# Postoperative Outcomes of Pre-Pectoral Versus Sub-Pectoral Implant Immediate Breast Reconstruction

Gilles Houvenaeghel, Marie Bannier, Catherine Bouteille, Camille Tallet, Laura Sabiani, Axelle Charavil, Arthur Bertrand, Aurore van Troy, Max Buttarelli, Charlène Teyssandier, et al.

► To cite this version:

Gilles Houvenaeghel, Marie Bannier, Catherine Bouteille, Camille Tallet, Laura Sabiani, et al. Postoperative Outcomes of Pre-Pectoral Versus Sub-Pectoral Implant Immediate Breast Reconstruction. Cancers, 2024, 16 (6), pp.1129. 10.3390/cancers16061129. [https://doi.org/10.3390/cancers16061129](https://doi.org/10.3390/cancers16061129)

HAL Id: hal-05141530

https://amu.hal.science/hal-05141530v1

Submitted on 7 Jul 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
<figure><img src="image_2.png" /></figure>

Article

# Postoperative Outcomes of Pre-Pectoral Versus Sub-Pectoral Implant Immediate Breast Reconstruction

Gilles Houvenaeghel <fnref n="1" />,*, Marie Bannier <fnref n="2" />, Catherine Bouteille <fnref n="2" />, Camille Tallet <fnref n="3" />, Laura Sabiani <fnref n="2" />, Axelle Charavil <fnref n="2" />, Arthur Bertrand <fnref n="2" />, Aurore Van Troy <fnref n="2" />, Max Buttarelli <fnref n="2" />, Charlène Teyssandier <fnref n="3" />, Agnès Tallet <fnref n="3" />, Alexandre de Nonneville <fnref n="4" /> and Monique Cohen <fnref n="2" />

<figure><img src="image_3.png" /></figure>

check for
updates

**Citation:** Houvenaeghel, G.; Bannier, M.; Bouteille, C.; Tallet, C.; Sabiani, L.; Charavil, A.; Bertrand, A.; Van Troy, A.; Buttarelli, M.; Teyssandier, C.; et al. Postoperative Outcomes of Pre-Pectoral Versus Sub-Pectoral Implant Immediate Breast Reconstruction. *Cancers* **2024**, *16*, 1129. https://doi.org/10.3390/cancers16061129

Academic Editor: Kwok-Leung Cheung

Received: 22 February 2024

Revised: 6 March 2024

Accepted: 8 March 2024

Published: 12 March 2024

<figure><img src="image_4.png" /></figure>

**Copyright:** © 2024 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).

**Simple Summary:** A rapid evolution of IBR techniques has been reported, including prepectoral implant immediate breast reconstruction (IBR) with a mesh. In a monocentric cohort, subpectoral implant IBR was performed in 529 mastectomies (62.0%) and prepectoral implant IBR in 324 (38.0%), with a significant increase in prepectoral placement in recent years. Mesh was used in 176 prepectoral placements (54.3%). Any grade of complication was reported in 147 mastectomies (17.2%), with a significantly higher rate for prepectoral implant IBR, with no significant difference for grade 2–3 complications. Regression analysis showed that prepectoral implant was not significantly associated with any grade of complication, or with grade 2–3 complications. Prepectoral implant-IBR was associated with significantly shorter operative times. Costs above the median were significantly associated with subpectoral placement and mesh use. Prepectoral implantation can be considered a good and safe technique. However, patient selection may be necessary and we propose a complication risk score to aid decision-making.

**Abstract:** Introduction: Immediate breast reconstruction (IBR) techniques are rapidly evolving. We compared the results from a single-center implant IBR cohort between subpectoral and prepectoral implants with and without a mesh. Methods: We analyzed all complications and grade 2-3 complications, the implant loss rate, the surgery time, the length of stay (LOS), patient satisfaction, the interval time to adjuvant therapy and cost, with a comparison between subpectoral and prepectoral implant IBR. Results: Subpectoral implant IBR was carried out in 529 mastectomies (62.0%) and prepectoral in 324, with a significant increase in prepectoral placement in recent years. Mesh was used in 176 prepectoral placements (54.3%). Any grade of complication was reported in 147 mastectomies (17.2%), with a significantly higher rate for prepectoral implant IBR (p = 0.036). Regression analysis showed that prepectoral implant was not significantly associated with any grade of complication or with grade 2-3 complications. Prepectoral implant IBR was associated with a significantly shorter operative time and lower LOS. Grade 2-3 complications were significantly associated with lower satisfaction. Higher costs were significantly associated with the subpectoral placement and mesh. A complication rate predictive score identified five groups with a significant increase in grade 2-3 complications. Conclusions: Prepectoral-M-IBR increased over time with no difference in complication rates compared to subpectoral-M-IBR. Prepectoral implant placement can be considered a safe technique.

<footnote n="1">¹ Aix-Marseille University, CNRS (National Center of Scientific Research), INSERM (National Institute of Health and Medical Research), Paoli-Calmettes Institute, Department of Surgical Oncology, CRCM (Research Cancer Centre of Marseille), 13009 Marseille, France</footnote>

<footnote n="2">² Paoli-Calmettes Institute, Department of Surgical Oncology, CRCM (Research Cancer Centre of Marseille), 13009 Marseille, France; bannierm@ipc.unicancer.fr (M.B.); laurentc2@ipc.unicancer.fr (C.B.); sabianil@ipc.unicancer.fr (L.S.); charavila@ipc.unicancer.fr (A.C.); bertranda@ipc.unicancer.fr (A.B.); vantroya@ipc.unicancer.fr (A.V.T.); buttarellim@ipc.unicancer.fr (M.B.); cohenm@ipc.unicancer.fr (M.C.)</footnote>

