Postoperatively Adjustable Breast Implant

Anatomy and Physiology

The breast or mammary gland is found on the thorax underneath the skin and is considered a subcutaneous organ. Boundaries of the breast are as follows: clavicle superiorly, inframammary fold inferiorly, sternum medially, serratus anterior laterally, pectoral muscles posteriorly, and skin anteriorly. The breast spans from the second to the sixth intercostal space.

The subpectoral space boundary follows the pectoralis major muscle anteriorly, rib cage and pectoralis minor posteriorly, serratus anterior laterally, and subcutaneous tissue inferiorly covered with mastectomy flap.[4]

The pre-pectoral space is defined as the space between the pectoralis major muscle fascia and the mastectomy flap.

Indications

Bilateral breast reconstruction is better suited to the small and medium-sized breasts. If unilateral breast reconstruction, the contralateral breast may necessitate mastopexy, reduction, or augmentation to achieve bilateral symmetry.

Large breasted patients can also undergo implant-based reconstruction if they are willing to undergo skin/breast reduction and contralateral surgery.[1] These patients are otherwise offered autologous tissue breast reconstruction.

Contraindications

Medical conditions that can compromise the skin envelope for the breast implant include scleroderma, history of radiation, and history of smoking. The previously irradiated breast can lead to implant infection and extrusion; therefore, for these patients, autologous tissue reconstruction is preferred. If a patient needs adjuvant radiation therapy after mastectomy, immediate implant-based reconstruction is advised against until radiation is completed.[1]

For pre-pectoral (subcutaneous) implant placement, high body mass index, history of smoking, and pre-operative radiation are absolute contraindications due to the high risk of implant extrusion.[5]

Equipment

Tissue expanders are utilized to maximize skin volume before implant placement. There are two types of tissue expanders that have been used for breast reconstruction. One is filled with compressed carbon dioxide and the second type with saline. 

Saline tissue expanders are sequentially filled with saline in the outpatient setting. This requires weekly or biweekly clinic visits to reach the desired volume. The saline infusions are performed with percutaneous needle sticks that can cause patient anxiety and discomfort as well as an increased risk of infection. Another potential complication is skin dehiscence due to the sudden expansion with saline bolus causing pressure necrosis on mastectomy flaps. The advantages of the saline tissue expander include not requiring adjustment of radiation therapy protocol, and the saline can be removed from the expander if indicated.[6]

Carbon dioxide expanders are remote-controlled, allowing for gradual expansion to be performed by the patient in the outpatient, home setting. It does not require percutaneous needle sticks, thus reducing the potential for infections. The expansion is more gradual, and the volume is achieved faster than with traditional saline tissue expander. The patients can receive adjuvant radiotherapy; however, the radiation oncologist may have to modify radiation protocol. Another disadvantage is that the carbon dioxide cannot be expelled from the tissue expander if it is required.[6] Unfortunately, the company filed for bankruptcy in 2019, and this product is no longer available in the market. 

Breast implant (saline vs. silicone) remains one of the more popular methods of breast reconstruction. In the case of a rupture, those with saline may feel more comfortable knowing that nothing more than saline is entering their body. Implants still tend to be a much simpler surgery comparatively. On the other hand, saline implants typically last only 10 to 15 years, are palpable, and can be prone to causing a rippling of the skin. Silicone implants are lighter weight, have a longevity of 20 to 25 years, and look more aesthetically natural with less rippling. According to the FDA, there is a possible associated risk of developing breast-implant associated anaplastic large cell lymphoma with either type of implant. The minimal increased risk of developing BIA-ALCL is linked only with textured implants.

The acellular dermal matrix material (ADM) can be derived from porcine, bovine, or cadaver tissue versus synthetic mesh.[1] ADM is indicated for soft tissue reinforcement and allows the reconstruction to stay within the boundaries of the breast. ADM is an aseptic product (not sterile), which can be concerning for increased risk of infection.[7]

Drains are utilized to extract potential fluid collections, whether it is a seroma or a hematoma. A variety of sizes are available, and it is surgeon preference on which size is utilized. 

