Bleeding after radiosurgery for cerebral arteriovenous malformations.
OBJECTIVE
Obliteration is progressive after radiosurgery (RS) for cerebral arteriovenous malformation (AVM), and until it is complete, there is still a risk of hemorrhage. The aim of our study was to evaluate the severity of hemorrhage after RS, the actuarial risk of hemorrhage, and the parameters associated with hemorrhage.


METHODS
Of 756 patients treated by linear accelerator RS for AVM, 51 (6.5%) had one or more hemorrhages after the RS. We studied the clinical, anatomic, and dosimetric parameters and obliteration rate before hemorrhage and then calculated the actuarial risk per patient and per hemorrhage before and after RS. Correlations between parameters and risk were studied by univariate and multivariate analysis using Kaplan-Meier hemorrhage-free survival curves and the Cox model.


RESULTS
Apart from one exclusively ventricular hemorrhage, which caused the death of the patient, only parenchymal hemorrhages were associated with morbidity and neurological deficits (64.5% of all cases of hemorrhage had neurological deficits, 45% had a permanent deficit). The overall mortality rate per hemorrhage was 7.14%. The overall morbidity rate was 47.6%, 26.2% with a permanent deficit. In all but one patient, the AVM was not cured before hemorrhage; thus, the mean obliteration rate before hemorrhage was 24%. The actuarial hemorrhage rates were 3.08% per year per patient and 3.31% per year per hemorrhage. The actuarial rate per patient increased from 1.66% the 1st year to 3.87% in the 5th year after RS but was not statistically different from the rate before radiosurgery. The parameters found to be correlated with hemorrhage risk after RS using multivariate analysis were intranidal or paranidal aneurysms, complete coverage, and minimum dose.


CONCLUSIONS
The risk of hemorrhage after RS would seem to be the sum of hemorrhage risk factors of the AVM and factors predicting a poor level of obliteration. These factors can be predicted in some cases but rarely avoided.
Nataf
François
F
Department of Neurosurgery, Centre Hospitalier Sainte-Anne, Paris, France. nataf@chsa.broca.inserm.fr
Ghossoub
May
M
Schlienger
Michel
M
Moussa
Ronald
R
Meder
Jean-François
JF
Roux
François-Xavier
FX
D000206:Actuarial Analysis; D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001925:Brain Damage, Chronic / Q000401:mortality; D002423:Cause of Death; D002543:Cerebral Hemorrhage / Q000209:etiology* / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D005260:Female; D005602:France; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D002538:Intracranial Arteriovenous Malformations / Q000401:mortality / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000706:statistics & numerical data; D019106:Postoperative Hemorrhage / Q000209:etiology* / Q000401:mortality; D016634:Radiosurgery / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis