Chapter 51: Breast Augmentation

There are five generations of breast implants. The first generation, which appeared in the 1960s, had a thick shell and thick filler with a Dacron patch to help secure it. The second generation appeared in the 1970s and had a thin shell and a less viscous filler. In the 1980s, the third-generation implants were released, and these reverted back to a thicker silicone shell with the addition of a barrier coating. Fourth- and fifth-generation implants represent refined third-generation implants with textured shells and cohesive or form-stable gel fillers. They are available in anatomic or round shapes. Cohesive gel implants rather than saline-filled implants represent the current gold standard because they are more natural in feel, ripple less, and retain their integrity following rupture. Breast augmentation is one of the most common cosmetic procedures, and in 1992 (not 2001) a moratorium was placed on its use by the FDA over safety concerns with silicone implants.1 This was subsequently retracted in 2006, and a number of silicone prostheses are currently approved for use in the United States, both for primary augmentation and reconstruction. Such implants currently include smooth and textured subtypes, although there was debate in 2019 with regards to whether textured subtype should be banned due to an association with breast implant–associated anaplastic large cell lymphoma (BIA-ALCL). However, there is not conclusive evidence to support this action at present. Furthermore, there is no proven link between silicone implant use and breast cancer or systemic autoimmune disease.1,2

2. Spear SL, Parikh PM, Goldstein JA. History of breast implants and the food and drug administration. Clin Plast Surg 2009;36(1):15–21, v Although assessment of a patient’s status for breast cancer is important, mammograms are not routinely required prior to undertaking breast augmentation. A general rule of thumb is to arrange a mammogram in patients over the age of 40 or those with a personal or family history of breast cancer. Assessment of the other parameters is absolutely necessary to optimize patient outcomes for implant selection and placement. First, the psychosocial elements must be explored and the patient must be given in-depth information to help understand what the long-term implications are for breast implant placement. Examination must include assessment not only of the breast but also the chest wall shape to identify any asymmetries or irregularities which may affect outcome. Assessment of the breasts themselves will include evaluation of the skin and soft tissues of the breast as well as specific measurements of breast base width, notch-to-nipple, and nipple-to-IMF distances.1–4

26 cm. There are no chest wall deformities evident, and tissue quality is good. Which one of the following is most useful to guide decision-making for plane of implant placement? There are a number of key decisions to be made when assessing a patient for breast augmentation. These include implant volume, implant shape, and implant pocket selection. In addition, decisions need to be made on textured versus smooth shell devices and saline versus silicone fill. Assessment of the superior pole fullness is considered to be a key step in helping to decide on the implant pocket selection as where there is minimal upper pole soft tissue cover, submuscular implant placement is generally advocated. Where there is greater volume present, subglandular placement may be preferred.1 There are a number of key steps used to help decide what implant size should be used. The first is to measure breast base width and height; this will enable the surgeon to select an appropriate size implant for this patient’s current breast and frame size. The next step is to confirm what appearance the patient wishes to achieve and how much bigger she wishes her breasts to be. To achieve this, implant sizers placed in a bra may be helpful to establish a visual image for the patient and surgeon. Alternatively, the use of computer-generated images may be helpful and many surgeons are using this approach for their patients. The risk of using computer-generated imagery is that expectations may be unrealistically set. Once this information is available, the appropriate implant sizes can be selected. Intraoperative decisions on final precise volume can be supported by the use of temporary sizer placement; however, this may increase the risk of complications such as infection as there is more tissue manipulation and passing of the implant multiple times. This can also increase the costs because of increased theater time and equipment. The distance from nipple-areola complex (NAC) to inframammary fold is important when considering the implant base dimensions and the volume of breast implant with respect to the final NAC position. It can also be a factor in decision-making for the need for mastopexy.2–5

