Two-stage dual-plane reconstruction with prosthetic devices

Current state of alloplastic breast reconstruction

The current standard of care in alloplastic breast reconstruction has been developed over several decades to encompass a variety of different techniques. Despite significant variation in procedures today, several principles remain steadfast across the spectrum of implant-based breast reconstruction. These critical factors include the quality of the mastectomy and vascularity of the skin flaps, prosthesis choice and handling, pocket control, individualized treatment algorithms, intra-operative flexibility, and expedient and efficient management of postoperative complications.

Modern implant-based breast reconstruction is the result of a convergence of advances in mastectomy techniques, implant technology, adjunctive tools such as soft tissue support materials and autologous fat transfer. With regards to the mastectomy, movement toward more anatomic procedures with preservation of critical aesthetic structures are routinely performed when oncologically feasible and have contributed to achieving ideal aesthetic outcomes. Nipple-sparing mastectomy (NSM) is the culmination of this evolution, preserving the nipple–areola complex, skin envelope and subcutaneous tissue through an anatomic dissection. In the appropriate patients, this technique has allowed for improved patient satisfaction and quality of life with comparative oncologic outcomes to more radical procedures.

The concept of the bioengineered breast utilizes these advanced mastectomy techniques and new generation implants along with fat grafting and acellular dermal matrices to address the shortcomings of implants with regards to upper pole contour and minimizing capsular contracture. Today, prepectoral breast reconstruction and immediate implant placement have moved to the forefront of the breast reconstruction literature. While these may represent ideal modalities in certain situations and for particular patients, there still remain many reconstructive choices in the plastic surgeon’s armamentarium.

It is imperative for the plastic surgeon to be comfortable with multiple different techniques to be able to individualize treatment plans for each patient and maintain the flexibility to adjust these plans in the operating room when needed. Two-stage techniques afford the surgeon flexibility with regards to the eventual size and shape of the breast mound while maintaining safety by minimizing pressure on mastectomy flaps at the immediate reconstruction. When combined with dual-plane prosthesis placement, this allows for greater vascularized coverage of the upper pole and an aesthetic lower pole contour due to the expansion of acellular dermal matrix (ADM). Two-stage dual-plane techniques therefore remain an important reconstructive modality in the spectrum of implant-based breast reconstruction.

The evolution of implant planes

Implant-based breast reconstruction began with subcutaneous placement of silicone-filled prostheses in the 1960s. This was a relatively rapid technique but was plagued with high rates of complications, including skin breakdown, exposure, implant malposition and capsular contracture. These complications led to the transition to a total submuscular plane under the pectoralis muscle and serratus muscle and subsequently serratus fascia, ¹¹ adding a layer of vascularized tissue between the implant and skin. Total submuscular techniques remained the mainstay of breast reconstruction throughout the late twentieth and early twenty-first centuries. However, total submuscular coverage was a trade-off between decreased complications and what some surgeons perceive as a less aesthetic outcome given restriction of lower pole expansion, less natural ptosis and decreased projection.

Breuing and Warren brought the use of ADM, already utilized in revisionary breast surgery, to primary breast reconstruction as a dual-plane technique with upper muscular coverage and an inferolateral ADM sling. Benefits of the ADM dual-plane technique include additional lower pole soft tissue support (compared with non-ADM partial submuscular techniques), more rapid expansion, precise control of the expander pocket and delineation of the inframammary fold (IMF), improved lower pole projection and decreased rates of capsular contracture. Infection and seroma rates, however, have been found to be higher in some studies in the ADM-assisted reconstruction setting. Through advancements in ADM processing, including sterile ready-to-use matrices over aseptic preparations, infection rates have decreased.

Recently, prepectoral reconstruction both with and without the use of ADM has gained traction as a means of avoiding the morbidity of pectoralis muscle elevation and the potential for animation deformity seen with pectoralis contraction. Today, total submuscular, ADM-assisted dual-plane and prepectoral techniques can all be utilized, each with its specific indications. This chapter focuses on two-stage ADM-assisted dual-plane reconstruction as a mean of providing adequate prosthesis coverage in immediate reconstruction while maintaining breast, and specifically lower pole, aesthetics.

General considerations

The preoperative evaluation of patients for implant-based breast reconstruction is a synthesis of data from the patient’s history, physical exam findings, and relevant information of other providers, notably the breast surgeon and oncologist. Similarly, formulating a surgical plan should involve all members of the team, notably the patient and the breast surgeon. A coordinated, team-based approached to the pre-, intra- and postoperative care of these patients cannot be overemphasized as the optimal method of achieving the best oncologic, reconstructive, and patient-reported outcomes.

Patient counseling in breast reconstruction goes beyond the process of informed consent that reviews the standard risks, benefits and alternatives. While this aspect of the preoperative consultation is critical, equally important is the explanation of reconstructive options and reception of patients’ desires and questions, to arrive at a surgical plan through a process of shared decision-making. Studies have demonstrated the majority of patients do not make high-quality decisions about reconstruction and that unclear patient expectations preoperatively are associated with patient dissatisfaction postoperatively. In this regard, it is highly recommended to understand patient concerns and effectively communicate and discuss expected outcomes preoperatively.

