As refinements in breast reconstruction techniques have occurred over the years, the aesthetic goals and expectations of our patients have risen. While many women are happy with their implant reconstructions following mastectomy, some voice disappointment with the aesthetics, particularly unclothed. Rippling following implant reconstructions may be improved by converting a saline implant to silicone or camouflaged by use of capsular augmentation or acellular dermis.^1–3

Sharp transition zones, particularly in the superior pole, are a frequent clue that this is an implant-based breast reconstruction. While satisfaction with autologous flap reconstructions for breast reconstruction is high, addressing some limitations of implant-based reconstruction, some may also have contour irregularities or sharp transition zones, particularly at the borders of flap inset. Lastly, deformities associated with breast conservation therapy may lead to dissatisfaction in our breast cancer survivors. One surgical technique gaining popularity and acceptance that can improve upon these contour deformities and increase patient satisfaction with their breast reconstructions is autologous fat grafting.

Many advancements in autologous fat grafting techniques have occurred since its initial use in 1893 when Neuber⁴ transferred arm fat to the orbit for the correction of an adherent, depressed scar. In 1895, Czerny⁵ was the first to use autologous fat to reconstruct a breast deformity transferring a back lipoma to replace breast tissue following removal of an adenoma. Fat injection through cannulas was described by Charles C. Miller⁶ of Chicago in 1926, advocating its use for the correction of nasolabial folds. Inconsistent rates of fat survival led to poor adoption. However, fat as an injectable experienced a rediscovery with liposuction in the 1980s.⁷ Once considered controversial, fat grafting to the breast has been refined with overall results now more predictable and reliable.⁸ Recently, the American Society of Plastic Surgeons Fat Graft Task Force issued a new statement regarding fat grafting to the breast stating, “Fat grafting may be considered for breast augmentation and correction of defects associated with medical conditions and previous breast surgery; however, results are dependent on technique and surgeon’s expertise.”⁹ Currently, autologous fat grafting has been integrated into many plastic surgeons’ armamentarium to enhance surgical results for both reconstructive and aesthetic procedures. Improved clinical outcomes following autologous fat grafting have been increasingly appreciated by plastic surgeons and their reconstructive breast patients.

While there are numerous variations in fat grafting techniques used by surgeons, there are commonalities to all methods. Fat is harvested from a donor site through mechanical aspiration. The fat is then processed to isolate the fat for injection and the graft is placed to address the contour irregularity. Although techniques differ, most surgeons agree the ultimate success of fat grafting depends on the quality of the fat and the ability of recipient bed to revascularize the transplanted fat for definitive graft take. The quality of fat graft can be influenced by donor site as well as harvest and processing methods. Finally, the method of graft placement can affect the ability of the fat to engraft. The science behind each component of the fat grafting technique is discussed in section “Scientific Evidence for Technique Selection” after the section on operative technique.

There are numerous defects or contour irregularities that may occur after breast cancer treatment and reconstruction. The most common area of contour deformities arises at the peripheries of the reconstructed breast mound. Many of these deformities can be improved with autologous fat grafting.

Implant-Based Reconstructions

Volume deficiency in the upper pole may manifest as a “shelf” or disruption in the transition between the chest wall and the implant. This volume deficiency can be even more pronounced following a staged breast reconstruction where the initial tissue expander was placed higher on the chest wall than the eventual final implant is placed, occurring more commonly after total muscle coverage. Women interested in a more natural appearing implant reconstruction will often desire additional volume at the superior pole to create a more gentle transition between the chest wall and implant. This volume deficit can be addressed by using fat grafting to provide soft tissue fill.

Autologous Reconstructions

Contour irregularities or sharp transition zones may occur after autologous reconstructions, particularly at the borders of flap inset. This is often seen at the superior chest wall and breast mound junction, manifesting as a concavity or “shelf.” It may also occur in the areas of skin closure or flap inset. Each of these areas may be improved with soft tissue fill from autologous fat grafts. (See Case 1.)

Breast Conservation

Lumpectomies followed by irradiation for early-stage breast cancer can lead to volume deficiency as well as distortion of the nipple-areolar complex (NAC). The soft tissue contracture surrounding the lumpectomy can be released and filled with fat graft. As volume is restored, the position of the NAC can be improved. The quality of the irradiated tissue is also frequently improved following fat grafting through the presumed trophic and rejuvenative effects of adipose-derived stem cells. (See Case 2.)

