De Novo Formation and Rupture of an Intracranial Aneurysm 10 Months After Normal Findings on Conventional Magnetic Resonance Angiography in a Patient With No History of Intracranial Lesions -Case Report-

Abstract

A 40-year-old male smoker presented with a ruptured saccular aneurysm that formed de novo 10 months after normal magnetic resonance (MR) angiography findings. Computed tomography of the head at the second admission showed subarachnoid hemorrhage in the interhemispheric fissure and anterior basal cistern. MR and conventional cerebral angiography revealed an aneurysm arising from the anterior communicating artery (AcomA). MR angiography performed 10 months earlier, when he experienced transient loss of consciousness, revealed no anomalies at the AcomA. Intraoperatively, the de novo aneurysm was found to be a typical saccular aneurysm with a fragile wall.

Risk of hemorrhage from de novo cerebral aneurysms

“…Previously published case reports suggest a high rate of SAH in rapidly developing de novo aneurysms, especially in hypertensive patients. 24,28,34,37,44 However, other reports suggest a longer time between discovery of the initial aneurysm and discovery of the de novo aneurysm. Yoneoka et al 45 reported on 12 patients with ruptured de novo aneurysms.…”

Rapid aneurysm growth and rupture in systemic lupus erythematosus

“…Abnormal flow produces local changes in blood pressure and wall sheer stress, which lead to endothelial remodeling and consequent changes in aneurysm geometry. [ 8 9 10 37 40 42 47 48 49 50 55 ] Progressive geometric alteration begets further hemodynamic stress, and the cycle of positive feedback propagates aneurysm growth and rupture. In parallel, inflammation and ischemia induce endothelial remodeling and seed aneurysm growth, via collagen and fibrin deposition within the walls, thinning of the domes, vascular smooth muscle deficiency, fibroblasts and leukocytes infiltration, degradation of matrix proteins, and elevated elastase and collagenase activity.…”

<i>De novo</i> cavernous aneurysms development after contralateral parent artery occlusion—Two cases report

“…Several events were regarded as risk factors with the development of de novo aneurysm, such as middle age, female, hypotension, alcohol consumption and subarachnoid hemorrhage [13][14][15]. Although the incidence of de novo aneurysm formation after PAO may be no higher than those patients with clipped aneurysms, some authors considered that PAO itself may contribute to the development of de novo aneurysms.…”

“…However, hemodynamic changes were regarded as an important contributory factor. Hemodynamic changes were characterized as high wall shear stress (WSS) and high wall shear stress gradient (WSSG) [2,13,14,[16][17][18]. To supply the ipsilateral circulation following PAO, contralateral blood flow was subject to increase, which leaded to high wall shear stress and high wall shear stress gradient mainly in contralateral carotid artery.…”