Resident Physician Beaumont Health Royal Oak, Michigan, United States
Introduction: Minimally invasive laminectomy (MIL) for the treatment of lumbar stenosis has been shown to reduce approach related morbidity. In this study at retrospective analysis was conducted of patient undergoing 3 or more levels of MIL.
Methods: A retrospective analysis of 78 patients undergoing multi-level MIL between September 2017-December 2020. Patients included 55 male (70%):23 female (30%), mean age 69 years (range 48-85). Variables analyzed included comorbidities, MIL levels, EBL, operative time, complications, and outcomes (VAS (Visual Analogue Scale), ODI (Oswestry Disability Index)) at 3, 6, 12, 24 months. Additionally, fusion rates and reoperation for adjacent segment pathology were analyzed.
Results: All patients underwent 3 or more levels of MIL for stenosis with majority at L2-L3, L3-L4, and L4-L5 (n=1, T10-T11; n=2, T12-L1; n=14, L1-L2; n=46, L2-L3; n=71, L3-L4; n=56, L4-L5; n=8, L5-S1). Technique performed was unilateral MIL approach followed by contralateral decompression by undercutting the spinous process and lamina. Followed by bilateral facet fusion using only locally harvested morselized autograph at each level. Finally, percutaneous pedicle screws applied spanning decompressed segments. No additional bone graph material was used. Total EBL averaged 152 cc (range 20-500cc). Averaged operative time was 160 min (range138-238min). Hospital stay averaged 3.77 days (range 1-9 days). Fusion rate was >95% at 6-month follow-up based on dynamic independently read plain radiographs with postoperative CT. Patients with two-year follow-up or longer average 6- point decrease in VAS leg pain and 6-point decrease in Oswestry scores. There were 6 minor postoperative complications. Five patients had reoperation with additional decompression along with fusion and instrumentation
Conclusion : MIL for multi-level lumbar stenosis is a highly effective and safe treatment for patients primarily in the elderly age group and is highly cost effective. Figure A. Illustration of MIS laminectomy B. removal ligamentum flavum, C. placement of drilled morselized autograph from surgical site into decorticated facets, D. pre-above and post-below images after 3-level and E. 5-level MIS laminectomy, posterior fusion and percutaneous instrumentation.
