CEREBRAL ARTERIOVENOUS MALFORMATION WITH PARANIDAL ANEURYSMS. CLINICAL COURSE AND OUTCOME AFTER ENDOVASCULAR EMBOLIZATION.

The association of cerebral arteriovenous malformations (bAVM) and associated paranidal aneurysms, that is closely related to the AVM nidus, carry a high risk of rapture and re-rapture after initial hemorrhage. This association is consider as therapeutic challenge and supportive data about their natural history and best treatment modalities are still lacking. In this article we report our experience of their treatment. We reviewed 443 cases of patients with AVMs between 2004 and 2018, who were treated at our institution and found 73 (16,5%) cases of AVM association with paranidal aneurysms (22 (30,2%) arterial - prenidal, 20 (27,4%) intranidal, and 19 (26,0%) venous - postnidal). Twelve (16,4 %) patients had multiple aneurysm. All patients received endovascular treatment with n-butyl cyanoacrylate (NBCA), ONYX or Embolin embolization. We evaluated clinical and radiological data, treatment and outcomes at discharge. Among 73 patients (32 (43,8 %) women and 41 (56,2 %) men, mean age - 34 years, 8 - 65 years) with AVM and paranidal aneurysms who were enrolled in our study, hemorrhage was the most frequent presenting symptom (47 patients (64.4%). The timing of procedure varied between 3 - 23 days. Total occlusion of AVM was achieved in 23 (31,5%) cases, in all other cases partial or target occlusion with obligatory aneurysm embolization was done. Seven (9,6%) patients had complication (5 ischemic and 2 hemorrhagic) after procedure. Clinical improvement was seen in all groups at discharge. Mean change of mRS score between admission and discharge was 0,2-0,5 point. Excellent or good outcome (mRS - 0,1,2) was observed in 58 (79,5%) patients at discharge. Unfavorable outcome (mRS - 3-5) had 13 (17,8%) patients, mRS - 6 - 2 (2,7%) patients. Patients sustaining AVM and multiple paranidal aneurysms had higher risk of hemorrhage comparing with single one (OR-17,5 (95% CI -1,0-309,8 (p=0,010). Relationship between AVM with paranidal aneurysms and hemorrhagic presentation is obvious, however definite source of hemorrhage is difficult to evaluate. To our belief arterial prenidal and intranidal aneurysms especially multiple are the most dangerous and should be in therapeutic focus after it's finding. Endovascular embolization has the potential to be effective and safe in treatment of AVM with paranidal aneurysms.