<footnote n="3">³ Paoli-Calmettes Institute, Department of Radiotherapy, CRCM (Research Cancer Centre of Marseille), 13009 Marseille, France; camille.tallet@etu.univ-amu.fr (C.T.); charlene.teyssandier@etu.univ-amu.fr (C.T.); richarda@ipc.unicancer.fr (A.T.)</footnote>

<footnote n="4">⁴ Aix-Marseille University, CNRS (National Center of Scientific Research), INSERM (National Institute of Health and Medical Research), Paoli-Calmettes Institute, Department of Medical Oncology, CRCM (Research Cancer Centre of Marseille), 13009 Marseille, France; tassindenonnevillea@ipc.unicancer.fr</footnote>

<footnote>* Correspondence: houvenaeghelg@ipc.unicancer.fr</footnote>
**Keywords:** breast cancer; reconstruction; prepectoral implant; post-surgical outcome; satisfaction; cost

# 1. Introduction

Breast cancer (BC) is the most common cancer and is the leading cause of cancer death in women, with 2.26 million new cases and 685.000 deaths expected in 2020 [1]. Although oncoplastic surgery has expanded the options for breast conservative surgery [2–5], mastectomy remains a common surgical option, ranging from 12 to 40%, as reported in the literature [6–11].

Many studies have reported the beneficial effects of immediate breast reconstruction (IBR) on patients’ quality of life without compromising oncological outcomes or time to adjuvant therapies. As a result, the incidence of IBR has increased in recent decades. It was reported to be 9.6% in China in 2018 [12], 14% between 2011 and 2016 in France (INCa report), and increased from 10% at the beginning of the 2000s to 23.3% in the year 2014 in the UK [13]. In our cancer center, the rate assessed between 2008 and 2014 was 16.1% (similar to that reported at the French level) and increased to 40.5% between 2016 and 2020 [14]. A large multicenter French cohort confirmed this trend, with a multivariate analysis showing odd ratios (ORs) of 2 between 2007 and 2009, and 2.5 between 2010 and 2019 compared with the previous periods 1999–2003 and 2004–2006 [15,16]. In the United States, breast reconstruction rates (IBR and delayed breast reconstruction) were 45% in 2010 and 54% in 2015.

Implant-based mastectomy IBR (implant-M-IBR) has long been the most common procedure [12,13,17,18]. However, in recent years, nipple-sparing mastectomy (NSM) has been increasingly used for both prophylactic mastectomy [19], primary BC [20–24] and local recurrence [25], offering better aesthetic results than skin-sparing mastectomy (SSM) [26–32]. IBR techniques rapidly evolved with the advent of prepectoral implant IBR [33,34], with or without a mesh, and robotic mastectomy IBR [35–38]. In addition, different types of mesh, acellular dermal matrices, synthetic absorbable matrices or non-absorbable matrices have been used [39–43].

The aim of this study was to report the results of a large single-center cohort of implant M-IBR in terms of postoperative complications, patient satisfaction and costs according to subpectoral or prepectoral implants with or without meshes. A predictive score for postoperative complications was established.

# 2. Materials and Methods

All implant M-IBR between January 2019 and November 2023 were prospectively included in the institutional database (study: M-IBR-PPRP-IPC 2022–014) and we retrospectively analyzed the data. The main prospectively recorded characteristics were as follows: age, year of surgery, reason for mastectomy, type of mastectomy, use of mesh (resorbable synthetic mesh TIGR Matrix® Novus Scientific, Uppsala, Sweden), implant type, ASA status (American Society of Anesthesiologists), body mass index (BMI), smoking status, diabetes, previous surgery, previous radiotherapy, neoadjuvant chemotherapy (NAC), breast cup size, implant volume, mastectomy weight, surgical incisions, axillary surgery, adjuvant therapies and surgeons.

We analyzed the total postoperative complication rate and grade 2–3 complication according to the Clavien Dindo classification [44] (occurring within 90 days of surgery), complication type, re-operation rate, implant loss rate, duration of surgery (operative time between skin incision and skin closure), length of postoperative stay (LOS) (from day of surgery to discharge), patient satisfaction (very good, good, medium, bad and failure), time to adjuvant therapy and costs. For patients with bilateral mastectomies, analyses were performed on two procedures, and the duration of surgery was halved. Per-operative antimicrobial prophylaxis was systematically given to all patients with implant M-IBR.

The results were compared between subpectoral and prepectoral IBR in univariate and multivariate analyses. The choice of implant position (subpectoral or prepectoral) and
the use of a mesh was at the surgeon's discretion. If the mastectomy compartment was very large, the prepectoral implant was held in place by absorbable sutures between the outer edge of the pectoralis major muscle and the outer subcutaneous tissue, without the use of a mesh. Locoregional anesthesia with a pectoral block was systematically performed.

The cost of the initial procedure was assessed by adding the cost of the implant (400 Euros), the number of hospital days (1495.69 Euros per day), the operating room time (402.54 Euros per hour) and the mesh (1390 Euros for 20 × 30 cm). The operating room occupancy time was determined by the duration of surgery and 90 min for patient set-up, anesthesia, local anesthesia and awakening from anesthesia.

### Statistics

Quantitative criteria were analyzed using median, mean and 95% confidence interval (CI). Comparisons were determined using the Chi-2 test for qualitative criteria and the t-test for quantitative criteria. Factors significantly associated with the criteria analyzed were determined by a binary logistic regression adjusted for significant variables identified using univariate analysis. For binary logistic regression, quantitative criteria were divided into several categories: mastectomy weight > or ≤300 gr, BMI ≤ 24.9, 25 to 29.9, ≥30. An odds ratio (OR) with a 95% CI was used as the effective measure.

