[Basic and clinical observations on an improved microwave coagulation method for hemostasis after liver biopsy and splenic puncture under laparoscopy].

An improved microwave coagulation (MC) method was devised for hemostasis after liver biopsy and puncture of the spleen under laparoscopy. Safety and hemostatic effects of the method were studied with the following results: 1) MC resulted in a wedge-shaped area around the electrode showing necrosis and degeneration of hepatic cells in the liver of five autopsied cases. The area of tissue damage became greater as the output and duration of microwave application were increased. When applied to rabbit livers, repair of the tissue damage caused by MC was almost completed within four weeks, leaving a mild fibrosis. Liver function tests showed no notable changes after application of the MC method in 34 clinical cases. 2) Significant diminution of the bleeding time after liver biopsy was attained by the MC method in comparison with the time required for spontaneous hemostasis in 50 patients subjected to the test. MC was more effective in shortening the bleeding time after liver biopsy than oppression of the bleeding site by forceps. Hemostasis occurred more rapidly with the MC method than without any treatment irrespective of diagnosis, severity of bleeding, laparoscopic findings, platelet count, or prothrombin time. Complete hemostasis was also achieved by the MC method within short periods of time after puncture of the spleen in 32 patients. It is concluded that the improved MC method is safe and effective for hemostasis in patients with liver diseases necessitating liver biopsy and /or splenic puncture for diagnosis.