on January 8, 2009
Published online before print January 8, 2009, doi: 10.1161/STROKEAHA.108.524124
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on May 7, 2008
From the Departments of Neurosurgery (C.N.I., A.M.P., K.R.H., E.I.L., L.N.H., S.R., J.M.) and Radiology (C.N.I., D.R.B., E.I.L., L.N.H., S.R.), Pathology (J.K.), and Physics (A.D., K.R.H., D.R.B.), and Toshiba Stroke Research Center (C.N.I., A.M.P., A.D., K.R.H., D.R.B., E.I.L., L.N.H., S.R.), School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY; Department of Neurosurgery (E.I.L., L.N.H., J.M.), Millard Fillmore Gates Hospital, Kaleida Health, Buffalo, NY. * To whom correspondence should be addressed. E-mail: cnionita{at}buffalo.edu.
Background and Purpose—Development of hemodynamic modifying devices to treat intracranial aneurysms is an active area of research. The asymmetrical vascular stent (AVS), a stent containing a low-porosity patch, is such device. We evaluate AVS efficacy in an in vivo intracranial aneurysm model. Methods—We created 24 elastase rabbit model aneurysms: 13 treated with the AVS, 5 treated with standard coronary stents, and 6 untreated controls. Four weeks after treatment, aneurysms underwent follow-up angiography, cone-beam micro-CT, histological evaluation, and selective electron microscopy scanning. Results—Four rabbits died early in the study: 3 during AVS treatment and 1 control (secondary to intraprocedural vessel injury and an unrelated tumor, respectively). AVS-treated aneurysms exhibited very weak or no aneurysm flow immediately after treatment and no flow in all aneurysms at follow-up. Standard stent-treated aneurysms showed flow both after treatment (5/5) and at follow-up (3/5). All control aneurysms remained patent during the study. Micro-CT scans showed: 9 of 9 scanned AVS aneurysms were occluded, 6 of 9 AVS were ideally placed, and 3 of 9 low-porosity region partially covered the aneurysm neck; standard stent-treated aneurysms were 1 of 5 occluded, 2 of 5 patent, and 2 of 5 partially patent. Histology results demonstrated: for AVS-treated aneurysms, advanced thrombus organization in the (9/9); for standard stent-treated aneurysms, (1/4) no thrombus, (2/4) partially thrombosed, and (1/4) fully thrombosed; for control aneurysms (4/4), no thrombus. Conclusion—The use of AVS shows promise as a viable new therapeutic in intracranial aneurysm treatment. These data encourage further investigation and provide substantial support to the AVS concept.
Revised on July 10, 2008
Accepted on August 1, 2008
The Asymmetric Vascular Stent. Efficacy in a Rabbit Aneurysm Model
Ciprian N. Ionita PhD*;
Key words: aneurysm • asymmetrical • elastase • hemodynamics • modification • stent model • vascular