DETAILED PROSTATIC INTERSTITIAL THERMAL MAPPING DURING TRANSURETHRAL GROOVED ROLLERBALL ELECTROVAPORIZATION AND LOOP ELECTROSURGERY FOR BENIGN PROSTATIC HYPERPLASIA

Objectives. To determine the detailed pattern of prostatic interstitia l temperature change during rollerball electrovaporization and loop el ectrosurgery in patients with benign prostatic hyperplasia (BPH). Meth ods. Four patients with symptomatic BPH necessitating prostate surgery were subjected to rollerball electrovaporization on one side of their prostate glands, as well as contralateral loop electrosurgery. Contin uous temperature readings were recorded from 20 to 24 interstitially i mplanted fiber-optic thermosensors using a novel stereotactic thermal mapping technique. Ultrasound and video endoscopic visualization were used to evaluate and quantify the spatial relationship between the the rmosensors and the rollerball or loop. Results. The patterns of temper ature change during rollerball electrovaporization and loop electrosur gery were substantially similar. Temperatures decreased steeply and si gnificantly with increasing distance from both the rollerball (P <0.00 1) and loop (P <0.001). Marked mean temperature increases occurred at 1 to 2 mm from both the rollerball (30.8 degrees C, 95% confidence int erval [CI] 27.8 to 33.8 degrees C) and loop (34.8 degrees C, 95% CI 24 .0 to 45.6 degrees C), and temperatures at this distance were signific antly higher than those at greater distances (P <0.05). At 3 to 5 mm, the mean temperature increases declined by 58% for the rollerball and 68% for the loop. Further declines of 68% and 63%, respectively, were observed at 6 to 10 mm, and at distances exceeding 10 mm the temperatu re changes were minimal (0.5 degrees C [95% CI 0.3 to 0.8 degrees C] f or the rollerball and 0.5 degrees C [95% CI 0.1 to 0.8 degrees C] for the loop). There was no change in temperature at any of the thermosens ors near the neurovascular bundles and rectum. Conclusions. The patter ns of temperature change with rollerball electrovaporization and loop electrosurgery are closely similar. Interstitial temperature changes d uring use of the rollerball and loop are transient and highly localize d, posing minimal risk of unintended thermal damage to adjacent tissue s, including the neurovascular bundles and rectum.