Introduction: The lateral cutaneous branch (LCB) of the intercostal nerves (ICNs) is classically described as a sensory nerve supplying the lateral thoracic wall. However, it may also contribute to the innervation of the intercostal muscles and the digitations of the serratus anterior. Objective: This study aimed to investigate the course, variations, and divisions of the LCB along its path within the intercostal space. Methods: This anatomical study was conducted between January and April 2024 on 11 formalin-fixed adult cadavers. The third to sixth ICNs were dissected. The origin of the LCB relative to the midaxillary line, its length before division, and the number and destination of its branches (muscular or cutaneous) were recorded. Results: Five females (45%) and six males (55%) were included (age range: 66-103 years). A total of 75 LCBs were identified and dissected. The mean distance from the midaxillary line was 3.72 cm ± 2.43 cm, and the mean length before division was 3.71 cm ± 1.84 cm. The LCB was divided into two branches in 56 cases (75%) and into three branches in 19 cases (25%). One branch consistently demonstrated a cutaneous distribution, while one or two branches exhibited a motor distribution. Conclusion: Within its intramuscular course, the LCB provides motor branches to the intercostal muscles and the digitations of the serratus anterior before becoming purely sensory.
Huttin et al. (Fri,) studied this question.