TECHNICAL ASPECTS OF DEFECT REPAIR AFTER PARTIAL MASTECTOMY

Oncoplastic surgery for breast cancer

TECHNICAL ASPECTS OF DEFECT REPAIR AFTER PARTIAL MASTECTOMY

Options for repair of defects resulting from partial mastec-tomy can generally be grouped into three main categories:

local tissue rearrangement with composite breast flaps, reduction mammaplasty, and transfer of remote tissue in the form of a vascularized regional or distant flap.

Local tissue rearrangement

Local tissue rearrangement is the most straightforward option for repair of partial mastectomy defects, and for this reason, it should be the first option considered. Esthetic outcomes of local tissue rearrangement are best when the defect is of limited size and the rearrangement is performed during the same operative procedure as the oncological resection.

To ensure that the tissues to be transferred are well vas-cularized, the breast parenchyma is elevated along one plane just overlying the pectoralis major muscle and another plane below the subdermal plexus of the skin, and the breast parenchyma is then advanced over the muscle to fill in the tissue defect. Breast tissue is reapproximated with

absorbable suture at the deepest and superficial surfaces of the parenchyma. Care must be taken to avoid undue ten-sion or excessive parenchymal sutures as this may result in areas of tissue compromise and fat necrosis. The overlying subcutaneous tissue and skin are then closed. If there is a risk of nipple malposition, elevation of the breast paren-chyma is extended beneath the nipple–areolar complex to avoid pulling of the nipple-areolar complex toward the scar.

Care should be taken to preserve the vascular supply of the breast, which is derived primarily from perforators from the lateral thoracic, internal mammary and intercos-tal arteries. The extensive collateral blood supply permits flexibility in operative approaches, but in all cases an ade-quate vascular supply must be assured for the breast skin and parenchyma, and the nipplenareolar complex.

Composite breast flaps include full-thickness breast parenchyma plus skin and are rotated or transposed en bloc (Figure 13.6). These flaps, which were popularized by the late Stephen Kroll and others, are primarily used to effect a subaxillary shift of tissues from lateral to medial ²⁴ ^, ²⁵ . Composite flaps assure a reliable vascular base and breast contour but are not appropriate for large defects, for which composite flaps can result in very noticeable scar-ring and distortion of the nipple .

With all methods of local tissue rearrangement, predict-able patterns of tissue advancement are necessary to avoid confusion regarding the location of the original defect, and clips should be placed at the original margins of excision. These precautions ensure that targeted margin re-excision will be possible if positive or close margins are discovered on final pathology review.

Batwing mastopexy

The ‘batwing’ mastopexy can be used in patients when the tumor is adjacent to or under the nipple-areolar complex, but not directly involving it. In this technique, two semi-circular incisions of equal size are made, one around the areola and the other parallel to the first incision on the other side of the tumor ( Figure 13.7 ). The skin incisions are then extended laterally so that the two incisions together resem-ble the wings of a bat. The skin between the incisions, the underlying subcutaneous tissue, and the tumor and a sur-rounding margin of normal breast tissue are then excised en bloc, and the remaining breast tissues are advanced medially to close the defect. This technique works extremely well with tumors located superior to the nipple-areolar complex and can be designed in any circumnipple-areolar orientation, as dictated by the individual tumor.

Quadrantectomy

Quadrantectomy may be the best approach for larger tumors and tumors extending along a ductal system.

The incision is oriented radially, and skin, subcutaneous tissue and breast tissue down to the pectoral muscle are resected en bloc. To preserve breast shape and contour, the remaining tissues are advanced together without ten-sion and closed meticulously in layers to minimize con-tour deformities and nipple distortion. Scarring may result in contracture, which can be exacerbated by irradia-tion and can lead to significant and difficult-to-correct deformities.

Donut mastopexy

The ‘donut’ mastopexy – more appropriately termed round block mastopexy – credited to Benelli ²⁸ is a variation of

‘short scar’ reduction mammaplasty technique. The round block approach limits scars on the breast because it is per-formed through a periareolar incision, eliminating the ver-tical and horizontal scars associated with the more traditional mastopexy/reduction mammaplasty incision design.

Figure 13.6 Local tissue rearrangement. A 33-year-old woman 15 months after superior composite rotation flap. This technique should generally be limited to small volume defects. Note contour deformity overlying pectoralis muscle (arrow). Replacement of a skin resection in this location would result in a poorly color matched and highly visible ‘patch’. Reproduced in part from reference 26 , with permission.