4. Alpert BS, Lalonde DH. MOC-PS(SM) CME article: breast augmentation. Plast Reconstr Surg 2008;121(4, Suppl):1–7

5. de Jong D, Vasmel WLE, de Boer JP, et al. Anaplastic large-cell lymphoma in women with breast implants. JAMA 2008;300(17):2030–2035 There are four approaches to breast augmentation: inframammary, transaxillary, periareolar, and transumbilical. The pocket dissection may be performed under direct vision where the incision is on the breast as in the IMF or periareolar approaches. Where more distant incisions are used such as the transaxillary or periumbilical approaches, then endoscopic pocket dissection is required. The transaxillary approach is less commonly used than the IMF approach but does offer some potential advantages. In experienced hands, it can be a useful technique where avoidance of a breast scar is important to the patient. It begins with an open approach in the axilla with subcutaneous dissection to the lateral border of pectoralis major. Dissection then continues under pectoralis and using the endoscope, the implant pocket is created. The implant, which may be saline or silicone gel filled, can then be passed using an introducer such as a Keller funnel with a no skin touch technique. A disadvantage of this technique (aside from the endoscope skill set required) is the potential risk of injury to sensory nerves including the intercostobrachial and medial brachial cutaneous nerves.1–3 The IMF approach is commonly used and allows good access to the breast pocket with a scar usually hidden by natural ptosis within a well-defined IMF. The scar should be slightly lateral to the NAC, not in line with it, to minimize visibility medially (1 cm medial and 4 cm lateral). Tissue recruitment from the chest wall may occur during breast augmentation, and this must be considered when choosing the incision height to avoid placing the scar too high or too low on the final augmented breast or chest wall. The periareolar approach can be performed with either direct parenchymal dissection or using a stair-step approach that involves dissection in a subcutaneous plane to the inferior breast before undermining the gland to create the implant pocket. The stair-step approach is considered preferable since it avoids the need to breach the parenchyma, which could lead to potential damage to the ducts and may impact on infection risk. The transumbilical approach is only suitable for saline implants and involves difficult and blind dissection. It is also more challenging to make adjustments or corrections with this approach and can lead to high or asymmetrical implant placement. Because of these limitations, it is the least commonly used approach.4–6

6. Mofid MM, Klatsky SA, Singh NK, Nahabedian MY. Nipple-areola complex sensitivity after primary breast augmentation: a comparison of periareolar and inframammary incision approaches. Plast Reconstr Surg 2006;117(6):1694–1698 Placement of the implant under the pectoralis major can result in movement of the implant during activity. This is called an “animation deformity” and may be a major problem for patients involved in athletic activities, such as this patient.1,2 Various techniques have been described to minimize this including splitting pectoralis major.2,3 Nipple sensation is usually preserved following breast augmentation but it is more likely to be preserved with submuscular placement because the fourth intercostal nerve runs within the pectoralis fascia. Standard mammography may be affected by placement of subglandular breast implants, so it is important for patients to inform the radiographer in advance so that screening views may be adapted. Despite this, there is no evidence to suggest breast cancer diagnosis is delayed following breast implant placement in either plane.4 Capsular contracture rates are traditionally lower with submuscular implant placement and textured implants.5,6 Given that she is thin, this patient may benefit from the increased soft tissue coverage that a submuscular site offers. This usually depends on the upper pole soft tissue cover, with more than 2 cm usually required on a pinch test to proceed with subglandular implants.

The use of the term “dual plane” can sometimes seem confusing in its terminology, but in simple terms it is development of the submuscular approach to breast augmentation that may help reduce some of the problems with either a total submuscular or subglandular implant placement. The dual plane refers to the fact that the upper part of the implant is submuscular and the lower part is subglandular. However, the implant only lies in one plane, but this plane starts under one tissue type and continues under another. The perceived benefits of using a dual plane approach include a greater soft tissue cover in the upper pole, accurate implant placement at the IMF, and better expansion of the breast parenchyma in the lower pole, thereby helping to reduce a waterfall deformity where the breast tissue slides over the implant. The dual plane I technique releases the lower border of the pectoralis major at the IMF and continues with a subpectoral dissection. This is used for most typical breasts. The criteria include the following: all of the breast is above the IMF, there is a tight attachment of parenchyma to the pectoralis, and the lower pole is minimally stretched. Dual planes II and III are used for more ptotic breasts, where there is breast tissue below the IMF and the lower pole is therefore stretched. Dual plane III is also advocated for a constricted breast. The difference between dual planes II and III is the extent of dissection of the subglandular pocket. In dual plane II this is continued to the lower border of the areola, and in dual plane III this is continued to the top of the areola (not the full extent of the superior pole).1,2

