Subglandular Breast Augmentation

One of the great debates in plastic surgery has focused on whether to place breast implants over or under the pectoralis major muscle. This author's strong feeling is that, in most instances, the implant should be placed in the subglandular position, that is, over the muscle. A subglandular implant is shown below.

Breast augmentation first was attempted in the early 1900s. The site of placement was always subglandular. Everything from ivory to ebony to paraffin was implanted and, of course, rejected. In the 1950s, Ivalon sponges were used. Although they were biocompatible, fibrous tissue grew into them, making them extremely hard. Breast augmentation was begun in earnest in the mid-1960s when silicone implants were introduced. Again, the placement always was subglandular.

The major problem with breast implants consistently has been hardness. The implants themselves do not become hard; the problem is that the human body recognizes that the implant is a foreign object. Since the body cannot reject the implant (silicone has no active binding sites), the defense mechanism is for the body to wall it off with a membrane consisting of myofibrils and collagen. This commonly is termed a capsule. If the capsule contracts around the implant, the consequence is similar to squeezing a balloon partially filled with water—it feels hard. This is known as fibrous capsular contracture. Why the capsule contracts in some patients remains a mystery. Even more mysterious is the fact that it frequently occurs in only one breast and not the other.

The early silicone implants had backing made of Dacron that was meant to hold the implant in place. What was not realized for several years was that the Dacron caused a severe tissue reaction, resulting in extreme capsular contracture. In the late 1960s, the idea of putting the implant under the muscle was introduced. This placement was popularized in the mid-1970s because of the belief that the breast felt softer with subpectoral implantation. Unfortunately, the characterization of the degree of hardness is difficult to quantify. Although the Baker system of classification is widely accepted for this purpose, determining just how much firmness a breast may have remains subjective, and therein lies the problem of finding the procedure that minimizes the problem.

The argument for subpectoral (under the muscle) placement is as follows:

• The muscle covers the implant, thus any capsular contracture (breasts that feel hard) is less common

• For the same reason, rippling (wrinkling) of the implant is less apparent

• Mammograms are more accurate

• In very small-breasted women, the outline of the implant is less visible

• The surgery takes less time

The argument for subglandular (under the breast tissue) placement is as follows:

• The breast is obviously over the muscle, thus the implant belongs there

• Because of this, subglandular placement most often looks more natural

• Because the muscle covers only one third to one half of the implant when the implant is placed below it, minimal advantages exist in placing the implant there (this does not apply for the rarely performed true submuscular implant that also uses the serratus anterior muscle for coverage)

• Because most of the implant is not covered by muscle when placed below it, minimal advantages exist in placing the implant there; only a slight diminution of the incidence of capsular contracture and implant rippling occurs (although study results on capsular contracture rates in subglandular vs submuscular augmentation vary[1, 2, 3] )

• Subpectoral placement requires cutting the muscle insertion; because of this and/or the pressure of the underlying implant, the pectoralis muscle becomes very atrophic and virtually is destroyed; the assertion that the implant "falls" into a more natural position within weeks of the surgery is false; actually, the muscle is atrophying (dying), causing the diminution of the initial upper pole fullness

• If any degree of ptosis is present, a subglandular implant lifts the breasts much better

• A properly performed mammogram shows 95% of breast tissue; magnetic resonance imaging (MRI), however, can visualize 100% of the breast and will, eventually, be the criterion standard for cancer detection

• Lower risk of postoperative bleeding is involved

• Significantly less postoperative pain occurs[4]

• The procedure can be performed with intravenous sedation and local anesthesia, which is a safer alternative to general (complete) anesthesia

Nevertheless, approximately 50-60% of plastic surgeons perform submuscular implantations. This author places approximately 2% of implants under the muscle, usually only when requested by the patient. The difference in appearance is depicted in the image below.

Frequency

Micromastia is a common occurrence.

Determine the patient's motivation and expectation. Be wary of the patient who wants the surgery to please her partner. Try to match the patient's expectation to the effects that can be achieved. When a patient asks for very large breasts, the author inquires if she wants a natural appearance. The answer is almost always affirmative. In that situation, the author states that he will make the breasts as large as possible and still have them appear natural.

