Objective: The main goal is bilateral microsurgical decompression of the cauda equina using a unilateral over the top approach. The challenge is to achieve decompression with minimal iatrogenic trauma to anatomical structures in the approach region and in the target area.
Indications: Degenerative spinal disorders including lumbar central stenosis, lumbar lateral recess spinal stenosis, and foraminal narrowing. This technique is performed in patients presenting primarily with neurogenic claudication, leg or buttock symptoms, heaviness in the legs with or without radicular symptoms, with or without neurological deficits, and comparable MRI findings. There are no limitations regarding number of affected segments or the extent of narrowing.
Contraindications: All available conservative treatment modalities not exhausted. Lack of serious neurological deficit.
Surgical technique: Minimally invasive, muscle-sparing and facet-joint-sparing bilateral enlargement of the lumbar spinal canal through a unilateral microsurgical cross-over approach.
Postoperative management: Patients are mobilized early 4-6 h postoperatively. Light sports activities (e.g., ergometer cycling, swimming) are allowed after 2 weeks. The same is true for the return to normal daily or work activities except for heavy physical work (usually 4 weeks out of work). Soft lumbar brace for 4 weeks (optional).
Results: The clinical outcomes are good to excellent. Meta-analyses and large case series report success rates for microsurgical decompression procedures of 73.5-95%. The reoperation rates are low (0.5-10%).
Keywords: Cross-over technique; Microsurgery; Minimally invasive surgery; Spinal canal disorders; Surgical decompression.