Refining the treatment of spinal cord lesions: experience from 500 cases.

Objective: Tumorous lesions of the spinal cord, as well as some vascular lesions like cavernous hemangiomas, demand careful consideration as to the indication and approach for surgery. As these lesions are rare in any departmental series, refinement of treatment strategies evolves over long periods. In this context, the authors evaluated a series of 500 intramedullary lesions for approach, technique, outcome, complications, and follow-up.

Methods: Five hundred intramedullary lesions in 460 patients were treated with a continuously evolving departmental strategy between 1985 and 2020. No lesions of the cauda equina or filum terminale were included. The focus of the evaluation was on the adaptation of exposure, resective methodology, sequelae, imaging, and rate of recurrence. Thirty-seven patients were children at the time of diagnosis.

Results: Among the 348 neoplastic lesions, the largest subtype was ependymoma (n = 192, 55.2%), followed by astrocytoma (n = 89, 25.6%). As a trend, metastases (n = 21) have become more frequent and more apparent only in the past 15 years. Reoperations for recurrent or progressive cases or referrals after incomplete resection were performed in 56 cases, mostly for progressive diffuse or pilocytic astrocytomas. Among the vascular lesions, 68 (54.8%) were hemangioblastomas, followed by 56 (45.2%) cavernous hemangiomas. All intramedullary tumors were approached through a midline myelotomy, refining an en bloc resection technique for endophytic tumors to increase the rate of radical resection. Cavernous hemangiomas reaching the surface and hemangioblastomas were approached directly. Complete removal was possible in 77.2% of endophytic tumors but in only 41.7% of diffuse tumors. All WHO grade II diffuse astrocytomas, WHO grade III tumors, and glioblastoma progressed despite treatment according to standard regimens. Vascular lesions were regularly removed completely, with only 1 recurrence of a large hemorrhagic thoracic cavernous hemangioma. The major sequelae were sensory deficits and neuropathic pain. Stabilizing instrumentation was placed in 5 cases of spinal deformity, mostly when more than 4 levels were affected, and in the pediatric population.

Conclusions: In a large series of intramedullary surgeries, refinement of treatment strategies related to exposure, implementation of intraoperative adjuncts such as ultrasound, intraoperative neuromonitoring, resective strategies, and reconstruction were evaluated. The authors found that for almost any defined, endophytic medullary lesion, a safe and complete removal can be offered.