Cine magnetic resonance imaging provides novel predictors of early continence recovery after radical prostatectomy: Assessment of the dynamics of pelvic floor muscles

Abstract

Aims: Postprostatectomy incontinence is a major complication of prostatectomy. Although pelvic floor muscle training can successfully treat postprostatectomy incontinence, evidence for how muscle movement affects continence recovery is lacking. We evaluated dynamic factors of prostatectomy patients using cine magnetic resonance imaging to identify risk factors for postprostatectomy incontinence and reveal the contribution of pelvic floor muscles to continence recovery. Methods: A total of 128 prostate cancer patients who underwent robotassisted laparoscopic surgery were enrolled. Cine magnetic resonance imaging was performed preoperatively and 6 months after surgery. Continence was defined as pad-free or use of safety pads. We defined the bladder neck elevation distance during pelvic floor muscle training as the bladder elevation distance. Patients with continence recovery within 1 month comprised the continence group (n = 48); other patients comprised the incontinence group (n = 80). Results: The preoperative bladder elevation distance was significantly longer in the continence group than in the incontinence group (10.4 vs. 8.2 mm; p < .001). The postoperative bladder elevation distance of the continence group tended to be longer (9.9 vs. 8.9 mm; p = .057). Multivariate analysis showed that the preoperative bladder elevation distance significantly contributed to continence recovery (p = .016). Patients with a longer preoperative bladder elevation distance (>8.5 mm) experienced continence recovery significantly faster than patients with a shorter distance (<8.5mm) (p = .038).

Contribution of Retzius-sparing robot-assisted radical prostatectomy to the mechanism of urinary continence as demonstrated by dynamic MRI

“…Variation in individual mastery may have affected the overall PFMT effectiveness, but its mastery is difficult to assess and was not assessed in any RCTs 18 . Reportedly, PFMT guided by transperineal echocardiography was effective in reducing urinary incontinence in patients with prolonged urinary incontinence after RP 26 , and that urinary incontinence was less in patients with a large bladder neck elevation during PFMT as observed by dynamic MRI 9 , 11 . Teaching PFMT using the image-guided bladder neck elevation and the anterior rectal wall movement toward the pubic bone as a guide may be effective in reducing postoperative urinary incontinence.…”

“…The PB-AR during abdominal pressure is thought to move in the direction of shortening (positive distribution) and UVJ movement in the cephalic direction (zero to negative distribution) when PFMT are effective in urinary continence, and these movements are reportedly effective in urinary continence 8 , 9 , 11 . Several RCTs have been conducted on the effect of PFMT on reducing urinary incontinence after RP.…”

“…Maintaining urethral closure pressure at rest and preserving the mechanisms that effectively work when intravesical pressure increases during abdominal pressure is necessary to maintain favorable urinary continence, and not losing these functions will be important to maintain urinary continence after RP. Preserving a longer urethra 28 and NS 17 are useful to avoid losing urethral closure pressure at rest after RP, and Retzius-sparing 10 and PFMT instruction with biofeedback, such as imaging 9 , 11 , 26 , may contribute to urinary continence mechanism preservation during abdominal pressure. The patient’s potential may also have an effect on the original urinary sphincter function, and age is probably representative of this 22 – 24 .…”