Purpose: We identified and characterized predictive factors associated with an unfavorable outcome of collagen injection therapy in post-radical prostatectomy incontinence.
Materials and methods: A total of 46 patients, 49 to 85 years old (mean age 67) and incontinent after radical retropubic prostatectomy, underwent a mean of 2.8 transurethral injections of collagen (mean cumulative volume injected 31 ml.). Preoperatively, all patients underwent fluoroscopic multichannel video urodynamics including determination of Valsalva's leak point pressure. Stress urinary incontinence was subjectively graded as 1 (0 to 1 pad per day), 2 (2 to 3 pads per day) and 3 (greater than 3 pads per day). Patient age, duration and severity of pretreatment incontinence, presence of detrusor instability and anastomotic strictures, number of injections, total volume of collagen delivered and the impact of a nerve sparing procedure plus adjuvant radiation therapy were assessed and correlated with treatment outcome.
Results: Of the patients 11 (24%) became completely dry (9 after 3 or fewer treatments), 21 (41%) improved (17 after 3 or fewer treatments) and 14 (30%) showed no benefit (after more than 3 treatments). Of the 14 patients in whom treatment failed 6 had undergone adjuvant radiation treatment, pretreatment urinary incontinence was grade 3 in all, and concomitant detrusor instability was present in 11 (79%). All patients had received more than 3 treatments (mean total volume injected 37 ml.).
Conclusions: Notwithstanding the need for multiple treatments, the prospect for cure by collagen injection of the post-radical prostatectomy incontinent patient is significantly affected by the severity of pretreatment incontinence, concomitant detrusor overactivity and exposure to radiation therapy. Age, duration of incontinence, presence of mild to moderate anastomotic strictures and a nerve sparing technique did not seem to influence treatment outcome.