Update on detrusor hyperactivity with impaired contractility

Abstract

Detrusor hyperactivity with impaired contractile function (DHIC) is a complex voiding dysfunction that is often misdiagnosed as incontinence resulting from benign prostatic hyperplasia with outlet obstruction, underactive detrusor with chronic retention, and stress urinary incontinence due to sphincter incompetence, particularly in women. Urodynamic assessments have shown that these subjects exhibit low pressure and almost unrecognizable involuntary detrusor contractions associated with reflex urethral relaxation accompanied with inefficient bladder emptying. These patients therefore tend to develop high residual volumes with a tendency towards chronic urinary retention. DHIC is a major cause of urinary incontinence in institutionalized elderly women. Accurate diagnosis requires awareness of this condition, careful video-urodynamic evaluation, and elimination of other disorders such as outlet obstruction and neurogenic bladder that confound DHIC. The exact causes are unclear, although some studies indicate that this entity may be a coincidental association of two separate etiologies, with each one independently contributing to the two different components of DHIC. Alternately, impaired detrusor function could emerge as a long-term sequelae of detrusor overactivity. Recent ultrastructural studies of the bladder in those with DHIC show distinct morphological patterns characteristic of both detrusor overactivity and impaired contractility. Management of this condition requires knowing that the condition potentially causes incontinence in women and lower urinary tract symptoms in men. Failure to diagnose DHIC in symptomatic patients may lead to inappropriate therapies including morbidity-prone surgical misadventures.