Laser‐induced hyperthermia: Comparison of two different methods

摘要

AbstractThe effectiveness of two different techniques of laser‐induced hyperthermia was analyzed in healthy piglet livers. Hyperthermia was produced using a continuous‐wave Nd:YAG laser with both a contact sapphire probe and a bare quartz fibre. In both methods the tip was inserted into the liver, and the temperature 1 cm from the tip was raised and held between 42°C and 44°C for 600 seconds. Specimens were taken 0, 7 and 14 days after the treatment. The tissue effects of 36 treatment sites were analysed using standard van Gieson's method. In addition, a histochemical method for demonstrating lactate dehydrogenase activity was employed to show damage not observable by routine methods. No statistically significant difference in the extent of the treatment sites at d 0 and after 7 days was seen when comparing the two laser methods. After 2 weeks, the diameter of the lesion with the bare fibre was significantly larger (3,7 mm with both analysing methods) than by using the contact probe (2,6 with LDH demonstration;P<0.01 and 2,1 mm with van Gieson's staining;P<0.001). It can be concluded that the simple fibre tip seems more effective in causing tissue necrosis than the sapphire tip. © 1992 Wiley‐L