Focal middle cerebral artery ischemia in rats via a transfemoral approach using a custom designed microwire.
OBJECTIVE
The aim of this study was to develop a reliable and repeatable method of inducing focal middle cerebral artery occlusion (MCAo) in rats without ligation of the external carotid artery (ECA), while reducing the risk of subarachnoid hemorrhage.


METHODS
We prototyped microwires with different diameters (0.0120 inch, 0.0115 inch, 0.0110 inch), materials, and construction methods (coil-on-core, extruded polymer jacket-on-core). Under fluoroscopic guidance and using femoral artery access, the microwires were navigated into the internal carotid artery of male Wistar rats (n=50, weight 376±64 g) to induce MCAo for 1 or 2 h. We performed neurological assessments at baseline, and at 3, 24, 72, and 168 h after MCAo. MRI measurements were performed on a 9.4 T scanner at 1 and 7 days post-injury.


RESULTS
The 0.0115 inch microwire with polymer jacket-on-core provided the most successful outcome. At 1 and 7 days post-injury, we observed similar infarction volumes for 1 and 2 h MCAo in the MRI study. Infarcted lesion volumes in both MCAo groups were significantly reduced at 7 days compared with 1 day post-injury. The trend in longitudinal changes for the scores of different neurological assessments was confirmed to be significant after the injury, but both groups showed a similar trend of neurological deficits over the course of the study.


CONCLUSIONS
We have developed a reliable and repeatable MCAo method in rats, allowing for precise occlusion of the MCA under direct fluoroscopic visualization without alteration of the cerebral hemodynamics associated with ECA ligation. The custom designed microwire can also be sized for targeted focal ischemia in larger animals.
Department of Neurology, University of Minnesota, Minneapolis, Minnesota, USA Department of Neurological Surgery, University of Minnesota, Minneapolis, Minnesota, USA Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota, USA.
Afshin A
AA
Divani
Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota, USA Lake Region Medical, Chaska, Minnesota, USA.
Ricky
R
Chow
Neurosciences Research Center, Tabriz University of Medical Sciences, Iran Department of Public Health Sciences, Karolinska Institute, Stockholm, Sweden.
Homayoun
H
Sadeghi-Bazargani
Department of Neurology, University of Minnesota, Minneapolis, Minnesota, USA Medical School, University of Minnesota, Minneapolis, Minnesota, USA.
Amanda J
AJ
Murphy
Department of Neurology, University of Minnesota, Minneapolis, Minnesota, USA.
Jessica A
JA
Nordberg
Department of Neurology, University of Minnesota, Minneapolis, Minnesota, USA Medical School, University of Minnesota, Minneapolis, Minnesota, USA.
Julian V
JV
Tokarev
Department of Neurology, University of Minnesota, Minneapolis, Minnesota, USA Medical School, University of Minnesota, Minneapolis, Minnesota, USA.
Mario
M
Hevesi
Department of Radiology, Center for Magnetic Imaging Research, University of Minnesota, Minneapolis, Minnesota, USA.
Xiao
X
Wang
Department of Radiology, Center for Magnetic Imaging Research, University of Minnesota, Minneapolis, Minnesota, USA.
Xiao-Hong
XH
Zhu
Lake Region Medical, Chaska, Minnesota, USA.
Tommy
T
Acompanado
Lake Region Medical, Chaska, Minnesota, USA.
Peter A
PA
Edwards
Department of Radiology, Center for Magnetic Imaging Research, University of Minnesota, Minneapolis, Minnesota, USA.
Yi
Y
Zhang
Department of Radiology, Center for Magnetic Imaging Research, University of Minnesota, Minneapolis, Minnesota, USA.
Wei
W
Chen
D000818:Animals; D002545:Brain Ischemia / Q000209:etiology*; D004195:Disease Models, Animal; D005263:Femoral Artery / Q000601:surgery*; D005471:Fluoroscopy; D020244:Infarction, Middle Cerebral Artery / Q000150:complications*; D008297:Male; D020768:Middle Cerebral Artery / Q000293:injuries*; D051381:Rats; D017208:Rats, Wistar
Angiography; Device; Stroke; guidewire