Urodynamic evaluation of surgical outcome in patients with urinary retention due to central lumbar disc prolapse.

AIMS To investigate whether acute urinary retention due to central lumbar disc prolapse is reversible after emergency spinal surgery. METHODS Eight patients (two males, six females) with a mean age of 31.5 years (range, 18-42 years) with urinary retention due to lumbar disc prolapse were studied. An emergency surgery was performed within 48 hours (mean, 42 hours) after the onset of urinary retention. Urodynamic study was performed before and after the operation. RESULTS All patients had acontractile detrusor without bladder sensation and four of seven patients had inactive external sphincter on electromyogram at presentation. Two patients were unable to void up to 1 and 5 months after surgery and were then lost for follow-up. The remaining six patients could void with straining or changing their voiding postures (bending forward), postoperatively. A follow-up urodynamic study was performed in all patients from 1 month to 6 years postoperatively. All patients demonstrated acontractile detrusor on cystometrogram. On external sphincter electromyogram, four patients had normal activities. The remaining four patients recovered electromyographic activities, but two of them had denervation motor unit potentials and two had low activities. CONCLUSIONS Bladder function was irreversible after spinal surgery, whereas urethral function showed a better recovery in patients with acute urinary retention due to central lumbar disc prolapse. However, most of our patients could empty their bladder only by straining or changing their voiding postures postoperatively.