Urodynamic interpretation of changing bladder function and voiding pattern after radical prostatectomy: a long-term follow-up

Abstract

Objective: To investigate and compare changes in the bladder function after radical prostatectomy (RP) and to correlate changes in subjective voiding symptoms with the observed changes in function.

Patients and methods: In 72 patients who had RP between 2003 and 2004, we serially evaluated urodynamic studies (UDS) before RP and at 3, 6 and 36 months afterward. The short-form International Continence Society-male symptom questionnaire was also repeated at corresponding periods. Changes in bladder contraction and storage function after RP were compared for changes in subjective symptoms.

Results: On serial UDS, there were reductions in maximum cystometric capacity, maximum detrusor pressure and maximum urethral closure pressure (MUCP) at 3 months, after which all remained relatively unchanged. On the questionnaire, the voiding symptom domain score improved (8.04 to 4.82, P < 0.001) while the storage domain score significantly and progressively worsened, beginning from 3 months (2.25 to 3.78, P= 0.04), resulting in an unchanged overall urinary symptom-related quality of life at 3 years. The incidence of detrusor overactivity increased from 37.5% before RP, to 45.8% at 3 months and 51.4% at 3 years. At 3 years, a recurring postvoid residual urine volume was the cause of the deterioration in the voiding symptom domain score, while a prominent reduction in MUCP resulted in a deterioration in the storage symptom score.

Conclusions: There is a reduction in bladder capacity, detrusor and sphincteric activity immediately after RP, stabilizing thereafter but remaining significantly reduced at 3 years. Although voiding symptoms improved in most men, the significant deterioration in storage symptoms, which might be attributed to sphincteric incompetence in addition to increased detrusor overactivity, became a source of overall urinary bother in the long term.