OBJECTIVEThere are small smount of literatures on the study of the anterior surgical approaches to the upper thoracic spine (UTS). Moreover, there are many differences among the results of these studies. This study is to investigate the exposure ranges of different anterior surgical approaches to the UTS for making the preoperative plan by means of CT images analysis.

METHODSFrom October to December in 2008, 120 CT images of normal chests were chosen. These subjects (58 males, 62 females) ranged in age from 16 to 75 years (mean 40.3 +/- 12.3 years). By using the X-ray positioning images of these CT images,following indexes were studied: the location of the superior margin of the left brachiocephalic vein on the sagittal plane, the confluence of the bilateral brachiocephalic veins, and the vertebrae level of the tracheal bifurcation. The caudal access of E1 (the interval between the tracheo esophageal sheath and the bilateral carotid sheath), E2 (the interval between the right brachiocephalic vein and the brachiocephalic artery), and E3 (the interval between the ascending aorta and superior caval vein) were respectively defined as the above mentioned three points.

RESULTSAmong the 120 studies, 105 T2 vertebral bodies could be exposed through E1 (87.5%), 82 T3 vertebral bodies could be exposed through E2 (68.3%), and 89 T4 vertebral bodies could be exposed through E3 (74.2%).

CONCLUSIONThe exposure ranges of three different anterior surgical approaches to the upper thoracic spine are different. Proper surgical approaches could be selected according to the chest CT images of the patients.