On physical examination, noting asymmetry is important because the patient may be unaware of the problem; she may only note it postoperatively and blame the surgeon. Differences in nipple and breast height, size, and shape are common.

Look for stretch marks and assess their depth. Also observe any thinning of the breast tissues since these problems cause a higher degree of rippling (wrinkling) of the implants.

Note any degree of ptosis and advise the patient regarding how much will remain postoperatively. Except in extreme situations, the author prefers not to perform a mastopexy, since most patients are satisfied with the augmentation and whatever lift it provides and do not want the additional scarring. Failing that, a nipple lift is often sufficient. Obviously, locate any breast masses or discharge. During the physical examination, discuss the patient's desires and the size of the implant.

Micromastia (ie, small breasts) is obviously the reason patients seek an enlargement procedure. However, surprisingly, what may appear to be ample breasts to the surgeon may seem quite small to the patient requesting augmentation.

A patient occasionally requests surgery because of asymmetry.

In many cases, subglandular implants lift a drooping breast without the need for additional visible scarring.

Breast shape varies among patients, but knowing and understanding the anatomy of the breast (see the image below) ensures safe surgical planning. When the breasts are carefully examined, significant asymmetries are revealed in most patients. Any preexisting asymmetries, spinal curvature, or chest wall deformities must be recognized and demonstrated to the patient, as these may be difficult to correct and can become noticeable in the postoperative period. Preoperative photographs with multiple views are obtained on all patients and maintained as part of the office record.

The female breast covers the anterior chest wall from approximately the second rib superiorly to the fourth or fifth rib inferiorly. Its upper one half overlies the pectoralis major muscle, the serratus anterior its lower one half, and some of the axillary fascia laterally.

The breast is essentially a skin organ. It is attached intimately to the skin by suspensory ligaments (Cooper ligaments). This is because developmentally it forms from the ectoderm of the anterolateral body wall, and epithelial proliferation from that site creates the gland. For this reason, opening the natural plane between the muscle and the breast is easy; an implant can be inserted into this space.

The blood supply of the breast is derived from branches of the axillary artery, the intercostal arteries, and the internal mammary artery. Few if any vessels penetrate into the gland from the underlying gland.

Its nerve supply comes from the anterior and lateral cutaneous branches of the fourth, fifth, and sixth thoracic nerves. One of the larger lateral cutaneous branches often can be visualized and preserved during augmentation surgery.

For more information about the relevant anatomy, see Breast Anatomy.

The one absolute contraindication to subglandular augmentation is an irradiated breast. Because of interference with the blood supply caused by radiation, a subpectoral placement is much safer.

Another reason to consider placing the implant under the muscle is very thin breast tissue, as can occur after pregnancy.

Some surgeons also believe that a subpectoral implantation should be used in extremely small-breasted patients, although the author feels this is necessary only in a very few patients.

Because a small amount of the breast may be obscured during a mammogram, a patient with a strong history of breast cancer probably should be augmented under the muscle, as should a patient undergoing postmastectomy reconstruction when the contralateral breast also is being augmented.

Although the author much prefers silicone gel implants, patients with a history of autoimmune diseases are advised to have saline implants.

Perform routine blood tests, including a CBC and clotting studies, preoperatively.

Obtain a pregnancy test on the day of surgery.

Obtain a baseline mammogram in a patient who is aged 35 years or older and who has not undergone the examination previously.

Despite occasional false advertising to the contrary, no drug enlarges a female breast permanently.

However, a device that stretches the skin externally is purported to cause proliferation of the underlying tissue to provide an increase of up to one cup size. It currently is undergoing testing as to its efficacy and the permanence of the result. Thus far, the device has not proved to be very well accepted.

In the author's opinion, micromastia is best treated with a subglandular breast augmentation.

Thoroughly discuss the procedure and its risks with the patient during the preoperative consultation. Especially assess the patient's personality and expectations.

• Inform the patient of details of what to expect before, during, and after the surgery.

• Attempting to meet the patient's expectations regarding size is very important. When a patient asks for an implant that the author feels is too large, he explains why he believes that the implant would be deforming and informs the patient that he will place the largest implant that appears natural.

