Morphometry of cerebral arterial bifurcations harbouring aneurysms: a case-control study

Endovascular treatment of intracranial internal carotid artery bifurcation region aneurysms

Intracranial internal carotid artery (ICA) bifurcation region aneurysms are uncommon. When treatment is necessary for ICA, endovascular treatment (EVT) can be a useful option. Due to the complexity of these aneurysms and the variability of EVT techniques, EVT for ICA bifurcation aneurysms is challenging. Currently, it is necessary to perform a review to explore this issue further. In this review, the following issues were discussed: the anatomy of the ICA bifurcation region; the classification, natural history and EVT status of ICA bifurcation region aneurysms; the technique used for identifying ICA bifurcation region aneurysms; and the prognosis and complications of EVT for ICA bifurcation region aneurysms. According to the review and our experience, traditional coiling is currently the preferred therapy for ICA bifurcation region aneurysms. In addition, in select cases, new devices, such as flow diverters and Woven EndoBridge devices, can also be used to treat ICA bifurcation region aneurysms. Generally, EVT is an alternative treatment option for ICA bifurcation region aneurysms.

The Association of Morphological Differences of Middle Cerebral Artery Bifurcation and Aneurysm Formation: A Systematic Review and Meta-Analysis

OBJECTIVE

We explored the relationships between morphological parameters of middle cerebral artery (MCA) bifurcations based on imaging and the development of middle cerebral aneurysms. Artery bifurcations can form disordered hemodynamics which can promote the development of aneurysms, whereas the hemodynamic environment at the bifurcation tip is highly reliant on the bifurcation's geometry.

METHODS

We searched 3 electronic databases for all relevant, publicly available publications as of March 18, 2022. Through the screening of abstracts and full texts, a meta-analysis was performed to compare the daughter-to-daughter angle, the inclination angle (γ), and the parent vessel diameter of MCA bifurcations between patients in MCA aneurysm and non-aneurysm controls.

RESULTS

Ten articles describing 1012 patients with MCA aneurysms and 1106 control individuals without aneurysms were included in the analysis. The aneurysm group showed a larger daughter-to-daughter branch angle at MCA bifurcations than the non-aneurysm group (weighted mean difference [WMD] = 42.00; 95% confidence interval [CI], 33.77 to 50.23; P < 0.00001). The daughter-to-daughter angle was also larger in the MCA aneurysm group with than without an aneurysm side branch (WMD = 37.03; 95% CI, 26.57 to 47.50; P < 0.00001), and in the MCA aneurysm group than in the non-aneurysm control group (WMD = 41.87; 95% CI, 29.19 to 54.54; P < 0.00001). The aneurysm group had a larger inclination angle than the control group (WMD = 28.73; 95% CI, 18.78 to 38.69; P < 0.00001). In patients with a MCA aneurysm, the parent vessel of the branch with the MCA aneurysm tended to be smaller in diameter than the contralateral branch without the aneurysm (WMD = -0.12; 95% CI, -0.24 to 0.00; P = 0.05).

CONCLUSIONS

A larger daughter-to-daughter angle and larger inclination angle at MCA bifurcations are closely related to MCA bifurcation aneurysms. The parent vessel diameter is negatively related to MCA bifurcation aneurysms.