One-stage dual-plane reconstruction with prosthetic devices

Background

Recent innovations in surgical technique and technology have expanded the breast reconstruction options available to plastic surgeons. There are often numerous suitable modalities for a given patient. To select the optimal treatment, one must have a thorough understanding of the advantages and disadvantages of each technique within the context of individualized patient assessment.

Prosthetic breast reconstruction remains the most common reconstructive modality in the US, despite the popularization of autologous techniques in the early 2000s. The enduring popularity of implant-based reconstruction likely stems from the improved outcomes seen with recent surgical and technological advancements, as well as an increased awareness of the morbidity associated with use of autologous tissue. Further, the rise of bilateral and prophylactic mastectomies in younger at-risk women has changed the demographic of the reconstructive population, underscoring the importance of the expedited postoperative recovery provided by prosthetic breast reconstruction. Alloplastic reconstruction has traditionally required multiple stages, with tissue expander placement at the time of mastectomy, subsequent outpatient expansion over a period of months, and, finally, exchange for a permanent implant in a planned second operation. However, over the past several years an increasing rate of direct-to-implant (DTI) breast reconstruction has been observed.

Patient Selection

Appropriate patient selection is critical to successful outcomes and begins at the initial consultation ( Algorithm 21.1 ). DTI reconstruction is reliant on adequate soft-tissue coverage and viability. The preoperative evaluation aims to carefully assess these two factors, with attention to the related comorbidities, baseline breast characteristics and aesthetic goals of the patient.

Algorithm 21.1

Patient selection algorithm for breast reconstruction.

Medical and Surgical History

Poor skin perfusion, whether a result of the mastectomy or baseline patient physiology, will not safely accommodate the pressure of an immediate implant without significant risk of necrosis. Patient factors that compromise vascularity are considered contraindications, including poor skin quality and medical comorbidities such as uncontrolled diabetes, recent or current tobacco use, and long-term immunosuppressive therapies. Advanced age, obesity and prior incisions on the breast from lumpectomy, breast reduction or augmentation are not considered contraindications ( Fig. 21.1 ). Interestingly, some institutions may preferentially offer DTI reconstruction to elderly patients and those with significant medical comorbidities to mitigate the anesthetic risk of a second exchange procedure.

Chemotherapy/Radiotherapy

Neoadjuvant and adjuvant chemotherapy have well-documented systemic side effects; however, concomitant use in immediate breast reconstruction is considered safe with regard to surgical complications and reconstructive failure. Radiation therapy, on the other hand, universally increases complications in alloplastic breast reconstruction, with deleterious clinical effects of atrophy, fibrosis, vascular compromise and inhibition of normal wound-healing mechanisms. Patients with a history of prior radiation have traditionally been offered autologous reconstruction to replace the damaged tissue with a healthy substitute. However, not all patients are a candidate for, or willing to undergo, autologous tissue transfer. Patients with a history of failed breast conservation therapy and mild-to-moderate radiation-induced skin changes can often safely undergo immediate prosthetic reconstruction. If possible, it is our preference in this circumstance to place a conservative-volume implant rather than tissue expander at the time of mastectomy, given the inherent limitation to expansion of fibrotic tissue and, more importantly, the additional surgical risk of a planned second procedure on compromised tissue with poor healing potential.

In cases of anticipated postmastectomy radiation, the management strategy for prosthetic breast reconstruction varies widely between institutions and remains an active area of controversy and research. A number of studies have shown enhanced safety with radiation to the permanent implant compared to a tissue expander, prompting some centers to develop protocols for implant exchange prior to adjuvant radiation in two-stage reconstruction. In our experience with postmastectomy radiation, DTI reconstruction had lower rates of complications and reconstructive failure when compared with two-stage reconstruction in patients followed for 2–10 years, and thus is the procedure of choice at our institution ( Fig. 21.2 ).

Given the persistent clinical challenge of combining radiation and alloplastic breast reconstruction, a number of groups have begun to critically evaluate the techniques used for radiotherapy in this high-risk population. More specifically, the clinical benefit of practices such as chest wall and incisional boosts of radiation have been under increased investigation in the postmastectomy population. On this topic, our group recently showed that a chest wall boost of radiation was associated with a significantly higher risk of infection, skin necrosis, implant exposure and reconstructive failure, without conferring the therapeutic benefit of local tumor control. Ongoing evaluation of radiation delivery, such as prone positioning to reduce the maximum skin dosage, may help to further reduce complications in alloplastic breast reconstruction in the future.

Ablative Technique

The treatment of breast cancer requires multidisciplinary integration of medical oncologists, radiation oncologists, pathologists, oncologic surgeons and reconstructive surgeons. Successful collaboration between the extirpative and reconstructive surgical teams is especially germane in DTI reconstruction, as the feasibility of immediate permanent implant placement is often dependent on mastectomy technique. Precise anatomic extirpation at the level of the superficial breast fascia maximizes oncologic resection and minimizes trauma to the superficial circulation of the skin envelope. Meticulous dissection, in conjunction with gentle tissue handling and retraction, leaves behind a uniform mastectomy flap of maximal thickness and vascularity to optimize reconstructive potential. Furthermore, care must be taken to maintain the native breast footprint during the mastectomy, with special attention to preservation of the IMF and avoidance of unnecessary lateral dissection.

