Hybrid breast reconstruction: combining flaps and implants

Introduction

Over 260,000 new cases of breast cancer are diagnosed annually in the US. Since the first report of implant-based breast reconstruction five decades ago, tremendous advances have been made in regard to surgical approaches to postmastectomy reconstruction. These advances have been paralleled by a substantial improvement of clinical outcomes, thus cementing the central role of breast reconstruction in breast cancer care.

Advances in breast cancer treatment have led to improved survival rates, as evidenced by a 40% decline in breast cancer deaths in the US between 1989 and 2016. Thus, in the face of an ever-growing number of breast cancer survivors, quality of life (QOL) considerations have become increasingly important. With over 100,000 reconstructions performed annually , postmastectomy breast reconstruction now plays a central role in the management of breast cancer and can help restore patients’ QOL and sense of identity. Today, success following breast reconstruction is no longer measured only by surgical complication rates but equally as important, by patient-reported outcomes. The impact of this transition to patient-centric outcome metrics is also felt in the realm of ablative surgery. The emphasis on aesthetic outcomes and drive for improved QOL after breast cancer treatment has motivated breast surgeons to offer nipple–areolar complex (NAC)-preserving approaches to mastectomy. Initially reserved for patients with small tumors remote from the nipple, indications for nipple-sparing mastectomy (NSM) have broadened to include both the risk-reducing setting and larger tumors, resulting in an increase in the use of NSM. Staged approaches aimed to enhance blood flow to the central skin envelope have been introduced to increase the safety profile of NSM. Furthermore, staged control of the breast skin envelope in patients with macromastia and/or ptosis has expanded the indication of NSM to patients previously not considered eligible. A retrospective review of 61 patients who underwent 122 immediate microsurgical breast reconstructions demonstrated that oncoplastic procedures in preparation for NSM can be offered safely.

In addition to the complex decisions regarding to the ablative procedure, reconstructive choices have evolved considerably over the past five decades, thus providing patients myriad options. The decision regarding reconstructive modality must take into consideration a number of factors, such as patient preferences, prior surgeries, and oncologic care. Considerations in contemporary breast reconstruction range from differences in the plane of device insertion in implant-based reconstruction and donor-site considerations in autologous reconstruction to hybrid reconstructions. Given the range of options, the importance of preoperative patient counseling cannot be overstated and tools such as patient education classes have been introduced to facilitate the shared decision-making process.

Historically, patients have been offered either implant-based or autologous modalities in order to achieve the goals of breast reconstruction, namely reconstruction of breasts of adequate size, shape, symmetry, softness, and sensation (i.e., “5 S”). While this binary approach is appropriate in the vast majority of patients, there remains a subset of patients for whom this simplistic approach is not appropriate. These patients desire autologous reconstruction and have adequate donor-site tissue laxity; yet, they lack sufficient donor-site tissue volume, particularly for bilateral reconstruction. Alternative donor-sites, such as thigh- or gluteal-based flaps may then be considered; however, these procedures can be associated with higher flap loss and complication rates. Additional solutions that have been proposed include primary and/or secondary fat grafting following flap transfer and reconstruction with stacked flaps. Finally, immediate hybrid breast reconstruction, i.e., the combination of autologous tissue with prosthetic implants, has been proposed as a solution. Given the increasing number of bilateral mastectomies being performed in the US, these considerations are progressively more relevant in clinical practice.

A thorough understanding of the pros and cons of the various reconstructive modalities is paramount to ensure that the ideal reconstructive approach is chosen for any given patient. The challenge of insufficient donor-site tissue volume can, for example, be addressed in a single stage using stacked flaps, whereby a large soft tissue volume can be transferred, thus, permitting a totally autologous breast reconstruction of appealing shape and volume in a patient who otherwise would not have been considered a good candidate for autologous reconstruction. The ability to perform these complex reconstructions is a testament to innovations in surgical technique, such as in-flap microvascular anastomoses or use of the retrograde internal mammary vessels. However, flap harvest from multiple donor-sites not only increases surgical duration and complexity but also may have an impact on patient morbidity. Furthermore, while excellent results can be achieved with stacked flaps, the technical expertise necessary to perform these reconstructions may not be widely available.

In contrast to stacked flaps that permit total autologous reconstruction using multiple donor sites, autologous fat grafting has been used in different capacities. While it has been used for total breast reconstruction, fat grafting is more commonly used for secondary revision following implant-based and autologous reconstruction. Its advantages include short surgical duration, outpatient procedure, and the ability to improve clinical outcomes and patient satisfaction by correcting contour deformities and volume deficiencies; however, drawbacks include a variable fat absorption rate ranging from 25% to 80%, risk of fat necrosis, need for multiple procedures, and lack of structural support to the reconstructed breast.

Hybrid breast reconstruction performed immediately following mastectomy may, therefore, represent an ideal solution to address the reconstructive challenge of patients who desire autologous reconstruction and have adequate donor-site tissue laxity, yet lack adequate donor-site volume.

Hybrid breast reconstruction

Hybrid breast reconstruction is characterized by the combination of autologous tissue with prosthetic implants that often results in superior breast shape and volume. The concept is not new with its most common implementation being the combination of implant placement with latissimus dorsi (LD) flap transfer. Disadvantages of this approach, however, include the donor-site morbidity associated with LD muscle harvest, need for intraoperative repositioning, risk of postoperative animation deformity (unless the thoracodorsal nerve is divided at the time of flap transfer), difficulty in creating a natural breast ptosis, and secondary soft tissue atrophy with resultant implant visibility and rippling. Therefore, the most appropriate and advantageous approach seems to be the combination of free abdominal flap transfer with simultaneous implant placement, which represents an expansion of this time-honored concept and successfully addresses the aforementioned shortcomings ( Table 38.1 ).

Advantages of the combination of free abdominal flap transfer with simultaneous implant placement include scar placement in a more concealed location as well as transfer of a greater amount of soft tissue that is not prone to atrophy. Thus, a single-stage reconstruction is possible that limits morbidity to a single donor-site while potentially decreasing postoperative implant-related complications such as implant palpability and rippling, capsular contracture, and reconstructive failures. In hybrid breast reconstruction with abdominal flaps, the ratio of flap to implant volume is shifted in favor of the former as a larger flap is available for reconstruction. This is in contrast to LD flap-based reconstructions where the volume of the implant or tissue expander often exceeds the volume of the flap. Final breast appearance following hybrid breast reconstruction with free abdominal flaps is thus determined by the abdominal flap rather than the implant. The different purpose of the implant in either setting, i.e., abdominal vs. LD flap-based reconstruction, is important to consider. In abdominal flap-based reconstruction, the implant is used to define projection and serves as a foundation over which the abdominal flap is draped with the bulk of volume being provided by the abdominal flap. Thus, the final breast shape, size, and suppleness are defined by the abdominal flap. Decreasing the ratio of implant contribution to overall breast volume is, furthermore, believed to reduce long-term implant-related complications. In contrast, the implant is the major determinant of breast volume and appearance in LD flap-based reconstruction, with the LD flap merely serving as a vascularized soft tissue cover.

While the concept of immediate breast reconstruction via a combination of free abdominal flap transfer and simultaneous implant placement is not new, early reports commented on difficulties associated with implant positioning. The introduction of mesh products, however, has been demonstrated to easily address challenges with implant pocket control in hybrid breast reconstruction to minimize the risk of implant malposition. Despite the purported advantages of hybrid breast reconstruction, several important parameters need to be considered preoperatively; these include plane and timing of implant placement, and the issue of radiotherapy.