[Minimally invasive treatment of cervical_1-2 epidural neurilemmoma]

To explore the minimally invasive surgical method for cervical_1-2 epidural neurilemmoma.

The clinical features, imaging characteristics and surgical methods of 63 cases of cervical_1-2 epidural neurilemmoma from July 2010 to December 2018 were reviewed and analyzed. Pain and numbness in occipitocervical region were the common clinical symptoms. There were 58 cases with pain, 30 cases with numbness, 3 cases with limb weakness and 2 cases with asymptomatic mass. Magnetic resonance imaging (MRI) showed that the tumors located in the cervical_1-2 epidural space with diameter of 1-3 cm. The equal or slightly lower T₁ and equal or slightly higher T₂ signals were found on MRI. The tumors had obvious enhancement. Individualized laminotomy was performed according to the location and size of the tumors, and axis spinous processes were preserved as far as possible. Resection of tumor was performed strictly within the capsule.

Total and subtotal resection of tumor were achieved in 60 and 3 cases respectively, and no vertebral artery injury was found. The operation time ranged from 60 to 180 minutes, with an average of 92.83 minutes. The hospitalization time ranged from 3 to 9 days, with an average of 5.97 days. All tumors were confirmed as neurilemmoma by pathology. There was no postoperative infection or cerebrospinal fluid leakage. There was no new-onset dysfunction except 9 cases of numbness in the nerve innervation area. The period of follow-up ranged from 6 months to 8 years (median: 3 years). All the new-onset dysfunction recovered completely. Pain disappeared in all of the 58 patients with pain. Numbness recovered completely in 27 patients while slight numbness remained in another 3 patients. Three patients with muscle weakness recovered completely. The spinal function of all the patients restored to McCormick grade Ⅰ. No recurrence was found on MRI. No cervical spine instability or deformity was found on X-rays.

It is feasible to resect cervical_1-2 epidural neurilemmoma by full use of the anatomical space between atlas and axis and individual laminotomy. It is helpful to prevent cervical instability or deformity by minimizing the destruction of cervical₂ bone and preserving normal muscle attachment to cervical₂ spinous process. Strict intracapsular resection can effectively prevent vertebral artery injury.