The course of the intercostobrachial nerve in the axillary region and as it is related to transaxillary breast augmentation

Purpose: The aim of this study was to precisely determine the course of the intercostobrachial nerve (ICBN) in the axillary region and as it is related to bony landmarks, and all of this might be of use for transaxillary breast augmentation. Methods: Thirty hemithoraxes of 15 fresh cadavers of Korean adults were dissected. After removal of the skin, the ICBN from its origin was identified. The point of emergence (EP) and the branching point (BP) were marked on translucent paper. Results: The ICBN appeared at the second intercostal space approximately (mean T SD; 33.4 ± 12.7) mm lateral to the midclavicular line and 9.8 ± 6.4 mm medial to the lateral border of the pectoralis minor (P minor) muscle. The mean (SD) distance fromthe lower border of the second rib to the EPwas 5.2 ± 2.0mm. The mean ± SD distance from the upper border of the third rib to the EPwas 12.7 ± 3.3mm. It traveled inferolaterally (mean ± SD) 15.1 ± 10.4 degrees fromthe horizontal plane) 39.4 ± 19.2mmto reach to the BP. The BPwas located at the second intercostal space approximately (mean ± SD) 59.4 ± 21.2mmlateral to the midclavicular line and 28.5 ± 18.2 mm lateral to the lateral border of the P minormuscle. Themean ± SD distance fromthe lower border of the second rib to the BP was 11.3 ± 5.4 mm. The mean ± SD distance from the upper border of the third rib to the BP was 6.3 ± 7.1 mm. At the BP, the ICBN gave off a medial brachial cutaneous nerve, and this coursed superolaterally [mean (mean ± SD, 50.7 ± 15.1 degrees from the horizontal plane) toward the medial surface of the upper arm. The mean T SD depth of the ICBN from the superficial surface of the pectoralis major and Pminor was 22.7 ± 5.7mmand 15.0 ± 5.2mm, respectively. Conclusion: When performing mammary augmentation, care should be taken not to dissect the undersurface of the P minor at the second intercostal space to avoid injury to the ICBN.