Breast Augmentation

      With breast augmentation perhaps one of the most crucial responsibilities of the plastic surgeon is to determine the aesthetic ideal for each individual patient.  The concept of the perfect breast is vaguely defined at best, and is profoundly influenced by a host of cultural, sociological and psychological factors. Therefore, poor communication between surgeon and patient can easily lead to less than satisfying results, as well as those incongruous with patient morphology. It is imperative that both agree upon size and shape, this being typically accomplished through the medium of photographs and demonstration of actual implants, as well as thoughtful discussion between patient and surgeon, including the informed consent process. To aid in this collaborative decision, the following assessments are key in selecting an appropriate implant as well as designing the operation best suited for the patient: 

• Current breast volume and shape

• Desired size and shape

• Symmetry

• Degree of ptosis (Regnault’s grading)

• Skeletal abnormalities

• Measurement of sternal notch to nipple

• Measurement of midline to nipple

• Measurement of nipple to inframammary fold

• Base diameter of each breast

• Tissue laxity of the breast envelope

• Location of prospective access incisions

Development 

      The breast develops from the integument along the anterior chest wall early in the embryonic stage, and begins maturation during puberty. It is comprised of glandular, connective and fatty tissue. Attached to the pectoralis major muscle are Cooper’s ligaments which progress through the breast parenchyma, dividing lobules and spanning between the deep muscle fascia and dermis. There is a pectoral fat pad, which resides above the fascia of the pectoralis major, and can be released to create a subglandular plane. In direct contact with this fat pad are the mammary glands, containing secretory lobules filled with lactiferous ducts.

      These glands receive their blood supply via the lateral thoracic and internal thoracic arteries by means of the intercostal perforators. These vessels, in turn, converge to form a dense subdermal vascular plexus, which supplies the skin. The nipple and areola are innervated predominately by the 4^th intercostal nerve, as well as the 3^rd and 5^th,to some extent, by means of the anterolateral and anteromedial cutaneous branches.

      The pectoralis major muscle originates at the inferomedial region of the clavicle, with attachments to the sternum and medial cartilages of the 2^nd to 6^th ribs, and inserts on the superior aspect of the humerus. It overlies the rib cage as well as pectoralis minor muscle, and is fixed by loose areolar tissue. This muscle can be elevated from these deep structures with blunt dissection to create a submuscular plane. 

Implant type

        A significant consideration when planning augmentation mammaplasty is whether to utilize silicone or saline implants. Both types may be used to produce excellent results, and each has its merits and potential drawbacks.

      The silicone implant resembles breast tissue to a greater extent, producing a more natural appearance and feel. This is often a pre-requisite for the patient, and is reflected in the largely increased use of silicone since FDA re-approval in the United States in November 2006. However, in view of the fact that the implants are pre-filled, they usually necessitate a somewhat larger incision. It is usually no more than 1-2 cm longer, but is of course dependant upon implant size. Additionally, many women are still apprehensive about the perceived health risks associated with silicone. Despite the validation of safety regarding systemic autoimmune disease, the local inflammatory responses to free silicone from extracapsular rupture can produce cosmetic issues that may be challenging to manage. However, this has become much less of an issue in recent years with the additional barrier layer of the third generation silicone implants, and increased cross linking of the silicone to produce a more cohesive gel.

      For a time, saline implants were the only prostheses available for use in the United States except for clinical trials, and therefore operative techniques have become highly advanced. Remote incisions such as those used in the transaxillary endoscopic approach have evolved with the use of saline implants, and become more popular during the time period of the silicone implant moratorium. They can be placed by way of a relatively small incision, and this option allows the surgeon to intraoperatively adjust fill volumes to more readily correct asymmetries. They are also less costly than their gel counterparts, and are regarded by some to provide for more natural movement with activity. Saline implants are, on the other hand, further prone to rippling as well as spontaneous deflation.

Placement

      The breast pocket may be created in either the subglandular or subpectoral space. The subglandular technique is usually reserved for patients who have substantial breast tissue or a mild degree of ptosis, since greater projection may be obtained. Also, women who are avid bodybuilders may prefer subglandular implants for the reason that placing them submuscularly in some instances may produce breast animation and distortions when the pectoral muscles are flexed. Increased risks of capsular contracture, rippling and implant palpability are typically issues discouraging the routine use of such placement.

