title: Deep arteriovenous malformations in the Basal Ganglia, thalamus, and insula: microsurgical management, techniques, and results.
abstract: BACKGROUND
  Arteriovenous malformations (AVMs) in the basal ganglia, thalamus, and insula are considered inoperable given their depth, eloquence, and limited surgical exposure. Although many neurosurgeons opt for radiosurgery or observation, others have challenged the belief that deep AVMs are inoperable. Further discussion of patient selection, technique, and multimodality management is needed.
  
  
  OBJECTIVE
  To describe and discuss the technical considerations of microsurgical resection for deep-seated AVMs.
  
  
  METHODS
  Patients with deep AVMs who underwent surgery during a 14-year period were reviewed through the use of a prospective AVM registry.
  
  
  RESULTS
  Microsurgery was performed in 48 patients with AVMs in the basal ganglia (n=10), thalamus (n=13), or insula (n=25). The most common Spetzler-Martin grade was III- (68%). Surgical approaches included transsylvian (67%), transcallosal (19%), and transcortical (15%). Complete resection was achieved in 34 patients (71%), and patients with incomplete resection were treated with radiosurgery. Forty-five patients (94%) were improved or unchanged (mean follow-up, 1.6 years).
  
  
  CONCLUSIONS
  This experience advances the notion that select deep AVMs may be operable lesions. Patients were highly selected for small size, hemorrhagic presentation, young age, and compactness-factors embodied in the Spetzler-Martin and Supplementary grading systems. Overall, 10 different approaches were used, exploiting direct, transcortical corridors created by hemorrhage or maximizing anatomic corridors through subarachnoid spaces and ventricles that minimize brain transgression. The same cautious attitude exercised in selecting patients for surgery was also exercised in deciding extent of resection, opting for incomplete resection and radiosurgery more than with other AVMs to prioritize neurological outcomes.
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco, CA 94143-0112, USA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Potts
authors.forename: William L
authors.initials: WL
authors.lastname: Young
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lawton
mesh_terms: D000328:Adult; D001479:Basal Ganglia / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D002533:Cerebral Angiography; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D003337:Corpus Callosum / Q000601:surgery; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000473:pathology* / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008866:Microsurgery / Q000379:methods*; D059906:Neuroimaging; D011183:Postoperative Complications; D012189:Retrospective Studies; D013788:Thalamus / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult