Symmetrization using submuscular implants to achieve lasting results in breast reconstruction

Introduction: In breast reconstruction with implants, ptosis is uncommon over time, in contrast to symmetrization mammoplasty without implants, which causes premature recurrence of breast asymmetry. The objective of this study was to describe the procedure and results of contralateral symmetrization mammoplasty with the use of submuscular implants. Methods: A total of 18 cases of symmetrization mammoplasty with submuscular implants performed over a 2-year period were retrospectively studied. Results: The most common comorbidity was obesity (p = 0.007). Obese patients had a higher volume of resected breast tissue (p = 0.0013). The mean follow-up was 13 months. The reoperation rate was 5.5% (1 case) for pseudoptosis. There were no implant infections. Complications included partial necrosis of the nipple-areola complex in 1 case, superficial wound dehiscence in 1 case, seroma in 3 cases, and moderate pain in 3 cases. Conclusion: Contralateral symmetrization mammoplasty with submuscular implants, associated with adequate emptying of breast tissue, provided long-lasting results with a low rate of complications, minimizing the sequelae of mastectomy. ■ ABSTRACT


INTRODUCTION
According to estimates by the National Cancer Institute in Brazil, approximately 57,120 women were diagnosed with breast cancer in 2014 1 .The standard treatment for non-metastatic breast cancer is surgery, with or without radiotherapy and/or chemotherapy in accordance with the cancer stage.Breast reconstruction preserves self-image while minimizing the psychosocial sequelae resulting from mastectomy.This results in a positive impact on the quality of life 2 and makes the procedure more accepted and requested by younger patients 3 , in whom breast expanders and implants have been increasingly used 4 .
Regardless of the technique, there will almost always be asymmetry between the breasts after unilateral breast reconstruction, especially when a silicone prosthesis is used in only one breast.Therefore, breast symmetrization surgery is, almost always, an inevitable indication.
All patients signed an Informed Consent Form and the study followed the guidelines of the Declaration of Helsinki, pending approval by an ethics committee.

Statistical analysis
The data were collected and stored in a database created with Microsoft Excel, which was also used for statistical analysis and construction of graphs and tables.The distribution frequencies of the categorical and ordinal variables collected from medical records and clinical-surgical observations were analyzed.All data are presented in the tables as measures ± standard deviation or absolute values (percentage).The Kolmogorov-Smirnov test was used to evaluate the normality of the quantitative variables.Continuous variables were analyzed with Student's t-test.Categorical variables were analyzed with the chi-square or Fisher's exact test when appropriate.A p value was considered significant when less than 0.05.The analysis was performed with SPSS software for Macintosh version 20.0 (SPSS, Chicago, IL, USA).

Description of the operative technique
During a mastectomy, the excess skin and degree of ptosis in the cancerous breast were evaluated and, when necessary, Pitanguy-type or similar marking, was performed to remove excess skin.In the second symmetrization phase in the contralateral breast, we followed the same skin marking as for correction of ptosis and removed adequate mammary tissue to mimic the mastectomy, but preserved the vascularization of the nipple-areola complex (NAC) and the contour of the breast for adequate coverage of the implant to be placed in the submuscular plane.In the mastectomy area, we performed fat grafting following the same concept (Figure 2). of the rectus abdominis, but with preservation of the adherence of the muscle to the fat pad for coverage and non-exposure of the implant at the lower pole, enabling lower anatomical positioning in relation to the mammary groove.This same concept was used in the placement of the expander in immediate reconstruction (Figure 3).The placement of the submuscular implant follows a previously published approach 6 : with access between the fibers of the pectoralis major muscle and preparation of a partial submuscular pocket, through the inferior disinsertion of the pectoral muscle by incision and release of the connection between the muscle and the fascia Another important point is the disinsertion of muscle in the mid-sternal region up to the level of the 4 th intercostal space, minimizing the inconvenience resulting from mobilization of the implant with muscle contraction 7 .The total closure of the fibers and global coverage of the implant in the central portion may not be possible, depending on the size of the implant, and one should only perform approximation of the fibers without compromising the stability of the implant (Figure 4).
Elevation of the NAC is performed with a superior pedicle or medial pedicle technique, depending on the case.Tall, textured, round implants are used; the implant pocket is irrigated with 500 ml of saline solution plus 1 g of cefazolin.Tubular drains are placed routinely, and remain until drainage is less than 50 ml/24 h.

RESULTS
Symmetrization with submuscular implantation was performed in 18 patients (Figures 5, 6, 7, and 8).Seventeen cases underwent reconstructed breast symmetrization with expanders and 1 case was reconstructed with a latissimus dorsi muscle flap and prosthesis.Ten patients, about 56%, underwent adjuvant

