Abstract
Stenosis of perforating artery, which occurs during neck clipping of cerebral saccular aneurysm or in trapping operation of cerebral fusiform aneurysm, was examined using the chicken ascending aortic artery. In neck clippings, the orifice of the perforating artery became narrow when the aneurysmal clip was applied pointing to the perforating artery which was just in the vicinity of the aneurysmal neck, although its outward appearance did not show the stenosis. When the clip was applied passing beside the perforating artery, the artery was patent. Therefore, the clip should be applied passing beside the perforating artery and not occlude its orifice. In trapping, When the clip was applied parallel to the perforating artery, the intima of the perforating artery was approximated and its vascular lumen became narrow despite its normal outward appearance. On the contrary, when the clip was applied at a right angle to the perforating artery, its orifice was left open. When the fusiform aneurysm is hard and a tiny perforating artery is just in the vicinity of the aneurysm, the trapping clip must be applied at a right angle to the perforating artery.
