Introduction

Over the past 30 years, treatment of breast cancer has evolved dramatically. This can be attributed to a better understanding of tumor biology, improved adjuvant and neoadjuvant therapy, and refinements in surgical technique [1–4]. Many more women are now candidates for breast-conserving therapy (BCT) [5], and the surgical treatment of breast cancer is less radical, and more form preserving. The focus now is on decreasing morbidity and improving patient satisfaction, without compromising oncologic safety. Consequently, oncoplastic surgery developed, which combines plastic surgery techniques and oncologic surgery.

Oncoplastic breast surgery uses the remaining healthy breast tissue to reshape the breast immediately following partial mastectomy, in order to achieve the best possible esthetic outcome. Strategies may include local tissue rearrangement, local-regional flaps, mastopexy, and reduction mammoplasty. There is a growing body of evidence that women who undergo oncoplastic surgery have higher patient satisfaction, improved esthetic outcomes, and equivalent oncologic outcomes [6••, 7••, 8••, 9, 10••, 11].

In those women who require mastectomy, many modifications have been made on both the oncologic and reconstructive aspects of care. The most significant change to improve the overall esthetic result is the preservation of the skin envelope and entire nipple areola complex (NAC), coined as “nipple-sparing” or “total skin-sparing” mastectomy [12–15]. Preservation of all the external nipple skin and form has lead to greater patient satisfaction [16]. While implants remain the mainstay of reconstruction, autologous tissue reconstruction has gained popularity given its natural look, feel, and durability. Given the improved esthetic outcomes, more women are pursuing contralateral and bilateral prophylactic mastectomies [17••].

Despite the greater focus on esthetic outcomes, equivalent oncologic outcomes have been maintained [18••]. Radiation therapy plays a critical role in this finding [19] and also greatly influences reconstructive choices and outcomes. Radiation’s effects on the soft tissue envelope endure for a patient’s lifetime, and thus planning reconstruction is heavily dependent on the history, or prospect of, radiation. In this article, we will describe our reconstructive algorithm for partial mastectomy and mastectomy defects, and the key aspects which influence the decision-making process.

Partial Mastectomy Reconstruction

The key factors in determining whether a patient is a candidate for breast-conserving therapy is tumor size and location, breast size and shape, timing of radiation therapy, and tumor to breast size ratio [20, 21]. Reconstruction of partial mastectomy defects can be thought of in basic terms as either volume replacement or volume displacement [22]. Women with sufficient breast parenchyma and/or ptotic breasts often undergo reshaping procedures, while women with less breast tissue and minimal ptosis require displacement procedures [21]. Breast size and tumor to breast ratio are ultimately the most important factors in deciding which reconstructive method to use.

In women with moderate-large breasts, small-moderate tumors, and minimal ptosis, local tissue rearrangement following partial mastectomy can produce an excellent esthetic result [9, 22]. The skin and parenchyma adjacent to the partial mastectomy defect is shifted to fill the cavity left behind or to move the defect to a less noticeable area [23]. For this method to be effective, oncologic surgeons must be highly confident that they have achieved clear tumor margins. To do so, they often use additional modalities, such as intraoperative X-ray, to image the tumor specimen and visualize healthy breast tissue around the excised tumor.

Additional options for using local tissue for small defects include transposition or rotational soft tissue flaps [24], and for larger defects the latissimus dorsi flap. The latissimus dorsi is a robust flap that can include subcutaneous tissue and skin in addition to muscle, so it can correct most partial mastectomy defects [25, 26].

Women with large breasts or adequate breast volume but marked ptosis may benefit from various mastopexy (breast lift) techniques. The technique used depends on tumor location, breast size and shape, and surgeon experience. Superior pole tumors are best treated with a “batwing” mastopexy [23] or Benelli’s “round block” technique [27]. In these procedures, patients are left with a discrete scar, and the recreated breast mound is well supported at the dermal and glandular levels. Lateral tumors are best treated with “donut” mastopexy [28] or radial-segmental lumpectomy [23]. The radial segmental lumpectomy removes full thickness skin and glandular tissue and then flaps are advanced to close the skin. Lower pole tumors are best treated with reduction-mastopexy, where the skin and subcutaneous tissue flaps are raised and advanced over the remaining breast tissue to lift the breast through the creation of a smaller breast pocket. The overall goals with all of these techniques are to reshape and lift the breast parenchyma, reposition the NAC, and tighten the skin envelope, thus creating a more esthetically-pleasing breast.

