Voiding dysfunction following transurethral resection of the prostate: symptoms and urodynamic findings

Persistent voiding dysfunction following transurethral resection of the prostate is not uncommon. We determined the correlation, if any, between the subjective complaints in men with voiding dysfunction after transurethral resection of the prostate and the urodynamic findings.

A total of 50 consecutive men with voiding dysfunction following transurethral resection of the prostate was evaluated with the American Urological Association symptom index and multichannel urodynamics. Patients with urethral stricture, urinary retention or prostate cancer were excluded from the study. Urodynamic parameters assessed included detrusor instability, bladder capacity, sphincteric insufficiency using the Valsalva leak point pressure, voiding pressure-flow studies as determined by the Abrams-Griffiths nomogram (obstructed, unobstructed or equivocal) and post-void residual.

Mean patient age was 71 years and mean interval from last transurethral resection of the prostate was 58 months (range 2 to 252). Mean total, obstructive and irritative symptom scores were 16.3, 5.8 and 10.5, respectively. A total of 20 patients (40%) complained of incontinence (14 urge and 6 stress). According to the Abrams-Griffiths nomogram 62% of the cases were unobstructed, 16% obstructed and 22% equivocal. Urodynamic abnormalities were demonstrated in 43 patients (86%), and included detrusor instability (54%), obstruction with or without detrusor instability (16%), sphincteric insufficiency (8%), detrusor hypocontractility (4%) and sensory urgency (4%). There was no difference in the total, irritative or obstructive scores among obstructed, unobstructed or equivocal cases. Similarly there was no difference in scores among patients with and without detrusor instability. Age, number of transurethral resections and interval since last transurethral resection were unrelated to pressure-flow results or detrusor instability. Post-void residual was significantly greater in obstructed cases and bladder capacity was significantly less in those with detrusor instability. The cause of incontinence was demonstrated in 19 of 20 patients (95%): 4 (20%) had sphincteric insufficiency and 15 (75%) had detrusor instability.

Symptoms are unreliable in predicting urodynamic findings with respect to obstruction and detrusor instability. There is a high incidence of detrusor instability in patients with voiding dysfunction after transurethral resection of the prostate. Urodynamic obstruction is a less likely occurrence.