The importance of the anterior thoracic nerves in modified radical mastectomy

The medial anterior thoracic nerve supplies the pectoralis minor muscle and costal portion of the pectoralis major muscle. The lateral anterior thoracic nerve supplies the clavicular head and separately, three muscle groups of the sternal head. Any combination of these different muscle groups will become atrophic if the branches of the anterior thoracic nerves are injured. Muscle atrophy of the various groups of muscle bundles may not be apparent for as long as one year after the operation. These observations may be of some importance in the plastic reconstruction after modified radical mastectomy.