Abstract
Prior to clinical application of microwave therapy (MT) under percutaneous transhe-patic choledochoscopy (PTCS) to achieve recanalization for malignant biliary stenosis, an experimental study was carried out to determine conditioning of the optimal microwave coagulation. Microwave coagulation was performed for resected cattle liver and rat liver in saline using a ball type electrode (1.8 mm in diameter). In saline, liver tissue coagulation was obtained after microwave irradiation of "40 watts for 10 seconds" or more. Coagulation of normal canine bile duct occurred after microwave irradiation of 50 watts for 20 seconds, but the surrounding organs and vessels were not affected. Coagulation of normal canine bile duct occurred after microwave irradiation of 50 watts for 20 seconds, but the surrounding organs and vessels were not affected. Two patients with common hepatic duct cancer and hilar cholangiocarcinoma were treated by MT under PTCS. Recanalization of the stenosis area was achieved without clinical complications in both patients. The patient with the common hepatic duct cancer was discharged without an endoprosthesis. MT may be a useful procedure for bile duct cancer as a conservative therapy.
