What is involved in cranial vault surgery?

Cranial Vault Surgery: Procedure and Considerations

Cranial vault surgery involves removing and reshaping portions of the skull to correct deformities, relieve intracranial pressure, or repair defects, with the goal of restoring both structural integrity and surface morphology of the skull while minimizing complications. 1, 2

Types and Indications

• Cranial vault surgery may be performed for various conditions including:

  • Craniosynostosis (premature fusion of cranial sutures) 3, 4
  • Decompressive craniectomy for space-occupying lesions or cerebral edema 5
  • Repair of skull defects following trauma, tumor resection, or infection 2
  • Arteriovenous malformation (AVM) resection requiring cranial access 5

• The specific approach depends on:

  • Location and size of the defect or abnormality 2
  • Patient age (pediatric vs. adult considerations) 5, 3
  • Underlying condition requiring intervention 5

Surgical Techniques

Cranial Vault Remodeling for Craniosynostosis

• Posterior two-thirds cranial vault reconstruction:

  • Involves removing the posterior portion of the skull from the coronal suture to near the foramen magnum 4
  • Modern techniques use absorbable fixation plates and polydioxanone suture lattice networks 4
  • Eliminates need for post-operative molding helmets 4

• Posterior cranial vault expansion options:

  • Free-floating parieto-occipital bone flap (13-24% volume increase) 3
  • Spring-assisted expansion (18-25% volume increase) 3
  • Internal distractors (22-29% volume increase) 3

Decompressive Craniectomy

• Fronto-parieto-temporo-occipital craniectomy:
  • Extends to the midline with a diameter of at least 12 cm 5
  • Includes durotomy and duroplasty to allow for brain expansion 5
  • Performed urgently in cases of malignant cerebral edema 5

Cranioplasty (Skull Reconstruction)

• Performed to restore the cranial vault after previous craniectomy 1, 6

• Timing considerations:

  • Early cranioplasty (within 10 weeks) may have higher complication rates, especially with ventriculoperitoneal shunts 6
  • Delayed bone flap replacement may lead to communicating hydrocephalus 6

• Materials used:

  • Autologous bone (patient's own stored bone flap) 2
  • Alloplastic materials (synthetic alternatives) 2

Perioperative Considerations

Preoperative Assessment

• Comprehensive imaging:

  • MRI of the brain with contrast for detailed anatomical evaluation 5
  • CT imaging to assess degree of brain swelling/bulging 6
  • Angiography for vascular lesions or large hemispheric tumors 5

• Preoperative embolization may be considered for highly vascular lesions to reduce blood loss 5

Intraoperative Management

• Specialized techniques:

  • Image-guided surgery (frameless stereotaxy) for precise approach 5
  • Intraoperative electrophysiological monitoring of relevant cranial nerves 5
  • Careful attention to hemostasis, as blood loss can be significant (averaging 1.8 blood volumes in some procedures) 7

• For AVM resection:

  • Arterial feeders are typically addressed first, followed by nidus excision and finally draining vein resection 5
  • Intraoperative or postoperative angiography recommended to confirm complete obliteration 5

Postoperative Care

• Enhanced Recovery After Surgery (ERAS) protocols:

  • Associated with decreased narcotic usage and shorter ICU stays 8
  • Multimodal pain management approaches 9, 8

• Neurological monitoring:

  • Close monitoring for signs of neurological deterioration 1, 9
  • Hourly assessment of level of consciousness 9
  • Immediate notification of neurosurgical team for changes in neurological status 9

• Management of intracranial pressure:

  • Maintain cerebral perfusion pressure >60 mmHg 5, 9
  • Hyperosmolar therapy (mannitol 20% or hypertonic saline) for cerebral edema 5, 6
  • Target serum osmolality of 300-310 mOsmol/kg 5, 9

• Temperature control:

  • Careful attention to patient temperature in the intensive care unit 5
  • Postoperative hyperthermia may be detrimental 5

Potential Complications

• Neurological deficits:

  • Visual impairment 5
  • Hemiparesis 5
  • Developmental delay (in pediatric cases) 5

• Surgical complications:

  • Infection 6
  • Hemorrhage 5
  • Hydrocephalus 6

• Vascular complications:

  • Intraoperative sacrifice of en passage feeding vessels may result in deficits 5
  • Marginally perfused areas may be critically dependent on collateral perfusion 5

Special Considerations

• Pediatric patients:

  • Excessive blood loss is a greater concern due to smaller blood volume 5
  • Access to specialized pediatric neurosurgical expertise is crucial 5
  • Skull growth and development must be considered in reconstruction 3, 4

• Complex cases:

  • Multidisciplinary approach involving neurosurgeons, plastic surgeons, and other specialists as needed 5
  • Some tumors may be too difficult or dangerous to remove completely due to involvement of vital neural structures or major vessels 5