The benefit of hepatic arterial microembolization by
degradable starch microspheres (DSM) was investigated in regional
hyperthermia of the liver.
Hyperthermia with and without blood flow blockade of the hepatic artery using
degradable starch microspheres was performed on six pigs. Heat was given for 30 min in each treatment by 8 MHz radiofrequency capacitive heating equipment. To maintain blood flow blockade during
hyperthermia, 10 mg/kg of
degradable starch microspheres was administered into the hepatic artery as an initial dose and 5 mg/kg of the
drug was added periodically under the measurement of hepatic arterial blood flow by an electromagnetic
flowmeter. To evaluate the effect of
degradable starch microspheres, the temperature increase in the liver and rectum was compared between the treatment with and without DSM. All pigs showed a larger increase in intrahepatic temperature when heated in combination with
degradable starch microspheres than without. On the other hand, temperature increase in the rectum as a result of
hyperthermia to the liver was suppressed by DSM as compared with
hyperthermia alone. These results indicate that hepatic arterial embolization by
degradable starch microspheres potentiates radiofrequency capacitive heating of the liver. Although this study was not made with liver
tumors, regional
hyperthermia may be effective in the control of liver
tumors when heat is given after the blockade of the hepatic artery by DSM.