Preoperative and Intraoperative Measurements of Urethral Length as Predictors of Continence After Robot-Assisted Radical Prostatectomy

Abstract

Membranous urethral length is one of several factors that can influence return of continence after radical prostatectomy. Using our robot-assisted laparoscopic prostatectomy (RALP) database, we assessed which preoperative (with endorectal coil MRI [eMRI]) and intraoperative anatomic measurements correlate with return to urinary continence (no pads) and continence quality of life (CQOL) as determined by the International Consultation on Incontinence Questionnaire (ICIQ) score. A total of 75 patients who underwent RALP and eMRI by a single surgeon were analyzed. To emulate the distal continence zone intraoperatively, stretched urethral length (distance from the perineal membrane to the prostate apex on stretch) and cut urethral length (urethral stump length) were individually measured and recorded after apical dissection. Preoperative International Prostate Symptom Scores (IPSS) were recorded. Univariate and multivariate Cox regression analysis were performed to determine the association between MRI-measured and intraoperative urethral lengths and return to continence as well as CQOL. None of the urethral measurements as determined by eMRI correlated with continence or ICIQ scores. On multivariate analysis, only membranous urethral length on eMRI approached significance with respect to ICIQ (P=0.07). On multivariate analysis controlling for preoperative age, body mass index, IPSS score, and gland size, both stretched and cut urethral length correlated with decreased time to continence (P=0.03 and P=0.04 respectively). Longer stretched and cut urethral lengths appear to correlate with faster return to a pad-free state. Attention to maximal preservation of the distal continence mechanism is important for optimal continence outcomes after RALP.