Two-stage prosthetic reconstruction with total muscle coverage

Introduction

In reconstructive breast surgery, the surgeon strives to recreate a breast that looks and feels like a natural breast. Thus, the ideal reconstructive technique will create a breast mound with a natural contour, natural consistency, and minimal scarring. Ideally symmetry, with respect to the size and shape of the contralateral breast, will be achieved.

Implant reconstruction has the distinct advantage of combining a lesser operative procedure with the capability of achieving excellent results. Tissue expansion provides donor tissue with similar qualities of skin texture and color compared to the contralateral breast. Donor-site morbidity is eliminated with use of a prosthetic device; and, by using the patient’s mastectomy incision to place the prosthesis, no new scars are introduced.

Recent refinements in surgical technique and improvements in prosthetic technologies have continued to improve reconstructive outcomes. Current prosthetic reconstruction techniques include single-stage implant reconstruction with either a standard or an adjustable permanent prosthesis, two-stage tissue-expander/implant reconstruction and combined implant/autogenous tissue reconstruction.

A temporary tissue expander and/or permanent breast implant may be placed in a complete submuscular position. In this procedure, total muscle coverage of a device is achieved. Alternatively, a breast prosthesis may be placed in a subpectoral or prepectoral position with or without the use of a tissue substitute.

By placing an expander in a completely submuscular position, the risk of expander exposure and contamination in the setting of mastectomy flap necrosis is minimized. In the setting of immediate implant reconstruction, both infectious complications and wound healing problems can have negative consequences. Not only can these outcomes necessitate the explanation of a permanent prosthesis, delaying the reconstructive process, but more importantly, they can delay the administration of adjuvant therapy for breast cancer. Additionally, total muscle coverage of a device can help maintain an expander in a favorable position, maximizes the chance of a successful expansion and may ultimately improve the contour of the upper pole of the reconstructed breast at rest.

The following is an overview of postmastectomy reconstruction using implants and total muscle coverage.

Preoperative counseling

Clear communication regarding the nature of the reconstructive process is essential. During the preoperative consultation, it is important to set reasonable expectations regarding the likely aesthetic outcome and any possible complications. This discussion should also include options and timing for management of the contralateral breast. For patients considering immediate reconstruction, the implications of possible radiation should be delineated. There are few absolute contraindications to two-stage implant reconstruction with total muscle coverage; however, patients with an inadequate skin envelope due to prior severe radiation damage or extensive skin resection may benefit from the concurrent performance of a soft tissue flap.

Relative contraindications to expander/implant reconstruction include smoking, obesity and radiation. These comorbid conditions have been shown to contribute to increased local wound complications and are associated with an increased risk of reconstructive failure. It is important to note, however, that the overall incidence of complications following reconstruction with total muscle coverage in patients with these identifiable risk factors remains acceptably low. Thus, patients who have these factors, such as obesity, should not be discouraged from undergoing expander/implant reconstruction; instead, these patients should be informed about the risks and benefits of the procedure as they pertain to themselves as an individual.

Procedure selection

Implant-based reconstruction can be performed in a single stage or as a two-stage procedure. Although satisfactory results can be obtained with single-stage surgery, for most patients a more reliable approach involves the initial placement of a tissue expander with secondary placement of a permanent implant. A tissue expander is placed under the skin and muscles of the chest wall at the primary procedure. Postoperatively, tissue expansion is performed over a period of weeks or months, the soft tissues stretched until the desired breast volume is achieved.

This second stage allows for: (1) precise positioning of the inframammary fold; (2) capsulotomy to release soft tissue, thus increasing breast projection and ptosis; and (3) re-evaluation of breast height and width to achieve maximal symmetry with the contralateral breast. Candidates for single-stage reconstruction may include the occasional patient who has a small–medium volume, non-ptotic breast who is desiring of a smaller volume reconstructed breast and who has excellent skin quality, and in whom the anatomic limits of the breast, including the inframammary fold, have been preserved.

The success of implant reconstruction is significantly influenced by the manner in which the oncological surgery is performed. Placement of excision biopsy scars, design of the mastectomy incisions, maintenance of adequate flap thickness and vascularity, and preservation of the inframammary fold all impact heavily on the final reconstructive outcome. Close collaboration with oncological surgery colleagues is fundamental.

Whenever possible, a skin-sparing mastectomy should be performed. When the surface area of the skin is great and excess skin may be excised, excision of lower pole skin should generally be avoided. This can result in a lower, transverse scar that can inhibit expansion of the lower pole. Ideally, the inframammary fold should be well-marked preoperatively and respected as the inferior limit of the mastectomy. In addition, maintenance of the fascia overlying the inferomedial border of the pectoralis muscle, the superior edge of the rectus, and the medial extension of the serratus will greatly facilitate total musculofascial coverage of the expander.