Voiding dysfunction and urodynamic findings in patients with lumbar spinal stenosis and the effect of decompressive laminectomy.

Eighteen consecutive patients (12 men and 6 women, mean age 55) with clinically and radiologically verified lumbar spinal stenosis underwent urodynamic examinations before decompressive laminectomy (n = 16) and 15 afterwards. Twelve of the patients (67%) had symptoms of voiding dysfunction preoperatively but urodynamic findings were normal in most cases only one patient showing detrusor hyperreflexia and one obstruction. Three patients reported an improvement in voiding postoperatively. Three patients showed obstructive voiding postoperatively, one undergoing TURP with a good outcome. One patient developed detrusor areflexia after the operation, with difficulties in bladder emptying. The only statistically significant changes in urodynamic parameters were rises in the maximum urethral pressure and urethral closure pressure. When considering the radicular symptoms and back pains the overall outcome was assessed as excellent or good in 6 cases, 6 had a fair outcome and 4 poor. Decompressive laminectomy gives acceptable results but the effects on bladder and urethral function remain controversial and unexpected. Electrophysiological investigations are needed for more detailed analysis of these cases.