Background: Endoscopic placement of covered self-expandable metallic stents (CSEMSs) is effective for distal malignant biliary obstruction. However, management of dysfunctional CSEMSs has not been established.
Methods: Between March 1998 and July 2007, a total of 74 patients who underwent endoscopic re-interventions for CSEMS dysfunction were analyzed. Second stent insertion (CSEMS or plastic stent) or mechanical cleaning of the occluded CSEMS was performed endoscopically. The period between second stent insertion and stent dysfunction or patient death (time to dysfunction; TTD) was calculated. The cleaned initial CSEMSs were analyzed as second stents.
Results: Dysfunction of the second stent occurred in 17 of 37 patients (45.9%) in the CSEMS group, 16 of 20 (80.0%) in the plastic stent group, and 13 of 17 (76.5%) in the cleaning group. The median TTD of each group was 176, 57, and 46 days, respectively. The cumulative TTD was significantly higher in the CSEMS group than in the plastic stent and cleaning groups (P = 0.08). From the multivariate analysis, sludge occlusion of the first CSEMS was identified as a significant risk factor for second stent dysfunction (HR, 2.51; 95% CI, 1.19-5.46), and placement of the second CSEMS significantly reduced the risk of dysfunction (HR, 0.39; 95% CI, 0.18-0.79).
Conclusions: Insertion of a new CSEMS should be considered as the treatment of choice for the management of dysfunctional CSEMSs.