A B
radiotherapy.The age ranged from 32 to 77 years, with a mean of 52 years.The most frequent comorbidity was obesity in 8 cases (p = 0.007).Hypercholesterolemia was present in 7 cases, hypertension in 4, diabetes in 3, and arrhythmia, depression, and hypothyroidism in 1 case each.Some patients had combined comorbidities, e.g., 1 patient with NAC necrosis had diabetes, hypertension, hypercholesterolemia, and obesity.No patient reported smoking (Figure 9).Three patients had breasts with grade I ptosis, 2 had grade II ptosis, and 13 had grade III ptosis (Figure 10).The resection of breast tissue ranged from 177 to 1,152 g, with an average of 500 g.Obese women had a greater volume of breast tissue removed (p = 0.013).The 18 symmetrization procedures were performed with round, high-profile textured implants, with volumes ranging from 175 to 275 cm 3 .The time from breast reconstruction until symmetrization surgery ranged from 3 to 50 months, with an average of 10 months.
Follow-up ranged from 4 to 25 months, with an average of 13 months.A new mastopexy was required in a 77-year-old patient for pseudoptosis after 12 months of follow-up (Figure 11).There were no implant infections.One patient had vascular distress and partial necrosis (20%) of the NAC after elevation with a medial pedicle, without need for surgical reintervention, and with resolution by second intention healing (Figure 12).One patient had superficial dehiscence of the vertical mammoplasty scar, without exposure of the implant, and with resolution by secondary intention healing.Three patients developed seromas, with spontaneous resolution within 45 days.Three patients reported moderate pain in the symmetrized breast (Table 1).

DISCUSSION
After mastectomy, reconstruction with expanders or permanent submuscular prostheses tends to result in a breast cone without ptosis and with a shape similar to the implant, because of resection of breast tissue and sagging of subcutaneous tissue.Despite the availability of different techniques, we considered three major points as a basis for the choice of symmetrization method.
The first is the use of a contralateral breast prosthesis; the second is the placement of a prosthesis in the submuscular plane, similar to that in the reconstructed breast; and the third is the proper emptying of tissue in the remaining breast to minimize future ptosis and the development of a double-bubble deformity 8 .
In this sense, mastopexy or reductive mammoplasty alone, in which a good part of the breast tissue is preserved, would not be adequate, due to the high rate of recurrence of ptosis and asymmetry.In addition, the surgical tactic of breast emptying may have the benefit of exploring the contralateral breast and diagnosing a hidden cancer in up to 10 to 15% of cases 9 .Moreover, according to Spear et al. 10 , prophylactic subcutaneous adenomastectomy can be indicated in patients over 65 years old and in those with mutation in BRCA genes 1 and 2.
The results of this study suggest that the described technique can also be used in patients with obesity, which is the most frequent comorbidity (p = 0.007); these patients also had a larger resected breast volume (p = 0.0013).Thus, gigantomastia and grade III ptosis would not be contraindications for the technique, which in this study showed low reoperation rates (5.5%), varying only in the resulting scar and the NAC elevation technique.We believe it is important to continue the study to strengthen the results.
In this case, fat grafting was an important step in symmetrization.It was used to model the new breast, improve the thickness of subcutaneous tissue, and to minimize the complications of radiodermatitis and inelasticity of the skin resulting from radiotherapy.Ten patients who underwent radiotherapy benefited from this procedure without increasing locoregional recurrence 11 .
We irrigate the surgical area with saline solution mixed with antibiotic, although studies have demonstrated no statistical difference when compared to irrigation with saline solution alone, with regard to the rate of infection and capsular contracture 12 .These complications were more evident in patients with comorbidities 13 , and may be subject of a future study.

CONCLUSION
Contralateral symmetrization mammoplasty with the use of submuscular implants, after adequate emptying of breast tissue, provided long-lasting results, with a low

Figure 1 .
Figure 1.A: Reconstruction of left breast with expander and asymmetry arising from contralateral breast ptosis; B: Recurrence of breast asymmetry at 9 months after mastopexy with subglandular implant.

Figure 2 .
Figure 2. A: Preoperative aspect of patient with left breast cancer associated with grade III ptosis; B: At 6 months after breast reconstruction with a submuscular expander and Pitanguy-type marking for correction of excess skin; C: At three months after mammoplasty with submuscular implant.

Figure 3 .
Figure 3. Schematic drawing of the partial submuscular implant with coverage in the lower pole by preservation of the fat pad (B) and section of the connection of the pectoral muscle (C) to the rectus abdominis fascia (A), thus achieving a better implant position in relation to the mammary groove.

Figure 4 .
Figure 4. A: Preparation of the submuscular pocket via mammoplasty with disinsertion of muscle fibers in the inferomedial portion; B: Implant positioned with partial closing of muscle fibers and preservation of the fat pad in the lower pole for coverage of the implant.

Figure 5 .Figure 6 .Figure 8 .Figure 9 .
Figure 5. A: Preoperative aspect of left breast cancer; B: Seven months after left breast reconstruction with submuscular expander; C: Three months after postoperative exchange of expander with a prosthesis and symmetrization with submuscular implant.

Figure 7 .
Figure 7. A: Postoperative reconstruction of right breast with submuscular expander, followed by adjuvant radiotherapy; B: 5 months after expander replacement with a prosthesis associated with fat grafting and contralateral breast symmetrization with submuscular implant; C: 11 months after new fat grafting in the right breast and reconstruction of the nipple-areola complex without evidence of ptosis in the symmetrized breast.

Figure 10 .Figure 11 .
Figure10.This graph demonstrates that most patients had severe ptosis of the breast, which was not a contraindication for the technique.

Figure 12 .
Figure 12.A: Postoperative appearance of left breast reconstruction with submuscular expander followed by adjuvant radiotherapy; B: 3 months after expander exchange with a prosthesis combined with fat grafting and right breast symmetrization with submuscular prosthesis, complicated by partial necrosis of right nipple-areola complex, and resolution by second intention healing.

Table 1 .
Complications found in this study and the low reoperation rate (5.5%).