Percutaneous Translumbar Spinal Cord Compression Injury in a Dog Model That Uses Angioplasty Balloons: MR Imaging and Histopathologic Findings
Phillip D. Purdya,b,e,
Robert T. Duonga,
Charles L. White, IIIc,
Donna L. Baerd,
R. Ross Reichardc,
G. Lee Pride, Jr.a,
Christina Adamse,
Susan Millere,
Christa L. Hladikf and
Zerrin Yetkina,e
a Department of Radiology (Division of Neuroradiology), The University of Texas, Southwestern Medical Center at Dallas, Dallas, TX
b Department of Neurological Surgery, The University of Texas, Southwestern Medical Center at Dallas, Dallas, TX
c Department of Pathology (Division of Neuropathology), The University of Texas, Southwestern Medical Center at Dallas, Dallas, TX
d Animal Resources Center, The University of Texas, Southwestern Medical Center at Dallas, Dallas, TX
e Mobility Foundation Center, The University of Texas, Southwestern Medical Center at Dallas, Dallas, TX
f Department of Pathology (Immunohistochemistry Laboratories), The University of Texas, Southwestern Medical Center at Dallas, Dallas, TX
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FIG 1. Images from a pilot study. After induction of general endotracheal anesthesia, the lumbar subarachnoid space was entered with a needle. A guidewire was introduced via the needle and directed cephalad; then, the needle was withdrawn, and the guidewire was used for coaxial advancement of the angioplasty balloon, mimicking the method used in vascular access for angiography.
A, Guidewire introduced via neural foramen (lateral approach) and ascending in spinal canal.
B, Angioplasty balloon introduced over guidewire. Proximal and distal markers on balloon are shown by arrows.
C, Example of an MR image of a 7-mm balloon (black arrow) inflated against the compressed spinal cord in animal 2 (white arrow).
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FIG 2. Images of animal 4.
A, Example of hematoxylin and eosin staining obtained at the level of the balloon. Multiple regions of petechial hemorrhage are indicated by arrows. Petechial hemorrhage is a characteristic of spinal cord contusion.
B, Beta amyloid precursor protein immunostaining of the region shown in A. Amyloid precursor protein is synthesized in neurons in the CNS and peripheral nervous system and is transported to the nerve endings from the cell body. Amyloid precursor protein accumulates when axoplasmic flow is disrupted; it is therefore a sensitive marker of axonal injury. Regions of stain accumulation (arrows) indicate posterior axonal injury.
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FIG 3. Images of animal 3.
A, Example of axial view T2-weighted MR image obtained at the level of balloon inflation after the balloon was deflated and removed. The cord displays homogenous signal intensity with no signal intensity change in the dorsal region that shows contrast enhancement in C.
B, Unenhanced T1-weighted MR image obtained in the axial plane at the level of balloon inflation. No abnormal signal intensity is seen in the spinal cord.
C, Contrast-enhanced T1-weighted MR image of the region shown in B. A large region of enhancement is located at the dorsal region of the spinal cord (arrow).
D, Unenhanced sagittal view T1-weighted MR image of the region shown in B. Note that no abnormal signal intensity is seen in the spinal cord.
E, Focal enhancement is observed after the injection of contrast material (arrow).
F, Hematoxylin and eosin staining of the spinal cord shows parenchymal hemorrhage in the peripheral white matter (arrows).
G, Beta amyloid precursor protein immunostaining of the region shown in B highlights well-developed axonal swellings (stain accumulation) in the cross section (arrow).
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