Urinary incontinence following radical prostatectomy (RP) can be multifactorial and intrinsic urethral sphincter deficiency is a significant contributor in many patients. Our previous studies have demonstrated that transperineal ultrasound (TPUS) can be utilised to assess the male pelvic floor and changes in membranous urethral length (MUL) during pelvic floor contraction correlated with early continence post RP. This study reports the performance of our standardised transperineal ultrasound protocol in investigating changes in male pelvic floor (PF) structure and function post RP and correlation with long term continence outcomes.

A prospective study of functional and oncological outcomes in men undergoing radical prostatectomy was carried out. Patients underwent a standardised functional pelvic floor ultrasound assessment preoperatively and postoperatively at 3, 6 and 12 months. 250 men (mean age 66) completed functional assessment. Ultrasound examinations were conducted with a Phillips EPIQ-7 ultrasound machine using a standardised male TPUS protocol including 2D dynamic imaging of pelvic floor contraction (PFC, graded from 1-3), mobility and MUL measurements both at rest and on contraction.  Validation of TPUS grading of PFC versus clinical (DRE) examination was carried out on a subgroup of 30 men. Continence outcome at 12 months and 5 years was assessed using ICIQ and EPIC questionnaires, 24hour pad weights and correlated with pelvic floor imaging findings.

Pelvic floor structures are easily visualized on 2D TPUS pre and postoperatively. Longitudinal imaging studies demonstrated a reduction in MUL measurement from preoperatively (Mean 1.33cm, SD 0.18) to postoperatively  (Mean 1.15cm SD 0.17,  p<0.001). However there was no significant changes in PF anterior or superior displacement preop and 12 months postop. Similarly sonographic assessment of PFC strength showed no significant difference (p=0.45) at 12 months suggesting pelvic floor recovery. A longer pre and post-contraction MUL, a greater % change during PFC, and greater anterior PF movement were associated with improved subjective symptoms and reduced bother on the EPIC questionnaire, as well as lower pad weights at 5 years but not at 12 months.  Regression analyses showed TPUS parameters of greater % change in MUL with PFC, stronger PFC and cough reflex were associated with improved long term continence outcomes (5 yr pad weights) post RP (p<0.05).

This prospective study of 250 patients undergoing TPUS pre and post RP showed the imaging modality can be useful in assessment of the male pelvic floor. Whilst there is a consistent reduction in MUL post RP as expected from the surgery, pelvic floor imaging parameters return back to baseline at 12 months suggesting  this is the period of pelvic floor functional recovery postoperatively. TPUS parameters including shorter MUL with %change on PFC, weak PFC and cough reflex were associated with worse long term continence outcomes and as such can aid in counselling of patients both before surgery and in the setting of post-prostatectomy incontinence.

We have developed a reliable TPUS protocol to assess pelvic floor function in the setting of RP which can assist in patient counselling both pre and postoperatively. Longitudinal TPUS imaging showed parameters assessed preoperatively (PFC strength, PF cough reflex, change in MUL on contraction) return to baseline levels at 12 months. TPUS parameters of lower percentage change in MUL with PFC, poor PFC and cough reflex were associated with worse long term continence outcomes post RP.