Predictors of proximal migration of straight biliary plastic stents.

Abstract

Proximal biliary plastic stent migration (PSM) remains a challenging complication. The study aims at determiningthe PSM rate, retrieval outcomes and factors associated with PSM. Endoscopy database was analyzed from January 2016 to January 2021 to identify 1137 patients, who underwent stent removal or repeat endoscopic retrograde cholangiopancreatography (ERCP). Demography, methods of stent retrieval, outcomes and complications were noted. Logistic regression was performed to determine risk factors for PSM. Propensity score matching was done in a 1:1 manner using age, sex, comorbidities and indication to assess endoscopy-related factors. Clinical trial registration done (CTRI/2022/02/040516). PSM was noted in 74 (6.5%) cases. Stent retrieval was successful in 94.59% (70/74) of cases. A balloon catheter (46/74) was commonly used. Technical failure was due to an impacted stent (2) and stent above the stricture (2). Complications were seen in 2.7% of cases. On multi-variate regression, sphincteroplasty at index ERCP (Odds ratio [OR] = 5.68, 95%confidence interval [CI] = 2.7-11.89), stent length < 10cm (OR = 8.53, 95%CI = 3.2-22.47), 7-Fr stent (OR = 18.25, 95%CI = 6.5-50.64), dilated bile duct (mean diameter- 9.2 ± 3.94mm) (OR = 0.384, 95%CI = 0.18-0.72) and delayed ERCP by > 3months from index ERCP (OR = 15.28, 95%CI = 8.1-28.49). After performing propensity score matching for age, sex, comorbidities and indication to determine endoscopy-related factors, 7-Fr stent size (OR 3.495; 95%CI-1.23-9.93) and duration of indwelling stent for more than three months (OR-3.37; 95%CI-1.646-6.76) were significantly associated with proximal stent migration. Proximally migrated straight stents can be successfully retrieved using standard accessories. The use of 7-Fr size stent, stents indwelling for more than threemonths, sphincteroplasty at index ERCP, stent length < 10cm and dilated bile duct were associated with increased risk of proximal migration of straight biliary plastic stents. After propensity score matching, the use of 7-Fr size stents and stent indwelling for over threemonths were endoscopy-related factors associated with proximal migration.