a straight stent (group A) and 329 with a double-pigtail (group B). By Kaplan-Meier analysis, the DSM rates were 8.4 and 14.6% at 6 months, 21.4 and 27.7% at 12 months, 27 and 43.5% at 18 months, and 37.2 and 60.4% at 24 months, for groups A and B, respectively (p = 0.004). Double-pigtail stents were at higher risk for DSM (HR = 7.38, p = 0.04), whereas an inverse correlation was noted with age (HR = 0.97, p = 0.0001). Considering only temporary stenting procedures (≤ 6 months; n = 297), the probability of DSM was not significantly different between the two groups (p = 0.07).

Conclusions: In a setting of prolonged stenting for IBDS, the probability of DSM appears to be higher when a double-pigtail stent is used and in younger patients. A relative anti-migratory advantage of double-pigtail over straight stents appears negligible in this study.