Increased residual urine in patients with bladder neuropathy secondary to suprasacral spinal cord lesions.

Multichannel urodynamic studies were done on 30 patients with incomplete bladder emptying secondary to suprasacral spinal cord lesions. In 11 patients fluoroscopy was done simultaneously. A single most important factor accounting for the increased residual urine was present in 21 cases: inadequate detrusor contraction in 10, sphincter dyssynergia in 6 and bladder neck obstruction in 5. A combination of 2 of these factors was present in 3 patients. Although the initial residual urine volume was high in 6 patients voiding during the urodynamic study was efficient and no residual urine was demonstrated at that time. Urethral pressure profiles were variable, depending on whether a spastic external sphincter contraction was present during the procedure. It is concluded that bladder pressure and sphincter electromyographic measurement during voiding, combined with fluoroscopy, are ideal methods to identify the factors responsible for incomplete emptying in problem cases. The urethral pressure profile is of limited value in the initial assessment of these patients.