There are a number of steps which can be undertaken intraoperatively when performing breast augmentation in order to reduce the risk of implant infection. These begin with ensuring meticulous skin preparation with an agent such as alcohol-based chlorhexidine 2%, covering the nipple-areola complex with a temporary dressing, minimizing implant handling, maintaining meticulous prospective hemostasis, and performing irrigation of the newly created pocket. In terms of pocket washout, use of a triple antibiotic is generally advocated. This will include 80 mg of gentamicin, 50,000 units of bacitracin, and 1 g of cefazolin. It is used to soak the pocket for 5 minutes. Alternative pocket irrigation substances include 50 mL of povidone iodine with 1 g of cefazolin and 80 mg of gentamicin in 500 mL of sterile saline. In vitro, this has been shown to eliminate all organisms commonly identified in breast implant pockets. There was a previous FDA warning on directions for use (DFU) disallowing povidone iodine around implants as it was thought to damage the implant shell. This is no longer thought to be the case. A further alternative for pocket washout is hypochlorous acid (HOCl) which can provide antimicrobial activity without risk of cytotoxicity to fibroblasts. Intravenous antibiotics are given 30–60 minutes before surgery rather than at the time of implant placement. Form-stable implants generally require slightly longer, not shorter, incisions due to their construction. Minimizing skin contact with the implants when placing them is key as otherwise bacteria may be dragged in from the skin edges. For this reason, many surgeons will use a device that acts as a funnel (Keller funnel) somewhat like a cake icing bag that transfers the implant through the incision into the pocket with no skin contact at all. They will also change to fresh gloves at the time of implant placement.1–7

The Baker classification has four grades, I through IV. A grade I is a soft breast with no evidence of capsule contraction. A grade II breast has a palpable, firm capsule that is not visible; usually only the clinician would notice and diagnose a grade II. A patient is likely to notice grades III and IV. In both grades the breast will have an altered appearance and feel firm. The key difference between grades III and IV is the presence or absence of pain, with IV being painful.1–3

Traditional rates of capsular contracture before the 1992 FDA ban ranged from around 10% to almost 60%, depending on the type of implant used and its anatomic placement. Silicone implants were associated with much higher contracture rates than either saline or polyurethane. Smooth implants were associated with particularly high rates of capsular contracture and this was the reason for implants being subsequently textured. Placement of the implant in the subpectoral plane was also shown to reduce capsular contracture rates. Most recently collected data show less variation between the factors described above, and the most important factor appears to be the setting in which the implant is used. The rates of capsular contracture are lowest in primary breast augmentation, but are higher in both revision augmentation and reconstruction settings.1–7

The biofilm theory is currently the single most well-accepted theory for development of capsular contracture. There is a proposed correlation between subclinical infection and subsequent development of a biofilm, although the precise causal relationship has not been shown. As a single organism, Staphylococcus epidermidis is the most commonly implicated organism, but other types of bacteria may also be implicated and a polymicrobial cause is also likely. Streptococcus pyogenes is a gram-positive bacterium that is the cause of severe group A streptococcal infections. Staphylococcus saprophyticus is a gram-positive, coagulase-negative facultative species that is a common cause of urinary tract infections. Streptococcus viridans is a commensal of the gastrointestinal and genitourinary tracts that can cause severe infections in immune-compromised patients. Staphylococcus aureus is a bacterium that commonly colonizes human skin and mucosa without causing any problems. It can be implicated in severe soft tissue infections and also have a role in capsular contracture formation.1–8

The double-bubble deformity occurs when the native breast and silicone implant separate to give the appearance of two distinct overlapping mounds. A double-bubble deformity can occur either from the implant displacing inferiorly, leaving breast tissue superiorly, or it can occur with the implant remaining superior and the breast tissue sliding off the implant inferiorly. These deformities are classified as A if the implant is “Above” the breast or B if the implant is “Below” the breast. A type A double-bubble deformity can occur when a total submuscular plane is used because the implant is then held abnormally high on the chest wall, leaving the loose parenchyma to slide inferiorly. This is called a waterfall deformity. Type B can occur with over-dissection of the IMF, which allows the implant to slide into a lower pocket, resulting in the appearance of two separate IMFs. The native IMF will remain as a constricting band of soft tissue to create the classic double bubble.1,2

Ultrasonography can demonstrate implant rupture with two commonly described phenomena: the snowstorm and stepladder signs. The snowstorm sign is seen most commonly in conjunction with an extracapsular rupture from small amounts of free silicone mixing with the surrounding breast tissue. The stepladder sign is seen in association with an intracapsular rupture. It is observed as multiple curvilinear low signal intensity lines within a high signal intensity silicone gel. The lines represent the collapsed implant shell floating in the silicone gel. Magnetic resonance imaging (MRI) is the gold standard for assessment of implant rupture. The linguine sign is seen on MRI when intracapsular rupture is present; it is analogous to the stepladder sign on ultrasound. Achieving adequate mammographic views is more challenging when there are breast implants in place, and the Eklund view is a technique used to displace the implant from the breast. Posterosuperior displacement of the implants is performed with simultaneous anterior traction on the implant. Window shading occurs where there is release of the sternal attachments of pectoralis major during breast implantation. This can be avoided by limiting release of the pectoralis to the inferior border medially.1–4

