Urinary incontinence (UI) after robot-assisted radical prostatectomy (RARP) is a common complication and has a negative impact on patient’s quality of life. Most cases of Post-RARP UI are a result of intraoperative damage to the native urinary sphincteric mechanisms, which may include afferent denervation of the urethra. Pelvic floor muscle training (PFMT) is recommended as the first choice for post-RARP incontinence. Recently, some clinicians have started providing PFMT before RARP when patients preserved normal urethral sensation and function of the pelvic floor (1, 2). We developed a biofeedback method using transperineal ultrasound (US) images, which can visualize the urethral closure. Our previous study confirmed that preoperative US-guided PFMT rapidly promoted continence recovery compared with patients who received verbal PFMT only after RARP (3).  However, it remains unclear whether better continence recovery was caused by simple preoperative PFMT or that combined with US-guided biofeedback. The aim of this study was to compare continence recovery between preoperative US-guided PFMT and those added US-guided PFMT immediately after urethral catheter removal.

This prospective observational study included 72 patients who underwent RARP at a university hospital from March 2016 to December 2017. These patients were divided into two groups; 1) the preoperative PFMT group and 2) the perioperative PFMT group.
In the preoperative PFMT group, a team composed of a physiotherapist and a nurse gave PFMT combined with US-guided biofeedback at 2-3 weeks before RARP, and patients received verbal instruction of PFMT by the physiotherapist after the removal of the transurethral catheter in the ward. In the perioperative PFMT group, patients received US-guided PFMT by the team at 2-3 weeks before RARP and after the removal of a transurethral catheter. Both groups received US-guided PFMT about 1 month after RARP.
The biofeedback was carried out by using transperineal US images visualizing whether a patient was able to contract PFM correctly or not. The correct contraction of the pelvic floor muscle (PFM) was judged by shortening of the membranous urethral diameter and closing of the bladder neck on the US images. Thereby, patients could recognize the strength and sensation of PFM contractions before RARP and relearn them after RARP. 
Recovery of urinary continence status was defined as less than two pads use per day by self-report. Continence recovery was defined as no more than one small pad (20g) use per day. During monthly follow-up visits, patients were asked when the continence recovery status was achieved. Statistical analyses were carried out by Student t test or Fisher’s exact test.

There were some significant differences between the two groups; the perioperative PFMT group had significantly less volume of resected specimens (p = 0.044) and shorter duration of indwelling catheter (p = 0.004) [Table 1]. The continence recovery rates within 30 days were 51 % (19/37) and 37 % (13/35) in the preoperative PFMT group and perioperative PFMT group, respectively (p=0.225). A similar tendency remained for all observation period (p = 0.201 at 2 months, p = 0.548 at 3 months, p = 0.103 for all observation period) [Figure 1].

The US-guided PFMT immediately after catheter removal appears to have no additional benefit for early continence recovery after RARP. It is considered that the preoperative US-guided biofeedback has significant advantage to learn the correct contraction of PFM before surgery, when they have normal function and sensation of the urethral closure, This motor learning may promote relearning of PFM contraction after RARP. Intensive preoperative PFMT may be more effective to achieve early recovery of post-RARP incontinence, comparing with addition of PFMT immediately after catheter removal.

Our results suggest that the preoperative US-guided biofeedback is sufficient to induce continence recovery in the early phase after RARP.

Centemero A, Rigatti L, Giraudo D, Lazzeri M, Lughezzani G, Zugna D, Montorsi F, Rigatti P, Guazzoni G. Preoperative pelvic floor muscle exercise for early continence after radical prostatectomy: a randomised controlled study. Eur Urol 2010;57:1039-1043.
Patel MI, Yao J, Hirschhorn AD, Mungovan SF. Preoperative pelvic floor physiotherapy improves continence after radical retropubic prostatectomy. Int J Urol 2013;20:986-992.
Yoshida M, Matsunaga A, Fujimura T, Shinoda Y, Niimi A, Kamei J, Aizawa N, Homma Y, Sanada H, Igawa Y. Preoperative ultrasound-guided pelvic floor muscle training promotes early recovery of urinary continence after robot assisted radical prostatectomy. Abstract#215 (International Continence Society 2017, Florence, Italy, 11-15, September).