Anatomical justification of the contralateral transfer of the C7, spinal nerve to the C8 position

Contralateral transfer of the spinal nerve C 7 is used to restore the function of the upper limb. Aim of the study was to identify the anatomical conditions of direct anastomosis of the contralateral spinal nerves C 7 and C 8 by the pretracheal pathways. Material and methods . The lengths of the subcutaneous, combined, and posterior sternocleidomastoid pathways were determined in 165 corpses of men and women 34–97 years old. In 182 brachial plexuses (165 on the right and 17 on the left), the lengths of the spinal nerves C 7 and C 8 , the middle and lower trunks and their anterior divisions were measured twice: before and after the removal of the epineurium. Results and discussion . The total length of the subcutaneous pathway is 187.3 ± 11.5 mm, significantly less in the combined – 169.7 ± 11.5 mm and posterior sternocleidomastoid – 137.9 ± 11.4 mm. When the longest donor perineural complex, consisting of the C 7 spinal nerve, the middle trunk and its anterior division (79.5 ± 16.4 mm), is simultaneously transferred towards each other, on one side, and the recipient epineural complex, consisting of the C 8 spinal nerve, the lower trunk and its anterior division (73.6 ± 17.1 mm), on the other direct anastomosis by subcutaneous route is possible in 22 % cases, combined – in 42.9 %, behind the sternocleidomastoid – in 80.2 %. Conclusions . In contralateral transfer of the perineural donor complex consisting of the C 7 spinal nerve, the middle trunk and its anterior division, direct anastomosis behind the sternocleidomastoid pathway with the C 8 spinal nerve is possible in 80.2 % case, the lower trunk ‒ in 53.9 %, the anterior division ‒ in 11.5 %.