Anatomic study of intercostal to axillary nerve transfer

Objective To provide the anatomical basis for intercostal to axillary nerve transfer to restore shoulder abduction.Methods Thirty sides of thoracic walls of human cadaver specimens were used.The intercostal nerves Ⅲ to Ⅵ were dissected to measure the lengths of the intercostal nerves from the midaxillary line to the midclavicular line.Meanwhile the distances from the relevant intercostal space to the quadrilateral foramen (with 45° of shoulder abduction and 90° of shoulder abduction) through the subcutaneous tunnel were also measured.Results The differences between the length of the intercostal nerve Ⅲ to Ⅵ and the distance from the relevant intercostal space to the quadrilateral foramen were (3.89 ± 0.85) cm,(4.14 ± 1.15) cm,(2.99 ±1.33) cm and (0.25± 1.49) cm with 45° of shoulder abduction,and (2.54 ±0.87) cm,(2.37 ± 1.51) cm,(1.04 ± 1.74) cm and (-1.59 ± 1.95) cm with 90° of shoulder abduction.Conclusion It is feasible to perform direct coaptation between the axillary nerve and the intercostal nerves Ⅲ to Ⅴ at the quadrilateral foreman without nerve graft.To achieve tension-free coaptation of intercostal nerve Ⅵ and the axillary nerve at 90° of shoulder abduction,extra-length of the intercostal nerve Ⅵ or axillary nerve should be obtained. Key words: Intercostal nerves;  Brachial plexus;  Axillary nerve;  Anatomy,regional;  Intercostal nerve neurotization