Department of Spine Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
Spine (Phila Pa 1976). 2012 Feb 1;37(3):193-9. doi: 10.1097/BRS.0b013e3182285fb9.
A computed tomography (CT) study.
To evaluate the changed relative positions of esophagus in proximal thoracic (PT) curves of adolescent idiopathic scoliosis (AIS) patients and analyze the potential risks of esophageal injuries from thoracic pedicle screw (TPS) insertion.
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 (MT) curve have been comprehensively investigated; however, no studies have analyzed the relative position of esophagus in PT curve.
Twenty patients with complete proximal thoracic (CPT group) curve, 22 patients with fractional proximal thoracic (FPT group) curve, and 14 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 lateral to the left, 90° when strictly anterior, and 180° when directly lateral 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.
EVA in the FPT group was significantly smaller than that in the normal group (P < 0.05), whereas EVA in the CPT group was significantly greater than that in the normal group (P < 0.05) at each level. The esophagus was located approximately anterior to the vertebral body in the normal group but shifted anterolaterally to the right in the CPT group and anterolaterally to the left in the FPT group. The esophagus was at a high risk of injury with right anterior penetrated TPS in the CPT group and was at a high risk of injury with left anterior penetrated TPS in the FPT group.
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.
计算机断层扫描（CT）研究。
评估青少年特发性脊柱侧凸（AIS）患者近端胸椎（PT）曲度中食管的相对位置变化，并分析胸椎椎弓根螺钉（TPS）置入时食管损伤的潜在风险。
脊柱的平移和旋转可能导致 AIS 患者周围重要结构的相对位置发生改变。主胸（MT）曲度中主动脉和脊髓的位置变化已得到全面研究；然而，尚无研究分析 PT 曲度中食管的相对位置。
纳入 20 例完整近端胸椎（CPT 组）曲度患者、22 例部分近端胸椎（FPT 组）曲度患者和 14 例脊柱直患者（正常组）。在中椎体水平，从 T2 到 T5 获得轴向 CT 图像，以评估食管-椎体角（EVA，当食管位于左侧直接外侧时定义为 0°，当严格位于前方时定义为 90°，当直接位于右侧时定义为 180°）。计算食管在螺钉通道方向的百分比，以分析 TPS 插入过程中食管损伤的潜在风险。
FPT 组的 EVA 显著小于正常组（P < 0.05），而 CPT 组在每个水平的 EVA均显著大于正常组（P < 0.05）。正常组食管位于椎体前约，而 CPT 组则向右侧前外侧移位，FPT 组则向左侧前外侧移位。CPT 组右侧前穿透 TPS 时，食管有较高的损伤风险，FPT 组左侧前穿透 TPS 时，食管有较高的损伤风险。
不同的 PT 曲度解剖模式可能导致食管与脊柱的相对位置不同，从而导致 TPS 置入时食管损伤的潜在风险不同。脊柱外科医生应选择合适的椎弓根螺钉长度，以避免 AIS 患者 PT 区域的前皮质穿透。
