Abstract
Bilateral decompression of spinal stenosis may induce instability which compromises outcome. In an attempt to overcome this problem, bilateral decompression can be carried out through a unilateral approach. The ipsilateral side is decompressed by hemi-laminectomy with undercutting partial facetectomy and the contra-lateral side is treated by careful excavation beneath the spinous processes and laminae with preservation of the laminae, posterior ligament complexes and paraspinal muscles. This is achieved with the aid of an operating microscope or loupe and headlight. Previous reports contain little information about outcome and complications.
We reviewed 30 patients with bilateral spinal stenosis, but without significant spondylolisthesis who were decompressed bilaterally from a unilateral approach by a single surgeon during a calendar year. They represented a third of our annual operations for spinal stenosis. Thirty patients had 45 levels decompressed. Female to male ratio was 2:1 and average age was 66 years. The average duration of preoperative symptoms was 1.6 years. The mean follow up period was 30 weeks (12 weeks to one year).
Assessment was carried out using the Oswestry Disability Index, pre- and post-operative visual analogue pain scores for leg pain and back pain, walking distance and MacNab criteria of patient outcome.
Results: improvement in Oswestry Disability Index, pain scores for sciatica and back pain and improved walking distance. All but one case had good or excellent outcome.
Complications: one dural tear and two cases with temporary dermatomal sensory change.
Whilst the technique is safe, and effective, a longer randomised controlled study is needed to demonstrate any real advantage over traditional approaches.
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