The impact of cavernosal nerve preservation on continence after robotic radical prostatectomy

Abstract

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? Continence after radical prostatectomy (RP) has been linked to surgical techniques including careful dissection of the neurovascular bundles, bladder neck preservation, sparing of the puboprostatic ligaments and reconstruction of the posterior urethral plate or total reconstruction of the vesico‐urethral junction. Several authors have reported that men undergoing bilateral nerve‐sparing have quicker and better recovery of continence than men undergoing partial or non‐nerve‐sparing procedures. Others have reported that preoperative variables have a greater effect than technique on postoperative return to continence. We examine the association between baseline characteristics (age, International Index of Erectile Function [IIEF‐5] score, American Urological Association symptom score, body mass index [BMI], clinical T stage, Gleason score, and prostate‐specific antigen level), nerve‐sparing status, learning curve and overall continence at 1, 3 and 12 months after robotic RP. In addition, nerve‐sparing status was physically verified by comparing the amount of extraprostatic tissue seen on the wide excision side and nerve‐sparing side for unilateral nerve‐sparing procedures. After multivariate analysis, age, IIEF‐5 and BMI were found to affect continence in a statistically significant fashion, while nerve‐sparing status did not significantly affect continence. OBJECTIVE • To evaluate associations between baseline characteristics, nerve‐sparing (NS) status and return of continence, as a relationship may exist between return to continence and preservation of the neurovascular bundles for potency during radical prostatectomy (RP). PATIENTS AND METHODS • The study included 592 consecutive robotic RPs completed between 2002 and 2007. • All data were entered prospectively into an electronic database. • Continence data (defined as zero pads) was collected using self‐administered validated questionnaires. • Baseline characteristics (age, International Index of Erectile Function [IIEF‐5] score, American Urological Association symptom score, body mass index [BMI], clinical T‐stage, Gleason score, and prostate‐specific antigen level), NS status and learning curve were retrospectively evaluated for association with overall continence at 1, 3 and 12 months after RP using univariate and multivariable methods. • Any patient taking preoperative phosphodiesterase inhibitors was excluded from the postoperative analysis. RESULTS • Complete data were available for 537 of 592 patients (91%). • Continence rates at 12 months after RP were 89.2%, 88.9% and 84.8% for bilateral NS, unilateral NS and non‐NS respectively ( P = 0.56). • In multivariable analysis age, IIEF‐5 score and BMI were significant independent predictors of continence. • CavernosalNS status did not significantly affect continence after adjusting for other co‐variables. CONCLUSION • After careful multivariable analysis of baseline characteristics age, IIEF‐5 score and BMI affected continence in a statistically significant fashion. This suggests that baseline factors and not the physical preservation of the cavernosal nerves predict overall return to continence.