Risk factors for three phases of 12-month mortality in a defined population after subarachnoid hemorrhage

Quantifying asymmetry of anterior cerebral arteries as a predictor of anterior communicating artery complex aneurysm

OBJECTIVES

The aim of this study was to establish an anatomical index for early prediction of the risk of development of aneurysms in anterior communicating arterial complex (AcomAC). The asymmetric diameter of one anterior cerebral artery (ACA) to other could alter haemodynamics and may contribute to formation of aneurysms in AcomAC and be a reliable predictor of the risk of development of aneurysms.

DESIGN AND SETTING

This is a retrospective, observational and quantitative study, which used cerebral computed tomography angiography (CCTA) scans in South Australia.

PARTICIPANTS

CCTA scans of 166 adult patients of both sexes were studied.

MAIN OUTCOME MEASURES

The internal diameters of the proximal segments of ACAs (A1s) were measured. Position and presence or absence of aneurysms in AcomAC were determined. The ratio of A1 diameters was taken as a measure of A1 asymmetry.

RESULTS

The ratio of diameters of A1s correlated with the occurrence of AcomAC aneurysms. The risk of development of aneurysms in AcomAC was much greater (80%, OR=47.3) when one A1 segment's radius was at least 50% larger (ie, 2.25 times cross-sectional area) than the other.

CONCLUSION

The general information on asymmetric A1 has been published previously. The present findings have significant contribution since the A1s asymmetry ratios have been categorised in ascending order and matched with the presence of AcomAC aneurysms. The asymmetry ratio of the A1 is a good predictor for the development of AcomAC aneurysms. Reconstruction of the asymmetric A1 could be done if the technology gets advanced.