title: Microwave coagulation versus insertion of a second stent for occluded biliary metal stent.
abstract: OBJECTIVE
  There is no consensus regarding optimal management of self-expandable metallic stent occlusion. We investigated the efficacy of microwave coagulation therapy for recanalization as compared to second stent placement.
  
  
  METHODS
  Sixty patients with malignant obstruction of the common bile duct were treated with metal stent placement from January 1992 to July 1999. Of these, 13 patients subsequently developed stent occlusion due to tumor ingrowth. We compared stent patency and patient survival rates after microwave coagulation to those after insertion of a second stent. The influence of the duration of patency of the first stent on the second stent patency was also evaluated.
  
  
  RESULTS
  Of the 13 patients with stent occlusion, 7 were treated with microwave coagulation therapy, and 6 with insertion of a second metal stent. In all cases, occluded stents were successfully recanalized without any complications. There was no significant difference in duration of first stent patency between the two groups. The median duration of second stent patency was prolonged in microwave-treated patients (152 days vs. 104 days, P > 0.05). The median duration of patient survival after last recanalizing procedure was also prolonged in microwave-treated patients (131 days vs. 78 days, P > 0.05). Microwave energy did not induce destruction of the stent filament.
  
  
  CONCLUSIONS
  Microwave coagulation did not offer significantly longer duration of stent patency and patient survival compared to insertion of a second metal stent. However, this procedure is safe, feasible, and certainly as good as a second stent placement. It may be an alternative to insertion of a second stent within the occluded stent.
authors.affiliation: Third Department of Internal Medicine, Toho University Ohashi Hospital, 2-17-6 Ohashi, Meguro, Tokyo 153-8515, Japan. maet@oha.toho-u.ac.jp
authors.forename: I
authors.initials: I
authors.lastname: Maetani
authors.forename: T
authors.initials: T
authors.lastname: Ukita
authors.forename: H
authors.initials: H
authors.lastname: Inoue
authors.forename: M
authors.initials: M
authors.lastname: Sato
authors.forename: Y
authors.initials: Y
authors.lastname: Igarashi
authors.forename: Y
authors.initials: Y
authors.lastname: Sakai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001651:Cholestasis, Extrahepatic / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D003138:Common Bile Duct Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D004724:Endoscopy; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced; D008297:Male; D008670:Metals; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010166:Palliative Care; D019233:Retreatment; D015607:Stents; D015996:Survival Rate
chemical_list: D008670:Metals