The etiology of post-radical prostatectomy incontinence and correlation of symptoms with urodynamic findings

Abstract

Purpose: We evaluated men with post-radical prostatectomy incontinence to determine the incidence of intrinsic sphincter deficiency and bladder dysfunction, and the contribution of each to incontinence. In addition, we determined if subjective symptoms of stress urinary incontinence and urge incontinence correlated with urodynamic findings of intrinsic sphincter deficiency and bladder dysfunction, respectively.

Materials and methods: A total of 60 consecutive patients (mean age 64.8 years) were prospectively evaluated with multichannel video urodynamics. All patients were evaluated at least 6 months postoperatively and had achieved a stable level of continence. Patients characterized incontinence as stress or urge related, and stress urinary incontinence was graded from 0 to 3. Intrinsic sphincter deficiency was defined as incontinence associated with increased intraabdominal pressure and was further assessed by Valsalva's leak point pressure. Bladder dysfunction included urodynamic findings of detrusor instability or decreased compliance.

Results: Intrinsic sphincter deficiency was demonstrated in 54 patients (90%). Some component of bladder dysfunction was seen in 27 patients (45%), including detrusor instability in 24 and decreased compliance in 3, but incontinence was actually a result of bladder dysfunction in only 16 (27%). Incontinence was due to intrinsic sphincter deficiency alone in 40 patients (67%), intrinsic sphincter deficiency and bladder dysfunction in 14 (23%), and bladder dysfunction alone in only 2 (3%). Incontinence was not demonstrated on video urodynamics in 4 patients (7%). Of the 57 men who complained of stress urinary incontinence 54 demonstrated intrinsic sphincter deficiency for a positive predictive value of 95%. The 3 patients without stress urinary incontinence did not demonstrate intrinsic sphincter deficiency for a negative predictive value of 100%. Positive and negative predictive values for urge incontinence were 44 and 81%, respectively.

Conclusions: Incontinence after radical prostatectomy is associated with intrinsic sphincter deficiency in the overwhelming majority of patients. Bladder dysfunction rarely is an isolated cause. When present on urodynamic tests bladder dysfunction may not always be a significant contributor to incontinence. The symptom of stress urinary incontinence (or its absence) accurately predicts the finding (or absence) of intrinsic sphincter deficiency on urodynamics. Urge incontinence is not as reliable in predicting incontinence due to bladder dysfunction.