gms | German Medical Science

Objective: Spinal intradural tumors are generally removed by uni- or multilevel laminectomy with midline dural incision.

Delayed post-operative kyphosis and spinal instability, which occurs in 6% of the patients, may be reduced by a more conservative unilateral microsurgery, sparing bilateral damage.

Methods: 49 patients, 34 with neurinoma, 8 meningioma, 3 caudal ependymoma, 2 conus medullaris dermoid tumor, 1 each dorsal intramedullary melanoma, and cervical intramedullary metastasis were operated between June 2000 and June 2007. One had 3 lumbar tumors and required two operations because of MRI misinterpretation, one had 2 dorsal meningiomas removed during the same operation, 2 patients had dumbbell neurinoma. 1 neurinoma and 2 meningiomas were located at the C1-C2 level.

Surgery was performed in the prone position with a unilateral approach. The extension of the laminectomy was kept generally to one level, having care to remove all the ligamentum flavum. When necessary, it was extended cranio-caudally for 1.5–2 cm. The dura was opened paramedially and the tumor dissected and removed in one piece, or piecemeal. In one patient, it was deemed necessary to enlarge the exposure to a traditional approach because of concomitant severe stenosis and huge tumor. Dural closure is done with 5-0 or 6-0 stitches. Tumor dimensions ranged from 1,2 to 2.8 cm in maximum diameter. The patient that required the extension of the approach had a multilobulated neurofibroma of 6 cm.

Results: All the patients were mobilized on day 2–3 and discharged on day 4–5. We observed no complications due to the technique and post-operative pain was minimal. Plain X-ray films showed that none of them had kyphosis and/or instability 3 months post-op. Overall neurological results were good.

Conclusions: Hospital stay may be reduced and stability preserved with an appropriate microsurgical mininvasive technique. In selected patients it can be used also for small intramedullary lesions, although in our cases it was done because of preoperative misdiagnosis. In case of operative difficulty it can be converted rapidly into a traditional approach: only one case in the present series.