A New Aneurysm Occlusion Classification after the Impact of Flow Modification

Class 1A. A and B, Preoperative images show the ICA aneurysm in which the anterior choroidal artery (arrow) is originating from the aneurysm at the neck. C, Six-month control angiography after single Pipeline device (Covidien, Irvine, California) placement demonstrates total occlusion of the aneurysm with the anterior choroidal artery preserved (arrow). Reprinted from Saatci et al.¹⁸

Class 1C. A, Preoperative angiography shows right vertebral artery aneurysm with the posterior inferior cerebellar artery originating from the sac. B, Single Pipeline device was placed, and a 6-month control angiography demonstrates complete occlusion of the aneurysm sac, along with the posterior inferior cerebellar artery. The patient was asymptomatic.

Class 5 evolving into class 1B eventually. A, Preoperative angiography shows right MCA aneurysm with a branch coming off from the sac. B, A 3D image from a 6-month control angiography after treatment with single Pipeline device shows remodeling of the flow with a tortuous appearance of the branch proximally at its direct continuation with the parent artery, and no sac filling. This appearance is referred to as class 5. C, An 18-month control angiography shows complete occlusion of the aneurysm with the originating branch in reduced caliber, that is, class 1B. Reprinted from Yavuz et al.¹⁹

Class 5. A, Right internal carotid angiogram shows a posterior communicating artery aneurysm (the ipsilateral P1 is aplastic, not shown). B, A 2-year angiography after a single Pipeline device placement shows that the aneurysm sac is not filling and the origin of the posterior communicating artery is remodeled. Reprinted from Saatci et al.¹⁸

Class 5. A, Preoperative angiography shows a large left MCA aneurysm at the trifurcation, with the branches incorporated in the sac. B, Six months after the treatment with a WEB device (Sequent Medical, Aliso Viejo, California), control angiography shows neck filling at the trifurcation, with the branches patent, and this result is classified as class 2. C, An 18-month control angiography shows an unchanged appearance of the MCA trifurcation, and this result is classified as class 5, with the apparently “stable” remodeling.