[Comparison of transarterial and transportal heating bypass in canine regional liver hyperthermia].

We compared the efficacy of transarterial heating (group I; n = 5) with transportal heating (group II; n = 3) in regional liver hyperthermia. In beagles, the femoro-hepatic arterial (FA-HA) or the femoro-portal (FV-PV) heating bypass was made. Mean bypass flow rates in groups I and II were set at 120 ml/min and 260 ml/min, respectively, simulating either actual hepatic arterial flow or portal flow rates. Bypass heating was initiated by soaking a warmer coil into the water bath kept at 45 degrees C and maintained for 60 min. The temperature of the inflow line in groups I (44.4 +/- 0.1 degrees C) and II (44.5 +/- 0.1 degrees C) became similar 5 min after the start of heating. The liver parenchymal temperature of group I promptly reached 42.0 +/- 0.9 degrees C at 30 min and could be easily controlled at a range of 42.0-42.5 degrees C thereafter. However, despite a higher heated blood flow rate in group II, the liver parenchymal temperature remained 41.1 +/- 0.1 degrees C at 60 min (p < 0.01, vs. group I). The highest rectal temperature of group I was 38.9 +/- 0.8 degrees C, while that of group II was 40.5 +/- 0.2 degrees C (p < 0.05). In conclusion, the effect of transarterial heating was superior to that of transportal heating, indicating the different thermokinetics in regional liver hyperthermia in the two methods.