[Urinary continence prediction after laparoscopic radical prostatectomy according to preoperative urethral length measurement in multiparametric prostate resonance.]

Urinary incontinence (UI) is one of the main complications of radical prostatectomy. Multiple studies have attempted to find factors that may predict early recovery of urinary continence in surgically treated patients. The aim of this study is to evaluate the ability of the length of the membranous urethra (LUM) and the intraprostatic urethra (IUL) measured in preoperative by multiparametric prostate resonance imaging (MRI), to predict post-radical prostatectomy urinary continence. MATERIAL AND METHODS: A retrospective study between 2016 and 2018 was conducted. Patients who under went laparoscopic radical prostatectomy (LRP) and had a previous RMI were included. Different variables were evaluated: age, PSA, BMI, clinical and pathological stage, and the validated questionnaire of urinary incontinence (ICIQ-SF) was performed at 12 months postoperatively. LUM and LUIP were calculated and compared groups (continence vs incontinence) using the Student test (t). A value of p<0.05 was taken as significant. A ROC (Receiver Operating Characteristic) curve was made to predict continence according to LUM and LUIP. RESULTS: Forty-four patients were included. Mean age was 63 years (SD±7.2) and mean PSA was 9.2 ng/dL (SD±5.2). Seventy-five percent presented clinical stageT1c and 43.2% pathological stage pT2cN0. 20.5% (9 patients) presented some degree of UI. The mean LUM was 15.1 mm (SD±5.6) and LUIP 26 mm (SD±10.4). For patients with continence and incontinence, the mean LUM was 18.3 vs 9.5 mm (p=0.0001) and LUIP 31.5vs 15 mm (p=0.0001) respectively. The area under the curve taking as a value of LUM >10mm was 88% and LUIP>20mm was 86.7%. CONCLUSION: The use of preoperative mp RMN measurement of urethral membrane length and intraprostatic urethra may be useful in significantly predicting post-PR urinary continence.