title: A review of brain retraction and recommendations for minimizing intraoperative brain injury.
abstract: Brain retraction is required for adequate exposure during many intracranial procedures. The incidence of contusion or infarction from overzealous brain retraction is probably 10% in cranial base procedures and 5% in intracranial aneurysm procedures. The literature on brain retraction injury is reviewed, with particular attention to the use of intermittent retraction. Intraoperative monitoring techniques--brain electrical activity, cerebral blood flow, and brain retraction pressure--are evaluated. Various intraoperative interventions--anesthetic agents, positioning, cerebrospinal fluid drainage, operative approaches involving bone resection or osteotomy, hyperventilation, induced hypotension, induced hypertension, mannitol, and nimodipine--are assessed with regard to their effects on brain retraction. Because brain retraction injury, like other forms of focal cerebral ischemia, is multifactorial in its origins, a multifaceted approach probably will be most advantageous in minimizing retraction injury. Recommendations for operative management of cases involving significant brain retraction are made. These recommendations optimize the following goals: anesthesia and metabolic depression, improvement in cerebral blood flow and calcium channel blockade, intraoperative monitoring, and operative exposure and retraction efficacy. Through a combination of judicious retraction, appropriate anesthetic and pharmacological management, and aggressive intraoperative monitoring, brain retraction should become a much less common source of morbidity in the future.
authors.affiliation: Department of Neurosurgery, Stanford University Medical Center, California.
authors.forename: R J
authors.initials: RJ
authors.lastname: Andrews
authors.forename: J R
authors.initials: JR
authors.lastname: Bringas
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000777:Anesthetics; D000818:Animals; D001930:Brain Injuries / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D002543:Cerebral Hemorrhage / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D002544:Cerebral Infarction / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D002560:Cerebrovascular Circulation / Q000187:drug effects; D003288:Contusions / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D004285:Dogs; D004569:Electroencephalography; D005071:Evoked Potentials; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D008353:Mannitol / Q000627:therapeutic use; D016343:Monitoring, Intraoperative / Q000379:methods; D011312:Pressure; D051381:Rats; D013314:Stress, Mechanical; D013525:Surgical Instruments / Q000009:adverse effects*; D013552:Swine
chemical_list: D000305:Adrenal Cortex Hormones; D000777:Anesthetics; D002121:Calcium Channel Blockers; D008353:Mannitol