Clinical Scorecard: Anatomical Foundations for Sensory Retention in Robotic-Assisted Mastectomy

At a Glance

Key Highlights

• The anterior cutaneous branch (ACB) of the fourth intercostal nerve follows a superficial subdermal route, bypassing breast tissue, facilitating nerve preservation in rNSM.
• The lateral cutaneous branch (LCB) of the fourth intercostal nerve traverses deeper breast tissue and is a major contributor to NAC sensation.
• Robotic-assisted nipple-sparing mastectomy with lateral incisions preserves NAC sensation better (up to 55%) compared to traditional approaches (27–40%).

Guideline-Based Recommendations

Diagnosis

• Recognize the multi-nerve innervation pattern of the NAC, primarily involving the fourth intercostal nerve branches.
• Consider anatomical variability in sensory nerve pathways during preoperative planning.

Management

• Utilize robotic-assisted nipple-sparing mastectomy techniques with lateral incisions to minimize nerve injury.
• Avoid periareolar incisions to preserve the superficial anterior cutaneous branch of the fourth intercostal nerve.
• Incorporate nerve-preserving surgical planning based on detailed anatomical knowledge of NAC innervation.

Monitoring & Follow-up

• Assess postoperative nipple sensation to evaluate sensory preservation success.
• Monitor for sensory deficits related to injury of anterior and lateral cutaneous branches of intercostal nerves.

Risks

• Injury to anterior and lateral cutaneous branches of the fourth intercostal nerve can lead to significant loss of NAC sensation.
• Anatomical variability may increase risk of inadvertent nerve damage if not accounted for during surgery.

Patient & Prescribing Data

Adult female patients undergoing nipple-sparing mastectomy for breast cancer

Robotic-assisted nipple-sparing mastectomy with lateral incisions improves preservation of nipple sensation compared to traditional open approaches.

Clinical Best Practices

• Map and identify the anterior and lateral cutaneous branches of the fourth intercostal nerve intraoperatively to guide nerve-sparing dissection.
• Prefer lateral or axillary incisions distant from the NAC to protect superficial nerve pathways.
• Educate surgical teams on the anatomical variability of NAC innervation to optimize sensory outcomes.
• Consider adjunctive techniques such as neurotization or nerve grafting to restore sensation post-mastectomy when appropriate.

References

• Farr et al. clinical series on rNSM sensory preservation
• Systematic review by Smeele et al. on NAC innervation