The asymmetric vascular stent: efficacy in a rabbit aneurysm model.
OBJECTIVE
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.


CONCLUSIONS
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.
Ionita
Ciprian N
CN
Department of Neurosurgery, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA. cnionita@buffalo.edu
Paciorek
Ann M
AM
Dohatcu
Andreea
A
Hoffmann
Kenneth R
KR
Bednarek
Daniel R
DR
Kolega
John
J
Levy
Elad I
EI
Hopkins
L Nelson
LN
Rudin
Stephen
S
Mocco
J Duffy
JD
D000818:Animals; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000473:pathology; D005260:Female; D002532:Intracranial Aneurysm / Q000473:pathology / Q000628:therapy*; D008297:Male; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D011817:Rabbits; D015607:Stents; D013927:Thrombosis / Q000473:pathology; D014057:Tomography, X-Ray Computed