Assessment of Anterior Spinal Artery Blood Flow following Spinal Cord Injury

The incidence of spinal cord injury (SCI) in the US is approximately 12,000 individuals annually, due to various forms of trauma and disease. (1) Previous studies show that increased force on or prolonged compression of the spinal cord results in progressive ischemia, as indicated by a reduction in spinal cord perfusion (3). Diminished flow over a prolonged period of time can cause necrosis and permanent damage if perfusion falls below the critical level, or vascular threshold (4). We constructed a 3D finite element model of the cervical spinal cord to examine the role of compressive mechanical loading of the spinal cord on blood flow and ischemia, which could arise from acute compression, distraction, or vasospasms. It was found that the magnitude and direction of forces on the spinal cord model, including anterior, posterior, and axial loading, had distinct effects on blood flow. Maximal reduction in perfusion was shown in the posterior loading, while maximal reduction in flow of the anterior spinal artery was shown in the anterior loading. Changes in the mechanical properties of the spinal cord showed slight reduction in blood flow rate. Therefore, this study provides evidence that spinal damage at subclinical thresholds creates a decrease in blood flow that could progress into ischemia and makes the spinal cord susceptible to further damage.