Fig. 1. A : Intradural spinal lesion (red). B : hemilaminectomy after splitting of the spinous process (using ossillating saw or T-saw) and laminofacet jounction (using match head burr). C : Contralateral spinolamina junction undercutting and exposure contralateral dural margin. D : Removal intraldural lesions and performed hemilaminoplasty.