Patient history

A comprehensive assessment of a patient’s overall medical history and focused breast history is imperative. All medical comorbidities should be elucidated, especially known risk factors for complications such as diabetes and high body mass index (BMI), to aid in surgical decision-making and patient counseling. A complete surgical history is also elucidated with focus on prior breast reduction, mastopexy, augmentation or oncologic procedures including segmental excisions and partial mastectomies.

Additionally, obtaining a full oncologic history is paramount. Information on cancer stage, tumor type, size and location will help clarify the details of the ablative procedure that will subsequently dictate the reconstruction. Neoadjuvant and planned adjuvant therapies should also be taken into consideration. Chemotherapy is usually well tolerated; however, some studies have suggested that chemotherapy may increase breast reconstruction complications. Prior radiation as well as the potential need for adjuvant radiation has significant implications with regards to decision-making in implant-based reconstruction because of the increased incidence of capsular contracture leading to premature reconstructive failure.

Patient lifestyle should also be taken into consideration. Young, active patients and athletes may warrant stronger consideration of prepectoral techniques to avoid the morbidity of pectoralis disinsertion as well as the possibility of animation deformity. Smoking history is critical as active tobacco use is a known risk factor for complications such as delayed healing and infection. Elucidating details of prior tobacco use is also useful as patients with less than 10 pack-year history and greater than 5 years to quitting smoking have demonstrated equivalent outcomes to non-smokers in NSM.

Physical exam

Physical examination begins with a general breast exam for any obvious or palpable masses. Locations of any masses should be documented and correlated with distance to the nipple and skin in patients being evaluated for NSM. Along these lines, the nipple–areolar complex (NAC) should be evaluated for any stigmata of tumor involvement including discharge, retraction and palpable subareolar tumors. Scars from prior breast surgery should also be examined carefully to determine implications for perfusion to the skin envelope and incision design.

Accurate assessment and documentation of breast morphology is critical; in particular, the breast footprint on the chest wall, breast size, degree of ptosis, breast shape, deflation and IMF positions. Severe macromastia and ptosis increase the risk of ischemic complications after NSM, which should be discussed with the patient beforehand. Chest wall deformities as well as asymmetry of the breast and NAC should be noted and similarly shown to the patient and documented. Standard measurements, including sternal notch-to-nipple distance, nipple-to-IMF distance and breast width, are recorded as means of quantifying breast morphology and potential asymmetry in addition to aiding with preoperative planning (breast width and expander selection).

Assessment of subcutaneous tissue thickness is also important for preoperative planning. This thickness varies significantly among patients and has been correlated with BMI values. A pinch test of the upper pole can be used as a rough guide to estimate the amount of subcutaneous tissue that can later be corroborated with imaging studies as available. Along these lines, skin quality and laxity should also be noted, especially in cases where it is planned that the entire skin envelope is to be preserved.

Preoperative planning

A well-developed preoperative plan is a prerequisite for a well-executed operation. Development of a surgical plan requires a synthesis of multiple components including patient history, breast morphology, oncologic characteristics, and an understanding of patient expectations. Approaching this process in a team-based manner through an open discussion with both the breast surgeon and the patient affords the plastic surgeon the ability to optimize reconstructive and aesthetic outcomes, while ensuring an oncologically sound procedure and maximizing the potential for postoperative patient satisfaction.

In addition to the history and physical exam, preoperative imaging can be a useful modality for evaluation of breast morphology and subsequent surgical planning. Magnetic resonance imaging (MRI) is often obtained by breast surgeons as a preoperative diagnostic tool, and can be used to accurately visualize the thickness of the subcutaneous tissue superficial to the breast capsule throughout the breast. Decreased relative thickness of the subcutaneous layer after mastectomy compared to preoperative thickness has been correlated to ischemic complications of the mastectomy skin envelope after NSM secondary to compromise of the remaining superficial perfusion of the breast. Objective assessment of subcutaneous tissue thickness preoperatively and discussion with the breast surgeon will help plan the appropriate mastectomy dissection and assist in assessment of intra-operative flap thickness by providing a baseline measurement.

Two-stage dual-plane reconstruction is part of a decision-tree that takes into account multiple factors with regards to stages of reconstruction, implant plane, mastectomy technique and soft tissue support materials. Separating these interrelated components can help clarify the process ( Boxes 22.1–22.4 ) and should be considered as a whole in order to optimize outcomes for each individual patient. The decision-making algorithm for two-stage implant-based reconstruction is outlined in Algorithm 22.1 .

Algorithm 22.1

Decision-making algorithm for implant-based breast reconstruction. Two-stage dual-plane candidates typically desire implant size larger than their current breast size and do not have adequate subcutaneous tissue or have additional comorbidities that preclude prepectoral prosthesis placement.

