[Bilateral "over the top" decompression through unilateral laminotomy for lumbar and thoracic spinal canal stenosis].

OBJECTIVE

The standard surgical procedures used in degenerative thoracic and lumbar spinal canal stenosis allows decompression of the neural structures by unroofing the spinal canal, often resulted in destruction or insufficiency of facet joints, sacrifice the interspinosus/supraspinosus ligament complexes and stripping of the paraspinal muscles altering an already pathologic biomechanical milieu causing segmental instability. Various less invasive techniques exists to save the integrity and prevent the instability of the spine and allow decompression of neural structures located in the spinal canal. The authors discusses the experiences with technique of unilateral laminotomy for bilateral decompression.

METHODS

The unilateral laminotomy for bilateral decompression technique was performed at 60 levels in 51 patients to decompress the symptomatic degenerative stenosis of the thoracic and lumbar spinal canal. The inclusion criteria were used as follows: symptoms of neurogenic claudication and/or radiculopathy, myelopathy, neuroimaging evidence of degenerative stenosis and absence of instability. Symptoms were considered refractory to nonsurgical conservative management or myelopathy was detected.

RESULTS

The distribution of mostly affected segments were the L 4-5 (45%) and L3-4 (28.4%). Neurogenic claudication and walking distance improved during the follow up period in all patients. Seven patients (13.73%) reported excellent, 32 (62.74%) good, 12 (23.53%) fair outcome and no patient a poor overall outcome. The low back pain was the major residual postoperative complaint. 25 (49%) patients were very satisfied with their outcome, 23 (45.1%) were fairly satisfied, 2 (3.9%) were not very satisfied and 1 (2%) patients was dissatisfied.

CONCLUSION

The unilateral laminotomy for bilateral microdecompression technique minimizes resection of and injury to tissues not directly involved in the pathologic process, while affording a safe and through decompression of neural structures located in a degeneratively stenotic spinal canal.