We calculated predictive scores for [1] any complication and [2] grade 2-3 complications using the ORs of significant factors derived from the logistic regression. The performance of these scores was analyzed by calculating the area under the curve (AUC). Statistical significance was set at *p* ≤ 0.05. Analyses were performed using SPSS version 16.0 (SPSS Inc., Chicago, IL, USA).

## 3. Results

From January 2019 to November 2023, 2002 mastectomies were performed including 900 IBR (44.96%): 853 implant-M-IBR (42.6%) and 47 other procedures M-IBR. The implant M-IBR rates were 47.9%, 29.4%, 40.0%, 44.5% and 55.1% in the years 2019, 2020, 2021, 2022 and 2023, respectively.

Subpectoral implant M-IBR was performed in 529 mastectomies (62.0%) and prepectoral implant M-IBR in 324 (38.0%), with a significant increase in prepectoral placement according to the consecutive years: 3.1%, 5.5%, 40.1%, 63.5% and 61.7% in years 2019, 2020, 2021, 2022 and 2023, respectively (*p* < 0.0001).

Bilateral mastectomies were performed in 85 patients (170 mastectomies) with no significant difference between subpectoral and prepectoral implant M-IBR: 108 bilateral mastectomies for prophylactic purposes, 61 for primary BC and 1 for local recurrence (8 patients with mastectomy for primary BC on one side and prophylactic on the other side; 1 patient with mastectomy for primary BC on one side and local recurrence on the other side).

A mesh was concomitantly used in 9 subpectoral mastectomies (1.7%) and 176 prepectoral mastectomies (54.3%) with significantly different rates according to the year: 20.0%, 14.3%, 92.0%, 85.0% and 6.7% for prepectoral implants in years 2019, 2020, 2021, 2022 and 2023, respectively (*p* < 0.0001).

