Anatomic research on respiratory function reconstruction by transposition of accessory nerve to phrenic nerve in the rats with upper cervical cord injuries

Objective:To provide microanatomical data for respiratory function reconstruction by transposition of accessory nerve to phrenic nerve in rats with upper cervical cord injuries. Methods:The bilateral accessory nerves,phrenic nerves,and their branches of 30 male rats were dissected under operating microscopy. The diameter, length of the accessory nerve and its branches, the distance between the accessory nerve and the main trunk of the phrenic nerve were measured adopting the slide gauge with precision of 0.001 millimeter. Results: The proximal part of the main trunk of phrenic nerve was about 0.207±0.051 mm in diameter. At the point of 4.191±0.135mm from jugular foramen, the accessory nerve gave off muscular branches for sternocleidomastoid muscle, which were 5.657±0.283 mm in length and 0.221±0.039 mm in diameter. The distance between the former and the main trunk of the phrenic nerve was about 10.041±3.181 millimeters. The supraclavicular section of the accessory nerve, between its two muscular branches for trapezius, was about 0.274±0.032 mm in diameter and about 5.154±0.782 mm parting from the proximal part of the main trunk of the phrenic nerve. The length of infraclavicular section of the accessory nerve was about (0.216±0.027)mm before giving off medial and lateral branches horizontally. Its distance from the proximal part of main trunk of the phrenic nerve was about -1.416±0.216 mm. Conclusions: The diameter of infraclavicular section of the accessory nerve before giving off medial and lateral branches is similar to that of the proximal part of main trunk of phrenic nerve. It is possible to suture them directly.