Anatomical basis for sensory preservation in robotic mastectomy

Br J Surg. 2025 Nov 6;112(11):znaf232. doi: 10.1093/bjs/znaf232.

Abstract

Background: Sensory preservation of the nipple-areolar complex (NAC) is crucial for physical, psychological, and sexual health after mastectomy. Robotic-assisted nipple-sparing mastectomy (rNSM) techniques have shown promise in preserving NAC sensation, but there is limited detailed anatomical evidence supporting this observation. The aim of this study was to characterize the anatomical pathways and variability of sensory nerves innervating the NAC, particularly focusing on implications for the development of improved nerve-preserving techniques during breast surgery.

Methods: A cadaveric anatomical study on three adult female cadaveric donors (six breasts) was undertaken, which was complemented by a systematic review of the existing literature using a modified PRISMA approach.

Results: The anterior cutaneous branch (ACB) and the lateral cutaneous branch (LCB) of the fourth intercostal nerve (ICN) were consistently the primary cutaneous nerves innervating the NAC. The ACB of the fourth ICN, particularly its lateral division, followed a superficial and consistent subdermal route bypassing breast tissue in all cadavers. Conversely, the LCB of the fourth ICN, specifically its anterior division, traversed deeper breast tissue to reach the NAC. Variable supplementary contributions were observed from the second, third, and fifth ICNs, and previously undocumented ancillary branches. Significant inter-individual anatomical variability was noted.

Conclusion: The consistent superficial pathway of the ACB of the fourth ICN provides a clear anatomical rationale for improved sensory preservation observed in rNSM, given the procedure's lateral incision and precise dissection capabilities. Recognition of anatomical variability and detailed nerve trajectories should guide surgical planning to optimize sensory outcomes in breast cancer surgery and reconstruction.

Plain language summary

After breast cancer surgery, patients often lose feeling in their nipple area, but keeping the feeling in the nipple area is important for comfort and quality of life after surgery. This study aimed to map the nerves that give feeling to the nipple area, helping surgeons avoid damaging those nerves during breast surgery. The researchers studied six breasts donated for medical research. The nerves that give feeling to the nipple area were tracked and photographed. They also reviewed medical studies to support their results. The main nerves providing feeling to the nipple area run close to the skin’s surface. Robotic-assisted breast surgery uses small cuts away from the nipple area, helping to protect these nerves. This study provides guidance for surgeons to improve nipple feeling after breast surgery, leading to better patient outcomes.

MeSH terms

  • Adult
  • Breast Neoplasms / surgery
  • Breast* / anatomy & histology
  • Breast* / innervation
  • Breast* / surgery
  • Cadaver
  • Female
  • Humans
  • Intercostal Nerves / anatomy & histology
  • Mastectomy* / methods
  • Nipples* / anatomy & histology
  • Nipples* / innervation
  • Nipples* / surgery
  • Organ Sparing Treatments / methods
  • Robotic Surgical Procedures* / methods
  • Sensation