Reduction mammoplasty is now one of the most frequently used oncoplastic techniques in large-breasted women with grade II or III ptosis [29–31]. This technique relies upon excision of excess skin and parenchyma, following partial mastectomy, to reshape the breast mound and reposition the NAC. The incisions for the reduction are used to access and remove the tumor, and then once the partial mastectomy has been completed, the remaining breast parenchyma is shifted to recreate the breast mound. The most commonly used incisions are the Wise pattern [32] and vertical pattern [33, 34] techniques and are dictated by breast size and ptosis, and the quality of the skin envelope. The Wise pattern approach is versatile as it allows access to all areas of the breast and various pedicles can be used [35]. However, the ultimate durability is based on the skin, thus the breast parenchyma may settle more over time. The vertical scar technique has become more popular given the shorter skin incision, shorter pedicle, and straightforward resection [33–36], but fewer patients are candidates because less overall ptosis and better skin quality are required. The pedicle supporting the NAC is influenced by tumor location [37], and most frequently based on an inferior pedicle when a Wise pattern incision is used [32], and superomedial pedicle when a vertical incision is used [38].

Once the reduction has been performed in the breast with the tumor, the contralateral breast is reduced to match [39]. This technique has been shown to improve the overall cosmetic outcomes, and increase patient satisfaction [20,31,40,41]. Despite the significant tissue rearrangement that occurs, oncologic safety is not compromised [42••], in part because this technique allows for wider and more aggressive tumor resections. Thus, this technique has extended the option for BCT in many patients [7••, 8••, 31, 43]. Reduction mammoplasty has also been used as a strategy for reducing complications in women who will require radiation therapy [10••]. This technique enables more women to be candidates for BCT, thus avoiding the need for mastectomy and reconstruction altogether. Furthermore, this may be a safer technique when complete axillary dissection is required, relative to mastectomy and prosthetic reconstruction [44••].

Secondary lipofilling has gained popularity in the reconstruction of contour deformities following partial mastectomy. Fat is harvested via liposuction most commonly from the abdomen, flanks, and thighs, processed, and then injected to smooth out contour irregularities. Advantages of this technique include the use of autologous tissue, the ability to improve skin quality, and the subtle contour changes that are possible [45–47]. However, concerns exist over the oncologic safety of lipofilling. There is fear that future imaging will be obscured or clouded, that the transferred cells may promote tumorigenesis [48], and that the cells that do not survive may become firm and calcified leading to increased patient morbidity [48–51]. These fears, however, have not been supported scientifically, and no increased oncologic risk has been shown [52–54]. Lipofilling remains widely used in the reconstruction of partial mastectomy defects [55••], as well as smoothing out contour irregularities in mastectomy flaps and providing more volume in autologous reconstruction. This technique also works in the post-radiation setting.

Mastectomy Reconstruction

Many women now have the option of undergoing nipple-sparing or total skin-sparing mastectomy. This technique preserves the entire skin envelope and nipple areolar complex externally, and removes all breast parenchyma including coring out the internal nipple tissue [12, 56]. When this technique initially developed, there were many limitations regarding who were candidates. However, women are potential candidates now as long as the tumor does not involve the NAC based on MRI and as long as there is no skin involvement following neoadjuvant chemotherapy. Even larger breasted patients can be staged first with a reduction mammoplasty, followed several months later by mastectomy with preservation of the NAC [57••, 58]. The preservation of the NAC has greatly improved the overall esthetic outcome and patient satisfaction [16], without compromising oncologic safety [59••].

The mainstay of post-mastectomy reconstruction is with implants [17••]. Most commonly, tissue expanders are placed at the time of mastectomy and slightly filled with saline. Acellular dermal matrix, which is a cadaveric collagen matrix, is frequently used as a sling to support the tissue expander and provide another layer of coverage and support. Acellular dermal matrix has been shown to decrease reconstructive complications in implant-based reconstruction in the setting of radiation therapy [18••, 60••, 61–65].

If patients are undergoing two-stage expander-implant reconstruction, most commonly the tissue expansion process begins 2 weeks after mastectomy and continues over several weeks to months. The tissue expander is exchanged for a permanent implant several months after the breast has reached the desired volume. Waiting for greater than 6 months has been shown to decrease reconstructive complications and expander-implant reconstructive failure [61]. Silicone implants are typically preferred over saline implants given their more natural look and feel [66••].

Some women are candidates for immediate reconstruction with a permanent implant at the time of mastectomy [62, 67••]. These techniques require a healthy breast skin envelope that can tolerate the stretch from the full size implant, during acute healing from the mastectomy. If this is not the case, the risk of breast skin flap necrosis is high.

Another variation on implant reconstruction is the “delayed-immediate” approach. This uses an inflated tissue expander to preserve the breast envelope and shape without putting excess tension on the tissues, and then once final pathology results are available, the expander is exchanged for a permanent implant if the patient does not require post-mastectomy radiotherapy (PMRT) [68]. Delayed reconstruction has fallen out of favor because the esthetic outcomes are less optimal, and no difference in complication rates or oncologic safety has been demonstrated. When reconstruction is delayed, it is very difficult to correct nipple malposition and retraction, and the skin envelope does not regain a normal breast contour.

