title: Outcome after hemorrhage following Gamma Knife surgery for cerebral arteriovenous malformations.
abstract: OBJECTIVE
  Although the effects of Gamma Knife surgery (GKS) on the risk of hemorrhage are poorly understood, a certain subset of patients does suffer bleeding after GKS. This study was undertaken to analyze the outcome of patients sustaining hemorrhage after GKS; it is the most feared complication of radiosurgical management of cerebral arteriovenous malformations (AVMs).
  
  
  METHODS
  Between May 1997 and June 2006, 494 cerebral AVMs in 489 patients were treated using a Leksell Gamma Knife Model B, and follow-up evaluations were conducted until June 2007 at the All India Institute of Medical Sciences in New Delhi. Fourteen patients who sustained a hemorrhage after GKS formed the study group. In most of these patients conservative management was chosen.
  
  
  RESULTS
  The mortality rate was 0% and there was a 7% risk of sustaining a severe deficit following rebleeding after GKS. None of the patients sustained rebleeding after complete obliteration. Patients with Spetzler-Martin Grade III or less had increased chances of hemorrhage after GKS (p < 0.002). The presence of deep venous drainage, aneurysm, venous hypertension, or periventricular location on angiography was common in patients with hemorrhage after GKS.
  
  
  CONCLUSIONS
  The risk of hemorrhage that remains following GKS for cerebral AVMs is highest in the 1st year after treatment. The present study showed a relatively good outcome even in cases with hemorrhage following GKS, with no deaths and minimal morbidity, further substantiating the safety and efficacy of the procedure.
authors.affiliation: Gamma Knife Unit, Department of Neurosurgery, Neurosciences Centre, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Manish Kumar
authors.initials: MK
authors.lastname: Kasliwal
authors.forename: Shashank Sharad
authors.initials: SS
authors.lastname: Kale
authors.forename: Aditya
authors.initials: A
authors.lastname: Gupta
authors.forename: Narayanam Anantha Sai
authors.initials: NA
authors.lastname: Kiran
authors.forename: Manish Singh
authors.initials: MS
authors.lastname: Sharma
authors.forename: Bhawani Shanker
authors.initials: BS
authors.lastname: Sharma
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Mahapatra
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002543:Cerebral Hemorrhage / Q000209:etiology* / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D016634:Radiosurgery