Development of idiopathic detrusor underactivity in women: from isolated decrease in contraction velocity to obvious impairment of voiding function

Abstract

Objectives: To sequentially assess the evolution of urodynamic parameters in women who could be studied before and after the development of idiopathic detrusor underactivity (DUA).

Methods: We assessed retrospectively 32 consecutive postmenopausal women seen during the period 1989 to 2006. They had invasive urodynamics (cystometry and pressure/flow study) performed when first referred (time 1) and then after several months (time 2). Group A, 17 women with a history of recurrent acute uncomplicated cystitis, had time 2 assessment performed a median of 24 months after time 1, following the discovery of large postvoid residual urine volumes at follow-up. As controls we took 15 age-matched women (group B), referred to exclude anxiety as the main cause for lower urinary tract symptoms, who proved normal urodynamically at time 1, were then lost at follow-up, and proved still normal urodynamically when reassessed a median of 27 months later (time 2).

Results: At time 1, group A showed normal urodynamic findings, except for a reduced detrusor contraction velocity. During the period between times 1 and 2, antimicrobial prophylaxis caused a 17% decrease in acute cystitis recurrences. At time 2, group A showed an obvious DUA, with reduced bladder emptying efficiency, lowered detrusor contraction strength, and a further decrease in detrusor contraction velocity.

Conclusions: An isolated decrease in detrusor contraction velocity showed as the early phase of the process leading to obvious DUA in the patients studied. This appeared to be a pathological process rather than a natural evolution due to aging.