      In patients with a paucity of breast tissue and little to no ptosis, the subpectoral technique, in our opinion, produces optimum results. The pectoralis major drapes the superomedial aspect of the prosthesis, softening the transition, and thus creating a more anatomically shaped breast mound. This method also achieves a natural feel, which is especially desirable when using saline implants. The submuscular plane tends to be less vascular, and is associated with fewer sensory alterations of the nipple areolar complex. Also, rates of fibrous capsular contracture are demonstrably lowered with submuscular placement versus subglandular. In addition to improved aesthetic outcomes, there are prospective functional advantages in regard to breast-feeding as well as cancer screening. 

Surgical Approach

      Although numerous methods have been described in the literature, there are three preferred approaches for breast augmentation; inframammary, periareolar and transaxillary. Dissections may be performed in either plane, with or without the aid of an endoscope.

      The inframammary fold incision provides excellent results in terms of inconspicuous scars, accessibility for both implant types, and fold modifications. This incision allows for optimal view of the pectoral muscle and breast parenchyma, which permits the surgeon to perform an accurate dissection in either, the submuscular or subglandular plane. The downsides of this approach are the potential increased risk of iatrogenic rupture during wound reapproximation, and implant exposure during the postoperative period, given the weight of the implant on the healing incision. Additionally, the access incision must be carefully designed to avoid scar migration to the chest wall or inferior pole of the breast.

      In patients not requiring fold adjustment, the incision is made at the inframammary fold and is approximately 2.5-3 cm in length, extended laterally from below the nipple, and carried deep until the lateral aspect of the pectoralis major muscle is reached. If undertaking a subpectoral placement, the inferior muscular attachments are freed by means of a fine Mosquito clamp and cautery dissection. The pectoralis major can then be elevated from the chest wall using blunt finger dissection or an Agris-Dingman dissector, which is then replaced by a lighted retractor to allow assessment for hemostasis and the transection of any residual muscular bands via electrocautery. The only medial pectoralis muscle fibers released are those that appear anomalous and medially displaced. Otherwise, purely inferior muscle fibers are released. In cases of ptosis or tuberous breast deformity, the dual plane technique as described by Tebbetts, may be utilized to aid in redraping the breast tissue over the implant.

      An implant sizer may be placed to aid in prosthesis selection, and can also be over filled for intraoperative tissue expansion, as well as its tamponade effect to facilitate hemostasis. Using an antibiotic solution, the selected prostheses are bathed and the pockets are irrigated prior to insertion. The implants are placed, and the patient is situated in an upright position, to assess contour and symmetry. Once any final adjustments have been made, the patient is returned to the supine position, and the incisions are closed in a layered fashion with 3-0 and 4-0 Monocryl (Ethicon, Somerville, N.J.). For additional tissue support in the inframammary approach, we also employ a running, subcuticular 3-0 Prolene (Ethicon, Somerville, N.J.), which may be removed late in the postoperative course without sequelae.

      The periareolar incision requires a somewhat higher degree of technical skill, but provides a central point of access for pocket development as well as radial release. This incision is especially suitable for those who have an ill-defined fold, constricted breast tissue, or require nipple-areolar resizing. It also allows for conservative excision of redundant lower pole skin. In order to achieve discrete scars, the patient must have a sufficiently sized nipple-areolar complex to accommodate the selected implant, a well-defined areolar edge, and differentiation of pigment. The approach is generally limited to smaller silicone implants, but this is less of an issue with saline prostheses. Given the proximity of the incision to the lactiferous ducts, it may however, be a less favorable choice for patients who desire to breastfeed. Also, there may be an increased likelihood of nipple dysesthesias due to immediacy of the dissection.

      The incision lies on the lower border of the areola, and is approximately 3.0-4.0 cm long from 3 o’clock to 9 o’clock. This length may vary depending upon the individual anatomy, but should generally not extend beyond one half of the areolar circumference. After the initial incision is made, the breast parenchyma is dissected down to the fascia of the pectoralis major muscle in an inferior direction towards the breast base. If subpectoral placement is desired, the muscle is carefully dissected in order to enter the subpectoral space. The pectoralis muscle is then elevated, thus creating the breast pocket.

      Using a lighted retractor for visualization, electrocautery is employed to detach the muscle edge from the inferior chest wall and provide a hemostatic environment. Once the pockets have been adequately dissected, they are irrigated with antibiotic solution and the implants are placed. The patient is then maneuvered to a sitting position allowing the surgeon to evaluate the aesthetic effect and further fine tune any pocket modifications before closing. Again, we use 3-0 and 4-0 Monocryl for the deeper layers, while 5-0 nylon is employed on the skin as a running simple stitch.

