Severe Ingrowth Research Articles

Application of the “covered-stent-in-uncovered-stent” technique for easy and safe removal of embedded biliary uncovered SEMS with tissue ingrowth

Removal of embedded biliary uncovered self-expandable metal stents (uSEMS) is regarded as difficult or even impossible when the duration of indwell exceeds a couple of weeks, because of the ingrowth of tissue. The presence of diffuse and severe ingrowth is the main feature limiting SEMS removal [1]. In the esophagus, placement of a self-expanding plastic stent (SEPS) inside the SEMS has been shown to induce pressure necrosis of this tissue hyperplasia, allowing subsequent removal of the stent. We applied this technique in a 58-year-old patient with a history of alcohol abuse, obstructive jaundice, and suspected malignancy, in whom an uSEMS 10 mm wide and 6 cm long (Wallflex; Boston Scientific, Natick, Massachusetts, USA) had been mistakenly inserted more than 1 year before. The patient had experienced recurrent cholangitis due to stent obstruction caused by tissue ingrowth. Stent removal was therefore considered, but was unsuccessful using conventional maneuvers. A covered SEMS (Wallflex) was then placed inside the uSEMS.

Endoscopic removal of malfunctioning biliary self-expandable metallic stents

Endoscopic removal of malfunctioning self-expandable metallic biliary stents (SEMS) is difficult and not well described. The aim of this study is to review the indications, the techniques, and the results of SEMS removal in a cohort of patients with malfunctioning stents. All patients who underwent an attempt at endoscopic removal of biliary SEMS over a 5-year period were retrospectively identified. The main indications for SEMS removal were the following: distal migration of the stent or impaction to the duodenum, impaction into the bile-duct wall, tissue ingrowth, and inappropriate length of the stent causing occlusion of intrahepatic ducts. SEMS were removed by using foreign-body forceps or polypectomy snares. Endoscopic removal of 39 SEMS (13 uncovered and 26 covered) was attempted in 29 patients (17 men; mean age, 66 years). SEMS extraction was attempted after a mean of 7.5 months (8.75 months standard deviation) post-SEMS insertion. Removal was successful in 20 patients (68.9%) and in 29 SEMS (74.3%). Covered SEMS were effectively removed more frequently than uncovered ones: 24 of 26 (92.3%) and 5 of 13 (38.4%), respectively (p < 0.05). No major complications were recorded. Multivariate analysis showed that the time interval between insertion and removal, SEMS length, stent-mesh design (zigzag vs. interlaced), and indication for removal were not predictive of success at stent removal. Endoscopic removal of biliary SEMS is feasible and safe in more than 70% of cases. Because only 38% of uncovered SEMS were removable, the presence of a stent covering is the only factor predictive of successful stent extraction. The presence of diffuse and severe ingrowth was the main feature limiting SEMS removal.