Background
The goal of breast reconstruction is to recreate symmetrical, natural-appearing breasts while preserving patient safety and quality of life. Many techniques exist for breast reconstruction, but rarely do they produce true symmetry with the contralateral breast.
The safety of the patient is essential and always should remain the primary concern in reconstructive procedures. These procedures should be tailored to the individual patient, taking into account the ultimate aesthetic outcome and the impact the reconstruction may have on the patient's lifestyle. [1, 2, 3]
History of the Procedure
Silicone breast implants were introduced in the 1960s and offered the first opportunity to provide reconstruction of the breast following mastectomy. During those times, extirpative surgery resulted in significant breast deformities due to the more radical approaches used, and the breast implant allowed for really nothing more that the recreation of a breast mound. In the late 1970s, the latissimus dorsi myocutaneous flap was re-introduced and combined with implant placement to provide notably improved results in breast reconstruction. [4] Rather than simply placing an implant beneath thin skin flaps, the latissimus muscle served to replace or even augment the pectoralis muscle to provide coverage of the implant.
Radovan's subsequent introduction of tissue expanders allowed the implant to be placed beneath the residual skin and muscle while uninflated. [5] Once the skin and muscle flaps recovered from the trauma of surgery and could tolerate the stress, the implants were inflated. This spared additional injury to the chest wall tissues and permitted overinflation of the expander. More volume was placed in the expander than was needed by the permanent implant, which helped to create a degree of breast ptosis, resulting in a more natural-appearing breast mound. Until several years ago, permanent saline expander-implants or saline expanders replaced by permanent saline implants had been used because of the difficulty in obtaining silicone implants.
In November 2006, the Food and Drug Administration (FDA) reversed the moratorium on the use of silicone gel-filled implants. [6, 7] Objective and medically grounded information has confirmed the safety of using both silicone gel-filled and saline filled implants for breast reconstruction and aesthetic breast surgery. [8, 9, 10] (For more information, see Silicone Breast Implant Safety and Efficacy.) Most of the concern regarding the use of breast implants has focused on claims of a link between silicone and autoimmune diseases, a supposition now known to have no scientific foundation. Despite the data supporting the safety of breast implants, careful informed patient consent concerning these issues as well as other potential complications (see Complications) is essential prior to any procedure involving implants or expanders.
Problem
The use of expander-implants can lead to unsatisfactory outcomes if proper coverage of the implant is not obtained. Often, the only available coverage is a thin layer of skin and subcutaneous tissue. This predisposes to the formation of capsular contracture, producing an unnaturally round breast mound. By ensuring that sufficient vascularized soft tissue is provided to cover the implant, capsular contracture is less likely and, ideally, the excess skin and muscle redrapes in a shape that simulates the normal ptotic breast.
Options to improve coverage of the implant include the use of the latissimus dorsi muscle, which reduces capsular contracture and improves outcomes. [11] The development of suitable biologic materials such as decellularized dermal matrices has given surgeons the means to provide coverage of implants and expanders. [12]
Epidemiology
Frequency
In 2022, of 151,641 breast reconstructions performed, as projected by the American Society of Plastic Surgeons, 82,597 (54.5%) used a tissue expander and implant. [13]
A study by Ilonzo et al found that in the United States in 2014, among patients who underwent mastectomy for breast cancer, 43.30% had reconstructive surgery, compared with 26.94% in 2005. Within this time period, a dramatic increase in the performance of tissue-expander procedures occurred. [14]
In a survey of the reconstructive practices of 134 plastic surgeons who treated women with early stage breast cancer, as identified via the Georgia and Los Angeles Surveillance, Epidemiology, and End Results (SEER) program registries, Momoh et al found that expander-implant reconstruction was the most frequently employed technique (72.6%). [15]
Pathophysiology
Three concepts are essential to considering the problems that must be addressed to create symmetry in the reconstructed breast: the inframammary fold, ptosis, and projection. [16] The inframammary fold is an important landmark that frequently is disrupted or destroyed by modified radical mastectomy. Ptosis is the natural teardrop shape of the breast that occurs with the effect of gravity on the normal breast tissue and usually is lost when a noncompressible saline implant is placed beneath the skin. Projection is the anteroposterior fullness of the breast; projection also can be diminished when expander-implants are used. [17] Achieving an aesthetic outcome requires that each of these elements is visually similar to the contralateral breast mound.
Indications
Factors that can help determine whether expander-implant reconstruction is appropriate include the quality of the overlying skin, the condition of the pectoralis and serratus muscles, and available donor tissue for autologous reconstruction. Patients with inadequate in-situ donor tissue who cannot tolerate the increased length of surgery required for either pedicled or free-tissue transfer reconstruction may be candidates for expander-implant procedures. [18]
In addition, patients who are undergoing bilateral reconstruction but are otherwise candidates for transverse rectus abdominus muscle (TRAM) reconstruction may be considered for implant-expander reconstruction to avoid the morbidity of using both rectus muscles. Patients who are undergoing delayed reconstruction may require prolonged expansion to create a sufficient skin envelope for placement of the implant unless a latissimus dorsi flap with overlying skin is used to cover the implant.
Relevant Anatomy
The anatomic borders of the breast mound are the level of the second rib superiorly, the inframammary fold at the seventh rib inferiorly, the lateral border of the sternum medially, and the midaxillary line laterally. The breast parenchyma is within the superficial fascia of the chest wall superficial to the pectoralis major, serratus anterior, and superior portion of the rectus sheath.
The arterial supply includes the internal mammary artery, posterior intercostal arteries, and lateral thoracic and thoracoacromial arteries. Venous return is primarily via the axilla and secondarily via the internal thoracic and posterior intercostal perforating branches. Most lymphatic drainage is to the axillary nodes.
Sensory innervation of the breast is supplied by cutaneous branches of the second through sixth intercostal nerves.
For a detailed discussion, see Breast Anatomy.
Contraindications
Because any patient who is undergoing immediate reconstruction following mastectomy is already a surgical candidate, contraindications to expander-implant reconstruction are few. [19] Implant reconstruction is contraindicated in patients who have insufficient skin, soft tissue, and muscle to cover the prosthesis. This population is better suited for an implant covered by a latissimus dorsi flap. If muscle coverage is sufficient but skin coverage is limited, an expander can be placed and inflated over time to create a proper skin envelope. An additional relative contraindication is significant ptosis of the contralateral breast. Implants are unable to achieve a natural ptotic appearance; in these patients, autologous tissue reconstruction or a contralateral symmetry procedure is indicated.
-
Expander-implant breast reconstruction. Intraoperative photograph following bilateral skin-sparing mastectomy.
-
Expander-implant breast reconstruction. Intraoperative view of site ready for implant.
-
Expander-implant breast reconstruction. Intraoperative view of implant in place and wound closed.
-
Expander-implant breast reconstruction. Textured saline expandable implant with built-in port.
-
Expander-implant breast reconstruction. Anterior view 6 weeks after removal of expanders and replacement with implants covered by latissimus dorsi muscle flaps.
-
Expander-implant breast reconstruction. Lateral view 6 weeks after removal of expanders and replacement with implants covered by latissimus dorsi muscle flaps.
