Surgical anatomy of the superior hypophyseal artery and its relevance for endoscopic endonasal surgery

Abstract

OBJECTIVE The endoscopic endonasal approach has become a routine corridor to the suprasellar region. The superior hypophyseal arteries (SHAs) are intimately related to lesions in the suprasellar space, such as craniopharyngiomas and meningiomas. Here the authors investigate the surgical anatomy and variations of the SHA from the endoscopic endonasal perspective. METHODS Thirty anatomical specimens with vascular injection were used for endoscopic endonasal dissection. The number of SHAs and their origin, course, branching, anastomoses, and areas of supply were collected and analyzed. RESULTS A total of 110 SHAs arising from 60 internal carotid arteries (ICAs), or 1.83 SHAs per ICA (range 0-3), were found. The most proximal SHA always ran in the preinfundibular space and provided the major blood supply to the infundibulum, optic chiasm, and proximal optic nerve; it was defined as the primary SHA (pSHA). The more distal SHA(s), present in 78.3% of sides, ran in the retroinfundibular space and supplied the stalk and may also supply the tuber cinereum and optic tracts. In the two sides (3.3%) in which no SHA was present, the territory was covered by a pair of infundibular arteries originating from the posterior communicating artery. Two-thirds of the pSHAs originated proximal to the distal dural ring; half of these arose from the carotid cave portion of the ICA, whereas the other half originated proximal to the cave. Four branching patterns of the pSHA were recognized, with the most common pattern (41.7%) consisting of three or more branches with a tree-like pattern. Descending branches were absent in 25% of cases. Preinfundibular anastomoses between pSHAs were found in all specimens. Anastomoses between the pSHA and the secondary SHA (sSHA) or the infundibular arteries were found in 75% cases. CONCLUSIONS The first SHA almost always supplies the infundibulum, optic chiasm, and proximal optic nerve and represents the pSHA. Compromising this artery can cause a visual deficit. Unilateral injury to the pSHA is less likely to cause an endocrine deficit given the artery's abundant anastomoses. A detailed understanding of the surgical anatomy of the SHA and its many variations may help surgeons when approaching challenging lesions in the suprasellar region.

Efficacy and Safety of Willis Covered Stent for Treatment of Complex Vascular Diseases of the Internal Carotid Artery

“…Serious visual impairment could be caused by the covering of the superior hypophyseal artery. 19 In our series, the ophthalmic artery, anterior choroidal artery, and fetal-type posterior cerebral artery were not occluded by the covered stent, which may be attributed to appropriate case selection and careful evaluation of the location of the perforating arteries from multiple angles as well as the assistance of the two markers that point to the two ends of the Willis covered stent.…”

The expanded endoscopic endonasal approach for treatment of tuberculum sellae meningiomas in a series of 40 consecutive cases

“…The superior hypophyseal artery (SHA) originates from the ICA. Bilateral SHAs send out small branches to supply the lower surface of the optic chiasm, and branches from the ACAC provide the blood supply for the upper surface of the optic nerve 20,28 . Whether these blood vessels are preserved is closely related to the postoperative vision of patients 24 .…”

“…But whether occlusion of a unilateral SHA can lead to visual impairment is not known. In an anatomic study, Truong et al 28 showed that determination of visual outcome after occlusion of the SHA on one side was not possible. However, the overall impression was that the blood supply and vascular anastomosis of the optic nerve and optic chiasm were rich.…”

Principios generales de embriología hipofisaria y manifestaciones clínicas de las alteraciones en su desarrollo

“…La superior es una rama de la carótida interna que irriga la pars tuberalis (la parte superior de la adenohipófisis que envuelve el tallo hipofisario), el infundíbulo y la eminencia media. La arteria hipofisaria inferior es una rama del tronco meningohipofisario de la arteria carótida interna, que ingresa por la parte posterior de la glándula 13 . Las arterias forman capilares que permiten el movimiento de nutrientes y hormonas y drenan hacia las venas portales.…”