[Insufficient detrusor contractility: a urodynamic and morphologic entity in prostatism]

To analyze the urodynamic and ultrastructural characteristics of impaired detrusor contractility in patients with prostatism in comparison with lower urinary tract obstruction.

The study comprised 200 male patients (mean age 65.3 years) with prostatism submitted to a complete urodynamic study. An ultrastructural study was randomly performed in 40 patients and analyzed 600 detrusor muscle images to determine the smooth muscle cell and interstitial changes. Detrusor urodynamics were compared with the ultrastructural cell and interstitial changes of the bladder smooth muscle.

Urinary symptoms or free flowmetry alone failed to predict detrusor urodynamics. Urodynamic diagnosis was based on the detrusor pressure-flow study. We observed ultrastructural degenerative cell changes with statistical significance in impaired detrusor contractility such as no branching and intertwining of cells, absence of caveoles, perinuclear degeneration with vacuolization, destructured myofilament system with diminished anchorage plates and collagen infiltrating the interstitium with loss of bladder muscle fascicle organization.

Impaired detrusor contractility is a urodynamic diagnosis that should be taken into account in patients with prostatism. The diagnosis of this condition requires performing a pressure-flow study. Impaired detrusor contractility showed a morphological and ultrastructural correlation with degenerative changes of the bladder muscle.