Abstract
Clipping of paraclinoid internal carotid artery aneurysms related to the superior
hypophyseal artery (SHA) carries risk of occlusion of this artery when originating
distal to the neck of the aneurysm. Sometimes it is inevitable to sacrifice the artery
to achieve total aneurysm occlusion. Otherwise a residual aneurysm would remain, which
may lead to aneurysm regrowth and subsequent rupture. However, consequences of SHA
sacrifice are rarely reported in the literature. In the two presented cases, the SHA
was found originating distal to the neck and within the wall of the aneurysm, making
the optimal clipping of the aneurysm at the neck unfeasible without trapping of the
SHA. Intraoperative indocyanine green (ICG) angiography revealed a retrograde blood
flow in the SHA distal to the clip in both patients, indicating some collateral circulation.
No endocrinologic deficits were encountered after surgery. The vision was not affected
in one patient. In the other patient, bilateral visual field defects occurred, which
improved partially in the follow-up 2 months after surgery. The consequences of SHA
occlusion are difficult to predict. A large variety of anatomical variations of the
vascular anatomy exists. Intraoperative ICG angiography may help to estimate collateral
blood flow but is not able to predict visual decline. Although final conclusions cannot
be drawn from two patients, it seems that in case of multiplicity of superior hypophyseal
complex, sacrifice of one even larger branch is safe. However, visual sequelae have
to be taken into consideration when a single SHA has to be sacrificed for total aneurysm
clipping.
Keywords
superior hypophyseal artery aneurysm - superior hypophyseal artery sacrifice - aneurysm
clipping - collateral blood flow