The only absolute contraindication to fat grafting is lack of adequate donor sites. Thus, very thin patients with little excess subcutaneous donor fat are a contraindication to use of this technique. This is detailed more in the “Preoperative Assessment” section.

In addition, controversy arises when one considers use of autologous fat grafting to reconstruct the postlumpectomy deformity. Because there is a known recurrence rate associated with breast conservation therapy, any necrosis of autologous fat grafts may illicit anxiety surrounding the possibility of a recurrence. Nodularity following fat necrosis may prompt imaging. In cases where the radiological read is uncertain, biopsies will often be recommended.

Identification of Risk Factors

As the old adage in plastic surgery states, “you can donate to Peter from Paul only if Paul can afford it.” In the same way, the ability to use the technique of autologous fat grafting is dependent upon the availability of sufficient donor areas. For most patients, there is an abundance of options for donor sites. There are, however, some patients who are thin with low body mass indexes and not a lot of extra fat. If these areas of limited subcutaneous fat are aggressively liposuctioned to obtain needed graft material, the risk for donor site contour irregularities increases.

Key Points in Surgical Planning

TIMING

Because optimal fat engraftment relies on a well-vascularized recipient wound bed, timing is an important consideration. Waiting at least 3 months after the most recent breast surgery before proceeding with any autologous fat injections allows sufficient time for resolution of edema, revascularization, and stabilization of the contour deficit. Waiting 4 to 6 months between subsequent fat injections allows for dissipation of edema and inflammation, graft revascularization, and stabilization. Careful photographic documentation is helpful in accurately characterizing the three dimensionality of the contour irregularity. Three-dimensional cameras have recently been used to quantitate volume changes associated with both breast reconstruction and breast augmentation using fat grafting techniques^10,11 and may be particularly helpful in defining the volume deficit for both the patient and surgeon.¹²

INFORMED CONSENT

Although autologous fat grafting has been used for over 20 years for the correction of deformities in areas such as the face, trunk, and extremities, its use in the breast has been controversial. Much of the hesitance has been centered around the theoretical concerns that areas of fat necrosis might mimic or conceal a breast cancer recurrence. Thus, careful informed consent for autologous fat grafting to contour irregularities of the breast must be done. Most radiologists are able to distinguish fat necrosis and postoperative changes from cancer recurrence.¹³ If any questions linger regarding the appearance of a mass after fat grafting, then the mass should be treated as a cancer, until proven otherwise. All patients must be counseled in the possibility of biopsies to rule out breast cancer recurrence. Lastly, patients must understand not all fat graft survives and this procedure often involves multiple graft procedures to achieve the desired contour. Clinical estimates of volume resorption after fat grafting to the breast is described in the literature as ranging from 50% to 70% at 1 year.¹⁴ More objective use of three-dimensional cameras suggests fat retention is both volume and time dependent, with patients receiving higher volumes of injected fat having slower volume loss and greater volume retention. The retention of 140 days ranged from 27.1% to 52.3% in low (average, 51 cc) versus high (average, 151 cc) volume injected, respectively.¹⁰

DONOR SITES

Although donor sites are commonly chosen based on patient or surgeon preference as well as ease of access or convenience of the surgeon, the location of graft harvest may influence the quality of the graft. Despite some evidence, adipocyte viability is no different in abdomen, thighs, flanks, knees, and breasts.^15,16 Coleman, an early active proponent of the benefits of fat grafting, preferentially harvested from the lower abdomen and inner thighs, believing these areas to have the easiest graft harvest.⁸ Interestingly, there is evidence these areas may have higher concentration of adipose-derived stem cells (ADSCs) than other areas,¹⁷ with studies suggesting ADSCs may improve the take and survivability of fat grafts.^18,19 For patients reconstructed with implants, the lower abdomen is often available. However, for those who have had TRAM flap reconstructions, this area may no longer provide sufficient graft material and we then elect to harvest the inner thighs. If these areas will yield inadequate graft material, then alternate sites, such as flanks, are chosen based on availability.