Abstract
Extracorporeal systemic hyperthermia has drawn attention as an advanced cancer therapy in clinical. This study shows that the systemic hyperthermia with extracorporeal circulation (ECC) performed in healthy dogs at 41.5-43.0°C for 4-10 hours using the efficient heat exchanger made with multiple stainless tubings (effective area: 0.06m2). Under the general anesthesia, ECC was conducted by use of a common femoral arteriovenous (AV) bypass and ECC flow rate was kept at 20-30ml/kg/min (approximately 1/3 cardiac output) during the circulation. The animals' temperatures were controlled within ±0.1°C accurately by changing the temperature of heat exchanger in manual mode. In order to increase the rectal temperature from 38.0°C to 41.5°C, it took 30 minutes in 46°C of heat exchanger (the high blood-heating method) and 45 minutes in 43°C of heat exchanger (the low blood-heating method) respectively. Hyperthermia induced the thrombocytopenia, but the degree of this thrombocytopenia was moderate under the low-blood heating method compared with the high blood-heating method. Extracorporeal systemic hyperthermia can be carried out safely under the low blood-heating method using the efficient heat exchanger.