Patient characteristics according to subpectoral or prepectoral implant M-IBR are shown in Table 1. The type of mastectomy, previous ipsilateral surgery, neo-adjuvant chemotherapy, surgical incisions and surgeons involved were significantly different between the two groups. We could observe that within the same team of breast surgeons, the use of prepectoral implants widely varied, ranging from 0% to 60% (surgeon 1 placed 90 prepectoral implants out of 150 implantations). Median values and 95%CI are shown in Table 2, with no significant difference in age, BMI or mastectomy weight, but there is a significant difference in implant volume (higher volume in the prepectoral position) (*p* = 0.003).
<table><caption>**Table 1.** Characteristics of patients according to sub-pectoral or pre-pectoral implant M-IBR.</caption><thead><tr><th rowspan="2"></th><th rowspan="2"></th><th colspan="2">Sub Pectoral</th><th colspan="2">Pre Pectoral</th><th rowspan="2">Chi2<br/>p</th><th colspan="2">Total</th></tr><tr><th>Nb</th><th>%</th><th>Nb</th><th>%</th><th>Nb</th><th>%</th></tr></thead><tbody><tr><td rowspan="3">Indication</td><td>Primary BC</td><td>387</td><td>73.2</td><td>246</td><td>75.9</td><td rowspan="3">0.652</td><td>633</td><td>74.2</td></tr><tr><td>Local recurrence</td><td>44</td><td>8.3</td><td>23</td><td>7.1</td><td>67</td><td>7.9</td></tr><tr><td>Prophylactic</td><td>98</td><td>18.5</td><td>55</td><td>17.0</td><td>153</td><td>17.9</td></tr><tr><td rowspan="2">Mesh</td><td>No</td><td>520</td><td>98.3</td><td>148</td><td>45.7</td><td rowspan="2">&lt;0.0001</td><td>668</td><td>78.3</td></tr><tr><td>Yes</td><td>9</td><td>1.7</td><td>176</td><td>54.3</td><td>185</td><td>21.7</td></tr><tr><td rowspan="3">Mastectomy</td><td>NSM</td><td>236</td><td>44.6</td><td>215</td><td>66.4</td><td rowspan="3">&lt;0.0001</td><td>451</td><td>52.9</td></tr><tr><td>SSM</td><td>290</td><td>54.8</td><td>107</td><td>33.0</td><td>397</td><td>46.5</td></tr><tr><td>standard</td><td>3</td><td>0.6</td><td>2</td><td>0.6</td><td>5</td><td>0.6</td></tr><tr><td rowspan="2">Type<br/>reconstruction</td><td>definitive<br/>implant</td><td>501</td><td>94.7</td><td>324</td><td>100</td><td rowspan="2">&lt;0.0001</td><td>824</td><td>96.6</td></tr><tr><td>expander</td><td>28</td><td>5.3</td><td>0</td><td>0</td><td>28</td><td>3.3</td></tr><tr><td rowspan="2">bilateral<br/>mastectomy</td><td>No</td><td>428</td><td>80.9</td><td>255</td><td>78.7</td><td rowspan="2">0.243</td><td>683</td><td>78.7</td></tr><tr><td>Yes</td><td>101</td><td>19.1</td><td>69</td><td>21.3</td><td>170</td><td>21.3</td></tr><tr><td rowspan="3">ASA status</td><td>1</td><td>247</td><td>46.7</td><td>152</td><td>46.9</td><td rowspan="3">0.728</td><td>399</td><td>46.8</td></tr><tr><td>2</td><td>273</td><td>51.6</td><td>164</td><td>50.6</td><td>437</td><td>51.2</td></tr><tr><td>3</td><td>9</td><td>1.7</td><td>8</td><td>2.5</td><td>17</td><td>2.0</td></tr><tr><td rowspan="3">Breast cup size</td><td>A-B</td><td>278</td><td>52.6</td><td>177</td><td>54.6</td><td rowspan="3">0.782</td><td>455</td><td>53.3</td></tr><tr><td>C</td><td>173</td><td>32.7</td><td>104</td><td>32.1</td><td>277</td><td>32.5</td></tr><tr><td>&gt;C</td><td>78</td><td>14.7</td><td>43</td><td>13.3</td><td>121</td><td>14.2</td></tr><tr><td rowspan="2">Tobacco</td><td>No</td><td>437</td><td>82.6</td><td>268</td><td>82.7</td><td rowspan="2">0.968</td><td>705</td><td>82.6</td></tr><tr><td>Yes</td><td>92</td><td>17.4</td><td>56</td><td>17.3</td><td>148</td><td>17.4</td></tr><tr><td rowspan="2">Diabetes</td><td>No</td><td>525</td><td>99.2</td><td>321</td><td>99.1</td><td rowspan="2">0.536*</td><td>846</td><td>99.2</td></tr><tr><td>Yes</td><td>4</td><td>0.8</td><td>3</td><td>0.9</td><td>7</td><td>0.8</td></tr><tr><td rowspan="2">Previous<br/>surgery</td><td>No</td><td>331</td><td>62.6</td><td>238</td><td>73.5</td><td rowspan="2">0.001</td><td>569</td><td>66.7</td></tr><tr><td>Yes</td><td>198</td><td>37.4</td><td>86</td><td>26.5</td><td>284</td><td>33.3</td></tr><tr><td rowspan="2">NAC</td><td>No</td><td>469</td><td>88.7</td><td>269</td><td>83.0</td><td rowspan="2">0.013</td><td>738</td><td>86.5</td></tr><tr><td>Yes</td><td>60</td><td>11.3</td><td>55</td><td>17.0</td><td>115</td><td>13.5</td></tr><tr><td rowspan="2">Previous<br/>radiotherapy</td><td>No</td><td>476</td><td>90.0</td><td>292</td><td>90.1</td><td rowspan="2">0.523</td><td>768</td><td>90.0</td></tr><tr><td>Yes</td><td>53</td><td>10.0</td><td>32</td><td>9.9</td><td>85</td><td>10.0</td></tr><tr><td rowspan="2">Complication</td><td>No</td><td>448</td><td>84.7</td><td>258</td><td>79.6</td><td rowspan="2">0.036*</td><td>706</td><td>82.8</td></tr><tr><td>Yes</td><td>81</td><td>15.3</td><td>66</td><td>20.4</td><td>147</td><td>17.2</td></tr><tr><td rowspan="2">G2-3<br/>complication</td><td>No</td><td>477</td><td>90.2</td><td>282</td><td>87.0</td><td rowspan="2">0.097</td><td>759</td><td>89.0</td></tr><tr><td>Yes</td><td>52</td><td>9.8</td><td>42</td><td>13.0</td><td>84</td><td>11.0</td></tr><tr><td rowspan="2">Implant