Can filling phase urodynamic parameters predict the success of the bulbar artificial urinary sphincter in treating post-prostatectomy incontinence?

ABSTRACT

OBJECTIVE: To evaluate whether filling phase urodynamic parameters can predict the success of the artificial urinary sphincter (AUS) in treating post-prostatectomy incontinence (PPI). MATERIALS AND METHODS: We reviewed the pre-AUS urodynamics of 99 patients with PPI at two tertiary referral centers. We documented the peak DO pressure (Pdet ), capacity, and compliance (C). We defined success as patient-reported continence or only using one safety pad. Patients' perception of improvement was assessed using the PGI-I score. RESULTS: Sixty-eight percent (n = 68) of patients had a successful outcome. The mean compliance for the "success" and "failure" group was 112.3 mL/cmH2 O (±119.7) and 34.1 mL/cmH2 O (±36.2), respectively. Fifty-five percent (17/31) of patients in the "failure" group demonstrated DO(Pdet = 36.2 ± 18.2 cmH2 O) compared to 18% (12/68) in the success group. The differences between the two groups in Pdet and compliance were statistically significant (all P < 0.01). There was, however, no statistical difference between the mean cystometric capacities of patients in the two outcome groups. Thirteen out of 18 (72%) patients who had radiotherapy had a poor outcome ("success" group only 15% [9/59]). These results were used to develop a nomogram for the probability of AUS success. A good inverse correlation (r = -0.65) was demonstrated between the probability of AUS success as deduced from the nomogram and PGI-I score post-AUS implantation CONCLUSION: Compliance and Pdet are predictors of outcome following AUS implantation for PPI. We have developed and internally validated a nomogram that may be used to determine an individualized likelihood of AUS success. This nomogram may be used as a counseling tool to objectively set realistic expectations of continence post-AUS implantation.