Characteristic analysis of hemodynamics for trunk aneurysm of posterior communicating artery

Abstract

Objective To study the hemodynamic characteristics of the difference between the trunk aneurysm of posterior communicating artery (PCoA) and the internal carotid artery (ICA)-PCoA aneurysm. Methods A total of 15 patients with trunk aneurysm of PCoA (11 ruptured aneurysms, 4 unruptured aneurysms, for short PCoA trunk group) treated at the Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Capital Medical University from January 2014 to June 2015 were studied retrospectively. The 15 patients with ICA-PCoA aneurysm with approximately the same size and the same rupture state at the same time were used as a matched control group. A numerical simulation analysis was conducted for individual three-dimensional digital subtraction angiography (DSA) images of the patients using the method of computational fluid dynamics. The differences of hemodynamic parameters of the aneurysms were compared between the 2 groups. Results The PCoA trunk aneurysms were in accordance with the blood flow pattern of the lateral aneurysms, and the ICA-PCoA aneurysms were in accordance with the flow blood pattern of the aneurysms at the bifurcations. The hemodynamic parameters in the PCoA trunk group vs. the control group: The wall shear stress (WSS) of the PCoA trunk group and the control group was 0.48±0.08 and 0.63±0.07 respectively. The percentage of the low WSS area (LSA) was 23.20±6.94% and 4.50±2.29% respectively. There were significant differences (P=0.022, P=0.008). The oscillatory shear index (OSI) of the two groups was 0.0233±0.0071 and 0.0158±0.0044 respectively. There was no significant difference (P=0.411). The WSS of the ruptured group (n=22) and the unruptured group (n=8) was 0.45±0.05 and 0.84±0.08 respectively, and LSA was 18.22±5.11% and 1.84±1.76% respectively. There was significant difference (P<0.001, P=0.006). The OSI of the two groups was 0.0234±0.0054 and 0.0091±0.0027 respectively. There was no significant difference (P=0.132). Conclusion The low WSS may be one of the reasons for the high risk of PCoA trunk aneurysm rupture. Key words: Intracranial aneurysms; Aneurysm, ruptured; Hemodynamics; Posterior communicating artery; Computational fluid dynamics