Histological analysis of the effect of hyperthermia on normal rabbit hepatic vasculature.
The effects of hyperthermia on rabbit hepatic vasculature were studied histologically. To investigate heat-induced vascular damage in the central veins, portal veins, and hepatic arterioles, the left lobes of rabbit liver were heated locally for 30 min in the range of 40-46 degrees C. Hyperthermia was induced by an 8-MHz radiofrequency current heating device using a needle type interstitial applicator. This device allowed application of heat to a central area of 10 x 10 mm no more than 1 degree C below the preset temperature. Within the area of 1 cm2, the percentage of damaged (ruptured or thrombosed) vessels was estimated for each type of hepatic vasculature. Vascular damage following hyperthermia continued up to 24 h after heating for the three types of hepatic vasculature. Central veins were the most thermosensitive followed by portal veins, whereas hepatic arterioles were the most thermoresistant. The temperature causing 50% vascular damage 24 h after heating was 41.5-42.5 degrees C, 42.5-43.5 degrees C, and 44-45 degrees C for central veins, portal veins, and arterioles, respectively. This differential thermal responsiveness of hepatic vasculature may be attributed to the histological structure of the vessels.
Nishimura
Y
Y
Department of Radiology, Faculty of Medicine, Kyoto University, Japan.
Jo
S
S
Akuta
K
K
Masunaga
S
S
Fushiki
M
M
Hiraoka
M
M
Takahashi
M
M
Abe
M
M
D000818:Animals; D001160:Arterioles / Q000473:pathology; D006979:Hyperthermia, Induced; D008099:Liver / Q000098:blood supply* / Q000473:pathology; D008102:Liver Circulation; D011169:Portal Vein / Q000473:pathology; D011817:Rabbits