Morphological characteristics associated with rupture risk of multiple intracranial aneurysms

Objective: To identify the morphological parameters that are related to intracranial aneurysms(IAs) rupture using a case-control model.Methods: A total of 107 patients with multiple IAs and aneurysmal subarachnoid hemorrhage between August 2011 and February 2017 were enrolled in this study.Characteristics of IAs location, shape, neck width, perpendicular height, depth, maximum size, flow angle, parent vessel diameter(PVD), aspect ratio(AR) and size ratio(SR) were evaluated using CT angiography.Multiple logistic regression analysis was used to identify the independent risk factors associated with IAs rupture.Receiver operating characteristic curve analysis was performed on the final model, and the optimal thresholds were obtained.Results: IAs located in the internal carotid artery(ICA) was associated with a negative risk of rupture, whereas AR, SR1(height/PVD) and SR2(depth/PVD) were associated with increased risk of rupture.When SR was calculated differently, the odds ratio values of these factors were also different.The receiver operating characteristic curve showed that AR, SR1 and SR2 had cut-off values of 1.01, 1.48 and 1.40, respectively.SR3(maximum size/PVD) was not associated with IAs rupture.Conclusions: IAs located in the ICA are associated with a negative risk of rupture, while high AR(>1.01), SR1(>1.48) or SR2(>1.40) are risk factors for multiple IAs rupture.

Nonclassical Cause of Obstructive Jaundice: A Case Report of Multiple Visceral Arterial Aneurysms in a Young Patient

Multiple visceral artery aneurysms are relatively rare;the rarest are superior mesenteric artery and gastroduodenal artery aneurysms. The clinical presentation depends on the size and site of the aneurysm. We report the case of a 33-year-old man with recurrent episodes of obstructive jaundice and weight loss. Computed tomography with contrast revealed scattered hepatic arterial aneurysms with two other aneurysms along the course of the left gastro-duodenal and superior mesenteric artery. Investigations to determine the etiology were negative, but the patient had a history of smoking and substance abuse. Angiography revealed an occluded feeding artery. The patient developed multiorgan failure, leading to cardiac arrest and died. Diagnosing multiple visceral artery aneurysms needs a high index of suspicion;early diagnosis enables early intervention, which can reduce the high mortality of this condition.

Wall shear stress in intracranial aneurysms and adjacent arteries

Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries.