[Local control of hepatic malignant tumors by percutaneous microwave]

We investigated the effects of percutaneous microwave coagulation under general anesthesia in the local control of hepatic malignant tumors. Coagulation at 60 W was done for normal liver of living swine using a percutaneous electrode. Wide-range coagulation at the tip of an electrode, 3 mm in diameter, was conducted. Clinically, echo-guided percutaneous microwave tumor coagulation was done for a total of 11 lesions in 5 patients with hepatocellular carcinoma and 4 with metastatic tumors in the liver under general anesthesia. Coagulation at 60 W of the liver of living swine for 1.5 and 10 min, using a percutaneous electrode, produced a maximal coagulation of 10, 20 and 30 mm, respectively. The trial electrode permitted coagulation almost at the tip of the electrode only. Percutaneous microwave coagulation of 11 lesions of the clinical cases resulted in complete coagulation in 7 lesions and incomplete coagulation in 4. The lesions showing complete coagulation were all less than 23 mm.