The development of anaplastic large cell lymphoma in women with breast implants has made headlines recently. These tumors most often arise from the implant capsule, and the most common presenting sign is late seroma (median time to development 9 years). The underlying etiology is hypothesized to be multifactorial, but likely a chronic inflammatory response to the texturing of the silicone implant surface. To date, no cases of ALCL of the breast have been reported with smooth silicone implants. The management depends on the extent of disease, with tumor limited to the capsule treated by implant removal with total capsulectomies, and for extracapsular involvement the addition of multiagent chemotherapy with or without radiation [69].

Autologous reconstruction is the other primary option for reconstruction of post-mastectomy defects. The patient’s own tissue is moved from one part of the body to the chest wall, and its blood supply is often re-established using microsurgery. The most common donor site is the abdomen, in the form of the deep inferior epigastric perforator flap (DIEP), the muscle-sparing transverse rectus abdominis myocutaneous flap (msTRAM), or the transverse rectus abdominis myocutaneous flap (TRAM). These flaps are reliable and usually provide enough tissue bulk to reconstruct the breast without requiring additional augmentation. Complete TRAM flaps, with harvest of the entire rectus abdominis muscle complex, can be rotated on their vascular pedicle, or can be transferred as free flaps, but put patients at a greater risk for developing abdominal hernias because both muscle and fascia are removed from the abdominal wall. The muscle-sparing TRAM flaps minimize the muscle and fascia removed, thus decreasing donor site morbidity. The DIEP flap further limits morbidity, with complete preservation of the innervated rectus abdominis muscle and fascia, but can be more technically challenging to perform.

Additional options for autologous reconstruction include the latissimus dorsi myocutaneous flap [70], flaps based on the gluteus muscle and underlying gluteal artery perforator blood supply [71], flaps based on the gracilis muscle, and various perforator flaps. However, many of these flaps may not provide enough soft tissue and thus require augmentation with implants to achieve sufficient bulk. Secondary lipofilling is another option for adding some soft tissue bulk to autologous flaps, whereby adipose cells can be injected into the mastectomy flaps, as well as the autologous tissue flaps. While breast reconstruction with autologous tissue does require a longer operation and several days in an inpatient unit, reconstruction is often achieved with fewer operative procedures and less time to complete reconstruction than expander-implant reconstruction [70, 72••, 73]. It provides an excellent esthetic outcome and high overall patient satisfaction.

Modifications in the Setting of Radiation

The timing of reconstruction when PMRT is anticipated is controversial, both in prosthetic and autologous reconstruction. Some institutions advocate for irradiation once the tissue expander has been fully expanded, others partially deflate the expander prior to PMRT, and others wait until the permanent implant has been placed. With autologous reconstruction, some advocate for performing immediate autologous tissue reconstruction at the time of mastectomy, followed by PMRT. Others recommend delaying autologous reconstruction until after completion of PMRT. However, no randomized controlled trials have been performed to date to truly evaluate which protocol has the lowest complication rates and better esthetic outcomes.

We propose several modifications if PMRT is anticipated. Radiation’s effects last a woman’s lifetime, thus she will always have a compromised skin envelope and be at risk for implant loss [74••]. Autologous tissue fares better than implant-based reconstruction in the setting of radiation therapy because healthy, vascularized tissue is brought to an area of compromised tissue. Therefore, if a woman has adequate soft tissue to reconstruct the breast, we advocate autologous reconstruction. Another long-term negative effect of radiation therapy is fibrosis of blood vessels, which leads to higher levels of fat necrosis and flap fibrosis. We have found that augmenting both arterial inflow and venous outflow to DIEP flaps decreases the incidence of fat necrosis by enhancing perfusion [75••]. Thus, if radiation is anticipated, we attempt to augment both arterial and venous flow to the flap. An additional measure we take is working closely with our radiation oncologists with radiation planning and delivery. Our radiation oncologists use custom bolus to minimize radiation to the vascular pedicle in autologous reconstruction, and limit radiation to the skin and scar [76••]. We have found that the implementation of these modifications has led to improved esthetic outcomes and softer, less fibrotic breasts.

Conclusions

Dramatic improvements in the surgical management of breast cancer have been made over the last 30 years. Many more patients are now candidates for breast-conserving therapy attributed to improved chemotherapy regimens and the use of radiation therapy. Oncoplastic surgery, mastopexy, reduction mammoplasty, and lipofilling are methods used to minimize contour deformities and improve esthetic outcomes following partial mastectomy. For those women who require mastectomy, techniques are now much less morbid and the preservation of the entire skin envelope and NAC has markedly improved esthetic outcomes. Implant-based reconstruction remains the most commonly used technique, but autologous reconstruction has gained popularity given its natural feel and appearance, and ability to tolerate radiation therapy. Current research is directed towards improving outcomes in the setting of radiation therapy, investigating the oncologic safety of secondary lipofilling of the breast, and evaluating patient-reported outcomes.