loss</td><td>No</td><td>504</td><td>95.3</td><td>303</td><td>93.5</td><td rowspan="2">0.271</td><td>807</td><td>94.6</td></tr><tr><td>Yes</td><td>25</td><td>4.7</td><td>21</td><td>6.5</td><td>46</td><td>5.4</td></tr><tr><td rowspan="2">Re-operation</td><td>No</td><td>490</td><td>92.6</td><td>289</td><td>89.2</td><td rowspan="2">0.056</td><td>779</td><td>91.3</td></tr><tr><td>Yes</td><td>39</td><td>7.4</td><td>35</td><td>10.8</td><td>74</td><td>8.7</td></tr><tr><td rowspan="11">Surgeon</td><td>1</td><td>60</td><td>11.3</td><td>90</td><td>27.8</td><td rowspan="11">&lt;0.0001</td><td>150</td><td>17.6</td></tr><tr><td>2</td><td>82</td><td>15.5</td><td>15</td><td>4.6</td><td>97</td><td>11.4</td></tr><tr><td>3</td><td>117</td><td>22.1</td><td>40</td><td>12.3</td><td>157</td><td>18.4</td></tr><tr><td>4</td><td>50</td><td>9.5</td><td>0</td><td>0</td><td>50</td><td>5.9</td></tr><tr><td>5</td><td>74</td><td>14.0</td><td>50</td><td>15.4</td><td>124</td><td>14.5</td></tr><tr><td>6</td><td>40</td><td>7.6</td><td>48</td><td>14.8</td><td>88</td><td>10.3</td></tr><tr><td>7</td><td>69</td><td>13.0</td><td>1</td><td>0.3</td><td>70</td><td>8.2</td></tr><tr><td>8</td><td>11</td><td>2.1</td><td>6</td><td>1.9</td><td>17</td><td>2.0</td></tr><tr><td>9</td><td>15</td><td>2.8</td><td>18</td><td>5.6</td><td>33</td><td>3.9</td></tr><tr><td>10</td><td>7</td><td>1.3</td><td>56</td><td>17.3</td><td>63</td><td>7.4</td></tr><tr><td>11</td><td>4</td><td>0.8</td><td>0</td><td>0</td><td>4</td><td>0.5</td></tr><tr><td rowspan="5">Complication<br/>type</td><td>skin—NACx</td><td>37</td><td>48.7</td><td>25</td><td>41.7</td><td rowspan="5">0.179</td><td>62</td><td>45.6</td></tr><tr><td>hematoma</td><td>21</td><td>27.6</td><td>20</td><td>33.3</td><td>41</td><td>30.1</td></tr><tr><td>infection</td><td>13</td><td>17.1</td><td>9</td><td>15.0</td><td>22</td><td>16.2</td></tr><tr><td>lymphocel</td><td>2</td><td>2.6</td><td>6</td><td>75.0</td><td>8</td><td>5.9</td></tr><tr><td>others</td><td>3</td><td>3.9</td><td>0</td><td>0</td><td>3</td><td>2.2</td></tr><tr><td rowspan="5">Satisfaction</td><td>failure</td><td>29</td><td>5.5</td><td>22</td><td>6.8</td><td rowspan="5">0.346</td><td>51</td><td>6.0</td></tr><tr><td>bad</td><td>17</td><td>3.2</td><td>13</td><td>4.0</td><td>30</td><td>3.5</td></tr><tr><td>medium</td><td>96</td><td>18.1</td><td>43</td><td>13.3</td><td>139</td><td>16.3</td></tr><tr><td>good</td><td>263</td><td>49.7</td><td>173</td><td>53.4</td><td>436</td><td>51.1</td></tr><tr><td>very good</td><td>124</td><td>23.4</td><td>73</td><td>22.5</td><td>197</td><td>23.1</td></tr><tr><td rowspan="2">Interval time<br/>to<br/>adjuvant<br/>therapy</td><td>&le;60 days</td><td>96</td><td>73.8</td><td>52</td><td>69.3</td><td rowspan="2">0.487</td><td>148</td><td>72.2</td></tr><tr><td>&gt;60 days</td><td>34</td><td>26.2</td><td>23</td><td>30.7</td><td>57</td><td>27.8</td></tr></tbody></table>
<table><caption>**Table 1. Cont.**</caption><thead><tr><th rowspan="2"></th><th rowspan="2"></th><th colspan="2">Sub Pectoral</th><th colspan="2">Pre Pectoral</th><th>Chi2</th><th colspan="2">Total</th></tr><tr><th>Nb</th><th>%</th><th>Nb</th><th>%</th><th><i>p</i></th><th>Nb</th><th>%</th></tr></thead><tbody><tr><td rowspan="6">Surgical incision</td><td>axillary</td><td>29</td><td>5.5</td><td>12</td><td>3.7</td><td rowspan="6">&lt;0.0001</td><td>41</td><td>4.8</td></tr><tr><td>areolar</td><td>16</td><td>3.0</td><td>2</td><td>0.6</td><td>18</td><td>2.1</td></tr><tr><td>central</td><td>269</td><td>50.9</td><td>107</td><td>33.0</td><td>376</td><td>44.1</td></tr><tr><td>previous incision</td><td>12</td><td>2.3</td><td>4</td><td>1.2</td><td>16</td><td>1.9</td></tr><tr><td>inversed T</td><td>23</td><td>4.3</td><td>4</td><td>1.2</td><td>27</td><td>3.2</td></tr><tr><td>areolar + radial</td><td>83</td><td>15.7</td><td>54</td><td>16.7</td><td>137</td><td>16.1</td></tr><tr><td rowspan="3">LOS</td><td>radial</td><td>11</td><td>2.1</td><td>3</td><td>0.9</td><td>14</td><td>1.6</td></tr><tr><td>inferior fold</td><td>86</td><td>16.3</td><td>138</td><td>42.6</td><td>224</td><td>26.3</td></tr><tr><td>1 day</td><td>295</td><td>55.8</td><td>239</td><td>73.8</td><td rowspan="5">&lt;0.0001</td><td>534</td><td>62.6</td></tr><tr><td>2</td><td>146</td><td>27.6</td><td>59</td><td>18.2</td><td>205</td><td>24.0</td></tr><tr><td>3</td><td>66</td><td>12.5</td><td>13</td><td>4.0</td><td>79</td><td>9.3</td></tr><tr><td>4</td><td>11</td><td>2.1</td><td>6</td><td>1.9</td><td>17</td><td>2.0</td></tr><tr><td>5</td><td>7</td><td>1.3</td><td>5</td><td>1.5</td><td>12</td><td>1.4</td></tr><tr><td>&gt;5</td><td>4</td><td>0.8</td><td>2</td><td>0.6</td><td>6</td><td>0.6</td></tr><tr><td rowspan="3">Axillary surgery</td><td>No</td><td>211</td><td>39.9</td><td>129</td><td>39.8</td><td rowspan="3">0.156</td><td>340</td><td>39.9</td></tr><tr><td>SLNB</td><td>279</td><td>52.7</td><td>159</td><td>49.1</td><td>438</td><td>51.3</td></tr><tr><td>ALND</td><td>39</td><td>7.4</td><td>36</td><td>11.1</td><td>75</td><td>8.8</td></tr></tbody></table>

