Breast Anatomy and Augmentation in Transfeminine Individuals

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

Augmentation mammaplasty, otherwise known as a breast augmentation, is one of the most common cosmetic procedures performed in cisgender females. Gynecologists routinely perform annual breast examinations and order screening mammography in cisgender women with breast implants. Similarly, there is an increasing number of transgender women seeking breast augmentation – with approximately 60%-70% of patients having desired or undergone the procedure.¹ Consequently, these patients are instructed by their surgeons to follow up with gynecologists for annual examinations and screening. While there are many similarities in technique and procedure, there are nuances in patient demographics, anatomy, and surgical technique that obstetricians/gynecologists should be aware of when examining these patients or prior to referring them to a surgeon for augmentation.²

Many patients who are dissatisfied with breast size from hormone therapy alone will seek out augmentation mammaplasty. In patients taking estrogen for hormone therapy, breast growth will commence around 2-3 months and peak over 1-2 years.³ Unlike chest surgery for transmasculine individuals, it is recommended that transfeminine patients seeking breast augmentation wait a minimum of 12 months before to surgery to allow for maximum breast enlargement. As with breast growth in cisgender females, the extent of breast development is multifactorial and varies from individual to individual. Current literature does not suggest that estrogen type or dose affects the ultimate breast size; however, younger age, tissue sensitivity, and body weight may affect breast volume.³ Referral to a genetic counselor and preoperative imaging may be necessary if a patient has a history concerning for a genetic or familial predisposition to breast cancer.

Implant selection and placement is determined by a variety of factors. While the overall principles of augmentation mammaplasty are essentially the same, there are anatomic differences in transfeminine patients that surgeons must take into consideration at the time of the consultation and during the surgery itself. For example, the pectoralis major muscle is more defined, there is a longer sternal notch-to-nipple distance, the chest wall is broader and more barrel-shaped, and there is a shorter distance between the nipple and the inframammary crease.^2-4 As a result of the broader chest wall, it is extremely difficult to achieve central cleavage even with larger implant selection. The surgeon must also ensure that the nipple and areola overlie the implant centrally. Medial placement of the implant will result in lateral displacement of the nipples, which can have an unsatisfactory cosmetic appearance.

Incision location can be axillary, inframammary, or even transareolar, although the latter is less common due to the smaller areolar size and larger implant choice.³ If the inframammary incision is used, it should be placed lower than the natural inframammary fold because the distance between the inferior areolar margin and inframammary fold is shorter and will expand after the implant is placed.⁴ While both saline and silicone implants are available, many surgeons (myself included), favor more form-stable silicone implants. Given the association between anaplastic large-cell lymphoma and textured implants, many surgeons also use nontextured, or smooth, cohesive gel silicone implants.⁵

Pocket selection of the implant itself can be subglandular – directly under the breast mound – or subpectoral – behind the pectoralis muscle. For patients with a pinch test of greater than 1.5 cm (outside of the area of the breast bud), good skin softening, and marked pectoralis hypertrophy, subglandular placement is reasonable.⁶ In thin patients with minimal breast development, subglandular placement can result in a "double-mound" appearance and can lead to visible implant edges on the periphery.⁶ Use of the subpectoral plane is more common and is associated with less implant visibility due to an increased amount of soft-tissue coverage and has lower rates of capsular contracture.⁴ However, due to the more robust pectoralis muscle in transfeminine patients, implant displacement can occur more frequently compared to subglandular placement. The surgeon and patient must have a thorough discussion about the location of the incision, implant material, and pocket placement along with the benefits and complications of the surgical plan.

Complications of augmentation mammaplasty are rare. However, when they occur it can include capsular contracture, breast asymmetry, hematoma formation, loss of nipple sensation, implant malposition, implant displacement below the inframammary crease, implant rupture, and need for revisional surgery.⁷ If an obstetrician/gynecologist observes any of the aforementioned findings in a postoperative patient, consultation and referral to a plastic surgeon is imperative.

Postoperative assessment and screening are mandatory in all patients who undergo breast augmentation. It is important for the gynecologist to note the incision placement, know the type of implant used (saline or silicone), and delineate where the implant was placed. If silicone implants are used, breast MRI is more sensitive in detecting implant rupture compared to mammography alone. Given the relatively poor epidemiologic data on breast cancer in transgender women, the Endocrine Society recommends that these patients follow the same screening guidelines as cisgender women.^4,6

Brandt is an ob.gyn. and fellowship-trained gender-affirming surgeon in West Reading, Pa.

References

1. Wierckx K et al. J Sex Med. 2014;11(5):1240-7.

2. Mehra G et al. Plast Reconstr Surg Glob Open 2021 Jan 21;9(1):e3362. doi: 10.1097/GOX.0000000000003362.

3. Schecter LS, Schechter RB. Breast and chest surgery for transgender patients. In: Ferrando CA, ed. Comprehensive Care of the Transgender Patient. Philadelphia, PA: Elsevier, 2020:73-81.

4. Colebunders B et al. Top surgery. In: Salgado CJ et al. ed. Gender Affirmation: Medical and Surgical Perspectives. New York, NY: Thieme, 2017:51-66.

5. De Boer M et al. Aesthet Surg J. 2017;37:NP83-NP87.

6. Coon D et al. Plast Reconstr Surg. 2020 Jun;145(6):1343-53.

7. Kanhai RC et al. Br J Plast Surg. 2000;53:209-11.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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Cite this: Breast Anatomy and Augmentation in Transfeminine Individuals - Medscape - Apr 22, 2022.