Figure 13.7 Batwing mastopexy. Two semicircular incisions of equal size are made, one around the areola and the other parallel to the first incision on the other side of the tumor. The skin incisions are then extended laterally so that the two incisions together resemble the wings of a bat. The skin between the incisions, the underlying subcutaneous tissue, and the tumor and a surrounding margin of normal breast tissue are then excised en bloc, and the remaining breast tissues are advanced medially to close the defect. Reproduced from reference 27 , with permission.

While a reduction in breast scarring is appealing, the clinical results of the donut mastopexy approach have been disappointing. Use of a periareolar cerclage (purse-string suture) without a vertical component results in flattening and loss of projection of the breast mound off the chest wall and may lead to a widened and unattractive periareolar scar. Reduced scarring has been noted with use of a permanent cerclage suture of Gortex or Prolene to prevent recidivism and widening of the scar. Use of the donut mastopexy technique for repair of partial mastec-tomy defects is best limited to small defects in which the tissue can be safely removed through a periareolar incision.

A periareolar ‘donut’ of skin is removed, and the defect is closed with a purse-string suture after meticulous closure of the parenchymal defect in layers. Deep and superficial sutures in the skin around the nipple are imperative to avoid flattening of the nipple. The patient must be reas-sured that the ‘gathering’ of skin around the nipple will settle over several weeks.

Reduction mammaplasty techniques Rationale

Macromastia has traditionally been considered a relative contraindication to partial mastectomy, primarily because of concerns that it is difficult to achieve radiation dose homogeneity in women with large breasts ²⁹ and because the risk of moderate to severe late radiation changes is increased in women with large breasts owing to an increase in breast fibrosis ³⁰ ^– ³² . In women with macromastia, per-forming breast reduction in conjunction with the onco-logical surgery permits BCT and produces excellent cosmetic results ³³ ^– ³⁵ ( Figures 13.8 , 13.9 and 13.10 ). The reduction surgery permits better dosimetry and reduces the number of ‘hot spots’ and the volume of the lung and thoracic struc-tures in the irradiation field. Reduction mammaplasty also relieves symptomatic macromastia, a disease complex that manifests with shoulder grooving, cervical and thoracic strain, and mastodynia and can be considered to improve breast health ³⁷ ^– ⁴¹ . Reduction mammaplasty applications to partial mastectomy are quite favorable reconstructive options in the obese and large breasted patients as these women often have limited traditional reconstructive options after total mastectomy. In large breasted women with a small abdominal pannus, autologous tissue is insuf-ficient to create a large breast. In obese women autologous tissue options carry a high, often prohibitive, complication rate. Breast implants are inadequate in both volume and shape to replicate a large native breast.

Other potential benefits of reduction mammaplasty for oncoplastic breast surgery are reduction in the risk of cancer of the contralateral breast. Although the efficacy of

reduction mammaplasty as a risk reduction procedure is controversial, this premise has some support ³⁹ ^, ⁴² ^, ⁴³ . While the incidence of finding an occult cancer in a routine breast reduction specimen is low (0.16–0.5%), the risk may be higher when a contralateral breast cancer has already been diagnosed ⁴⁴ . This highlights the need for bilateral diag-nostic mammography prior to any surgical interventions.

Patient selection and counseling

Successful use of the reduction mammaplasty approach to oncoplastic breast surgery requires that the affected breast be large enough to permit reduction without deformation and that the patient be amenable to an operation on the contralateral breast. Patients must be counseled preopera-tively about the potential complications, which can affect the contralateral breast as well as the index breast and include unfavorable scarring, temporary or permanent loss of nip-ple sensibility, and poor healing resulting in loss of tissue, potentially including loss of the nipple-areolar complex.

