Endoscopic Re-Intervention for the Management of Dysfunction of Covered Metallic Stents in Patients with Malignant Distal Biliary Obstructions

Abstract

Background: Covered self-expandable metallic stents (CMSs) are widely used for the palliation of unresectable malignant distal biliary obstruction. Although short- and long-term results of the initial CMS have been evaluated, management and outcome of the dysfunctional CMS have not been addressed. Methods: Between April 1996 and May 2007, 102 patients who had received a CMS placement for the treatment of malignant distal biliary obstructions developed stent dysfunction requiring re-interventions. Of these, 81 patients (56% men; mean age, 69 years) in whom stent dysfunction was endoscopically treated were included in the present study. Patients were divided into 4 groups according to the type of re-intervention employed; CMS insertion (n = 37), plastic stent (PS) insertion (22), cleaning (17), and uncovered self-expandable metallic stent (UMS) insertion group (5). Short- and long-term outcomes of re-interventions were evaluated and compared among the 4 groups. The success of re-intervention was defined as no evidence of cholangitis or jaundice within 14 days after the procedure. The patency period of the re-interventon was calculated as the interval between the re-intervention and its dysfunction or the patient's death. Results: The first CMSs were occluded 86 days (median; range, 0 - 556) after their placement due to sludge occlusion (n = 42), stent migration (21), tumor overgrowth (14), and kinking (4). The failure of the re-intervention occurred in 4 patients (two in the PS, and one each in the CMS and in the UMS group). Removal of the first CMSs was attempted using forceps and polypectomy snears in 40 patients, and successful removal was achieved in 37 patients (93%). The median patency periods after re-interventions in the CMS, the PS, the cleaning, and the UMS group were 176, 38, 34, and 173 days, respectively. The cumulative patency rate was significantly higher in the CMS group than in the PS group (p = 0.0030) and the cleaning group (p = 0.0030). Cox-proportional hazard model identified two risk factors for short stent patency of re-intervention; sludge occlusion of the initial CMS and insertion of PSs. During follow-up period, acute cholecystitis occurred in two patients (one each in the UMS and in the PS group), and one patient in the UMS group developed liver abscess. There was no significant difference with regard to survival among 4 groups. Conclusion: Placement of a new CMS should be considered as the treatment of choice for dysfunction of CMSs. As sludge occlusion of the initial CMSs may be associated with the short patency of the stent after re-intervention, further strategies are mandatory in this group of patients.