Relationship between the integrity of the pelvic floor muscles and early recovery of continence after radical prostatectomy

PURPOSE: We investigated how the preoperatively estimated integrity of pelvic floor muscles related to the recovery of continence after radical prostatectomy. MATERIALS AND METHODS: A total of 94 patients underwent magnetic resonance image of the prostate and urodynamic studies before undergoing radical prostatectomy and evaluation of voiding symptoms before, and 3 and 6 months after surgery. Incontinence was defined as any unwanted urine leakage. On the magnetic resonance image the thickness of the levator ani and pelvic diaphragm, and prostate volume were measured to correlate with continence status. RESULTS: Incontinence was noted in 41.5% and 15.9% of the patients at 3 and 6 months, respectively. Recovery of continence 3 months after RP was related to the thickness of the pelvic diaphragm on sagittal imaging (p=0.017), the ratio of the levator ani on the axial image to prostate volume (p=0.047), functional urethral length (p=0.007) and incontinence before surgery (p=0.009). Recovery at 6 months was related to neurovascular bundle sparing (p=0.013) and marginally to the pelvic diaphragm on sagittal imaging (p=0.059). On multivariate analysis the pelvic diaphragm on sagittal imaging (HR 2.455, 95% CI 0.894-6.739, p=0.008) and the ratio of the levator ani on the axial image to prostate volume (HR 1.886, 95% CI 0.952-3.736, p=0.011) significantly predicted continence at 3 months, while at 6 months only the pelvic diaphragm on sagittal imaging showed a significant relationship (p=0.024). CONCLUSIONS: Pelvic diaphragm thickness and the ratio of levator ani thickness to prostate volume are independent factors predictive of post-prostatectomy incontinence. Patients with better developed pelvic floor muscles, especially in relation to the size of the prostate, can be expected to achieve earlier recovery of continence after radical prostatectomy.