Paravertebral soft tissue swelling associated with traumatic thoracolumbar spine injury is a risk factor for a segmental artery injury

Introduction. Traumatic thoracolumbar spine injury (TLI) can be associated with a segmental artery injury, which can lead to a fatal outcome if not handled appropriately at an early stage. Moreover, a segmental artery injury cannot be detected by contrast-enhanced CT(ceCT) in a patient with hypotension due to hemorrhagic shock in some cases. Therefore, it is very important to be able to diagnose spinal injuries with vascular injuries using only simple CT in order not to look them over. However, few reports have provided details.
AIMs. In order not to miss a segmental artery injury complicated by a spinal injury, we determined that a segmental artery injury index in the axial plane image of simple CT was necessary, and focused on the paravertebral soft tissue swelling(PVSTS).
Methods. We included 240 vertebrae in 215 patients with TLI of AO classification A3 or higher who underwent surgical treatment at our emergency center between January 2012 and August 2022 (male:female = 128:87, mean age 55.9 years, 108 thoracic vertebrae: 132 lumbar vertebrae). The thickness of the swelling soft tissue around the injured vertebral body was measured, and the sum of the thickness at the anterior, left and right sides of the vertebral body was used as the PVSTS using the most recent CT images after the injury. Segmental artery injuries were confirmed by ceCT or angiography. The relationship between PVSTS and segmental artery injury was statistically determined for thoracic and lumbar spine levels, and the cutoff was calculated using ROC curves.
Results. Segmental artery injuries were found in 18 vertebrae (7.5%), 10 in the thoracic spine and 8 in the lumbar spine. There was no significant relationship between segmental artery injury and gender, but the incidence of segmental artery injury was significantly higher in older patients. Both thoracic and lumbar PVSTS were significantly associated with segmental artery injury, with cutoff values of 19.4 mm for thoracic PVSTS (sensitivity: 80.0%, specificity: 90.8%, AUC: 0.9, p< 0.01) and 10.4 mm for lumbar PVSTS (sensitivity: 100%, specificity: 80.6%, AUC: 0.91, p< 0.01).
Conclusions. The PVSTS was associated with segmental artery injury, and a thoracic spine of 19.4 mm and a lumbar spine of 10.4 mm or more were risk factors for segmental artery injury. When the PVSTS is large, it is very important to perform ceCT and/or angiography, close vital checks, and, in case, early hemostasis such as TAE and spinal stabilization, while keeping in mind segmental artery injury.