Correlation of Thermocouple Data With Voiding Function After Prostate Cryoablation

Objectives To identify possible correlations of thermocouple recorded data with altered postoperative voiding function after prostate cryosurgery. Methods A retrospective analysis of the records of 58 patients treated with prostate cryoablation from October 2005 through April 2009 was conducted. Multivariate analysis of patient age, presenting prostate-specific antigen level, Gleason score, clinical T stage, prostate volume, maximum low temperature thermocouple recordings, history of radiation and or hormonal therapy, were studied as possible correlative factors for altered postoperative voiding function. Results Of 58 patients, 22 (37.9%) manifested postcryoablation urgency and frequency (n = 13) requiring medical therapy or retention (n = 9). On multivariate analysis, age ( P = .037) and an external sphincter temperature ≤ 23°C ( P = .012) were associated with voiding frequency, urgency, or retention (odds ratio = 6.26, 95% CI: 1.62-24.16), whereas anterior rectal wall temperature (Denon) was weakly associated ( P = .079). Conclusions Thermocouple data provide an objective means of assessing cryosurgical outcomes. This is the first report of a correlation of such data to post-treatment voiding function. A total of 37.9% of patients experienced urgency and/or frequency or urinary retention after cryoablation of the prostate for localized disease. Older age and external sphincter temperature ≤ 23°C were statistically significant predictors of these events. The data suggest that limiting the degree of freezing at the external sphincter may decrease procedure related morbidity. Further study is warranted to better delineate temperature-related data on treatment outcomes.