Anatomical Variants of the Intercostobrachial Nerve and their Clinical Implications in Axillary Dissection

Abstract

Currently, there are multiple treatment options for breast cancer including chemo‐ and radiotherapy. When these treatment options do not work, a radical mastectomy may be considered. This procedure includes an axillary lymph node dissection. During this type of dissection, the intercostobrachial nerve (ICBN) is commonly encountered. Originating from the T2 spinal level, the ICBN is a lateral cutaneous branch of the second intercostal nerve. After piercing the intercostal and the serratus anterior muscles, it traverses the axilla to the medial side of the arm and joins the medial cutaneous nerve of the arm. Here, we report ICBN variations on two distinct cadavers encountered during dissection of the axilla at the Department of Anatomy of the Universidad Central del Caribe School of Medicine. One of the ICBN has three branches on the left upper extremity, while another cadaver has two branches on the right upper extremity. It is important to be aware of these variations while performing an axillary lymph node dissection for breast cancer or any other procedure that involves the axillary region (e.g., regional nerve blocks). Lesions of the ICBN have been associated to post‐operative pain, paresthesia, and loss of upper extremity sensation in the dermatome supplied by this nerve. Therefore, preservation of the ICBN is an important aspect of axillary region procedures.