Asymmetric vascular stent: feasibility study of a new low-porosity patch-containing stent.
OBJECTIVE
Intracranial aneurysm (IA) treatment through hemodynamic modification with novel stent designs is a burgeoning area of research. We present a feasibility study for a new low-porosity patch-containing stent designed to treat intracranial aneurysms. The device is deployed so the patch covers the aneurysm neck ensuring strong flow diversion away from the aneurysm while keeping a low probability of occlusion of perforating vessels.


METHODS
We created 17 side-wall aneurysms in 6 dogs, 2 per carotid artery if animal size permitted. Twelve proximal aneurysms were treated with AVSs: 5 distal aneurysms were untreated, serving as controls against self-thrombosis; 7 treated aneurysms were fully-covered; and 5 were partially-covered. After 4 weeks, a final angiogram was performed and aneurysms were explanted. Angiograms acquired pre- and posttreatment and at 4-week follow-up were analyzed quantitatively using normalized time-density curves (NTDC). Cone-beam micro-CT and histological specimen analysis were then performed.


RESULTS
Posttreatment, NTDC average peaks dropped to 45% of initial values for the partially-covered aneurysms and 78% for the fully-covered aneurysms. Cone-beam micro-CT imaging performed at 4 weeks posttreatment showed partial thrombosis in 4 of 5 partially-covered aneurysms and complete thrombosis in all fully-covered aneurysms. Histology revealed neointimal coverage of all asymmetrical patch regions and thrombus formation in both fully- and partially-covered aneurysms. Four-week follow-up was not done for 1 animal (2 controls, 2 treated) that expired because of groin hemorrhage and for another animal (1 aneurysm) with an occluded carotid.


CONCLUSIONS
We demonstrate aneurysmal blood flow diversion using a new low-porosity patch-containing asymmetrical vascular stent in a canine side-wall aneurysm model. Overall results are encouraging and support continued AVS development.
Ionita
Ciprian N
CN
Department of Neurosurgery, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14209, USA.
Paciorek
Ann M
AM
Hoffmann
Kenneth R
KR
Bednarek
Daniel R
DR
Yamamoto
Junichi
J
Kolega
John
J
Levy
Elad I
EI
Hopkins
L Nelson
LN
Rudin
Stephen
S
Mocco
J
J
D000792:Angiography; D000818:Animals; D001807:Blood Vessel Prosthesis; D002339:Carotid Arteries / Q000473:pathology; D015331:Cohort Studies; D054893:Cone-Beam Computed Tomography / Q000379:methods; D004285:Dogs; D004867:Equipment Design; D005240:Feasibility Studies; D006439:Hemodynamics; D002532:Intracranial Aneurysm; D016062:Porosity; D011336:Probability; D015607:Stents; D014057:Tomography, X-Ray Computed