When a reduction mammaplasty approach is being con-sidered, the expected oncological and esthetic outcomes must be carefully considered. If there are concerns about obtaining negative margins or about significant distortion of the breast, remote flaps or conversion to a total mastec-tomy need to be carefully considered. These concerns are most common in small breasted patients. In patients with macromastia, the volume of the partial mastectomy

Reduction mammaplasty for BCT: tumor location and breast pedicle

Inferior

Figure 13.8 Application of the reduction mammaplasty approach in partial mastectomy by tumor location. Adjusting the neurovascular base of the breast tissue used for reconstruction of the breast may permit application of the reduction mammaplasty technique with tumors in essentially any location in the breast. As tumors are primarily focused in the upper outer quadrant of the breast, a superior or superomedial flap is the most commonly utilized for a reduction approach, and is quite reliable due to the robust vascular supply afforded by the medially based perforating vessels from the internal mammary system. Adapted from reference 36 .

specimen is most often significantly smaller than the vol-ume of tissue removed for breast reduction. Provided that preoperative assessment is careful, it is usually possible to achieve adequate margins with a reduction mammaplasty approach.

The effects of radiation on the breast after partial mas-tectomy and reduction mammaplasty are difficult to antic-ipate. In the early postoperative setting, edema and residual seroma pockets give the breast a quite favorable appear-ance that may be different from the final outcome at 18–36 months after radiation therapy. Some authors sug-gest ‘overreducing’ the contralateral breast to account for the likely fibrosis and shrinkage of the index breast in response to irradiation. However, this approach is not universally endorsed given the highly variable and unpredictable

outcome of radiotherapy. The patient should be advised preoperatively that an additional small balancing proce-dure may be required on the non-irradiated contralateral breast. Breast reduction and adjustment of the irradiated breast has been reported but is associated with a high risk of complications and should be avoided. The reports of successful use of this approach noted poor wound healing, tissue loss and nipple compromise ⁴⁵ ^, ⁴⁶ .

Technical aspects

Several principles must be followed to achieve the best possible esthetic results of reduction mammaplasty. It is imperative that both the parenchyma and the skin of the index breast be considered. Unless the patient has true

(a) (b)

Figure 13.9 Immediate reduction mammaplasty for reconstruction after partial mastectomy. (a) The patient had a small inferior defect after partial mastectomy, ideally suited to a reduction mammaplasty approach. (b) The defect was corrected with medial and lateral advancement of breast flaps on the index breast and a contralateral mastopexy. There was minimal volume change in the breasts and excellent symmetry of the breasts. (c) and (d) The patient's result is demonstrated 3 months postoperatively. Case figures reproduced from reference 26 , with permission.

macromastia, resection of more than 30% of the breast will usually result in a defect that is unattractive. When such extensive resection is anticipated, mastectomy and recon-struction may be a better option. To achieve symmetry, similar reduction techniques and scar placement must be used for the index breast and the contralateral breast.

This is best achieved if the contralateral breast is shaped after the oncological surgery on the index breast has been completed.

The reduction mammaplasty approach to oncoplastic breast surgery is based on standard techniques of breast reduction. Both the skin envelope and the breast mound must be tailored such that an esthetic breast shape results without compromise of the skin or parenchymal vascular supply. The vascular pedicle of the breast mound, which supports the parenchyma and nipple-areolar complex, has traditionally been based inferiorly, centrally, and/or superomedially ⁴⁷ ^– ⁴⁹ . The ultimate shape of the breast may be considered to result from the parenchyma as well as the skin which in a ‘Wise pattern’ approach may be consid-ered to function as a ‘brassiere’ to help shape the breast.

The traditional basis of surgical technique for reduc-tion mammaplasty has been the combinareduc-tion of a

vertical and a horizontal skin excision, known as a Wise pattern ⁵⁰ or ‘inverted T’ incision. This approach is reliable, easily learned and permits control of breast shape and size intraoperatively.

Hypertrophic scars and long-term ‘bottoming out’ of the breast in which the parenchyma of the breast descends inferiorly resulting in an elongated distance from the inframammary fold and an upward pointing ‘stargazing’

nipple have prompted more attention to short scar/vertical approaches for mammaplasty. These techniques use more aggressive shaping of the parenchyma and minimize or eliminate the horizontal component of the scar in an effort to limit breast scarring and maximize breast projection ⁵¹ ^– ⁵⁶ . Either the short scar or the inverted T scar can be used, with the vascular pedicle adjusted to the tumor location as nicely delineated by Losken ³⁶ . As tumors more commonly occur in the lateral quadrants, medially based pedicles, which derive their vascular supply from the internal mam-mary perforators, are very useful.