Legend: M-IBR: mastectomy immediate breast reconstruction, BC: breast cancer, NSM: Nipple-sparing mastectomy, SSM: Skin-sparing mastectomy, ASA: American Society of Anesthesiologists, NAC: neo-adjuvant chemotherapy, NACx: nipple areolar complex, LOS: Length of post-operative stay, SLNB: sentinel lymph node biopsy, ALND: axillary lymph node dissection. *: Fisher test.

<table><caption>**Table 2. Characteristics according to sub-pectoral or pre-pectoral implant-M-IBR: Median values and CI 95%**</caption><thead><tr><th rowspan="2"></th><th colspan="2">Sub Pectoral</th><th colspan="2">Pre Pectoral</th><th>t-Test</th><th colspan="2">Total</th></tr><tr><th>Value</th><th>CI 95%</th><th>Value</th><th>CI 95%</th><th><i>p</i></th><th>Value</th><th>CI 95%</th></tr></thead><tbody><tr><td>Median age</td><td>48.0</td><td>48.46–50.50</td><td>48.0</td><td>48.82–51.57</td><td>0.408</td><td>48.0</td><td>48.94–50.57</td></tr><tr><td>Median BMI</td><td>22.26</td><td>22.76–23.41</td><td>22.74</td><td>22.73–23.51</td><td>0.882</td><td>22.49</td><td>22.85–23.34</td></tr><tr><td>Median PLOH</td><td>1.0</td><td>1.60–1.78</td><td>1.0</td><td>1.32–1.50</td><td>&lt;0.0001</td><td>1.0</td><td>1.52–1.65</td></tr><tr><td>Median Length Surgery</td><td>105</td><td>104.8–110.8</td><td>90.5</td><td>93.0–99.8</td><td>&lt;0.0001</td><td>100</td><td>101.2–105.8</td></tr><tr><td>Median mastectomy weight</td><td>308</td><td>328–363</td><td>315</td><td>338–383</td><td>0.304</td><td>310</td><td>337–365</td></tr><tr><td>Median implant volume</td><td>300</td><td>289–308</td><td>300</td><td>309–332</td><td>0.003</td><td>300</td><td>300–314</td></tr><tr><td>Median cost</td><td>3560</td><td>4101–4371</td><td>4426</td><td>4360–4670</td><td>0.009</td><td>4178</td><td>4240–4444</td></tr><tr><td>Median cost without mesh</td><td>3513</td><td>4037–4265</td><td>3305</td><td>3668–4084</td><td>0.025</td><td>3442</td><td>3990–4190</td></tr><tr><td>Median cost with mesh</td><td>7752</td><td>5463–12848</td><td>4567</td><td>4859–5246</td><td>&lt;0.0001</td><td>4581</td><td>4985–5519</td></tr></tbody></table>

Legend: PLOH: Length of post-operative hospitalization.

Regression analysis showed significant prepectoral implant placement in the last 3 years, which was used less frequently in patients with previous breast surgery and by some surgeons. There was no significant difference between patients with or without NAC (Table 3).

<table><caption>**Table 3. Factors associated with pre-pectoral versus sub-pectoral implant IBR: regression analysis.**</caption><thead><tr><th colspan="2">Pre vs. Sub-Pectoral: Regression</th><th rowspan="2">Nb</th><th rowspan="2">p</th><th rowspan="2">OR</th><th colspan="2">CI 95%</th></tr><tr><th></th><th></th><th>Inferior</th><th>Superior</th></tr></thead><tbody><tr><td rowspan="3">Mastectomy</td><td>NSM</td><td>451</td><td>0.076</td><td>1</td><td></td><td></td></tr><tr><td>SSM</td><td>397</td><td>0.023</td><td>0.603</td><td>0.390</td><td>0.933</td></tr><tr><td>Standard</td><td>5</td><td>0.871</td><td>0.783</td><td>0.040</td><td>15.152</td></tr><tr><td>Implant type</td><td>Expander vs. definitive</td><td>28/825</td><td>0.998</td><td>&lt;0.0001</td><td>0.000</td><td></td></tr><tr><td rowspan="5">Years</td><td>2019</td><td>167</td><td>&lt;0.0001</td><td>1</td><td></td><td></td></tr><tr><td>2020</td><td>128</td><td>0.325</td><td>1.708</td><td>0.589</td><td>4.955</td></tr><tr><td>2021</td><td>187</td><td>&lt;0.0001</td><td>17.292</td><td>7.806</td><td>38.305</td></tr><tr><td>2022</td><td>178</td><td>&lt;0.0001</td><td>148.59</td><td>57.052</td><td>387.03</td></tr><tr><td>2023</td><td>193</td><td>&lt;0.0001</td><td>209.79</td><td>73.340</td><td>600.13</td></tr></tbody></table>
<table><caption>**Table 3.** *Cont.*</caption><thead><tr><th colspan="7">Pre vs. Sub-Pectoral: Regression</th></tr><tr><th></th><th></th><th>Nb</th><th>p</th><th>OR</th><th colspan="2">CI 95%</th></tr><tr><th></th><th></th><th></th><th></th><th></th><th>Inferior</th><th>Superior</th></tr></thead><tbody><tr><td rowspan="11">Surgeon</td><td>1</td><td>150</td><td>&lt;0.0001</td><td>1</td><td></td><td></td></tr><tr><td>2</td><td>97</td><td>&lt;0.0001</td><td>0.017</td><td>0.006</td><td>0.047</td></tr><tr><td>3</td><td>157</td><td>&lt;0.0001</td><td>0.187</td><td>0.089</td><td>0.393</td></tr><tr><td>4</td><td>50</td><td>&lt;0.0001</td><td>0.000</td><td>0.000</td><td></td></tr><tr><td>5</td><td>124</td><td>&lt;0.0001</td><td>0.457</td><td>0.230</td><td>0.909</td></tr><tr><td>6</td><td>88</td><td>&lt;0.0001</td><td>0.163</td><td>0.067</td><td>0.397</td></tr><tr><td>7</td><td>70</td><td>&lt;0.0001</td><td>0.001</td><td>0.000</td><td>0.009</td></tr><tr><td>8</td><td>17</td><td>0.002</td><td>0.085</td><td>0.018</td><td>0.405</td></tr><tr><td>9</td><td>33</td><td>&lt;0.0001</td><td>0.037</td><td>0.012</td><td>0.118</td></tr><tr><td>10</td><td>63</td><td>0.025</td><td>0.275</td><td>0.089</td><td>0.850</td></tr><tr><td>11</td><td>4</td><td>0.999</td><td>0.000</td><td>0.000</td><td></td></tr><tr><td>Previous surgery</td><td>Yes vs. No</td><td>284/569</td><td>0.005</td><td>0.517</td><td>0.326</td><td>0.821</td></tr><tr><td>NAC</td><td>Yes vs. No</td><td>115/738</td><td>0.742</td><td>1.103</td><td>0.615</td><td>1.979</td></tr></tbody></table>

Legend: M-IBR: Mastectomy immediate breast reconstruction, NSM: Nipple-sparing mastectomy, SSM: Skin-sparing mastectomy, NAC: neo-adjuvant chemotherapy.

