Membranous urethral length and urinary incontinence following robot-assisted radical prostatectomy: a systematic review and meta-analysis

Objective: To provide an update on the association between preoperative membranous urethral length (MUL) and postoperative urinary incontinence (UI) in men who undergo robot-assisted radical prostatectomy (RARP)/robot-assisted laparoscopic prostatectomy (RALP). 

Materials and Methods: Urinary incontinence is common after RARP/RALP, and early recovery of continence is one of the most important functional outcomes following surgery. MUL has been identified as a factor associated with continence recovery after RARP/RALP. A systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using PubMed, Embase, and Scopus databases. Inclusion criteria were English language full journal articles authored within the last 5 years that assessed continence using the Expanded Prostate Cancer Index Composite. The Critical Appraisal Skills Programme tool for retrospective cohort studies was used to evaluate study quality. A random-effects meta-analysis was performed to pool odds ratios (ORs) from available studies relating to continence as a function of MUL. The Grading of Recommendations, Assessment, Development and Evaluations framework was used to synthesise evidence. 

Results: Six studies including 970 patients reported an association between MUL and continence at 12 months. Longer MUL was associated with reduced UI odds at 12 months after surgery (pooled OR 0.74, 95% confidence interval 0.68–0.87, P < 0.001). Significant methodological and statistical heterogeneity was encountered. 

Conclusions: Preoperative MUL measured on magnetic resonance imaging (MRI) is significantly associated with postoperative continence in men undergoing RARP/RALP. We recommend consideration of MRI measurement of MUL prior to RARP/RALP to guide treatment decisions in this population.