Detrusor biopsy as a potential clinical tool

Previous published work suggests that electron microscopic findings in bladder biopsies correlate with urodynamic diagnoses of bladder dysfunction in geriatric patients. Our goal was to determine the reproducibility of this previous work and to evaluate the use of detrusor biopsy as a clinical tool in the diagnosis and management in a urogynecology referral population. All patients underwent an initial evaluation, including history, physical examination and urodynamics. Urodynamic evaluation included uroflowmetry, provocative cystometry, instrumented voiding study, urethral profilometry, pressure-flow studies, and evaluation of postvoid residual urine. A cystoscopic-guided detrusor muscle biopsy was obtained from all patients. Each patient was assigned one of four urodynamic diagnoses: detrusor overactivity, obstructed voiding, both overactivity and obstruction, or neither. Each was given a subgroup of normal or ineffective contractility. All detrusor biopsies were evaluated by electron microscopy. Each biopsy was assigned one of four pathologic diagnoses: dysjunction, hypertrophy, both dysjunction and hypertrophy, or neither. Each was given a subgroup of the presence or absence of degeneration. All diagnoses were assigned in a double-blind fashion. All urodynamic and pathologic diagnoses were then compared to determine the percentage agreement. Twenty-six women participated, mean age 52.7 years, range 29-77. Overall agreement among diagnoses was 30% (95% CI 11%-50%). Comparison of each category revealed the following percentage agreements: detrusor overactivity/dysjunction, 52% (95% CI 32%-73%); obstructed voiding/hypertrophy, 78% (95% CI 61%-95%); ineffective contractility/degeneration, 65% (95% CI 45%-85%). The use of detrusor biopsy as a clinical tool was not supported in this population, as demonstrated by the low percentage agreement between urodynamic and pathologic diagnoses. The etiology of bladder dysfunction should be investigated by looking beyond organ-specific structural changes.