Abstract: Objective　To study the anatomical relationship between thoracic  vertebral body (T2~T5) and adjacent tissue structure, and to explore the feasibility of treating the T2~T5 vertebral body lesion through the middle axillary approach.　Methods　Ten (20 sides) formalin-treated cadaveric specimens with intact thoracic and upper limbs  were selected to simulate T2~T5 vertebral surgery through the left and right mid-axillary thoracic approaches, respectively, and then dissected layer by layer to the lateral front of the thoracic spine. The length of the skin incision, the longitudinal width of the rib fracture were observed.  The upper and lower ends of the opening, the upper edge of the aortic arch, the highest point of the sacral arch, the position of the vertebral body of the thoracic duct, and the distance between the thoracic sympathetic trunk and the anterior edge of the costal joint were extended to simulate the operation of T3 vertebral body resection + rib bone graft + plate screw internal fixation.　Results　The length of the mid-axillary skin incision was (11.63 ±0.50) cm, and the width of the third rib was (7.04±0.47) cm. The upper and lower ends of the brace were flat on the 2nd and 5th thoracic vertebrae. The upper edge of the aortic arch flat T3 was 70%, the highest point of the venous arch flat T4 was 60%, and the thoracic duct crossing T5 from the front was 70%. The distance from the sympathetic trunk to the leading edge of the first rib joint was (6.84±0.55) mm, (6.99±0.51) mm, (6.98±0.56) mm, (7.07±0.47) mm, respectively. The simulated surgical field can exposed the T2~T5 vertebra. The adjacent structures were relatively fixed, which can safely and effectively complete the surgical operation of removing the bone graft and internal fixation and reconstructing the stability of the thoracic spine. Conclusions　The middle axillary approach is a treatment for T2~T5 vertebral lesions, which has the advantages of good visual field, less trauma, and high safety.

Key words: Thoracic spine; ,  , Mid-axillary line; ,  , Surgical approach; ,  , Anatomy; ,  , Internal fixation