Oncologic Plan – Mastectomy Type and Incision

DTI breast reconstruction can be employed in unilateral and bilateral mastectomies, and in reconstruction for cancer or prophylaxis ( Fig. 21.3 ). If the patient has a genetic predisposition for developing cancer, the mastectomies are bilateral ( Fig. 21.4 ). Patients with unilateral breast cancer may undergo unilateral or bilateral mastectomy. The surgical treatment of breast cancer recently evolved to include nipple-sparing mastectomy (NSM), which maximally preserves the skin envelope to facilitate DTI reconstruction. Nipple preservation allows for more natural-appearing outcomes and has been shown to improve patient satisfaction and quality of life. NSM has become the default procedure in many larger centers, with numerous studies demonstrating equivalent oncologic outcomes, including locoregional recurrence, when compared with traditional mastectomy techniques. The oncologic feasibility of nipple preservation is based on tumor proximity to nipple, tumor size, and tumor pathology. From a reconstructive standpoint, the optimal candidates for NSM are those with grade 1–2 ptosis. Select patients with grade 3 ptosis may be considered; however, most will require a staged approach to optimize nipple position or are better candidates for skin-sparing mastectomy.

Incision placement is multifactorial and should be a joint decision between surgical teams ( Table 21.2 ). In NSM, an inferolateral IMF incision maximizes breast cosmesis with a scar hidden in the IMF ( Fig. 21.5 ). Once mastered, this incision also optimizes access for breast and lymph node extirpation for the oncologic team; however, care must be taken to avoid excessive flap retraction as this will compromise the vasculature between the nipple and incision. A vertical incision can be used to narrow large breasts and can also help elevate and centralize the nipple–areolar complex (NAC) ( Fig. 21.6 ). A periareolar incision is associated with increased risk of nipple necrosis but is often most familiar to the oncologic surgeon because the access provided is similar to a skin-sparing mastectomy. A full thickness periareolar incision is typically avoided due to the high risk of nipple and skin necrosis. A lateral incision is a safe option, with the best preservation of nipple blood supply; however, the scar is prominent and can laterally displace the nipple. It is possible to extend a prior incision on the breast to avoid new scars; however, this depends on the location and should be pursued cautiously in previously irradiated skin due to the increased risk of complications.

If nipple preservation is not possible, an areola-sparing procedure can be considered. This preserves more of the soft-tissue envelope than traditional skin-sparing procedures, which is particularly advantageous in DTI reconstruction. In some women the preserved areola can obviate the desire for further nipple reconstruction; however, the thickened pigmented areola also makes an excellent substrate for delayed nipple creation.

In the case of skin-sparing mastectomies, the incision can be oriented horizontally (most common), vertically, or obliquely. A horizontal incision minimizes skin tension with closure and is the incision of choice for small-to-moderate and some large-sized breasts. A vertical incision will narrow and improve the overall shape of large or wide breasts, but care should be taken to avoid chasing dog ears superiorly as this can be visible in clothing. A wise-pattern closure can be considered in very large and ptotic breasts, however this is typically avoided due to the higher risk of skin necrosis with this approach.

Plane for Reconstruction

Currently, the most common plane for implant-based breast reconstruction is beneath the pectoralis major muscle superiorly, with a sling of ADM or synthetic mesh inferiorly. This technique has numerous advantages. When compared with total muscle coverage, this technique enhances the inferior pole to create a more natural shape and a larger implant pocket for DTI reconstruction. When compared with prepectoral reconstruction, partial submuscular implant coverage reduces overall operative costs, elevates the breast, minimizes rippling, and creates a more natural-appearing transition from breast to chest wall without the need for fat grafting in most cases.

The major disadvantage of a submuscular reconstruction is the potential for animation deformity with pectoralis contraction; however, in practice we have found this to be mild and unbothersome to most affected patients. Although uncommon, severely affected patients can be treated with conversion to a prepectoral plane. Future outcomes research will help determine if the two approaches result in clinically significant differences in postoperative pain, functional recovery, and patient satisfaction. Current data and our personal experience suggests greater postoperative pain in the first week following dual-plane reconstruction but no difference in pain or functional recovery between the techniques long-term.

Clinical strategies for deciding between implant planes vary between providers and institutions. In our experience ( Table 21.3 ), the implant tends to sit higher on the chest wall with subpectoral implants compared with prepectoral. This is an important consideration in unilateral breast reconstruction, as prepectoral reconstruction will better match a ptotic contralateral breast, while a subpectoral implant will provide good symmetry in women with minimal ptosis. In general, subpectoral implant placement is preferred for bilateral cases due to the favorable lift and smoother contour of the reconstructed breasts. Notably, if postmastectomy radiation is anticipated we more strongly consider a prepectoral reconstruction ( Algorithm 21.2 ), as our early experience has shown reduced post-radiation pain when the pectoralis muscle is excluded. Unfortunately, some degree of skin tightening and IMF elevation is seen with both techniques. Refer to Chapter 20 for a more thorough discussion of prepectoral reconstruction. In this chapter, the authors describe their preferred technique for partial submuscular implant coverage with an inferior sling of human ADM.

Algorithm 21.2

Algorithm for prepectoral versus subpectoral reconstruction.