Urodynamics and the etiology of post-prostatectomy urinary incontinence: the initial Columbia experience.

Post-prostatectomy incontinence is a disabling disorder. Urodynamic studies in 56 patients with post-prostatectomy incontinence were reviewed to determine its etiology. Of the patients 31 had undergone transurethral prostatectomy and 25 radical retropubic prostatectomy. After careful history and neurourological examination, uroflowmetry, post-void residual determination and synchronous multichannel video pressure/flow studies were done. The most common etiology for incontinence was detrusor instability alone, which was present in 34 patients (61%), including 24 (77%) after transurethral resection of the prostate and 10 (40%) after radical retropubic prostatectomy. Stress incontinence alone was present in only 3 patients (5%), including 1 (3%) after transurethral resection of the prostate and 2 (8%) after radical retropubic prostatectomy. Detrusor instability with stress incontinence was present in 19 patients (34%), including 6 (19%) after transurethral resection of the prostate and 13 (52%) after radical retropubic prostatectomy. Of these 19 patients 4 (21%) had poorly compliant bladders. This study demonstrates that stress incontinence alone is a relatively rare cause of post-prostatectomy incontinence, with detrusor instability present in more than 90% of the patients. Accurate diagnosis of post-prostatectomy incontinence etiology could ensure proper treatment for this disorder.