### 3.1. Complications

One hundred and forty-seven mastectomies (17.2%) showed any grade of complication, with a significantly higher rate in prepectoral implant M-IBR (20.4%: 66/324) compared to the subpectoral position (15.3%: 81/529) (*p* = 0.036). However, there was no difference between the two groups for grade 2–3 complications (*p* = 0.097: 13.0% versus 9.8%), the implant loss rate (*p* = 0.271: 6.5% versus 4.7%) and the re-operation rate (*p* = 0.056: 10.8% versus 7.4%) (Table 1). The most common complications were poor blood supply or necrosis of the skin or nipple are-olar complex (45.6% of complications), hematoma (30.1%) and infection (16.2%), with no significant difference between subpectoral and prepectoral implant M-IBR (*p* = 0.179) (Table 1).

In terms of regression analysis, prepectoral implant was not significantly associated with any grade of complications (Table 4). Higher complications were observed in smokers (OR = 1.713, *p* = 0.022) and areolar and inverted T incisions (OR = 8.431, *p* = 0.004 and OR = 6.794, *p* = 0.004, respectively) and lower complications were observed in SSM (OR = 0.394, *p* = 0.035).

<table><caption>**Table 4.** Factors associated with all complications and grade 2–3 complications according to prepectoral versus subpectoral implant placement in regression analysis.</caption><thead><tr><th colspan="7">All Complications: Regression</th></tr><tr><th></th><th></th><th>Nb</th><th>p</th><th>OR</th><th colspan="2">CI 95%</th></tr><tr><th></th><th></th><th></th><th></th><th></th><th>Inferior</th><th>Superior</th></tr></thead><tbody><tr><td rowspan="7">Incision</td><td>axillar</td><td>41</td><td>&lt;0.0001</td><td>1</td><td></td><td></td></tr><tr><td>areolar</td><td>18</td><td>0.004</td><td>8.431</td><td>2.011</td><td>35.336</td></tr><tr><td>central</td><td>376</td><td>0.300</td><td>1.978</td><td>0.545</td><td>7.172</td></tr><tr><td>previous</td><td>16</td><td>0.992</td><td>0.991</td><td>0.159</td><td>6.173</td></tr><tr><td>inversed T</td><td>27</td><td>0.004</td><td>6.794</td><td>1.816</td><td>25.423</td></tr><tr><td>areolar +</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>radial</td><td>137</td><td>0.060</td><td>2.717</td><td>0.958</td><td>7.709</td></tr><tr><td rowspan="3">Breast Cup size</td><td>radial</td><td>14</td><td>0.563</td><td>0.511</td><td>0.053</td><td>4.961</td></tr><tr><td>inferior fold</td><td>224</td><td>0.698</td><td>1.233</td><td>0.428</td><td>3.553</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="3">Smokers</td><td>A-B</td><td>455</td><td>0.346</td><td>1</td><td></td><td></td></tr><tr><td>C</td><td>277</td><td>0.366</td><td>1.243</td><td>0.776</td><td>1.993</td></tr><tr><td>&gt;C</td><td>121</td><td>0.152</td><td>1.538</td><td>0.853</td><td>2.771</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td rowspan="3">ASA status</td><td>1</td><td>399</td><td>0.178</td><td>1</td><td></td><td></td></tr><tr><td>2</td><td>437</td><td>0.193</td><td>1.295</td><td>0.877</td><td>1.910</td></tr><tr><td>3</td><td>17</td><td>0.118</td><td>2.526</td><td>0.791</td><td>8.064</td></tr><tr><td>Mesh</td><td>Yes vs. No</td><td>185/668</td><td>0.002</td><td>2.558</td><td>1.392</td><td>4.702</td></tr><tr><td rowspan="3">Mastectomy</td><td>NSM</td><td>451</td><td>0.065</td><td>1</td><td></td><td></td></tr><tr><td>SSM</td><td>397</td><td>0.035</td><td>0.394</td><td>0.166</td><td>0.935</td></tr><tr><td>Standard</td><td>5</td><td>0.808</td><td>1.300</td><td>0.158</td><td>10.716</td></tr></tbody></table>
<table><caption>**Table 4.** *Cont.*</caption><thead><tr><th colspan="4">All Complications: Regression</th><th colspan="2">CI 95%</th></tr><tr><th></th><th></th><th>Nb</th><th>p</th><th>OR</th><th>Inferior</th><th>Superior</th></tr></thead><tbody><tr><td>Implant position</td><td>Pre vs. Sub</td><td>324/529</td><td>0.529</td><td>0.846</td><td>0.502</td><td>1.424</td></tr><tr><td>Mastectomy weight</td><td>&gt; vs. ≤ 300 gr</td><td>448/405</td><td>0.111</td><td>1.451</td><td>0.918</td><td>2.292</td></tr><tr><th colspan="4">Grade 2-3 complication: regression</th><th colspan="2">CI 95%</th></tr><tr><th></th><th></th><th>Nb</th><th>p</th><th>OR</th><th>Inferior</th><th>Superior</th></tr><tr><td>Smoker</td><td>Yes vs. No</td><td>148/705</td><td>0.022</td><td>1.844</td><td>1.094</td><td>3.107</td></tr><tr><td>Mesh</td><td>Yes vs. No</td><td>185/668</td><td>0.023</td><td>2.194</td><td>1.117</td><td>4.309</td></tr><tr><td>Implant position</td><td>Pre vs. Sub</td><td>324/529</td><td>0.784</td><td>0.916</td><td>0.491</td><td>1.711</td></tr><tr><td>Mastectomy weight</td><td>&gt; vs. ≤ 300 gr</td><td>448/405</td><td>0.002</td><td>2.125</td><td>1.320</td><td>3.422</td></tr><tr><td>NAC</td><td>Yes vs. No</td><td>115/738</td><td>0.113</td><td>0.477</td><td>0.190</td><td>1.193</td></tr><tr><td>Diabetes</td><td>Yes vs. No</td><td>7/846</td><td>0.046</td><td>5.053</td><td>1.030</td><td>24.789</td></tr><tr><td rowspan="3">Indication</td><td>Primary BC</td><td>633</td><td>0.031</td><td>1</td><td></td><td></td></tr><tr><td>Recurrence</td><td>67</td><td>0.009</td><td>2.645</td><td>1.281</td><td>5.461</td></tr><tr><td>Prophylactic</td><td>153</td><td>0.444</td><td>1.397</td><td>0.594</td><td>3.284</td></tr><tr><td rowspan="3">Axillary surgery</td><td>No</td><td>340</td><td>0.048</td><td>1</td><td></td><td></td></tr><tr><td>SLNB</td><td>438</td><td>0.016</td><td>2.240</td><td>1.160</td><td>4.328</td></tr><tr><td>ALND</td><td>75</td><td>0.491</td><td>1.419</td><td>0.524</td><td>3.841</td></tr></tbody></table>