Successful reduction mammaplasty requires extensive and accurate intraoperative processing of margins. The need for re-excision because a positive margin is discovered on the final pathology review is not only oncologically significant

(d)

(e)

(a) (b) (c)

(f)

Figure 13.10 Immediate reduction mammaplasty for partial mastectomy. This patient underwent partial mastectomy for a lower outer quadrant tumor. A medially based breast flap and contralateral reduction mammaplasty for symmetry were employed for immediate reconstruction. This technique is well suited to patients with baseline macromastia who desire smaller breasts. (a) Preoperative needle localization bracketing the area to be resected. (b) and (c) Preoperative markings of critical breast landmarks, including the proposed new nipple point and paramedian line of the breast (where the inframammary fold intersects the nipple line) will help with ultimate symmetry of the two sides. (d) Extensive intraoperative processing of surgical margins is critical to the success of this approach, and the reconstructive

‘reassembly’ the breast is best deferred until all margins are confirmed. (e) A total of 256 g of breast tissue was removed, resulting in a central and lateral deficit. (f) The patient had an uneventful postoperative course, with preservation of the nipple sensibility bilaterally.

Early postoperative result 6 weeks after reduction mammaplasty utilizing a modified vertical reduction mammaplasty approach.

but also can seriously compromise the esthetic outcome.

Therefore, every attempt should be made to avoid the need for re-excision. Some authors suggest that in light of these considerations, the contralateral breast reduction should be deferred until the final pathology review on the index breast is complete. However, most patients prefer to undergo immediate reduction of the contralateral breast to minimize the number of operative procedures, and this has been our standard approach except when there are extenuating circumstances. Patients must be counseled pre-operatively that if there are questions about margin status or if the tumor is more extensive than initially suspected, contralateral breast reduction might be delayed or an alter-nate reconstructive approach might be needed. In cases in which margins are a concern – for example, in patients with large tumors managed with neoadjuvant chemotherapy – reduction mammaplasty can be performed after the final pathology review but prior to radiation therapy. As performing the mammaplasty as a separate procedure can delay the delivery of radiation, it is important to discuss this possibility with all members of the multidisciplinary breast team.

Use of regional and distant flaps

Regional or distant flaps can be used for oncoplastic breast surgery if the amount of breast tissue remaining after the oncological resection is not sufficient for tissue rearrange-ment. In patients with an established breast deformity after BCT, vascularized autologous flaps are the mainstay for re-establishment of a normal breast form because of the extraordinarily high complication rate of implant-based reconstruction of irradiated breasts. Autologous tissue pro-vides an unparalleled match for the native breast, remains stable over time, and in some circumstances can obviate the need for significant contralateral breast surgery to achieve symmetry. The potential disadvantages of vascu-larized flaps are related to the donor site: these flaps involve an additional scar and can result in morbidity as a result of flap harvest, including contour deformity, pain, dysesthe-sias, and even hernia formation. A wide variety of flaps are available for reconstruction, but those from the back, lower abdomen and buttock are most often used for breast recon-struction because they are optimal in terms of the amount of tissue available for reconstruction and functional and esthetic donor-site issues.

Flap choices were traditionally considered in order from simplest to most complex. Current knowledge, however, favors an approach in which the most appropriate recon-structive option is considered first even if this option is not the simplest. In general, the most appropriate flap is the one that results in the best outcomes in terms of repair of the defect and minimization of donor site morbidity.

It should be noted that repair of partial mastectomy defects using autologous tissue from the abdomen or but-tocks limits the patient's future breast reconstruction options.

In the event that the patient later requires total mastectomy and total breast reconstruction, the abdominal and but-tock tissues will not be available.

Latissimus dorsi flap

The latissimus dorsi (LD) myocutaneous flap, based on the thoracodorsal vessels, has long been a mainstay of breast reconstruction after partial mastectomy ( Figure 13.11 ).

The LD flap is robust, reliable and relatively easy to har-vest and has been utilized for reconstructive purposes as a pedicled flap for more than 100 years ⁵⁷ ^, ⁵⁸ . LD flaps are often employed to repair defects in the lateral quadrants and the upper inner pole and are especially useful for repair of defects in small breasts, where even a relatively small-volume resection may result in distortion of the nipple posi-tion and loss of breast contour and volume.

Compared with delayed defect repair, immediate defect repair with the LD flap is technically easier, is associated with a lower complication rate, and potentially involves fewer operative steps. The difficulty with the immediate approach is that it is difficult to predict the degree of LD

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