Anatomical mapping of the 4th intercostal nerve's lateral cutaneous branch in both sexes: implications for advanced breast Reconstruction.

Purpose: This study aims to map the point of emergence of the lateral cutaneous branch of the fourth intercostal nerve in both sexes, addressing gaps in the current literature. The findings are intended to support surgeons in restoring breast function by providing precise anatomical data, regardless of the specific surgical technique employed.

Methods: An anatomical study was conducted using 50 sides from 25 formalin-preserved full-body donors, with equal representation of male and female subjects. Measurements were taken to determine the fascial point of emergence of the lateral cutaneous branch of the fourth intercostal nerve relative to the anterior axillary line and the transverse line. Multiple linear regression models were applied to evaluate the influence of variables such as sex, height, and side.

Results: Our findings indicate that the fascial point of emergence of the lateral cutaneous branch of the fourth intercostal nerve is consistently located within 20 to 24 mm relative to the transverse line in 37 (74%) cases, and within 4 to 10 mm relative to the anterior axillary line in 39 (78%) cases, regardless of sex, height, or side. The multiple linear regression analysis showed no significant correlation between these variables and the position of the point of emergence (p > 0.05).

Conclusion: These results provide surgeons with a practical tool for nerve coaptation during breast reconstruction, showing that sex and height do not affect the anatomical localization of the point of emergence. Precise knowledge of this point can improve surgical accuracy and enhance sensory recovery, leading to better patient outcomes.