Post-radical prostatectomy incontinence: How to conduct a urodynamic evaluation

November 1, 2008

Many post-prostatectomy incontinence patients have concomitant sphincteric and bladder dysfunctions.

However, comprehensive urodynamic testing is indicated prior to invasive surgery to treat PPI. Urodynamics enable the clinician to evaluate the underlying pathophysiology of PPI (sphincteric vs. bladder dysfunctions), assess the relative contribution of each component to the incontinence, and help to direct rational and efficacious PPI treatment.

This article explains several aspects of urodynamic evaluation of the patient with PPI, including patient preparation, steps in the testing process, practical pearls, and the impact of test results on treatments.

One randomized, controlled trial has showed a reduction of infection with a single dose of ciprofloxacin (Cipro, Proquin) (Urology 2006; 67:1149-53), while other randomized trials did not show benefits (Obstet Gynecol 1999; 93:749-52, Int Urogynecol J Pelvic Floor Dysfunct 2001; 12:254-7). Documentation of negative urine culture is recommended prior to elective urodynamic testing. Sometimes such documentation is lacking or not up to date. A negative urinalysis is reassuring, but does not preclude the possibility of post-procedure infection. Prophylaxis is warranted in that scenario.

If the patient is al-ready receiving anticholinergic medication prior to testing, the medication should be continued during urodynamics to assess its effectiveness in managing bladder dysfunctions. Fleet enema should be administrated well in advance prior to the study to avoid eliciting rhythmic rectal contractions.

Testing should start with uroflowmetry, followed by measurement of post-void residual. A 7F dual lumen bladder catheter is adhered to the tip of the penis to avoid slippage during voiding and straining. The catheter should be taped in such a way that the urine flow is not disrupted and stress incontinence can be easily observed. If resistance is encountered during catheter insertion, cystoscopy should be performed to rule out bladder neck contracture. The risk of developing bladder neck contracture is particularly high in post-irradiated PPI patients (J Urol 2007; 177:1021-5) (36% in PPI patients vs. 57% in irradiated PPI patients).