Stop-flow measurement of detrusor contractility in bladder outflow obstruction.

Detrusor contractility was evaluated by measuring the increase in isometric pressure during a stop test in 25 men with benign prostatic hyperplasia. Before transurethral prostatic resection (TUR), a low pressure increase (delta P det iso) was associated with a large volume of residual urine. After TUR both the speed and the amplitude of isometric detrusor contractions during the stop test increased. A pre-operative low detrusor pressure increase was correlated with a great improvement in flow rate after TUR. The value of the stop-flow test was limited, however, since improvement in other urodynamic parameters could not be predicted.