Embolization of an Unruptured Distal Lenticulostriate Aneurysm Associated with Moyamoya Disease

Abstract

SUMMARY: Lenticulostriate aneurysms are rare and usually present with intracranial hemorrhage, limiting understanding of their natural course. We describe an unusual case of an unruptured rapidly growing distal LSA aneurysm in the setting of Moyamoya disease, successfully embolized with n-BCA following functional neurologic testing with amobarbital.ABBREVIATIONS: n-BCA ϭ n-butyl cyanoacrylate; MCA ϭ middle cerebral artery; ACA ϭ anterior cerebral artery; LSA ϭ lenticulostriate artery; DSA ϭ digital subtraction angiography R eports of LSA aneurysms are rare in the literature, numbering in the low 20s, with most cases diagnosed following intracranial hemorrhage due to rupture. [1][2][3][4][5] The natural history of these aneurysms is, therefore, largely uncertain. Predisposing factors include hypertension, arteriovenous malformation, infection, systemic lupus erythematosus, and Moyamoya disease. 4,5 The inherent difficulty in surgical treatment of these aneurysms, due to deep location, small size, and sometimes unfavorable morphology, is compounded in the setting of Moyamoya disease by vessel hemodynamic fragility.2,6-8 We discuss the utility of functional testing with amobarbital (Amytal) before endovascular embolization with n-BCA of an unruptured distal LSA aneurysm in the setting of Moyamoya disease. Case ReportA 35-year-old woman with Moyamoya disease and a history of 2 ruptured aneurysms was referred for follow-up. Physical examination demonstrated mildly decreased strength on the left, decreased bilateral upper quadrant peripheral vision and right-sided hearing loss, and slightly unsteady gait. Reflexes and sensory examination findings were normal. Mental status examination demonstrated normal higher cortical and language function. The findings of the remainder of her physical examination and medical history were unremarkable.CT angiography demonstrated a 3-mm right distal LSA aneurysm and a Moyamoya vascular pattern, with numerous small-vessel collaterals supplying the MCA and ACA territories bilaterally. A right frontal pericallosal artery branch aneurysm clip was present. Conventional angiography 1 month later again demonstrated a right LSA aneurysm, now measuring 4.2 ϫ 3.9 ϫ 3.8 mm with a 1.8-mm neck, and collateral supply to a posterior frontal MCA branch. She was referred for endovascular treatment 10 days later.A 6F Guider catheter (Boston Scientific, Fremont, California) was positioned in the distal right internal carotid artery, through which an Excelsior SL-10 microcatheter (Target Therapeutics/Boston Scientific, Fremont, California) was advanced over a Synchro-10 microguidewire (Boston Scientific, Natick, Massachusetts) and positioned proximal to the aneurysm within the involved LSA. Superselective contrast injection demonstrated a 4.4-mm LSA aneurysm, retrograde filling of a dilated right posterior frontal MCA branch collateral from the aneurysm, and faint basal ganglia blush (Fig 1A). We administered 25 mg of Amytal via the microcatheter; subsequent neurologic examination demonstrated left faci...

Lenticulostriate aneurysms: a case series and review of the literature

“…Several cases have been reported using n-butyl-2-cyanoacrylate and Onyx to sacrifice the parent LSA in order to treat the aneurysm 6 9 11 13 22. Three of five cases treated in this manner did not have any evidence of basal ganglia infarct postprocedurally.…”

“…Seven cases have been reported in the pediatric literature, of which two were associated with an underlying AVM 5 6 17–21. Most cases have been treated with open surgical clipping or excision but increasingly less invasive treatment options are becoming available, such as endovascular embolization9 11 13 22 and gamma knife radiosurgery 23. Conservative management has also been described, with angiographic resolution or near resolution of the aneurysm 1 10 24 25…”

“…As the LSAs supply the basal ganglia, care should be taken before sacrificing these vessels. Endovascular treatment allows for evaluation of the vascular territory supplied by individual LSAs through injection of amobarbital injection or test occlusion with subsequent intraprocedural neurological examination 11. Patients with moyamoya-like blood vessels deserve special consideration as their vasculature can be frail and susceptible to damage.…”

Resolution of bilateral moyamoya associated collateral vessel aneurysms: Rationale for endovascular versus surgical intervention

“…In such cases, superselective Amytal injection has been reported as one method to discern the safety of embolization. [7] We refrained from Amytal testing, as it was felt that any sacrifice of major collateral circulation would increase the risk of subsequent, if not acute, stroke. On the other hand, endovascular treatment of the right-sided aneurysm presenting with hemorrhage posed no significant risk of further deficit, as the distal territory had already been affected by the hemorrhage.…”

Surgical management of a ruptured posterior choroidal intraventricular aneurysm associated with moyamoya disease

“…Aneurysms are thought to arise in collateral vascular structures in moyamoya disease, like perforator and choroidal artery because of altered hemodynamics and the inherent vascular fragility [1] The cause of hemorrhage is reportedly moyamoya vessel failure from hemodynamic stress. Therefore, the rate of rebleeding is higher, especially in the presence of an aneurysm [2].…”