One-stage versus two-stage reconstruction

The decision between single- and two-stage reconstruction is multifactorial and involves both preoperative and intra-operative factors. These factors include patient size desires, preoperative risk factors, breast morphology and mastectomy skin flap quality. Typically, ideal candidates for single-stage reconstruction are patients who desire implant size that is similar or smaller than their current breast size and do not have any significant comorbidities or preoperative risk factors. When NSM is planned, more importance is placed on favorable breast morphology that includes small-to-medium sized breasts without significant ptosis. Significant manipulation of the skin envelope can compromise vascularity.

Single-stage reconstructions have been found to be cost-effective with a comparable safety profile to tissue-expander reconstructions. However, an increased risk of ischemic complications has been reported in the setting of NSM and one-stage reconstruction when compared with two-stage reconstructions. This is likely secondary to stress on the skin envelope that further highlights the importance of not only preoperative but also intra-operative technique selection. Importantly, patients are counseled that intra-operative factors can affect the ability to proceed with single-stage implant reconstruction. In cases with poor mastectomy flap quality on intra-operative evaluation or a tight closure of the skin envelope, conversion to a smaller implant or a tissue expander may be the safest option. Patients should understand and be comfortable with the notion that tissue-expander placement at the time of mastectomy is always a possibility.

Two-stage tissue-expander reconstruction candidates include patients who desire a breast size larger than their current size or are undecided ( Fig. 22.1 ). Tissue expansion affords the surgeon the opportunity to carefully control the desired breast size through the expansion process and allows for greater flexibility in determining the final outcome. Along these lines, placement of tissue expanders can help control final breast shape in patients with more challenging breast morphology ( Fig. 22.2 ). Initial skin tailoring is performed at the immediate reconstruction with the expansion process allowing for more predictable control of the breast mound and further adjustments of the skin envelope at the time of implant exchange. While immediate implant placement is also a feasible option for unilateral cases, tissue expansion allows more precise control of breast size with an additional opportunity for modification of shape and contour at the exchange to better match the contralateral breast ( Fig. 22.3 ).

Radiation also plays an important role in decision-making. Patients who have received preoperative radiation have a higher overall risk of postoperative complications after implant-based reconstruction. While immediate implant placement in possible in these cases, a fibrotic and damaged skin envelope may warrant a staged approach with tissue expanders to minimize stress on the flaps at the time of mastectomy (if autologous reconstruction is not an option). Adjuvant radiation therapy is also linked to increased overall complications and has important implications with regards to both tissue expanders (reconstructive failure) and permanent implants (aesthetic deformity and capsular contracture). While the need for adjuvant radiation is often not known at the time of mastectomy, the potential for implant radiation may warrant a more conservative approach to minimize the aesthetic and reconstructive sequelae associated with this therapy ( Fig. 22.4 ).

Implant plane

Similar to decisions on single- versus two-stage reconstruction, determining implant plane is dependent on multiple factors and subject to intra-operative change. Prepectoral reconstruction requires strict preoperative patient selection to minimize complications. Ideal candidates are non-smokers without medical comorbidities that have favorable breast morphology with adequate subcutaneous tissue thickness superficial to the breast capsule. Younger, active patients can particularly benefit from this technique to avoid the morbidity of animation deformity.

Dual-plane reconstruction provides mid- and upper pole muscular coverage while allowing for increasing expansion of the lower pole, which is one of the benefits of using ADM. In patients with thin subcutaneous tissue visualized on preoperative imaging or exam, this technique can provide excellent upper pole fullness without comprising lower pole aesthetics. This can help to improve upper pole contour ( Fig. 22.5 ) (in addition to adjunctive techniques such as fat grafting) as well as to minimize complications such as rippling. Additionally, partial muscular coverage provides an additional layer of vascularized tissue in patients who were not ideal candidates for prepectoral prosthesis placement, e.g., comorbidities and active smokers.

Oncologic considerations also influence choice of implant plane. Patients with tumors close to the chest wall that may have a higher rate of chest wall recurrence are best served with submuscular prosthesis placement to improve postoperative imaging and surveillance as well as facilitating the delivery of radiation therapy to the pectoralis major muscle, if necessary. Patients with a prior history of radiation are also better served with a submuscular technique, given the fibrotic and usually damaged skin envelope that is often prone to wound healing complications, which may lead to reconstructive failure ( Fig. 22.6 ). On the other hand, patients who are expected to receive adjuvant radiation may benefit from prepectoral prosthesis placement to avoid the distortion that can occur with submuscular implants secondary to radiation-induced fibrosis and contraction of the pectoralis muscle.

Total submuscular coverage represents the “safest” implant plane as the prosthesis is contained within a well-vascularized pocket of pectoralis major muscle and serratus fascia. This technique is typically utilized with two-stage tissue-expander reconstruction because an adequately-sized pocket cannot usually be created to facilitate immediate implant placement. While not always in the primary plan, total submuscular coverage should be considered when there is intra-operative concern for mastectomy flap viability.