Intramedullary cavernous malformations: clinical features and surgical technique via hemilaminectomy.

OBJECTIVE: The purpose of this study was to define the clinical features and the surgical technique of unilateral hemilaminectomy for treating intramedullary cavernous malformations.
MATERIALS AND METHODS: Retrospective chart was performed in 16 patients with histologically diagnosed intramedullary cavernous malformations. All patients were treated with unilateral hemilaminectomy and microsurgical resection of the malformations. The pre- and postoperative neurological state was evaluated using Frankel scale.
RESULTS: There were nine females and seven males (mean age 38 years) harbouring symptomatic intramedullary cavernous malformations. The annual retrospective haemorrhage rate was 3.1% per patient/year. All cavernous malformations were completely resected. Twelve of 16 patients experienced the improvement of the neurological state and in four patients, clinical features remained unchanged during the follow-up period. Static and dynamic plain radiograph film showed none of them had spinal deformity or spinal instability.
CONCLUSION: According to the defined bleeding risk, symptomatic and MRI-morphologically growing intramedullary cavernous malformations should be totally surgically removed, to avoid the recurrence and rebleeding of the residue. A least traumatic myelotomy, as well as a meticulous microsurgical technique and the intraoperative somatosensory evoked potentials monitoring, together with selection of a minimally invasive microsurgical approach (hemilaminectomy), leads to a favourable outcome and prevents additional morbidity.