What muscles are cut during a bilateral mastectomy with reconstruction using the inframammary (below the breast) approach?

Muscles Affected During Inframammary Approach for Bilateral Mastectomy with Reconstruction

During a bilateral mastectomy with reconstruction using the inframammary approach, no major muscles are typically cut; instead, the pectoralis major muscle is detached from its inferior border and the serratus anterior muscle fascia is used for implant coverage rather than cutting the muscle itself.

Anatomical Considerations in Inframammary Approach

Muscle Preservation

• The inframammary approach utilizes the natural fold under the breast for surgical access
• This approach is designed to preserve major muscles while allowing for proper reconstruction 1
• Key muscles involved but not cut include:
  • Pectoralis major muscle - detached at inferior border but preserved
  • Serratus anterior muscle - fascia used rather than muscle itself

Tissue Handling During Reconstruction

• In implant-based reconstruction following mastectomy through the inframammary approach:
  • The pectoralis major muscle is elevated and released at its inferior attachment
  • The serratus anterior muscle fascia is used to create a lateral pocket for implant coverage 2
  • This technique preserves muscle function while providing adequate implant coverage

Benefits of Muscle-Preserving Techniques

Functional Advantages

• Preservation of the pectoralis major muscle's inferior border helps avoid:
  • Postoperative motor function deficits
  • Animation deformity (visible muscle movement when using chest muscles) 2
  • Decreased upper body strength

Surgical Innovations

• Recent techniques focus on using the serratus anterior muscle fascia rather than the muscle itself:
  • The fascia is connected to the lateral margin of the pectoralis major muscle
  • This creates a musculofascial pocket for implant coverage
  • Significantly reduces post-operative pain compared to using muscle fibers 3

Reconstruction Considerations

Implant Placement Options

• Submuscular placement:
  • Implant is placed beneath the pectoralis major muscle
  • Lateral and inferior coverage provided by serratus anterior fascia flap 2
  • No muscles are cut; instead, muscles are detached and repositioned

Tissue Expander Placement

• When using tissue expanders in two-stage reconstruction:
  • The expander is placed in a pocket beneath the pectoralis major
  • Inferolateral coverage can be achieved using serratus anterior fascia rather than muscle 3
  • This approach results in less post-operative pain and drainage

Common Pitfalls and Complications

Potential Issues to Monitor

• Lateral migration of implants is more common with partial muscle coverage approaches 4
• Mastectomy flap necrosis risk must be carefully assessed
• Complete muscle coverage may be preferred if there's high risk of mastectomy flap necrosis 4

Special Considerations

Nipple-Sparing Procedures

• When performing nipple-sparing mastectomy with the inframammary approach:
  • A wide-based inframammary fold flap can be used
  • This preserves the nipple-areolar complex while maintaining muscle integrity 5
  • Particularly useful for larger-breasted patients or those with significant ptosis

In summary, the inframammary approach for bilateral mastectomy with reconstruction is designed to preserve muscle function while providing adequate coverage for implants. The technique focuses on using muscle fascia rather than cutting muscles, which helps maintain upper body strength and reduces post-operative complications.