Submuscular Breast Augmentation Treatment & Management

Surgical approaches for breast implant placement include inframammary, periareolar, transaxillary, and periumbilical. Several issues contribute to the choice of approach, including surgeon preference and experience.

Three basic configurations of shapes are currently available for breast augmentation. The shapes of the implants are most easily described as low-, medium-, and high-profile. A low-profile implant has a broader base and lower height when viewed on a table next to a high-profile implant of comparable volume (a medium-profile implant has base and height dimensions in between the two).

Silicone implants require a larger incision for placement than do saline implants. Silicone implants are prefilled and are, therefore, available in fixed volumes, in contrast to saline implants, which are filled after they are placed in the patient and may be adjusted to compensate for any difference in volume between the patient's two breasts.

Inframammary approach

An inframammary incision is the most common approach for placement of a breast implant. This approach, which entails a 3- to 4-cm incision, attempts to place the incision in or adjacent to the inframammary crease. The inframammary approach provides the most direct route and generally requires the least operative time for placement of the implant. Problems associated with inframammary incisions include a visible scar on the anterior surface of the breast. Additional problems center on the difficulty in placing the incision in the inframammary crease; this difficulty is potentially exacerbated with low-profile implants.

Periareolar approach

Implants placed by an incision within the pigmented areolar tissue, referred to as a periareolar incision, often result in the least conspicuous scar. However, dissection of the pocket required for implant placement is more difficult with a periareolar incision. Dissection must proceed through a portion of the breast tissue or in the subcutaneous plane. Problems with subcutaneous dissection include nodularity and inflammation. Incisions placed through the breast tissue or in the subcutaneous plane are associated with microcalcification and cyst formation. Medial placement of the periareolar implant incision within the areola avoids the fourth intercostal nerve, which supplies sensation to the nipple and areola.^[10]

Transaxillary approach

In the transaxillary approach, incisions are placed in the axilla, which avoids placement of the scar on the breast.^{[11, 12]} However, the transaxillary approach provides the worst exposure for placement of the implant. This may be avoided using special instrumentation, including endoscopes and specific surgical instrumentation designed to aid the dissection.^[12] An increased incidence of paresthesia involving the nipple-areola complex exists with this approach has been reported; however, the author has not experienced this complication.

Obtaining symmetric pockets is more difficult with this approach, and damage to the intercostal brachial nerve and subclavian venous thrombosis has been reported. Additionally, if infection results, removal of the implant may require conversion of the transaxillary incision to one of the other incisions described. Hypertrophic scar formation also can occur in the axilla, and the incision may be visible when the patient elevates her arms while wearing a sleeveless shirt. Because silicone implants are prefilled and, therefore, require a larger incision for placement, only smaller silicone implants are typically placed via this route.

Periumbilical approach

A periumbilical approach, involving implant placement through the umbilicus, can also be used for augmentation. Placement of the implant is restricted to a prepectoral plane, and this approach provides the worst control for dissection of the pockets. Superior dissection and symmetry of placement are difficult, even in the most experienced hands. Complications of hematoma or infection require conversion to one of the other incisions for implant removal. Additionally, placement of saline-filled implants through a periumbilical approach requires a special type of valvular mechanism, and the long-term reliability of the valvular mechanism in these implants has not been fully clarified, at least to the author's satisfaction.

Implant placement

Implants may be placed directly beneath the mammary gland (subglandular) or in a plane below the pectoralis major muscle (submuscular). Advantages attributed to placement beneath the gland include ease of dissection, predictable sizing and contouring, and satisfactory results, provided that capsular contracture does not occur. The subglandular position also allows for placement of larger implants than are feasible in a submuscular position.

Submuscular placement of implants was developed in response to problems associated with subglandular placement, specifically, capsular contracture and visibility of the edge of the implant. Additional benefits attributed to submuscular placement include reduced sensory changes in the nipple, decreased rates of capsular contracture, and ease of interpretation of mammographic studies. The submuscular plane is avascular, and incidence of hematoma may be reduced by placement in the submuscular plane.

Submuscular breast implants can be placed completely or only partially below the muscle. In total submuscular placement, the implants are located beneath both the pectoralis major muscle and the anterior portion of the serratus magnus muscle. With subpectoral placement, the implant is placed behind the complete pectoralis major muscle. The third option has been described as the dual plane approach.^[13] As initially described, in the dual plane approach, the implant is placed under the superior portion of the pectoralis major muscle; inferiorly, the implant is placed in a subglandular plane. In some patients, this result is incidentally achieved because of the size of the pectoralis major muscle, while in other patients, the pectoralis major muscle is cut in the middle of the body of the muscle to facilitate implant placement. Surgeon experience, lower breast pole anatomy, and the patient's desired results may dictate the choice of implant placement.

Disadvantages of submuscular implant placement include potential limitations on the size of the implant, increased postoperative pain, and the possibility of lateral displacement of the implant. In addition, obtaining significant cleavage is more difficult with submuscular placement. If significant cleavage is desired, the inferior and/or medial portion of the pectoralis musculature must be detached from its sternal attachments. This results in increased postoperative discomfort.

