Analysis of Urinary Function Using Validated Instruments and Uroflowmetry After Primary and Salvage Prostate Cryoablation

Abstract

To evaluate changes in urinary function after cryoablation for clinically localized prostate cancer and to investigate risk factors that predict changes in urinary function after surgery. Among the patients who underwent primary or salvage cryoablation between January 2002 and May 2008, 74 patients (50 primary and 24 salvage) with both a preoperative and postoperative urinary function domain score and uroflowmetry were included in this study. The mean age was 66.8 ± 7.5 years and the mean follow-up period was 42.5 ± 20.3 months. The changes in postoperative urinary function were evaluated on the basis of several categorized groups, including surgical method, preoperative urinary symptoms, and prostate volume. Of 74 patients, 2 (2.7%) presented with mild stress incontinence after cryoablation. No patient presented with persistent urinary retention or urethral fistula. When comparing postoperative International Prostate Symptom Score (IPSS) and bother index scores with preoperative scores, it was found that on average IPSS and bother index recovered 12 and 18 months after cryoablation, respectively, and continued to improve after recovery. Only salvage cryoablation correlated with deteriorating urinary function in a logistic regression model (P = .032). However, it was noted that the patients with preoperative moderate to severe urinary symptoms and larger prostate volume showed improvement of urinary function after cryoablation. No associations were found between worsened urinary function and prostate volume, comorbidities (hypertension, obesity, and diabetes), or sexual function. Cryoablation is a minimally invasive surgery for localized prostate cancer. This study is the first to demonstrate the ability of cryoablation in terms of maintaining and potentially improving urinary function using validated instruments and uroflowmetry assessments.