Personnel

The following personnel is required for this procedure:

• Breast oncologic surgeon or general surgeon
• Plastic surgeon 
• Operating room support team 
• Medical/radiation oncologists

Preparation

Preoperative planning requires close communication between breast oncologic surgeons, medical/radiation oncologists, and plastic surgeons. Preferably, breast margins should be marked before the patient going under anesthesia while in the standing position. Important measurements to take into consideration are the distance from the sternal notch to the nipple, the distance between the nipple-areolar complex and the inframammary fold, and the total width of the breast.[1]

Smoking cessation is strongly advised before any type of reconstruction due to an increased risk of complications such as skin flap necrosis and infection. A window of at least three weeks between smoking cessation and breast reconstruction is recommended.[8]

Technique or Treatment

After mastectomy is completed, the skin flaps are assessed to ensure that the blood supply is not compromised. The surgeon can look at the capillary refill, color, dermal bleeding, and temperature of the skin. Other techniques include laser-assisted indocyanine green or fluorescein angiography.[1]

When performing immediate breast reconstruction, there are two options: single-stage vs. 2-stage reconstruction. The 2-stage approach is most commonly performed; the however single-stage approach is gaining popularity.[9]

In the single-stage approach, an all-in-one adjustable tissue expander and implant are placed at the same time. The adjustable expander has a subcutaneous port for post-operative adjustments to be performed by the patient in the outpatient setting. The benefit of this approach is the patient undergoes only one surgical intervention under general anesthesia. The subcutaneous port can be removed in the clinic setting under local anesthetic. The complications from this approach are comparable to the 2-stage approach.[9]

In the 2-stage approach, the tissue expander is placed immediately after mastectomy and left in place for sequential expansion until the desired breast volume is achieved. Patients must then undergo a second surgical intervention to remove the tissue expander and replace it with permanent implants that match the breast volume achieved. 

The subpectoral space (or submuscular) implant-based reconstruction is created by releasing the inferior and medial attachments of the pectoralis major muscle; the external oblique muscle aponeurosis released inferiorly; serratus anterior muscle laterally and costal cartilages medially.[4] Once this is performed, the pectoralis major can be lifted, and the pocket is dissected further cephalad, being careful not to injury the thoracoacromial bundle and the internal mammary perforators.[1]

For the pre-pectoral (subcutaneous) space, the implant is attached to a mesh or acellular dermal matrix before fixation within the space. Attachment points are at the inframammary fold inferiorly and to the pectoralis major muscle fascial superiorly.

It is important to mention the use of acellular dermal matrix (ADM) or synthetic mesh in either one or 2-stage reconstruction. This is attached at the inframammary fold to create a sling for the adjustable implant/tissue expander, or it can be utilized to cover the tissue expander circumferentially. In some studies, the use of ADM/synthetic mesh has shown decreased rates of complications with subcutaneous implant placement.[5]

Complications

Although the subpectoral (submuscular) placement allows for an extra tissue layer over the implant as well as preventing the implant from migrating inferiorly, this approach comes with its complications. Muscle dissection can cause an increase in postoperative pain levels. Other reported complications are animation deformity, shoulder dysfunction, and a less natural-appearing breast due to implant placement under the muscle.[5]

The pre-pectoral (subcutaneous) placement allows for a more natural-appearing breast and decreased postoperative pain since the muscle insertions are left intact. Complications associated with this approach are capsular contracture, implant loss or exposure, migration of the implant, and skin flap ischemia.[5]

Capsular contracture is defined as the development of an envelope around the implant that consists of fibrous tissue causing breast pain and deformity. There is an increased rate of this complication with breast reconstruction versus in breast augmentation patients. It has also been noted that capsular contracture occurs to a lesser degree in subpectoral placement because the muscle movement massages the implant and allows an extra coverage layer between the implant and skin with the muscle acting as a barrier from bacteria.[10] The introduction of textured implants has diminished the risk of capsular contracture. History of an irradiated breast is another predisposing factor that can lead to capsular contracture. Hematoma formation can be prevented with bulb suction drainage systems. It is important to evacuate hematomas since these can lead to capsular contracture.[1]

Complications to consider are seromas, skin flap necrosis, infection, implant exposure/loss.

Clinical Significance

With the increasing emergence of bilateral mastectomies with reconstruction, whether it is for cancer treatment or prophylactically, it is important as a general surgeon/plastic surgeon to be cognizant of different approaches to reconstruction. Breast cancer is a complex disease with very specific treatment modalities that are individualized to each patient. It is crucial to be aware of the indications and contraindications for the different types of reconstruction in order to decide what would be most appropriate for the patient.

Enhancing Healthcare Team Outcomes

The skills involved in post-mastectomy reconstruction with postoperative adjustable implants require specific technique and expertise, which takes time to develop. The strategy depends on the approach, whether concomitant mastectomy reconstruction versus delayed reconstruction is decided upon. It is important to educate the nursing staff to monitor flap integrity postoperatively. In the preoperative preparation for any of the reconstructions, it is very crucial to educate the patient on smoking cessation. Postoperatively, patient education on drain care, diabetes control as well as shoulder range of motion exercises play an important role in the recovery stage.