Percutaneous translumbar spinal cord compression injury in a dog model that uses angioplasty balloons: MR imaging and histopathologic findings.
OBJECTIVE
Previous animal models for spinal cord injury required laminectomy and exposure of the spinal cord to create direct trauma, compromising imaging by both surgical artifact and the nature of the production of the injury. Our purpose was to study a model that uses percutaneous intraspinal navigation with an angioplasty balloon, providing a controlled degree of spinal cord compression and allowing improved MR imaging of spinal cord injury.


METHODS
Nine mongrel dogs were studied. MR images were obtained of six dogs after technique development in three dogs. Angioplasty balloons measuring 7 or 4 mm in diameter and 2 cm in length were placed in the midthoracic subarachnoid space. Imaging was performed by using a 1.5-T MR imaging unit before and after balloon inflation. The balloon was inflated within 5 seconds and deflated after 30 minutes. T1- and T2-weighted and contrast-enhanced images were acquired. Spinal cords were submitted for pathologic examination.


RESULTS
All four animals with 7-mm balloons experienced hemorrhage, and three had axonal injury revealed by histopathologic examination. One of two animals with 4-mm balloons experienced no injury, and one had axonal injury without hemorrhage. Regional parenchymal enhancement was seen in two of the animals with 7-mm balloons.


CONCLUSIONS
This percutaneous spinal cord injury model results in a graduating degree of injury. It differs from previous techniques by avoiding surgical exposure and the associated artifacts, yet it offers histopathologic findings similar to those of human spinal cord injury. The canine spinal cord is amenable to MR imaging with clinical imaging units. Further evaluations with various durations of compression and various balloon sizes are warranted.
Purdy
Phillip D
PD
Department of Radiology (Division of Neuroradiology), The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
Duong
Robert T
RT
White
Charles L
CL
Baer
Donna L
DL
Reichard
R Ross
RR
Pride
G Lee
GL
Adams
Christina
C
Miller
Susan
S
Hladik
Christa L
CL
Yetkin
Zerrin
Z
D000800:Angioplasty, Balloon / Q000295:instrumentation*; D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D006470:Hemorrhage / Q000175:diagnosis / Q000473:pathology; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation*; D013117:Spinal Cord Compression / Q000175:diagnosis* / Q000473:pathology; D013119:Spinal Cord Injuries / Q000175:diagnosis* / Q000473:pathology