Operative Planning

• Review imaging (magnetic resonance imaging [MRI])
  
• Define rostral and caudal extent of the lesion
  
• Note location within the cord
  
• Note presence of hemorrhage, calcium, degree of edema, and enhancement pattern of lesion on MRI
  
• Note presence of syrinx
  
• Review patient’s clinical course to ascertain chronicity of neurologic symptoms as well as pertinent prior operative history: multiple sclerosis lesions can mimic intramedullary tumor; with an unusual appearing lesion, caution should be taken to elicit a history of relapsing and remitting symptoms
  
• Review patient’s past medical and family history for genetic disease
  
  
  
  • Von Hippel-Lindau disease is associated with intramedullary hemangio-blastoma
    
  • Neurofibromatosis type I is associated with intramedullary astrocytoma
    
  • Neurofibromatosis type II is associated with intramedullary ependymoma

Equipment

• Basic spine tray
  
• High-speed drill (Midas Rex with AM-8 bit)
  
• 1- and 2-mm Kerrison punches
  
• Operating microscope with bridge
  
• Somatosensory or direct evoked motor potential monitoring set-up
  
• Ultrasonic aspirator

Posterior Cervical Approach

• For lesions of the cervical cord or cervicothoracic junction

• For lesions of the thoracic cord, cervicothoracic or thoracolumbar junction

Posterior Lumbar Approach

• For lesions of the lumbar cord, thoracolumbar junction, or conus

Tumor Resection

• Standard laminectomy with patient in prone position
  
• Laminoplasty is performed in pediatric patients in an effort to foster long-term stability
  
• Dura is opened in the midline and tented laterally to the muscle
  
• The operating microscope is brought into position
  
• The cord is inspected for any obvious signs of tumor; ultrasonography may be used to confirm location of an associated syrinx
  
• Any associated syrinx, cyst, hematoma should be drained
  
• The extent and method of tumor resection will vary, depending on the pathology
  
  
  
  • For invasive lesions (metastatic tumors), refer to intramedullary astrocytoma
    
  • For lesions with more defined margins (schwannoma, neurocytoma), refer to intramedullary ependymoma
    
  • For juxtamedullary cysts of lesions of dysembryogenesis, refer to intramedullary lipoma or teratoma
  
  
• Diagnosis confirmed with intraoperative review of frozen section by neuropathology
  
• After removal of the resection, the tumor bed is inspected for bleeding
  
• Hemostasis of the resection cavity is methodically achieved with bipolar cautery, Avitene, Surgicel, or Gelfoam
  
• Pial traction sutures are removed
  
• The dura is closed, primarily with a running 5–0 Prolene suture in a watertight manner; some experts advocate the use of a dural patch graft to prevent tethering
  
• Vigilant closure techniques should be emphasized because cerebrospinal fluid (CSF) leak is a major postoperative complication
  
• Consider using Duragen and/or Duraseal to reduce chances of postoperative CSF leak

• Rapid steroid taper to begin on postoperative day 1 for low-grade tumors or lesions of dysembryogenesis
  
• Antibiotics continued for 24 hours
  
• Patient is confined to bedrest for 24–48 hours
  
• A postoperative MRI with and without contrast should be obtained within 48 hours for documentation of tumor resection