Fistula and Infratentorial Location, Characteristics That Contribute to Cerebral Arteriovenous Malformations, Lead to the Formation of Associated Aneurysms in Patients.

ABSTRACT

OBJECTIVE: Because the formation of associated aneurysms (AAs) related to the characteristics of cerebral artriovenous malformations (cAVMs) is poorly recognized, the purpose of this study was to identify the responsible characteristics of cAVMs related to the formation of AAs and to identify patients with responsible characteristics related to the formation of AAs through the analysis of the outcomes of these patients after treatment. METHODS: This study was performed to analyze the baseline characteristics of patients with cAVMs and AAs. The recurrent AA and residual size of cAVMs were used to evaluate the outcomes of patients after treatment. At the same time, the ROC curve was measured to gauge the relationship between the residual size of cAVMs and recurrent AAs in eligible patients. RESULTS: Fifty (15.0%) patients with cAVMs and AA were confirmed; these patients had twice the hazard of hemorrhage as patients with only isolated cAVMs. An infratentorial location (P < 0.001) and fistula (P = 0.002) were independent predictors of the formation of AAs. After a mean 22.7 months follow-up, 2 patients developed recurrent AAs, and the annual recurrence rate for patients with responsible characteristics was 17.6%, but for all patients was 7.2%. The ROC curve showed that patients, specifically patients with responsible characteristics, the residual size of the cAVM was closely related to recurrent AA (area = 0.89, 95% confidence interval 0.81-0.97, P = 0.023, cut-off value = 82.5%). CONCLUSIONS: Patients with cAVMs and AA who harbor a fistula or an infratentorial location tend to form AAs. To prevent recurrent AAs and decrease the subsequent risk of hemorrhage, complete obliteration of cAVMs or retrograding over 80% size of cAVMs is recommended.