[A clinical study of biliary endoprosthesis using an expandable metallic stent--evaluation of early results]

Self-expandable metallic stents were used to relieve biliary obstruction in 58 patients. Fifty-three of 57 patients with malignant obstruction were treated with EMS after radiotherapy. A percutaneous approach was employed in all patients without severe complications. Insertion of EMS was successful in all cases. Within one week of EMS placement, all stents expanded to at least 90% of their original diameter, with the caliber of the bile duct always smaller than that of the EMS due to ischemic edema of the mucosa. In fifty-one of 58 patients, the external biliary drainage catheter could be removed. Cholangioscopy revealed that epithelium covered the EMS from the early phase after placement, enabling the EMS to become a physiological endoprosthesis in the bile duct. Rapid re-obstruction after EMS placement had two mechanisms: reactive obstruction and rebound obstruction, to avoid which adequate therapy to reduce the volume of the tumor is required. Also it is necessary to continue external drainage for at least two weeks after EMS placement. For the management of biliary obstruction, EMBE combined with radiotherapy is a promising treatment modality, with encouraging early results obtained. Further studies will determine the role of EMS in the treatment of patients with non-operable biliary obstructions.