Different Proximal Thoracic Curve Patterns Have Different Relative Positions of Esophagus to Spine in Adolescent Idiopathic Scoliosis: A Computed Tomography Study.

By London Spine

Different Proximal Thoracic Curve Patterns Have Different Relative Positions of Esophagus to Spine in Adolescent Idiopathic Scoliosis: A Computed Tomography Study.

Spine (Phila Pa 1976). 2011 Jun 15;

Authors: Jiang J, Mao S, Zhao Q, Liu Z, Qian B, Zhu F, Qiu Y

STRUCTURED ABSTRACT: Study Design. A computed tomography (CT) studyObjective. To evaluate the changed relative positions of esophagus in proximal thoracic curves of AIS patients and analyze the potential risks of esophageal injuries from thoracic pedicle screw (TPS) insertion.Summary of Background Data. Translation and rotation of the vertebrae could lead to altered relative positions of surrounding vital structures in AIS patients. The changed positions of aorta and spinal cord in main thoracic curve have been comprehensively investigated, however, no studies have analyzed the relative position of esophagus in proximal thoracic curve.Methods. Twenty patients with complete proximal thoracic curve (CPT group), twenty-two patients with fractional proximal thoracic curve (FPT group) and fourteen normal patients with a straight spine (Normal group) were included. Axial CT images from T2 to T5 at the midvertebral body level were obtained to evaluate esophagus-vertebral angle (EVA, defined as 0° when the esophagus was located directly laterally to the left, 90° when strictly anteriorly, and 180° when directly laterally to the right). The percentages of esophagus in the direction of screw passage were calculated to analyze potential risks of esophageal injuries during TPS insertion.Results. The EVA in FPT group was significantly smaller than that in normal group (P<0.05) while the EVA in CPT group was significantly greater than that in normal group (P<0.05) at each level. The esophagus was located approximately anteriorly to vertebral body in normal group but shifted anterolaterally to the right in CPT Group and anterolaterally to the left in FPT Group. The esophagus was at a potential high risk of injury with right anterior penetrated TPS in CPT Group and was at a potential high risk of injury with left anterior penetrated TPS in FPT Group.Conclusion. Different anatomic patterns of PT curves could cause different altered positions of esophagus relative to spine, and result in different potential risks of esophageal injuries during TPS insertion. Spine surgeons should choose appropriate pedicle screw length to avoid anterior cortical perforation in the PT region of AIS patients.

PMID: 21681132 [PubMed – as supplied by publisher]