The pathophysiology of post-radical prostatectomy incontinence: A clinicaland video urodynamic study

Purpose: We examine various mechanisms of post-radical prostatectomy incont inence. Materials and Methods: A total of 83 consecutive men (mean age 68 +/- 6.6 y ears) referred for evaluation of persistent post-radical prostatectomy inco ntinence were enrolled in the study. All patients underwent clinical and ur odynamic evaluation. Final diagnosis was based on clinical judgment conside ring patient history, pad test, voiding diary, free (unintubated) uroflow m easurements, video urodynamics and linear passive urethral resistance relat ion curves. We compared free uroflow and pressure flow obtained with a 7Fr urethral catheter in place, and empirically defined low urethral compliance as at least 10 mi. per second difference between these measurements. Results: Sphincteric incontinence was the most common urodynamic finding, o ccurring in 73 patients (88%). Detrusor instability was identified in 28 pa tients (33.7%) and in 6 (7.2%) was the main cause of incontinence. In 2 oth er patients bladder outlet obstruction (1.2%) or impaired detrusor contract ility (1.2%) was the only urodynamic finding. Impaired detrusor contractili ty was diagnosed by linear passive urethral resistance relation in 82% of c ases but considered to be clinically relevant in only a third. In 25 cases (30.1%) low urethral compliance was noted, which we consider nearly synonym ous with urethral scarring. Conclusions: Sphincteric incontinence is the most common urodynamic finding in patients with post-radical prostatectomy incontinence, although other f indings may coexist. The most accurate diagnosis is attained when all objec tive measures are put in perspective with the clinical setting.