• In situations in which flexibility is possible and the author is not sure exactly what the patient wants, patients are asked to bring in a picture from a magazine or lingerie catalogue to provide an idea of what they envision for themselves.

• Aspirin and ibuprofen should be avoided for 2 weeks before surgery.

If the operation is performed by means of the inframammary route (author's preference), the incision need only be 2.5-3 cm if an inflatable implant is used.

• Mark the incision preoperatively with the patient in the upright position. Place the incision in the inframammary fold, lateral to the midmammary line. The author makes no other preoperative markings, relying on judgment during the operation regarding size and placement. Postoperatively, the expansion of the skin brings the incision up on the undersurface of the breast for a distance of 1-2 cm. This keeps the scar from being visible in a bikini bathing suit. The resulting scar is almost always acceptable and revision is rarely necessary.

• Carry the incision down through subcutaneous tissue and superficial fascia onto the fascia of the serratus anterior muscle. Continue dissection superiorly over the fascia of the pectoralis major muscle to a level of approximately the second rib, as a large pocket is essential. This can be accomplished with scissors in combination with finger dissection, spreading devices, or a sponge on a stick.

• Do not carry the medial dissection further than the lateral sternal border. An attempt to give the patient cleavage by dissecting further medially results in symmastia, an unsightly bridge of skin joining the breasts together that is also termed a unibreast.

• The lateral extent of the pocket is a matter of judgment. The author usually makes a modest dissection to the anterior axillary line, and after the implant is in place, the finger is used to extend the lateral dissection until the outline of the implant is no longer apparent.

• Meticulous hemostasis using electrocautery is absolutely essential. The author uses a fibro-optic lighted retractor for visualization. Usually the dissection is performed on one side, a few sponges are placed in the pocket, and then the other side is dissected. When returning to the first side, small bleeders occasionally are apparent and can be cauterized.

• Once the pocket is dissected and hemostasis is assured, the author first places an inflatable sizer corresponding to the projected size of the implant. After filling it with air, the judgment is made regarding which size best fits the patient and addresses her expectations.

• Then place the implant in the pocket and inflate it with saline. Adding anything to the saline is advised against strongly. Betadine is suspected to weaken the implant wall, and steroids are well known to cause erosion of the overlying tissue, resulting in exposure and extrusion of the implant.

• The author recommends filling the implant to the maximum amount allowed by the manufacturer. The author occasionally adds an additional 5-15 mL more than that amount, depending on the size of the implant, in the belief that this helps prevent rippling of the implant. However, if too much saline is added, scalloping of the implant edges results, which will appear as rippling.

• The author prefers smooth-walled, round implants. Textured implants have thicker shells; thus, any rippling becomes much more offensive. The author also has experienced a higher incidence of capsular contracture with textured implants and serious leakage problems with textured saline implants. Round implants are used because oval or teardrop-shaped implants that are not textured can rotate.

• Close the incision in layers. Suture the superficial fascia with absorbable sutures such as Dexon or Vicryl. The author also places interrupted subcuticular sutures that are absorbable and closes the skin with 6-0 nylon. Some surgeons prefer a continuous subcuticular closure. The bandage merely covers the incision, and the author employs no other taping.

The author uses postoperative antibiotics and prescribes a mild opioid analgesic and acetaminophen for pain. Aspirin and ibuprofen should be avoided for 2 weeks after surgery. Vitamin E, zafirlukast (Accolate), and echinacea are prescribed for possible prophylaxis against capsular contracture, although the evidence that they help is only anecdotal. Thus far, reports of success with these medications are anecdotal.

Remove sutures after 1 week.

Although the author does not require the patient to wear a bra in the first postoperative week, he has no objection to its use immediately after surgery. After the first postoperative week, a sports bra often makes the patient more comfortable for the next month.

Advise the patient to refrain from physical exercise for 3 weeks; the patient can return to work in approximately 3 days (vs 1-2 wk with submuscular augmentation). Patients are otherwise allowed to engage in whatever activities they feel comfortable doing.

Patients are seen 1, 2, and 6 weeks postoperatively. Although patients are instructed to massage their breasts after the second week, the author believes that this is of limited value, if any.

