ASSESSMENT OF BLADDER FUNCTION AFTER LUMBAR DECOMPRESSIVE LAMINECTOMYFOR SPINAL STENOSIS - A PROSPECTIVE-STUDY

Lumbar spinal stenosis is a common problem in elderly patients. In its more advanced forms, it typically causes intractable leg pain, but ma ny patients also manifest varying degrees of bladder dysfunction. The goal of lumbar decompressive laminectomy is relief of leg pain and par esthesias, yet some patients also achieve improvement in bladder funct ion. This study prospectively investigated patients with lumbar spinal stenosis to determine whether laminectomy had any effect on urologica l function. Of the 20 patients in the study, 10 were men and 10 women (average age 70.9 years). All patients had severe lumbar stenosis affe cting between two and four spinal segments, and all reported some degr ee of bladder dysfunction. Cystoscopy and urodynamic testing were comp leted preoperatively. A standard decompressive laminectomy was perform ed over the appropriate number of spinal segments. Urodynamic studies were repeated at 2 and 6 months postoperatively. At the 6-month follow -up review, bladder function was subjectively improved in 12 patients (60%) and unchanged in eight (40%). Postvoiding residual urine volume was the urodynamic factor most likely to be improved by laminectomy. I n nine patients (45%), baseline postvoiding residual urine volume was elevated and all nine had improvement postoperatively. In the remainin g 11 patients (55%), this urine volume was normal before and after sur gery. Maximum urine flow rates also improved, but the results of cytom etrography and electromyography, urine flow pattern, and bladder capac ity were unchanged postoperatively. Cystoscopy detected previously und iagnosed malignancy of the lower urinary tract in two patients (10%). It is concluded that lumbar decompressive laminectomy can have a benef icial effect on bladder function in a significant number of patients w ith advanced lumbar spinal stenosis.