Comparison of the utility of covered metal stents versus uncovered metal stents in the management of malignant biliary strictures in 749 patients

Abstract

Background: Self-expandable metal stents (SEMSs) are used to relieve malignant biliary obstruction.

Objective: To compare outcomes between covered self-expandable metal stents (CSEMSs) and uncovered self-expandable metal stents (USEMSs) in malignant biliary obstruction.

Design: Retrospective cohort study.

Setting: Tertiary cancer center.

Patients: Patients with malignant biliary obstruction.

Interventions: Placement of CSEMS or USEMS.

Main outcome measurements: Time to recurrent biliary obstruction (TRO), overall survival (OS), and adverse events.

Results: From January 2000 to June 2011, 749 patients received SEMSs: 171 CSEMSs and 578 USEMSs. At 1 year, there was no significant difference in the percentage of patients with recurrent obstruction (CSEMSs, 35% vs USEMSs, 38%) and survival (CSEMSs, 45% vs USEMSs, 49%). There was no significant difference in the median OS (CSEMSs, 10.4 months vs USEMSs, 11.8 months; P = .84) and the median TRO (CSEMSs, 15.4 months vs USEMSs, 26.3 months; P = .61). The adverse event rate was 27.5% for the CSEMS group and 27.7% for the USEMS group. Although tumor ingrowth with recurrent obstruction was more common in the USEMS group (76% vs 9%, P < .001), stent migration (36% vs 2%, P < .001) and acute pancreatitis (6% vs 1%, P < .001) were more common in the CSEMS group.

Limitations: Retrospective study.

Conclusions: There was no significant difference in the patency rate or overall survival between CSEMSs and USEMSs for malignant distal biliary strictures. The CSEMS group had a significantly higher rate of migration and pancreatitis than the USEMS group. No significant SEMS-related adverse events were observed in patients undergoing neoadjuvant chemoradiation or surgical resection.

Keywords: CSEMS; OS; ROFS; SE; SEMS; TRO; USEMS; covered self-expandable metal stent; overall survival; recurrent obstruction–free survival; self-expandable metal stent; standard error; time to recurrent biliary obstruction; uncovered self-expandable metal stent.