Experimental aneurysms.

Aneurysms were produced experimentally with vein patch grafts on the carotid artery in the neck in rats. Aneurysms created at the bifurcation of the common carotid artery had a greater tendency to enlarge than did those on the trunk of the common carotid artery. Four aneurysms on the carotid trunk thrombosed; none did so at the bifurcation. The aneurysms ruptured in nine cases, more often when they were covered with oxycell than when they were not. Experimental aneurysms were also produced on the middle cerebral arteries in dogs.