Anatomical Relationship between the Superior Hypophyseal Artery and the Carotid Cave

ABSTRACT

Interests in the microanatomy of the proximal segment of the internal carotid artery(ICA) have been increased due to the anatomical complexity of this region and the potential sites of the aneurysmal formation. In this study, microanatomical dissections were performed in 70 specimens obtained from 35 formalin-fixed human cadaveric heads to examine the superior hypophyseal arteries(SHAs), ophthalmic artery, and the carotid cave. In our study, 54(77%) carotid caves were presented in 70 specimens. Twenty-five(71%, 50 caves) cadavers harbored the carotid caves on both sides, 4(11%, 4 caves) cadavers only on the one side and the remaining 6(17%) didn't have the caval structure. Total of 162 SHAs which have showen to arise from the medial or posterior aspect of the ophthalmic(C6) segment of the ICA in all cases were identified 108(67%) arose from the proximal half of the C6 segment and 54(33%) from the distal half. Interestingly, in 54 specimens which had the carotid caves, one to four SHAs arose from the part of the C6 segment within the cave in the 43(80%) specimens. Total number of the SHAs originated within the carotid cave were 51. Sixty-four(91%) of ophthalmic arteries have shown to arise just distal to the distal dural ring on C6 segment, whereas 4(6%) from the clinoid(C5) segment and in 2(3%) cases, the ophthalmic artery arose just at the insertion of the distal dural ring level. The authors describe the microanatomical relationships between the SHA and the carotid cave, and the origin of the SHA and the ophthalmic artery. We hope to get better knowledge of the vascular relationship and the possible mechanism of the SHA aneurysm.