Bilateral decompression of multilevel lumbar spinal stenosis through a unilateral approach.

Lumbar canal stenosis due to hypertrophy and calcification of the facet joints and/or ligamentum flavum is a common condition in the elderly. Although a large number of individuals are symptom-free, the degenerative process, usually encroaching on both central and lateral pathways, may lead to symptoms of itself or decompensate a preexisting narrow canal. Even at an advanced age, decompression surgery is effective for symptomatic stenosis. Less invasive procedures preserving maximal bony and ligamentous structures have recently been recommended to reduce associated morbidity. This paper introduces a unilateral surgical approach for bilateral decompression by ligamentectomy, partial facetectomy and foraminal unroofing. Using a specially designed, one-side retractor, after the ipsilateral nerve root decompression the contralateral dural sac and nerve roots were approached through an 8 x 15 mm window in the interspinous ligament. The contralateral ligamentum flavum, facet joints and foraminal roof were resected, preserving the supraspinous ligament complex and much of the contralateral musculature. This technique, preserving anatomy and biomechanical function of the lumbar spine, is useful for surgery on multilevel lumbar canal stenoses.