An applied anatomical study of choosing transfer course of phrenic nerve harvested from thoracic cavity

Objective To provide anatomical data for choosing transfer course of phrenic nerve harvested from thoracic cavity in treatment of brachial plexus root avulsion. Methods 29 cadaveric specimens were involved in the study. The distances in the arm where the phrenic nerve harvested from the thoracic cavity and transferred by different courses can reach were determined. Results When the phrenic nerve was transferred from the thoracic cavity to the arm by the intercostal space, it was along a course by a hole on the anterior axillary line of the 2nd intercostal space that the distal stump of the phrenic nerve can reach its most distal range in the arm, which was on average 10.6 cm (38.6 percent of the length of the humerus) on the left side, and 14.2 cm (52.4 percent of the length of the humerus) on the right side, superior to the lateral and medial humerus epicondyles line. When the phrenic nerve in its full length was withdrawn out from the thoracic cavity by the superior aperture of thorax and transferred to the arm, it was along the same course of the brachial plexus that the distal stump of the phrenic nerve can reach its most distal range in the arm, which was on average 7.1 cm (25.9 percent of the length of the humerus) on the left side, and 10.5 cm (39.0 percent of the length of the humerus) on the right side, superior to the medial humerus epicondyle. Conclusions The two courses mentioned above are the shortest ones for transferring the phrenic nerve harvested in thoracic cavity to the arm by a way through the intercostal space or outside the thoracic cavity, respectively.