Hematoma

The frequency of hematomas is less than 2%. Associated symptoms of hematoma are unilateral pain, swelling, and, occasionally, fever. Hematomas may develop slowly without symptoms or rapidly with symptoms. Small hematomas may resolve without intervention, but large hematomas require drainage. Often, delaying drainage until liquefaction of the clot has occurred is preferable. However, if the hematoma is painful or large, it should be drained immediately.

Infection

Incidence of infection is approximately 2%. Infection typically becomes apparent 7-10 days postoperatively but may manifest at any point. Typical presenting symptoms of infection include swelling, discomfort, pain, drainage, and cellulitis overlying the breast. Typically, the wound should be drained and irrigated. Removal of the implant may not be necessary, particularly if the original surgery was by periareolar incision.^[14] Antibiotics should be prescribed immediately. If the implant is not removed, infection may result in severe capsular contracture. If the implant is removed following infection, it typically is replaced in 3-6 months. Staphylococcus epidermidis or Staphylococcus aureus commonly may cause infections.^[14] For more information, see eMedicine Infectious Diseases article Staphylococcal Infections.

Sensory changes

Postoperative changes in nipple-areolar sensation are common in patients who have undergone breast augmentation. Most patients exhibit a temporary dysesthesia, which tends to resolve in a period of months. However, a small percentage of individuals may present with long-term sensory changes in one or both nipples following breast augmentation. An increased incidence of sensory changes is noted with transaxillary augmentation, since this approach directly crosses the fourth intercostal nerve, which supplies sensation to the nipple-areolar area.

Scars

Hypertrophic or keloid scar formation is uncommon following breast augmentation. The lowest incidence of hypertrophic scarring appears in periareolar incisions. The presence of a hypertrophic scar in inframammary or axillary incisions may require re-excision and closure of the incision.

Asymmetry

Asymmetry of the implant position may result from shifting of the implant, increased contraction of the capsule unilaterally, or ptosis of the implant, which is attributed to placement of steroids in the pocket or breast prosthesis.^[15]

Contour irregularity and implant extrusion

Contour irregularity and implant extrusion may rarely be associated with the placement of implants. The most common cause of contour irregularity is a tight capsular contracture that develops around the implant.^[16] The incidence of capsular contracture following breast implantation appears to be approximately 30% of patients, but the reported incidence has varied widely, from 0-74% of patients. Classification of the contracture is highly subjective. In 1980, Little and Baker developed a classification system for capsular contracture following breast augmentation; it remains the standard for evaluating this complication. The grades of capsular contracture are divided into the following 4 types:

• Grade I: Capsular contracture of the augmented breast feels as soft as an unoperated breast.
• Grade II: Capsular contracture is minimal. The breast is less soft than an unoperated breast. The implant can be palpated but is not visible.
• Grade III: Capsular contracture is moderate. The breast is firmer. The implant can be palpated easily and may be distorted or visible.
• Grade IV: Capsular contracture is severe. The breast is hard, tender, and painful, with significant distortion present. The capsule thickness is not directly proportional to palpable firmness, although some relationship may exist.

The role of antibiotics in the prevention of capsular contracture is unclear.^{[17, 18, 19]} Antibiotics may benefit if subclinical infection is a factor (most often caused by S epidermidis). However, in patients in whom this is not a problem, antibiotics provide no benefit to the individual.

Various techniques, including massage, which expands the size of the capsule, attempt to reduce the incidence of this complication. Capsule formation may require surgical capsulotomy, which involves circumferential and radial division of the capsule and an increase in the extent of the pocket. Recurrence following capsulotomy approaches 30%. Complications of capsulotomy include bleeding, infection, and implant exposure. Capsulectomy, in which the capsule is excised, is also an option. A capsulectomy may be of benefit in some instances in which capsulotomy has failed or in cases of silicone implant rupture. The surgeon may also perform capsulectomy when a highly calcified capsule is present. Zafirlukast (Accolate), which causes smooth muscle relaxation, has been useful in some instances of capsular contracture and may obviate the need for surgery in select individuals.

Contour irregularities may arise because of rippling of the implant. Individuals with thin skin are more susceptible to this problem. Silicone implants seem to be subject to less rippling than saline implants. Numerous investigators are currently examining the role of fat injection to minimize contour irregularities, enhance breast symmetry, and reduce the visibility of rippling.

Medicolegal pitfalls

Medicolegal pitfalls typically relate to informed consent. The complications outlined above should be discussed with the patient preoperatively.

Despite the extensive list of potential complications, breast augmentation remains one of the safest and most predictable procedures performed. The surgery provides a balance between the size and shape of the patient's breasts and the rest of her body. The low incidence of complications and the predictability of surgical outcome have prompted an increasing number of individuals to undergo the procedure.

The FDA has identified a possible association between breast implants and the development of anaplastic large-cell lymphoma (ALCL), a rare type of non-Hodgkin's lymphoma. After review of the world literature, the FDA came to the conclusion that women with breast implants may have a low but increased risk of developing ALCL adjacent to the breast implant. This preliminary finding is based on 34 cases of ALCL in women with breast implants worldwide. This is a tiny fraction of the purported 5-10 million women who have received breast augmentation for reconstructive and cosmetic surgery. While this is a preliminary finding, which should not significantly reduce the benefit of the procedure, it certainly is an issue that will be closely followed in the future.^[20]