Efficacy of Unilateral Laminectomy for Bilateral Decompression in Elderly Lumbar Spinal Stenosis

Objective: The aim of our study is to evaluate the effectiveness of unilateral hemilaminectomy for bilateral decompression in elderly patients with degenerative spinal stenosis. For this purpose, we studied the co-morbid condition and clinical outcome of patients who underwent decompressive surgery using the unilateral approach technique. Methods: Thirty-four patients over 65years of age who underwent unilateral partial laminectomy for bilateral decompression from January 2000 to October 2003 were analyzed. These patients were studied for preoperative co-morbid condition and physical status according to the American Society of Anesthesiologists(ASA) classification, postoperative morphometrical change, and clinical outcomes, including visual analogue scale(VAS) score. The mean follow-up was 23months (range 6 - 48months). Results: A patient's physical status was recorded as class I, II, or III by ASA classification, which correlated to 41.2%, 44.1%, and 14.7% of patients, respectively. The cross-sectional area of the pre- and postoperative dural sac at the level of the stenosis was $52.5{\pm}19.9mm^2$ and $110.6{\pm}18.2mm^2$, respectively. The outcome was excellent in 8.8%, good in 58.8%, fair in 23.6%, and poor in 8.8% of the patients. The VAS was changed postoperatively to $3.1{\pm}1.2$. There was no operation-related transfusion yet there was no evidence of postoperative instability at the follow-up examination. Conclusion: Unilateral laminectomy for bilateral decompression, in spite of the limited exposure, can result in satisfactory decompression of the lumbar spinal stenosis and tolerable clinical outcome. This approach is thought to be appropriate for elderly patients who have a greater surgical burden.