COMPARISON OF THERMOCOAGULATION EFFECTS OF LOW-POWER, SLOW HEATING VERSUS HIGH-POWER, RAPID HEATING ND-YAG LASER REGIMENS IN A CANINE PROSTATE MODEL

We compared the thermocoagulation effects of low power, slow heating ( 15 W X 180 seconds) versus high power, rapid heating (50 W X 60 second s) laser regimens in the canine prostate. The study was performed in 2 0 mongrel canines. On each prostate, the low power regimen was deliver ed at the 2 and 4 o'clock positions, and the high power at the 8 and 1 0 o'clock positions. The laser power was measured at the fiber tip. Se ven dogs (acute group) were sacrificed 1 hour after the procedure. The other 13 dogs (chronic group) were sacrificed at different time inter vals from 3 days to 9 weeks after the procedure. The average depth of coagulation was significantly greater in lesions treated at low power (acute: 10.7 mm., chronic: 13.3 mm.) than in those treated at high pow er (acute: 8.5 mm., chronic: 11.6 mm.). Another potential benefit of t he low power regimen observed in the study was preservation of the int egrity and efficiency of the laser probe.