Abstract Number ‐ 133: Intraventricular Pseudoaneurysm embolization in Moyamoya disease with NBCA
Authors: Jafarli Alibay , Burns Joseph , Orru Emanuele , Wakhloo Ajay 
Published: April 2023

Introduction
Moyamoya is a chronic occlusive cerebrovascular disease characterized by progressive steno‐occlusion of intracranial internal carotid arteries (ICAs) and their proximal branches (ACA, MCA) with development of hypertrophied collateralizing perforators. [1] Affected adults can suffer intraventricular hemorrhages (IVH) from ruptures of hypertrophic collaterals in some cases with formation of a pseudoaneurysm. [2,3] Pseudoaneurysms can be treated conservatively, by microsurgical clipping or endovascular embolization). Endovascular therapy allows easier reach and multiple treatment modalities (coiling, liquid embolization). [4‐7]

Methods
We present the case of a 44 year old male with Moyamoya disease who suffered a large IVH.

Results
The patient was brought to the ED after becoming unresponsive. A CT head showed diffuse subarachnoid and intraventricular hemorrhage. CTA revealed extensive Moyamoya disease with prominent hypertrophied ICA‐MCA perforator collaterals and irregular appearance of a right basal ganglia perforator, concerning for pseudoaneurysm. DSA showeda 4.2×3.3 mm pseudoaneurysm of a large hypertrophied perforator originating from the right ICA. A Magic 1.2 microcatheter was used over a 0.007” Hybrid microwire (both Balt, Montmorency, FR) to cannulate the perforator. A mixture of 3 cc of Lipiodol and 1 cc of n‐BCA (N‐butyl‐2‐cyanoacrylate) was injected in the aneurysm with care taken to avoid reflux into in the normal‐appearing portion of the vessel. The aneurysm was excluded from the circulation and post‐operative cone beam CT showed no evidence of large infarction or new intracranial bleeding. After several weeks of neurointensive care, the patient was discharged to rehab. Image description: A. CTA of the head demonstrating diffuse intraventricular hemorrhage (stars) and a spot sign in the territory of the right perforator collaterals concerning for aneurysm. B. DSA of the right internal carotid artery (ICA) demonstrating classic findings of moyamoya disease and a pseudoaneurysm (arrow) at the level of ahypertrophiedICA‐middle cerebral artery perforator collateral. C. Single shot X Ray of the glue cast within the aneurysm and adjacent portions of the vessel. The microcatheter tip is seen at the proximal end of the cast. D. Right ICA DSA after removal of the microcatheter demonstrates exclusion of the aneurysm from the circulation and sparing of adjacent perforator collaterals.

Conclusions
This abstract illustrates a rare case of pseudoaneurysm formation after rupture of a hypertrophied perforator collateral in a case of severe moyamoya disease. Treatment of these lesions should aim to exclude the aneurysm from the circulation and to preserve as much perforator as possible as these vessels supply normal parench This abstract illustrates a rare case of pseudoaneurysm formation after rupture of a hypertrophied perforator collateral in a case of severe Moyamoya disease. Treatment of these lesions should aim to exclude the aneurysm from the circulation and to preserve as much perforator as possible as these vessels supply normal parenchyma.