The Existence of Axillary Arch in Human Fetus and Applied Importance and Clinical Implications in the Axillary Brachial Plexus Blocks

axillary arch is the most common muscle variation of axillary fossa that gains importance for regional interventional procedures, screening methods and physical examination. in order to avoid malpractice the variations must be borne in mind. this study has been planned to research the frequency and the features of the axillary arch in human fetus, to mention the potential clinical and functional significance of axillary arch while applying axillary brachial plexus block and reflect on possible complications. axillary fossa was examined with a stereomicroscope in 20 upper extremities of ten human fetuses. the gestation ages ranged from 16 to 36 weeks. axillary arch was determined in 2/20 specimen unilaterally. in both specimen, muscular slip detached from latissimus dorsi, passed anterior neurovascular bundle and ended posterior pectoralis major tendon and lateral border of intertubercular groove. in one specimen axillary arch was innervated with medial pectoral nerve whereas the other one did not have a particular innervating nerve branch. the possible effects of axillary arch in the axillary brachial plexus block applications are discussed. arcus axillaris may have a potential clinical and functional significance with regard the axillary brachial plexus block applications and may have possible effects on failure rate and acute complications. also, we think that this fetus study which the pure structure of the muscles without any usage effect can be observed will be beneficial regarding this topic.