Assessment of bladder and urethral sphincter function before and after radical retropubic prostatectomy

In a prospective study we analyzed the effects of radical retropubic prostatectomy (RRP) on detrusor and urethral sphincter function by comparing urodynamic status preoperatively with that during longitudinal followup.

A total of 49 consecutive patients underwent urodynamics with pressure flow studies and Valsalva leak point pressure measurements 3 to 7 days before RRP (baseline), and then 1 and 8 months after surgery. We assessed bladder compliance, detrusor overactivity, detrusor contractility and intrinsic sphincter deficiency (ISD).

There was no significant change in detrusor overactivity at 1 and 8 months of followup. Decreased bladder compliance was observed in 20.4% of patients at baseline, and in 38.7% and 30.6% at 1 and 8 months, respectively. De novo decreased compliance was detected in 18.4% and 10.2% of patients at the same points. Impaired bladder compliance was comparable to that before surgery in 20% of cases. Impaired detrusor contractility was detected in 42.8% of patients at baseline, and in 61.2% (p <0.05) and 42.8% at 1 and 8 months, respectively. De novo hypocontractility was observed in 28.6% and 10.2% of patients at 1 and 8 months, respectively. A strong association between detrusor overactivity and ISD was observed at 1 and 8 months (p <0.01).

Following RRP detrusor hypocontractility and decreased bladder compliance represent de novo transient dysfunction probably due to bladder denervation and an established condition not influenced by the operation. The strong association between overactivity and ISD suggests that stress urinary incontinence increases urethral afferent nerve activity and induces involuntary detrusor contractions.