Urethral sphincter function before and after radical prostatectomy: Systematic review of the prognostic value of various assessment techniques.

AIMS: Urethral sphincter incompetence is generally considered to be the most important contributing factor to post-radical prostatectomy incontinence (PRPI). The value of various assessment techniques used to objectify urethral sphincter function before and/or after RP is unclear. Our review addresses the following questions: In men having to undergo RP, which measurement techniques that assess pre-operative and post-operative urethral sphincter function have predictive value for the post-operative continence status or correlate with the post-operative continence status.
METHODS: A systematic and comprehensive search was performed using the terms: urethral sphincter, radical prostatectomy (RP), and urinary incontinence. Results were restricted to English-language papers published between 1980 and March 2012. Only techniques described by at least two studies were included.
RESULTS: Several assessment techniques for urethral sphincter function and anatomy were identified: sphincter electromyography, magnetic resonance imaging (MRI), perfusion sphincterometry and urethral pressure profilometry (UPP). A shorter urethral sphincter length on preoperative endorectal MRI might be associated with an increased risk of PRPI as well as longer time to achieve continence. UPP showed that both maximum urethral closure pressure (MUCP) and functional profile length (FPL) decrease significantly after RRP. Low preoperative MUCP and FPL are associated with an increased risk of PRPI. The other mentioned assessment techniques are not usable as preoperative diagnostic tools.
CONCLUSIONS: MRI and UPP might be valuable preoperative diagnostic tools in patients waiting for RRP. However, more and larger studies are needed to show the exact role of MRI and UPP in the preoperative management of patients waiting for RRP and for whom post-operative incontinence is a big concern.