Outcomes of Radiosurgery for Brainstem Arteriovenous Malformations

Neurosurgery. 2011 Jul;69(1):45-51; discussion 51-2. doi: 10.1227/NEU.0b013e31821421d1.

Abstract

Background: Arteriovenous malformations (AVMs) in the brainstem yield a high risk of hemorrhage. Although stereotactic radiosurgery (SRS) is accepted, because of high surgical morbidity and mortality, outcomes are still unclear.

Objective: We previously reported the early results of SRS for brainstem AVMs. Here, we obtained data from a longer follow-up for a larger number of patients and present precise outcomes based on the latest follow-up data.

Methods: Forty-four patients with brainstem AVMs were treated by SRS. Outcomes such as the rates of obliteration, hemorrhage after treatment, and adverse effects were retrospectively analyzed.

Results: The annual hemorrhage rate before SRS was 17.5%. The mean follow-up period after SRS was 71 months (range, 2-168 months). The actuarial obliteration rate confirmed by angiography was 52% at 5 years. Factors associated with higher obliteration rate were previous hemorrhage (P = .048) and higher margin dose (P = .048). For patients treated with a margin dose of ≥ 18 Gy, the obliteration rate was 71% at 5 years. Persistent worsening of neurological symptoms was observed in 5%. The annual hemorrhage rate after SRS was 2.4%. Four patients died of rebleeding, and disease-specific survival rate was 86% at 10 years after treatment.

Conclusion: Nidus obliteration must be achieved for brainstem AVMs because they possibly cause lethal hemorrhage even after SRS. Treatment with a high margin dose is desirable to obtain favorable outcomes for these lesions. Additional treatment should be considered for an incompletely obliterated nidus.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Arteriovenous Malformations / pathology*
  • Arteriovenous Malformations / surgery*
  • Brain Stem / surgery*
  • Cerebral Angiography / methods
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Longitudinal Studies
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Postoperative Complications
  • Radiosurgery / methods*
  • Retrospective Studies
  • Tomography, X-Ray Computed / methods
  • Treatment Outcome
  • Young Adult