      The transaxillary endoscopic technique is ideal for patients with minimal glandular tissue, little or no ptosis and an ill-defined inframammary fold. The incision is best suited for saline implants that can be filled once they have been placed, and the main advantage of this technique is that there are no scars created on the breast. However, as the breast pocket is further away from the incision, it is more difficult to precisely alter the inframammary fold and correct asymmetries. Inadequate muscle release with this technique may lead to persistently high riding implants. This approach is not appropriate for patients with tubular breast deformities, and although possible, is impractical for subglandular placement. Also, revision surgeries may require an alternate incision if substantial modifications are to be made.

      A 2.5-3 cm transverse incision is made posterior to the anterior axillary fold and inferior to the apex of the axilla, following the lines of Langer in an axillary crease. Blunt dissecting scissors are used to create a subcutaneous plane from the incision to the lateral pectoral fascia. It is important that this dissection is carried out superficially to avoid injury to the intercostobrachial nerve, which traverses this area. Once the lateral edge of the muscle has been raised, the inferior and lateral subpectoral spaces are digitally dissected much as possible. Following this, an Agris-Dingman dissector is introduced to develop the remaining subpectoral pocket. Using a sweeping motion, the pectoralis major is detached from the inferior costal cartilage and sternum, and the tissues are stretched in order to accommodate the implant. Care must be employed with this maneuver to avoid avulsion of the medial perforators and/or entry into the pleural space. If the use of an endoscopic retractor is desired, it may be introduced into the pocket at this point for precision muscle release inferiorly along the inframammary fold. We prefer a 30 degree, 10mm endoscope (Snowden-Pencer). To obtain optimal results, however, this type of dissection should be performed bilaterally prior to implant placement. Once the pockets have been irrigated and the implants inserted, the patient is elevated to a sitting position to assess cosmesis as well as symmetry, and allow the surgeon to make any final adjustments prior to closing. The wound is then sutured in a layered fashion using 3-0 and 4-0 Monocryl, with running 5-0 Nylon for skin. 
 

      Once the surgical incisions have been reapproximated, Steri-Strips (3M, ST.Paul, MN) are placed on the incisions, and a 6” elastic wrap is placed around the superior chest and the breasts. This bandage is positioned fairly taut in order to prevent displacement of the implants, as well as to minimize edema and ecchymosis. Broad-spectrum antibiotics are prescribed and begun in the immediate postoperative period. The patient is also placed on a narcotic analgesic for pain management and diazepam for its anxiolytic and muscle relaxing effects. At the first postoperative visit, the dressings are removed and replaced with a surgical bra or fitted bandeau, depending upon the specifics of the surgical technique. For smooth shelled implants, daily massage is recommended postoperatively at two weeks, to facilitate in keeping the breast capsules soft and involve the patient in her own care. Patients are advised to refrain from exercise or heavy lifting (over 10 lbs.) for the first two weeks after surgery. 

      Although rare, there is an estimated 0.5-3.0% incidence of hematoma following breast augmentation surgery depending upon the series in the literature. (Baker, Jr., J.L., Williams, PRS). This postoperative complication is typically heralded by the onset of unilateral pain, ecchymosis, and progressive enlargement. Risks are minimized by careful hemostasis intraoperatively as well as limiting hypertension and excessive activity in the postoperative period. Infection is also a potential complication, typically caused by flora indigenous to breast tissue such as Staphyloccus epidermidis and Stahpylococcus aureus. Intraoperatively, this is addressed with antibiotic irrigation, meticulous sterile technique, and prophylactic antibiotics prior to skin incision and then on a per os basis for the following 3-5 days. Nipple and areola sensation may be affected by breast surgery, resulting in hyperesthesia or dysesthesia. It is atypical for permanent changes in sensation to occur, as they generally resolve over time. Capsular contracture may arise, and is believed to be associated with residual blood or subclinical bacterial contamination. Again meticulous hemostasis and the use of antimicrobial prophylaxis are certainly helpful, and a daily postoperative massage regimen may also be advantageous and involve the patient. If subglandular placement is planned, the use of a textured implant may be of benefit, as has been previously suggested by the plastic surgery literature. However, downsides to textured implants include their thicker shell and potential palpability in patients with thin tissues. 

Tips:

• Surgical draping for breast augmentation should allow easy access both above and below the arm boards to facilitate pocket modification.
• Marking the patient in a standing position and upright positioning during the operation aids in  precise incision design and implant positioning.
• When employing an endoscopic technique, applying the evacuation tubing to the retractor as opposed to the cautery wand reduces potential clogging of the suction.

• Breast augmentation is a surgery that requires clear communication with the patient regarding risks, benefits, and trade-offs of the various approaches and implants so that informed choices can be made.