Patients usually return on their own if they experience a capsular contracture, which can be treated with closed capsulotomy.

The prospective patient must be informed of the risks and possible complications of the operation.

Infection

Infection is a rare complication, which occurs, in the author's personal experience, in approximately 1 patient per 1000. It usually necessitates removal of the implant and replacement at a future date.[5]

Postoperative bleeding

This occurs in 0.5-1% of patients. While it is not life threatening, it requires additional surgery to stop the bleeding.

Deflation

Several years ago, the author used textured saline implants in approximately 100 patients, and deflation resulted in 5 patients, which is highly unacceptable. In approximately 1600 patients in whom the author used smooth-walled saline implants, only one deflation had occurred at the time of this writing. However, deflation is certainly a known risk and could well happen due to fold faults, which are continuous flexing of the implant edge that, like repeated bending of a paper clip, can cause failure of the implant. Rarely, the filling valve can be defective.

Capsular contracture

Capsular contracture is the major problem with breast implants. If the capsule contracts around the implant, it squeezes it and makes it feel hard. This complication can be treated with closed capsulotomy but it may recur.

Many studies demonstrate no difference in contracture rates when the implant is over or under the muscle. However, a review study by Egeberg and Sørensen suggested that subglandular breast augmentation carries more than twice the risk of capsular contracture that the submuscular technique does. Results were derived from a meta-analysis of 10 studies, involving a total of 17,520 breast implants.[1]

Vitamin E and zafirlukast (Accolate) are believed by some to reduce the incidence of capsular contracture. The author's incidence of capsular contracture with 2500 subglandular augmentations is between 5% and 7%.[5, 6]

Rippling of the implant

Although this occurs more frequently in patients who have thin breast tissue following pregnancy or who have deep stretch marks, it can occur in any patient. Silicone implants have a much lower incidence of rippling because the gel adheres to the elastomer lining, which helps to keep it from rippling. Hydrogel, where available, also results in less rippling.[5]

Atrophy

A study by Weck Roxo et al found that at 12-month postoperative follow-up, women who underwent subglandular breast augmentation (24 patients) demonstrated significant atrophy of the breast parenchyma. In contrast, women who underwent submuscular breast augmentation (24 patients) demonstrated significant atrophy of the pectoralis major muscle.[7]

Subpectoral repositioning

A retrospective study by Hauch et al reported that the investigators’ technique for subpectoral repositioning of subglandular implants can be successfully performed on patients who present with complications of implant surgery years after subglandular augmentation. The patients, who presented a mean 18 years after their initial operation, had experienced “slide-down” deformity, along with complications such as capsular contracture, implant wrinkling, and enlarged areolas. Instead of using an acellular dermal matrix (ADM) or a mesh, the procedure, employing a partial capsulectomy, retained the inferior and posterior sections of the capsule to serve in place of the ADM or mesh. This ensured that the implant was adequately covered and avoided window shading of the pectoralis major muscle. Twenty-four patients were included in the study, of which, at average 3.1-year follow-up, two individuals underwent minor revisions under local anesthesia, with two more revisions (to correct malposition in one patient and to insert larger implants in the other) performed under general anesthesia.[8]

The implant manufacturers state that their products are not meant to be lifetime devices, but because of their long-term guarantees of replacement, they obviously hope that they will be used over the patient's life.

Overall, the author has found a high degree of patient satisfaction with subglandular placement of breast implants and recommends that approach. Whatever the complications with hardness or rippling, almost no one asks for the removal of the implants.

Results are shown in the images below.

A literature review by Azzi et al indicated that in women who develop breast cancer subsequent to breast augmentation, patient prognosis is not linked to implant location. Among breast cancer patients in the study, 26.5% of women with subglandular implants had tumors 2-5 cm in size, compared with 9.9% of women with subpectoral implants; the frequency of stage 2 tumors also varied (42.9% vs 23.7%, respectively). According to the investigators, these results suggest that radiologic detection of early tumors is delayed by increased distortion from subglandular implants. However, the study also found that lymphovascular invasion, as well as the frequency of tumors over 5 cm in size or that were diagnosed as stage 3, did not differ significantly between subglandular and subpectoral implant patients.[9]