title: Current surgical results with low-grade brain arteriovenous malformations.
abstract: OBJECTIVE
  Resection is an appealing therapy for brain arteriovenous malformations (AVMs) because of its high cure rate, low complication rate, and immediacy, and has become the first-line therapy for many AVMs. To clarify safety, efficacy, and outcomes associated with AVM resection in the aftermath of A Randomized Trial of Unruptured Brain AVMs (ARUBA), the authors reviewed their experience with low-grade AVMs-the most favorable AVMs for surgery and the ones most likely to have been selected for treatment outside of ARUBA's randomization process.
  
  
  METHODS
  A prospective AVM registry was searched to identify patients with Spetzler-Martin Grade I and II AVMs treated using resection during a 16-year period.
  
  
  RESULTS
  Of the 232 surgical patients included, 120 (52%) presented with hemorrhage, 33% had Spetzler-Martin Grade I, and 67% had Grade II AVMs. Overall, 99 patients (43%) underwent preoperative embolization, with unruptured AVMs embolized more often than ruptured AVMs. AVM resection was accomplished in all patients and confirmed angiographically in 218 patients (94%). There were no deaths among patients with unruptured AVMs. Good outcomes (modified Rankin Scale [mRS] score 0-1) were found in 78% of patients, with 97% improved or unchanged from their preoperative mRS scores. Patients with unruptured AVMs had better functional outcomes (91% good outcome vs 65% in the ruptured group, p = 0.0008), while relative outcomes were equivalent (98% improved/unchanged in patients with ruptured AVMs vs 96% in patients with unruptured AVMs).
  
  
  CONCLUSIONS
  Surgery should be regarded as the "gold standard" therapy for the majority of low-grade AVMs, utilizing conservative embolization as a preoperative adjunct. High surgical cure rates and excellent functional outcomes in patients with both ruptured and unruptured AVMs support a dominant surgical posture for low-grade AVMS, with radiosurgery reserved for risky AVMs in deep, inaccessible, and highly eloquent locations. Despite the technological advances in endovascular and radiosurgical therapy, surgery still offers the best cure rate, lowest risk profile, and greatest protection against hemorrhage for low-grade AVMs. ARUBA results are influenced by a low randomization rate, bias toward nonsurgical therapies, a shortage of surgical expertise, a lower rate of complete AVM obliteration, a higher rate of delayed hemorrhage, and short study duration. Another randomized trial is needed to reestablish the role of surgery in unruptured AVM management.
authors: Departments of 1 Neurological Surgery.
authors: Matthew B
authors: MB
authors: Potts
authors: Darryl
authors: D
authors: Lau
authors: Adib A
authors: AA
authors: Abla
authors: Helen
authors: H
authors: Kim
authors: William L
authors: WL
authors: Young
authors: Michael T
authors: MT
authors: Lawton
mesh_terms: D000368:Aged; D004621:Embolization, Therapeutic; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D012042:Registries; D016896:Treatment Outcome
keywords: ARUBA; ARUBA = A Randomized Trial of Unruptured Brain AVMs; AVM = arteriovenous malformation; OR = odds ratio; arteriovenous malformation; low grade; mRS = modified Rankin Scale; ruptured; unruptured; vascular disorders