The position of the aorta relative to the spine in patients with Pott's thoracolumbar angular kyphosis.

STUDY DESIGN: Analyze the position of the aorta in patients with Pott's thoracolumbar angular kyphosis by computed tomography.

OBJECTIVE: To investigate the anatomic position of the aorta relative to spine in patients with Pott's thoracolumbar angular kyphosis.

SUMMARY OF BACKGROUND DATA: The complication of aorta injury is rare in the procedure of spinal osteotomy for the correction of Pott's thoracolumbar angular kyphotic deformity. However, there would be a disastrous consequence once it happened. Therefore, knowing about the position of aorta relative to the spine is of great importance. From the authors' knowledge, there are no reports about the research on the position of the aorta relative to the spine in patients with Pott's thoracolumbar angular kyphosis.

METHODS: Thirty patients with Pott's thoracolumbar angular kyphosis and thirty patients without spine deformity were recruited and divided into two groups. The CT images of both groups from T10 to L1 were obtained to evaluate the left pedicle-aorta angle and distance. In the patients with Pott's thoracolumbar angular kyphosis, the affected vertebral bodies were fused, so we measured the left pedicle-aorta angle and distance of the fused vertebral bodies. For the normal group, we measured the left pedicle-aorta angle and distance from T10 to L1 and got the average data, then compared with the Pott's group with independent sample t test. The Pearson correlation analysis was used to evaluate the association between the change of the aortic position and Konstam's angle and LL.

RESULTS: The left pedicle-aorta angles (-8.95 + 2.89°) in Pott's group are smaller and the distances (6.36 + 0.77 cm) are larger than those in normal group (P < 0.05). In patients with Pott's thoracolumbar angular kyphosis, with increased Konstam's angle, the left pedicle-aorta angles becomes smaller (r = -0.495, P < 0.05) and the left pedicle-aorta distances becomes larger (r = 0.486, P < 0.05). However, there is no remarkable correlation between lumbar lordosis and the left pedicle-aorta angles or distances.

CONCLUSION: In patients with Pott's thoracolumbar angular kyphosis, the aorta of the fused vertebrate shifts anteromedially to the vertebral body, and the aorta is relatively farther away from the vertebral body compared with the normal subjects. Therefore, the surgeon should be aware of the change of the position of the aorta to avoid the disastrous complication vessel injury.