Collagen injection therapy for post-radical retropubic prostatectomy incontinence: role of Valsalva leak point pressure.

PURPOSE

We retrospectively evaluated the role of Valsalva leak point pressure as a predictor of successful management of post-radical retropubic prostatectomy incontinence with collagen injection.

MATERIALS AND METHODS

Urodynamic studies and Valsalva leak point pressures of 31 men who received retrograde collagen injection for post-radical retropubic prostatectomy incontinence were reviewed. Patients were interviewed before and after treatment to assess pad use and the American Urological Association quality of life index (scale 0 to 6). Parameters for success were postoperative quality of life score 3 or less or 50% or greater decrease in pad use and that the patient would recommend collagen therapy to someone else.

RESULTS

Of 31 patients 11 (35%) met the criteria for success, 2 (6%) were completely dry and 9 (29%) were improved. Successfully treated patients had a mean Valsalva leak point pressure of 64.0 cm. water compared to 42.2 cm. water in the failure group (p <0.01). Of patients with Valsalva leak point pressure of 60 cm. water or greater, 70% responded favorably to collagen injection (positive predictive value), while 81% with Valsalva leak point pressure less than 60 cm. water had treatment failure (negative predictive value) (p <0.02). There were no other statistically significant differences between those successfully treated with collagen injection and those in whom treatment failed, including mean age (62.7 to 68.1 years), mean volume of collagen (26.1 to 28.9 ml.), mean number of treatment sessions (2.45 to 2.65), mean followup (14.9 to 15.1 months), preoperative quality of life score (5.1 to 4.9), and preoperative pads per day (4.0 to 3.37).

CONCLUSIONS

Our data suggest that collagen injection improves 35% but cures a minority of patients (less than 10%) with post-radical retropubic prostatectomy incontinence. A pretreatment Valsalva leak point pressure of 60 cm. water or greater has high predictive value for a beneficial outcome after collagen injection. We propose a role for Valsalva leak point pressure to select men cost-effectively with post-radical retropubic prostatectomy incontinence for therapy with collagen injection.