Vasa Vasorum Formation is Associated With Rupture of Intracranial Aneurysms

Abstract

Abstract INTRODUCTION Subarachnoid hemorrhage has a poor outcome despite a modern advancement in medical care. The development of a novel therapeutic strategy to prevent rupture of intracranial aneurysms (IAs) or a novel diagnostic marker to predict rupture-prone lesions is thus mandatory. Therefore, in the present study, we established a rat model in which IAs spontaneously rupture and examined this model to clarify histopathological features associated with rupture of lesions. METHODS In detail, female Sprague-Dawley rats were subjected to the bilateral ovariectomy, the ligation of the left common carotid, the right external carotid, and the right pterygopalatine arteries, the induced systemic hypertension, and the administration of a lysyl oxidase inhibitor. RESULTS Aneurysmal subarachnoid hemorrhage occurred one-thirds of manipulated animals and locations of ruptured IAs were exclusively at a posterior or an anterior communicating artery. Histopathological examination using ruptured IAs, rupture-prone ones induced at a posterior or an anterior communicating artery, ones induced at an anterior cerebral artery-olfactory artery bifurcation that never rupture revealed the formation of vasa vasorum as an event associated with rupture of IAs. CONCLUSION We thus proposed the contribution of a structural change in an adventitia, vasa vasorum formation, to rupture of IAs. Findings from this study provide important insights about the pathogenesis of IAs.