Three-dimensional evaluation of pre- and postoperative arterial dynamics in patients with Lenke types 1 and 2 AIS

To quantitatively evaluate three-dimensional spatial changes in the thoracic aorta before and after posterior spinal correction in patients with Lenke types 1 and 2 adolescent idiopathic scoliosis (AIS), and to assess the relationship between spinal realignment and aortic morphology using advanced 3D reconstruction techniques.

This retrospective study included 31 patients with either Lenke type 1 or 2 AIS who underwent posterior spinal fusion using pedicle screw instrumentation. Pre- and postoperative computed tomography scans were used to construct 3D models of the vertebrae and thoracic aorta. Curvature indices-including the vertebral curvature index (CI) and aortic tortuosity index (TI)-and transverse-plane parameters including aorta-vertebral angle (α), vertebral rotation angle (γ), and spatial distances between aorta and vertebrae were measured.

Posterior correction significantly reduced CI (from 10.0 to 3.4%) and TI (from 13.6 to 6.5%) (both p < 0.001). The aorta underwent a measurable anteromedial shift, most prominently at thoracic levels T6-T10, which was reflected by decreased α and γ values. Changes in TI strongly correlated with changes in CI (r = 0.806, p < 0.001), indicating that vertebral realignment directly influenced aortic morphology.

Posterior spinal fusion in AIS patients induces significant three-dimensional changes in the thoracic aorta, including straightening and medial displacement. These findings highlight the need for comprehensive vascular evaluation and surgical planning to ensure safe pedicle screw placement, particularly in anatomically vulnerable regions.