The Clinical Problem ( Fig. 25.1 )
Hypomastia is usually a developmental issue but may also be seen after pregnancy, breastfeeding, or major weight loss. It is well known how negatively the size, shape, and symmetry of a woman’s breast may affect her mental and physical well-being.
Women with severe developmental hypomastia should not expect significant breast augmentation but aim to have more normal-looking breasts. This more conservative approach is intended to improve their negative self-image perception and their fear of very noticeable changes.
In contrast, women with involutional hypomastia are in their 30s, may have already breast-fed, and are disappointed with the loss of skin elasticity volume and consistency of residual breast tissue. Their aesthetic perception is linked to previous size or to the increased breast size seen in pregnancy. It is not uncommon to see a patient who carries a picture of her breastfeeding period showing this as the desired size.
Surgical Preparation and Technique
Management and Treatment Options
Smooth, round, silicone elastomer–containing silicone gel implants have been available since the beginning of modern breast augmentation surgery, when they were introduced in 1962 by Cronin and Gerow, but capsular contracture has always been of greatest concern in the years following. To lower capsular contracture rates, a coat of polyurethane foam was first applied to the implant’s surfaces in 1969 by Ashley ; since then, it has been reported as the most successful device to avoid periprosthetic capsular contracture.
Later on, in an attempt to reproduce the surface appearance of polyurethane, textured implants were developed. However, polyurethane implants, as compared to smooth and textured implants, remain the best option for the treatment of recalcitrant capsular contracture, although thicker shells and a more cohesive gel can also contribute to lowering the rate of this complication.
With the biodimensional concept, cohesive gel stable form implants, with different shapes and projections, became available to assist a wide spectrum of anatomic variations. Interestingly, Ashley’s first polyurethane implants were an anatomic teardrop shape. Round implants, containing less cohesive gel and placed in submuscular pockets, will assume a teardrop shape when the patient is standing.
A round implant has, on average, 15% more gel than an anatomic one with the same base and projection, making it heavier and leading to greater distention of the lower pole of the breast. This bottoming out is associated with an early relapse of breast ptosis after mastopexy with breast augmentation or with implant-induced breast ptosis.
As a general rule, the ideal implant should be as light as possible. Its volume distribution should be customized to individual anatomic variants and the patient’s preference.
Assessment of Problem: Anatomic Description
The breast parenchymal base width may not be adequate to hide the implant’s edges perfectly. Also, young patients may have very firm skin, which limits the available projection of the breast mound.
It must be stressed to the patient that selection of the ideal implant is based on biodimensional analysis and not on its volume, because obviously the same size of implant will look different in different body types. To customize breast augmentation, the width and height of the parenchyma footplate, the distances between the suprasternal notch to the nipple, between the nipples, and from the nipple to the inframammary sulcus, and the intermammary distance are measured.
Key landmarks are as follows ( Fig. 25.2 ):
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Suprasternal notch
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Nipple areola complex
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Inframammary fold
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Breast parenchyma footplate
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Height of the breast in the chest wall
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Chest width
In addition to these measurements, breast parenchyma distribution and mobility must be evaluated, together with estimating skin elasticity. A pinch test is used to evaluate the thickness of the tissues in the upper pole. In my opinion, a pinch test of less than 2 cm will often indicate the need for subpectoral placement of the implant. If polyurethane implants are chosen for very thin patients with poor tissue coverage, it is preferable to use the split muscle technique ( Fig. 25.3 ). This is a dual-plane approach from a subglandular dissection of the lower breast, followed by blunt division of the pectoralis major muscle fibers at the nipple areola complex level, entering a submuscular plane between the pectoralis major and minor. The retropectoral technique, as described by Tebbets, is better indicated for smooth and textured implants.
Implant Selection
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Tight skin and gland envelope—select implants with low to moderate projection.
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Involutional hypomastia in patients with more elastic skin and gland envelope—select high-profile implants.
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A constricted lower breast needs more filling in the lower breast than in the upper breast—select an anatomically shaped implant.
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A deflated breast with a flattened central mound needs more projection—select a round or polyurethane-coated conical implant.
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If a patient requires a fuller décolleté—select a round implant.
Treatment and Operative Technique
Anesthesia
Use local infiltrative and intravenous sedation, thoracic epidural blockade, and intravenous sedation, or use general anesthesia.
Incisions
Inframammary ( Fig. 25.4 )
This permits complete visualization of the prepectoral or subglandular pockets and allows precise placement of virtually all implants. The limits of the inframammary incision are the midline of the breast and anterior axillary line; its length is from 4 to 6 cm. This more lateral placement of the incision helps hide it under the breast.
The incision must be placed at the ideal position of the sulcus. If the distance from the areola to the real sulcus is too short to fit the lower pole of the implant, the sulcus has to be lowered; otherwise, the incision will be visible when the implant settles down in the chest.
The disadvantages may be troublesome scars.
Infra-areolar
This incision is placed in the bottom half of the areola and, although the scar is in a visible place, it fades very well.
Disadvantages are as follows:
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A small areolar perimeter is not suitable for larger implants.
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Transection of mammary ducts contaminated by Staphylococcus epidermidis can lead to the formation of biofilm.
Axillary
The axillary incision is ideal when no scar is desired in the breast, and hypertrophic scars are a major concern. It is best suited for small breasts with little or no ptosis.
Disadvantages include the following:
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There may be difficulty with hemostasis from this remote access port.
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Dissection of the lower breast is hampered, especially in constricted lower pole breast tissue.
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Placing the implant in a proper position may be difficult if anatomic implants are being used.
Plane of Dissection
Subglandular Plane
In my opinion, subglandular implants will more effectively restore breast shape and correct ptosis than submuscular implants. When considering prepectoral implantation, adequacy of soft tissue cover of the implant is critical, because rippling and waving deformities may arise.
Subfascial Plane
An additional pocket, which has been introduced more recently and advocated by some, is the subpectoral fascial pocket. Some studies have noted that this thin layer of tough tissue offers the advantage of subglandular placement, with a thicker soft tissue cover. For lower pole expansion, the pocket can be extrafascial inferiorly and subfascial superiorly for better results.
Submuscular Plane
The pectoral muscle can be horizontally divided at various levels, described as dual-plane maneuvers, to allow varying degrees of submuscular to subglandular implant coverage. The advantages of submuscular implantation are as follows:
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Lower incidence of capsular contracture
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Improved breast contour, because the edges of the implant are blunted by the muscle
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Less exposure of the prosthesis to bacterial contaminants from glandular tissue
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A plane of dissection that is less vascular than with retroglandular implant placement
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Maximal preservation of nipple sensation