Bilateral interlaminar fenestration and unroofing for the decompression of nerve roots by using a unilateral approach in lumbar canal stenosis

Background: Conventional laminectomy is a simple procedure that provides adequate decompression in cases of lumbar spinal canal stenosis. However, with this surgical modality, important posterior osteo ligamentous elements necessary for spinal stability are lost; and it is often accompanied by damage to the facet joint. Bilateral interlaminar fenestration and unroofing of the intervertebral foramen to achieve decompression of the nerve roots by using a unilateral microsurgical approach in lumbar spinal canal stenosis are less invasive compared with conventional laminectomy. Methods: We carried out bilateral interlaminar fenestration and unroofing of the intervertebral foramen to decompress the stenosed nerve roots under a microscope by using a unilateral approach. In particular, we performed the decompression of the contralateral nerve root with this surgical method by using a Caspar retractor. Surgery was performed on 47 patients (18 women and 29 men; 29-85 years; median age, 62 years). All cases were with single-level lumbar spinal canal stenosis and bilateral radiculopathy. Results: The mean preoperative NCOS was 29.8 (range, 8-48). The mean NCOS after a postoperative period of 3 months was 79.9 (range, 32-100). After a postoperative period of 2 years, the mean NCOS increased to 83.2 (range, 32-100). The satisfaction measures indicated that the procedure was "very successful" in 45 cases, providing "almost complete relief"; "fairly successful" in one case, providing "a good deal of relief"; and "not very successful" in another case, affording 11 only a little relief." Conclusions: This unilateral, minimally invasive decompression provided satisfactory results. (C) 2007 Elsevier Inc. All rights reserved.