一側pterional approach (同一頭位, 同一開頭)による多発性脳動脈瘤の処理

-可能性とその限界-

抄録

A patient is placed in the semi-Fowler's position, the upper body is elevated 15 degrees and the lower is also elevated 10 degrees from a supine position. The head is fixed with a three-point skull fixation device after being rotated 45 degrees toward the contralateral side.
This head position makes it easy to reach the Willis ring along the sphenoidal ridge with minimum retraction of the brain.
Most aneurysms are found on the main vessels around the Willis ring; looking at the main vessels from the same angle, and dissecting the vessels and the aneurysm in the same direction, one will have better orientation and surgical techniques.
Aneurysms around the Willis ring, including basilar top aneurysm and middle cerebral artery aneurysms, are operated on in the same position and through the same pterional approach.
In addition, neck clipping may be possible even in some contralateral aneurysms with an uilateral pterional approach.
This unilateral pterional approach is especially beneficial in treating cases of multiple aneurysms.
Over one half of all contralateral IC aneurysms and about one third of all contralateral MC aneurysms can be clipped with a unilateral pterional approach.
A contralateral anterior choroidal artery aneurysm cannot be clipped because it is hidden behind the optic chiasma.
In handling a basilar top aneurysm, it is rather easy when the length of the IC to the bifurcation of A₁ and M₁ is long enough, but it is difficult when the IC is arteriosclerotic and not movable, because the space for surgical maneuver is too narrow.