Uncommon configuration of intercostobrachial nerves, lateral roots, and absent medial cutaneous nerve of arm in a cadaveric study

Abstract

The intercostobrachial nerve (ICBN) originates from the second intercostal nerve's lateral cutaneous branch, while the median nerve (MN) typically arises from the brachial plexus's lateral and medial roots. The medial cutaneous nerve of the arm, a branch of the medial cord of the brachial plexus, often connects with the ICBN. Variations were observed during the dissection of a 50-year-old male cadaver, including MN having two lateral roots (LR), LR1 and LR2, joining at different levels. Three ICBNs innervated the arm in this case, with the absence of the medial cutaneous nerve of the arm compensated by branches from the medial cutaneous nerve of the forearm. Understanding these anatomical variations is crucial for surgical procedures like brachioplasty, breast augmentation, axillary lymph node dissection, and orthopedic surgery. Surgeons and medical professionals must be aware of these variations to enhance preoperative planning, minimize complications, and improve patient outcomes in these procedures.

Keywords: Anatomical variation; Axillary artery; Brachial plexus; Median nerve; Upper limb surgery.

Fig. 1

Image showing two lateral roots for median nerve instead of a single lateral root. LR1, lateral root 1; LR2, lateral root 2.

Fig. 2

Image showing three intercostobrachial nerves (ICBN 1, ICBN 2, ICBN 3) arising from first, second, and third intercostal nerves instead of a single undivided lateral branch of second intercostal nerve which serves as the ICBN through its communication with medial cutaneous nerve of arm.

Fig. 3

Image showing branches for medial cutaneous nerve of forearm in the arm to compensate for the absence of medial cutaneous nerve of arm.