The greatest risk of those listed above for a patient undergoing primary breast augmentation as in this case is alteration of nipple sensation. Permanent sensory change occurs in approximately 15% of patients. However, the highest overall risk is actually breast asymmetry as this will be an almost universal finding. The risk of implant rupture is low (probably around 1% per year based on most recent studies with overall rates below 10% at 10 years). Both postoperative infection and hematoma should be discussed with the patient but are also low risks (each less than 1%). The risk of developing capsular contracture is probably about 10% following primary augmentation based on current evidence. This has been traditionally higher for subglandular placement than submuscular placement but things seem to have evened out over time. These numbers highlight the importance of preoperative discussions about risk with patients and putting each into perspective. Often patients are most concerned about the risk of infection as they understand this can have serious negative effects on outcomes with the implant needing to be removed. Overall, each of the risks must be acknowledged and all steps taken to minimize each one from occurring.1–4

The main indications for capsulectomy are Baker III or IV capsules, evidence of a ruptured implant, silicone granulomas, a requirement for an upsized implant, and ALCL. There are different types of capsulectomy characterized by how much of the capsule is to be removed. When a patient generates a capsule early in the subglandular plane there is a strong indication for complete capsule removal and a change of implant pocket from subglandular to submuscular (dual plane). It would be reasonable to remain with the same plane if the capsular contracture was a much later finding or if the implant size was to be increased. Anterior-only capsulectomy is often considered in submuscular capsulectomy because removal of the posterior capsule can risk damage to the rib cage and cause a pneumothorax. Patients should be advised of this preoperatively. For this reason, the posterior capsule may be left in situ. Posterior-only capsulectomy may be indicated in cases where the skin is thin and the implant is subglandular as it provides an additional layer of implant cover and avoids the risk of skin damage. In general, capsulotomy is only indicated in cases where the capsule is healthy and soft, i.e., without significant contracture, and the breast needs to be reshaped perhaps with a larger implant. A good example of a setting for capsulotomy is where an expander is being replaced with a permanent implant after breast reconstruction.1 An alternative to capsulectomy, where a change of implant pocket is planned, is to leave it in situ and close it down with sutures. A new subpectoral pocket can then be created.2,3

Current implant rupture rates with fourth- and fifth-generation silicone or saline implants are estimated to be around 1% per year for both silicone and saline implants, so these are reasonable figures to quote to patients during their consultation. This is much lower than the historical rates which were as follows: • Mentor MemoryGel implant rupture rates through 8 years ○ 13.6% for primary augmentation ○ 15.5% for revision augmentation • Allergan Naturelle implant rupture rates through 10 years ○ 9.3% for primary augmentation ○ 5.4% for revision augmentation • Sientra cohesive gel implants through 8 years ○ 6.4% for primary augmentation ○ 5.2% for revision augmentation Factors implicated in rupture include manufacturing flaws, underfilling, fold flaws, and surgical technical errors such as passing a needle through the shell.1–5

When patients do develop BIA-ALCL, their prognosis is actually excellent and treatment is effective in most cases with complete capsulectomy, implant removal plus/minus chemotherapy, or radiation. Regardless of all the debate and media attention that BIA-ALCL has generated, the numbers remain relatively small overall (less than 600 cases worldwide).1,2 Contrast this with breast cancer risk at 1:8, which shows the relative risk is still low. That said, minimizing risk of developing BIA-ALCL is paramount and implant type and manufacturing process all seem to play a part. BIA-ALCL is associated with textured implants only (not smooth) and most, but not all, cases are associated with a salt loss texturing process. Mentor use negative imprinting or stamping of the surface, Sientra use ammonium carbonate and heat, while Allergan use sodium chloride crystals which are then washed off. Therefore, risks are affected by different implant types and makes. They are also likely affected by bacterial contamination and genetic predisposition. First presentation of BIA-ALCL is 9 years (median time) but can occur within the first year. The baseline risk is somewhere between 1:1000 and 1:30,000 depending on factors described above.1–5

Clinical suspicion should be raised for BIA-ALCL in patients who present with a late seroma around a breast implant. In this circumstance, fluid should be submitted for cytological evaluation with Wright-Giemsa-stained smears and cell block immunochemistry testing for cluster of differentiation (CD30) and anaplastic lymphoma kinase (ALK) markers. Once the information has been obtained further management may be planned. The surgical management will involve total capsulectomy and implant removal. The capsule tissue can at this stage be sent for histologic analysis. Imaging is useful in the form of ultrasound which can be used to visualize the seroma and sample the fluid. MRI can also be useful for the same reasons. Once a diagnosis has been made, liaison with the hematology team must be made and the case discussed at the appropriate multidisciplinary team meetings. All diagnoses must be recorded and in the US the FDA should be informed.1–5