Voiding patterns in patients with post-prostatectomy incontinence: Urodynamic and demographic analysis

Purpose: A significant percentage of patients with post-prostatectomy incontinence have been reported to void by Valsalva's maneuver, which is our observation as well. We determine the mechanism of voiding in patients with post-prostatectomy incontinence and correlate this to demographic data, urodynamic parameters and outcome after artificial urinary sphincter implantation, and identify possible risk factors. Materials and Methods: Videourodynamic data from 61 consecutive patients with post-prostatectomy incontinence were reviewed to determine voiding patterns. The causes of incontinence were radical prostatectomy in 58 patients and transurethral resection of the prostate followed by radiation therapy in 3. The relationship between voiding patterns and demographic data (age, diabetes mellitus, degree and duration of incontinence, history of radiation therapy or treated bladder neck contracture) as well as urodynamic parameters (bladder capacity, compliance, instability, sensation, leak point pressure and residual urine) were studied. After artificial urinary sphincter implantation outcome was assessed in relation to the voiding patterns. Results: Stress incontinence was present in all patients while concomitant urgency/urge incontinence was present in 48%. Of the patients 43 (70.5%) voided by detrusor contraction (group 1) while the remaining 18 (29.5%) voided by straining (group 2). Mean patient age +/- SD was 70.8 +/- 6.9 and 69.2 +/- 7.2 years, and duration of incontinence was 48 33 and 46 30 months in groups 1 and 2, respectively (p >0.05). Also, no significant differences were found between the groups with regard to other demographic data. Delayed first sensation (at volume greater than 140 ml.) was seen in 42.5% and 29.4%, capacity less than 300 ml. in 41.9% and 39%, impaired/poor compliance in 25.6% and 22.2%, bladder instability in 16.3% and 5.6%, abdominal leak point pressure 60 cm. H2O or less in 59.4% and 60% and residual urine greater than 50 ml. in 11.6% and 17.6% in groups 1 and 2, respectively (p >0.05). After artificial urinary sphincter implantation 35% and 22.2% of patients used greater than 1 pad a day in groups 1 and 2, respectively. One patient in each group reported difficulty during urination and both patients had no residual urine. Conclusions: No identifiable demographic or urodynamic risk factors could be detected in association with the strain pattern of voiding in patients with post-prostatectomy incontinence. The absence of a difference in bladder compliance, residual urine volume and outcome after artificial urinary sphincter implantation between detrusor and strain voiders would suggest no increased risk for complications in the strain voiding group.