• Consider an alternate to the transaxillary approach in patients with a long chest and/or low breast position.
• Avoid selection of prostheses with a significantly greater base diameter than the natural breast, as this often produces unnatural looking results, and leads to palpability of the implant edges.
• Upon initial dissection, when releasing pectoral attachments from the inferior chest wall, be certain to do so above the surface of a rib to avoid inadvertent entry into the pleural space.

Technical Steps

• After informed consent has been obtained, the patient is marked in an upright position using a surgical pen. These markings, at minimum, should reflect the midline below the sternal notch, as well as an outline of the inframammary folds and proposed breast pockets with incisions.

• Intravenous access is established and antibiotic prophylaxis is administered.

• The patient is placed in the supine position and anesthetized under general endotracheal anesthesia, or by means of a laryngeal mask airway. The author prefers this to local anesthesia with sedation, as it allows for optimal muscular relaxation and subsequently a more precise pocket dissection.

• The arms are secured on arm boards at 90 degrees, and at the level of the shoulders.

• The proposed access incisions and inframammary fold are injected with an approximate total of 50ccs 1/2% lidocaine with epinephrine 1:200,000.

• An incision is made, and one of the three approaches previously discussed are applied.

• Once the dissection is carried out to the pectoral fascia, a breast pocket is created in either the submuscular or subglandular plane, and hemostasis is attained. The author prefers submuscular or partial submuscular (dual plane) technique in the vast majority of cases.

• In moderate to severe cases of asymmetry using saline implants, and in most cases of asymmetry using silicone implants, an implant sizer is placed to determine size, and then overfilled with saline for intraoperative tissue expansion.

• Attention is then directed to the contralateral breast, and the operation is repeated in a similar manner.

• After the appropriate implant has been selected, the sizers are removed.
• The breast pockets are then copiously irrigated with an antibiotic solution, and again assessed for hemostasis. Triple antibiotic solution with bacitracin, cefazolin and gentamicin is preferred.

• The prostheses are dispensed to the sterile field, bathed in the antibiotic solution, and prepared as required.

• Once the implants have been placed, the patient is maneuvered into a sitting position to assess contour and symmetry, allowing the surgeon to make any final modifications. Assessment of the shoulders and clavicles is necessary to ensure proper positioning and therefore symmetry.

• When completed, the patient is returned to the supine position, and the surgical wounds are closed in a layered fashion.

• Steri Strips are applied to the incisions, and a 6” elastic wrap is placed circumferentially, prior to emergence and transfer to the Recovery Room.

References: 

Adams, W.P. Jr., Rios, J.L., Smith, S.J. Enhancing Patient Outcomes in Aesthetic and Reconstructive Breast Surgery Using Triple Antibiotic Breast Irrigation: Six Year Prospective Clinical Study. Plastic and Reconstructive Surgery. Advances in Breast Augmentation. 118(7S) Supplement: 46S-52S, 2006. 

Baker, Jr., J.L. Chapter 63 - Augmentation Mammaplasty, Surgery of the Breast Principles and Art, Spear, S.L. ed. Lippincott – Raven, pp. 845-854, 1998. 

Bostwick III, J. Plastic and Reconstructive Breast Surgery, Second Edition. Quality Medical Publishing, pp. 79-96, 193&228, 2000. 

Burkhardt, B.R., Demas, C.P. The Effect of Siltex Texturing and Povidone-Iodine Irrigation on Capsular Contracture Around Saline-Inflatable Breast Implants. Plastic and Reconstructive Surgery, 93(1): 123-130, 1994. 
 

FDA Approves Silicone Gel-Filled Breast Implants After In-Depth Evaluation News Release (16 November 2006). Available at: http://www.fda.gov/bbs/topics/NEWS/2006/NEW01512.html FDA. Accessed 21st July 2007.  

Hidalgo, DA. Breast Augmentation: Choosing the Optimal Incision, Implant, and Pocket Plane. Plastic and Reconstructive Surgery,105(6):2202-2216, 2000. 

Muzaffar A.R., Rohrich R.J. The Silicone Gel-Filled Breast Implant Controversy: An Update. Plastic and Reconstructive Surgery,109(2):742-748, 2004. 

Netter, F.H., Atlas of Human Anatomy, Ciba-Geigy Corporation, plates 167, 168 & 175, 1989.  

Takayanagi S., Chisato N. and Sugimoto Y. Augmentation Mammaplasty: Where Should the Implant Be Placed? Aesthetic Plastic Surgery, 28:83-88, 2004. 

Tebbetts, J.B. Dual Plane Breast Augmentation: Optimizing Implant-Soft Tissue Relationships in a Wide Range of Breast Types. Plastic and Reconstructive Surgery. 107(5): 1255-1272, 2001