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Lumbar artery avulsion after a low-energy Chance fracture

Kelly A. Larrabee, MPAS, PA-C; Mark H. Stevens, MD, FACS; Todd L. Allen, MD, FACEP

Kelly Larrabee and Mark Stevens work in the Department of Surgery and Todd Allen works in the Department of Emergency Medicine, all at LDS Hospital, Salt Lake City, Utah. The authors have indicated no relationships to disclose relating to the content of this article.

Fractures of the lumbar spine are common, but vascular injuries associated with such fractures are rare. We describe the case of an elderly woman who sustained a lumbar fracture with an associated lumbar artery avulsion and subsequent bleeding as the result of a ground-level fall.

CASE

A 91-year-old female fell onto a tile floor while transferring to her wheelchair. After reporting debilitating back pain, the patient was transported to the emergency department (ED) in full spinal precautions. On examination in the ED, no step-offs or deformities to the thoracic or lumbar spine were appreciated. There was tenderness to palpation around the thoracolumbar junction. No neurologic deficits were detected, and the patient had strong pulses and full range of motion in both of her lower extremities.

A plain film radiograph revealed a Chance fracture of the first lumbar vertebra (see Figure 1). The fracture was primarily in the axial plane, and there was spreading and distraction of the main fracture fragments cranially and caudally with resultant anterior opening of the vertebral body. Additionally, a large soft tissue hematoma in the paraspinous region and retroperitoneum was visualized. CT with contrast showed an expanding hematoma with active blush in the vicinity of the fracture.

The patient was taken emergently to the angiography suite, where cannulation via the right femoral artery was successfully performed (see Figure 2). Active bleeding was seen from a left lumbar arterial branch. Selective embolization was then performed, and cessation of bleeding was documented (see Figure 3).

The patient denied taking any antiplatelet or anticoagulant medications. On admission, her hematocrit was 27% with an international normalized ratio of 1.0. Three hours later, her hematocrit had dropped to 23%. She was transfused with 2 U of packed RBCs, which increased her hematocrit to 33%.

She was admitted to the ICU, where her hematocrit remained stable. The patient chose nonoperative management of the unstable Chance fracture, which prescribed bed rest for 6 weeks. She did well and progressed to discharge to an extended-care facility on the fourth day after the injury.

DISCUSSION

Nearly 30,000 injuries to the spinal column occur in the United States every year.¹ Approximately 40% to 50% of these injures involve a neurologic deficit, but far fewer involve vascular compromise.¹ Vascular injury associated with spinal fractures occurs most commonly in the cervical spine. As a result, these injuries are typically evaluated with CT angiography. Unlike cervical spine fractures, vascular complications related to lumbar fractures are rare. An extensive search of the literature produced no similar case reports.

Most isolated lumbar fractures without neurologic deficit are secondary to osteoporosis,² as was the case in this patient. In the United States, thoracic and lumbar fractures occur in 15,000 trauma patients annually.² Sixty percent occur at the thoracolumbar junction region between T11 and L2. Neurologic deficit accompanies 26% of these injuries.²

The Chance fracture, first described in 1948, is a bony injury with a fracture line extending in a posterior to anterior direction through the spinous processes, pedicles and body.³ Chance fractures involve disruption of the posterior and anterior portions of the vertebral body and have a high incidence of associated intra-abdominal injuries, including bowel rupture and liver or spleen lacerations.³

Chance fractures are commonly caused by hyperflexion combined with distraction and can be associated with a posterior ligament rupture.⁴ The degree of ligamentous injury is related to the amount of anterior compression associated with the traumatic force. Of patients with flexion distraction injuries, nearly half have rupture of the interspinous ligament, ligamentum flavum, facet capsule, posterior annulus, or thoracodorsal fascia, but rarely do they have vascular injury.

Blood is supplied to the vertebral column at the lumbar level by pairs of arteries that originate from the abdominal aorta. A blush and increasing hematoma on CT or signs and symptoms of hypotension, shock, or neurovascular compromise could indicate a serious complication or active bleeding and require immediate attention.

Angiographic arterial embolization involves a direct approach to the bleeding vessel by inserting a catheter into the artery. Once isolated, the most distal aspect of the bleeding vessel is occluded, and bleeding stopped, with specialized products such as coils or foam. Angiographic embolization has long been studied and has been proven to be a reliable treatment for resultant bleeding from spinal fractures.⁵ Embolization has been found to be the most direct means to control hemorrhage.⁵ More recently, as in our case, it has been found to be effective in controlling bleeding in many locations and should be considered early in the management of these unusual injuries.

In a rural setting where CT is not readily available, any hemodynamically unstable patient must be stabilized according to Advanced Trauma Life Support protocols and transferred to an appropriate facility for definitive care.

Steve Wilson, PA-C, department editor

REFERENCES

	1.	Bagley LJ. Imaging of spinal trauma. Radiol Clin North Am. 2006;44(1):1-12, vii.
	2.	Bolesta M, Rechtine G. Fractures and dislocations of the thoracolumbar spine. In: Bucholz RW, Heckman, JD, eds. Rockwood and Green's Fractures in Adults. Philadelphia, PA: Lippincott Williams and Wilkins; 2001:1405-1458.
	3.	Levine AM. Low lumbar fractures. In: Browner BD, Jupiter JB, eds. Skeletal Trauma—Basic Science, Management and Reconstruction. Philadelphia, PA: W.B. Saunders; 2003: 944-981.
	4.	Groves CJ, Cassar-Pullicino VN, Tins BJ, et al. Chance-type flexion-distraction injuries in the thoracolumbar spine: MR imaging characteristics. Radiology. 2005;236(2):601-608.
	5.	Cothren CC, Moore EE, Biffl WL, Ciesla DJ. Cervical spine fracture patterns predictive of blunt vertebral artery injury. J Trauma. 2003:55(5):811-813.