Ultrasound evaluation of the striated urethral sphincter as a predictive parameter of urinary continence after radical prostatectomy

Objectives: The purpose of this study was to evaluate preoperatively the results of transrectal ultrasound (TRUS) in the detection of morphological, vascularization status of urethral rhabdosphincter (RS) and evaluate the correlation with urinary continence after radical prostatectomy (RP). Methods: 211 patients who underwent RP were prospectively studied using TRUS scan of the RS thickness. At the end of the examination a study was performed with the use of colour-Doppler for the assessment of the RS vascularity pattern. The level of continence was graded on a 5 point scale as: 1 = complete continence, 2 = 1 pad daily, 3 = 2-3 pads daily, 4 = 4 or more pads daily, and 5 = complete incontinence. Results: It was possible to visualize the rhabdosphincter and its vascularity in all patients. Patients with normal continence (level 1 and 2) showed a sphincter-muscle thickness of 3.5 mm (± 0.4) and a hypoechoic ultrasound pattern. With respect to the other levels 3, 4 and 5 of urinary incontinence RS thickness was 2.8 mm (± 0.5), 2.1 mm (± 0.6), 1.7 (± 0.7) respectively. Incontinence after RP (≥ 3 level) was associated with urethral sphincter deficiency in the great majority of patients. Statistical significant differences were observed in the vascularity between continent and incontinent men in all measured vascularity variables (p < 0.005). Conclusions: This study suggests that RS integrity is a good predictor of urinary continence after RP and this information can be important during the preoperative phase as part of the informed consent.