Yonsei Med J.  2007 Aug;48(4):634-638. 10.3349/ymj.2007.48.4.634.

Association between Internal Carotid Artery Morphometry and Posterior Communicating Artery Aneurysm

• Kim DW
• Kang SD

• KMID: 2158168
• DOI: http://doi.org/10.3349/ymj.2007.48.4.634

Abstract

PURPOSE
The goal of this study was to directly measure the association between the internal carotid artery (ICA) morphometry and the presence of ICA-posterior communicating artery (PCOM) aneurysm. MATERIALS AND METHODS: The authors intraoperatively measured the length of the supraclinoid ICA because it is impossible to radiologically determine the exact location of the anterior clinoid process. We used an image analyzer with a CT angiogram to measure the angle between the skull midline and the terminal segment of the ICA (ICA angle), as well as the diameter of the ICA. The lengths and diameters of the supraclinoid ICA and the ICA angle were compared among PCOM aneurysms, anterior communicating artery (ACOM) aneurysms, and middle cerebral artery (MCA) bifurcation aneurysms (n=27 each). Additionally, the lengths and the diameters of M1 and A1 were compared for each aneurysm. RESULTS: The lengths of the supraclinoid ICA were 11.9+/-2.3mm. The lengths of the supraclinoid ICA in patients with ICA-PCOM aneurysms (9.7+/-2.8mm) were shorter than those of patients with ACOM aneurysms (13.8+/-2.2mm, Student's t-test, p<0.001) and with MCA bifurcation aneurysms (12.2+/-1.9 mm, Student's t-test, p<0.001). The diameters of the supraclinoid ICA and A1 in patients with ACOM aneurysms were larger than those in patients with MCA bifurcation aneurysms (Student's t-test, p<0.05). There were no significant differences in the lengths of M1 and A1, ICA angle, or diameter of M1 for each aneurysm. CONCLUSION: These results suggest that the relatively shorter length of the supraclinoid ICA may be a novel risk factor for the development of ICA-PCOM aneurysm with higher hemodynamic stress.

Keyword

Internal carotid artery, ,; morphometry; cerebral aneurysm

MeSH Terms

Carotid Artery Diseases/congenital/*radiography
Carotid Artery, Internal/abnormalities/*radiography
Humans
Intracranial Aneurysm/*radiography
Risk Factors

Figure

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  Fig. 1 Intraoperative photograph of the measurement obtained before anterior clinoidectomy. The length of the left supraclinoid internal carotid artery (ICA) was defined from the ICA bifurcation to the point where the ICA view becomes obstructed the anterior clinoid process (ACP). (a) ICA, (b) A1 portion of the anterior cerebral artery, (c) optic nerve, (d) ACP.

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  Fig. 2 The ICA angle and supraclinoid ICA diameter as measured with an image analyzer on CT angiogram. The ICA angle was defined as the angle between the skull midline and terminal segment.

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  Fig. 3 Measurement of the length and diameter of the M1 portion of the middle cerebral artery (MCA) and dominant A1 portion of the anterior cerebral artery with an image analyzer on CT angiogram.

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  Fig. 4 The length of the supraclinoid ICA, A1, and M1 according to the aneurysm location. The lengths of the posterior communicating artery (PCOM) aneurysm (9.7 ± 2.8mm) are shorter than those of the anterior communicating artery (ACOM) aneurysms (13.8 ± 2.2mm) (Student's t-test, p < 0.001) and of MCA bifurcation aneurysms (12.2 ± 1.9mm) (Student's t-test, p < 0.001). Data are expressed as the mean ± standard deviation.

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  Fig. 5 The diameter of the supraclinoid ICA, A1, and M1 according to the aneurysm location. The diameters of the supraclinoid ICA in patients with ACOM aneurysm (4.7 ± 1.3mm) are larger than those of MCA bifurcation aneurysms (3.8 ± 1.0mm) (Student's t-test, p < 0.05) and of PCOM aneurysms (4.1 ± 0.9mm). Also, the diameters of the A1 in patients with ACOM aneurysms (2.4 ± 0.7mm) were larger than those of patients with MCA bifurcation aneurysms (2.0 ± 0.4mm) (Student's t-test, p < 0.05) or with Pcom aneurysms (2.1 ± 0.7mm). Data are expressed as the mean ± standard deviation.

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  Fig. 6 The ICA angle according to the aneurysm location. There are no significant differences among the different aneurysms. Data are expressed as the mean ± standard deviation.

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