Tubular Minimally Invasive Surgery for Cervical Laminectomy: Early Experience and Radiographic Outcomes

Introduction: Minimally-invasive surgery (MIS) can reduce EBL and hospitalization and potentially avoid fusion. Tubular MIS for "over-the-top" laminectomy is common for lumbar spine, but has potential limitations for cervical laminectomy. We report our early experience with MIS tubular posterior cervical laminectomy.

Methods: The technique for unilateral hemilaminectomy for bilateral decompression (UHBD) or "over-the-top" laminectomy in cervical spine involves docking laterally (on the facet to lower risk of injury to interlaminar structures [plunging]). After sequential dilation, the tubular retractor (16mm) can be medialized for ipsilateral hemilaminectomy. The retractor can be further medialized and the patient rotated for removal of the ventral spinous process and contralateral lamina. Then flavectomy can be performed. Meticulous hemostasis to avoid postoperative hematoma is critical. We performed this novel technique for cervical laminectomy and present the early radiographic (MRI) outcomes and complications.

Results: Over-the-top or UHBD was performed in 3 patients and 6 cervical levels: C2-3 (1), C3-4 (3), C4-5 (3), C5-6 (1). Mean OR time and EBL were 1hr and 25cc per level, respectively. Postoperative MRI T2 sagittal anterior-posterior distance of central canal improved from 7.0mm (range: 4.8 to 12) to 10.9mm (range: 10 to 13) (p < 0.05). Postoperative area of the central canal improved from 1.3cm2 (range: 0.8 to 1.8) to 1.6cm2 (range: 1.3 to 2.3) (p < 0.05). There were no complications.

Case 1: 75 yo female (BMI 27.2) presented with myelopathy from degenerative arthritis. She underwent fluoro-guided left-sided MIS UHBD at C2-3 C3-4 C4-5 C5-6. Discharged POD3.

Case 2: 43 yo female (BMI 37.6) presented with myelopathy and LUE radiculopathy from adjacent segment disease after prior C4-7 ACDF. She underwent CT-guided (O-arm) left-sided MIS UHBD at C3-4 as well as left C3-4 foraminotomy. Discharged POD1.

Case 3: 75 yo female (BMI 27.4) presented with myelopathy and LUE radiculopathy from degenerative arthritis. She underwent fluoro-guided left-sided MIS UHBD at C4-5 as well as a left C4-5 foraminotomy. Discharged POD1.

Conclusion : Tubular MIS "over-the-top" decompression in the cervical spine improved central canal dimensions and was safe. We plan to continue this novel apporach in the cervical spine with longer follow-up. Posterior cervical fusion may potentially be avoided in select cases.