Anatomic Basis Of The Upper Thoracic Vertebrae And Its Clinical Significance

Objectives: 1. To study the anatomic relationships between the upper thoracic vertebrae and correlated structures, including the recurrent laryngeal nerve, thoracic duct, blood vessels, so as to minimize the potential operative injuries and the postoperative complication. 2. To discuss the advantage and disadvantage of different surgical approachs exposing the upper thoracic vertebrae. Methods : 1. 20 caderveric were used in this group, including 13 male and 7 female. An anterior surgical approach to the upper thoracic vertebrae has been made from two sides on 20 adult cadaveric specimens. A Y-shaped skin incision is used, The manubrium sterni, as well as the upper third of the sternum, is splitted open. 2. To measure the origin, course of the recurrent laryngeal nerve, thoracic duct, blood vessels, and relationships with the upper thoracic vertebrae on 20 adult cadaveric specimens. 3. To study the surgical approach to the upper thoracic vertebrae. Results: 1. The right recurrent laryngeal nerve reaches the tracheoesophageal groove at the level of C6-7 disk in 55% and derives from vagus nerve at the level of T1-T2. 2. The thoracic duct empties into the systemic venous system from T1 to T2. 3. The left brachiocephalic vein is at T3 in 55%. The aortic arch is at T-3 and T-4 in 80%. The anterior aspect of T-3 can be easily exposed through a modified anterior approach to the upper thoracic vertebrae in 45%, compared with in 95% through outside space of the brachiocephalic trunk. Conclusion: 1. The transverse or crossing segment of the right recurrent laryngeal nerve may be injured by stretching caused by retraction on the trachea at the T1-T2 level. 2. The thoracic duct may be escaped the potential operative injuries and the postoperative complication when operating from the left side if the surgeon is familiar with the course of thoracic duct. 3. Outside space of the brachiocephalic trunk is recommended in exposing the upper thoracic vertebrae. This approach can expose 0.5-1 vertebrae more than inside space of the brachiocephalic trunk.