Pelvic Floor Muscle Function and Its Relationship with Post-Prostatectomy Incontinence

ObjectivesPost-prostatectomy incontinence (PPI) is a common condition, but the underlying mechanisms are not completely understood. Transperineal ultrasound (TPUS) assessment of voluntary pelvic floor muscle (PFM) function may be associated with PPI. This study investigates the relationship between PPI and pre- and postoperative displacement of anatomical landmarks related to PFM function. MethodsThis was a prospective longitudinal cohort study of 40 patients undergoing robotic-assisted radical prostatectomy (RARP) by a high-volume single surgeon. All patients underwent PFM training pre- and postoperatively. TPUS was used to obtain sagittal images of pelvic structures during maximal voluntary PFM contractions: (1) preoperatively, (2) 3 weeks postoperatively, and (3) 6 weeks postoperatively. TPUS images were analyzed to calculate displacement of anatomical landmarks associated with activation of striated urethral sphincter (SUS), bulbocavernosus muscle (BC), and puborectalis muscle (PR). Continence was assessed at 3 and 6 weeks postoperatively, defined as use of ≤ 1 pad/day. The relationship of continence to the displacement of SUS, BC, and PR was analyzed. ResultsSUS, BC, and PR displacement decreased significantly 3 weeks postoperatively (P = 0.042, P = 0.002, P < 0.001, respectively). Continent men exhibited significantly greater SUS displacement (median, 5.13 mm) than incontinent men (median, 3.90 mm) 3 weeks postoperatively (P = 0.029). Between 3 and 6 weeks following RARP, there was significant increase in SUS, BC, and PR displacement (P = 0.003, P = 0.030, P < 0.001, respectively). ConclusionsA significant decrease in PFM function occurs following RARP, with a subsequent recovery of postoperative PFM function between 3 and 6 weeks post-procedure in men who undergo PFM training. SUS activation was significantly greater in continent patients compared to incontinent patients at 3 weeks following RARP.