Legend: BC: breast cancer, NSM: Nipple-sparing mastectomy, SSM: Skin-sparing mastectomy, ASA: American Society of Anesthesiologists, NAC: neo-adjuvant chemotherapy, SLNB: sentinel lymph node biopsy, ALND: axillary lymph node dissection.

In addition, prepectoral implant was not significantly associated with grade 2-3 complications (Table 4). A higher rate of grade 2-3 complications was observed in smokers (OR = 1.844, *p* = 0.022), mesh use (OR = 2.194, *p* = 0.023), mastectomy weight > 300 gr (OR = 2.125, *p* = 0.002), diabetes (OR = 5.053, *p* = 0.046), mastectomy for local recurrence (OR = 2.645, *p* = 0.009) and concomitant sentinel lymph node biopsy (SLNB) (OR = 2.240, *p* = 0.016). There was no difference between patients with or without NAC.

## 3.2. Duration of Surgery

The median duration of surgery was 100 min, 105 mns for the subpectoral position (CI 95%: 104.8–110.8) and 90.5 mns for the prepectoral position (CI 95%: 93.0–99.8) (*p* < 0.0001). Regression analysis was evaluated for the duration of surgery > 120 min (260 patients: 30.5%) or ≤120 min (593 patients: 69.5%): prepectoral implant-M-IBR was associated with significantly shorter surgery duration (OR = 0.410, *p* = 0.002) and a significantly longer surgery duration was observed for mastectomy associated with SLNB and ALND, breast cup size > C and in three surgeons. Inferior breast fold incision and prophylactic mastectomy were associated with shorter operative times (Table 5).

<table><caption>**Table 5.** Regression analysis for length of surgery >120 min or ≤120 min.</caption><thead><tr><th colspan="4">Length of Surgery: Regression</th><th colspan="2">CI 95%</th></tr><tr><th></th><th></th><th>Nb</th><th>p</th><th>OR</th><th>Inferior</th><th>Superior</th></tr></thead><tbody><tr><td>Mesh</td><td>Yes vs. No</td><td>185/668</td><td>0.655</td><td>1.192</td><td>0.551</td><td>2.579</td></tr><tr><td>Implant position</td><td>Pre vs. Sub</td><td>324/529</td><td>0.011</td><td>0.426</td><td>0.221</td><td>0.821</td></tr><tr><td>Mastectomy weight</td><td>&gt; vs. ≤ 300 gr</td><td>448/405</td><td>0.559</td><td>1.149</td><td>0.721</td><td>1.832</td></tr><tr><td rowspan="3">Indication</td><td>Primary BC</td><td>633</td><td>0.127</td><td>1</td><td></td><td></td></tr><tr><td>Recurrence</td><td>67</td><td>0.942</td><td>1.028</td><td>0.494</td><td>2.136</td></tr><tr><td>Prophylactic</td><td>153</td><td>0.046</td><td>0.467</td><td>0.221</td><td>0.986</td></tr><tr><td rowspan="3">Axillary surgery</td><td>No</td><td>340</td><td>&lt;0.0001</td><td>1</td><td></td><td></td></tr><tr><td>SLNB</td><td>438</td><td>0.001</td><td>2.458</td><td>1.479</td><td>4.087</td></tr><tr><td>ALND</td><td>75</td><td>&lt;0.0001</td><td>8.911</td><td>4.299</td><td>18.470</td></tr><tr><td rowspan="3">Breast Cup Size</td><td>A-B</td><td>455</td><td>0.116</td><td>1</td><td></td><td></td></tr><tr><td>C</td><td>277</td><td>0.337</td><td>1.254</td><td>0.791</td><td>1.987</td></tr><tr><td>&gt;C</td><td>121</td><td>0.038</td><td>1.948</td><td>1.038</td><td>3.658</td></tr><tr><td rowspan="3">BMI</td><td>&lt;24.9</td><td>626</td><td>0.143</td><td>1</td><td></td><td></td></tr><tr><td>25–29.99</td><td>188</td><td>0.602</td><td>1.136</td><td>0.704</td><td>1.831</td></tr><tr><td>≥30</td><td>39</td><td>0.049</td><td>2.486</td><td>1.006</td><td>6.145</td></tr></tbody></table>
<table><caption>**Table 5.** *Cont.*</caption><thead><tr><th colspan="6">Length of Surgery: Regression</th></tr><tr><th></th><th>Nb</th><th>p</th><th>OR</th><th colspan="2">CI 95%</th></tr><tr><th></th><th></th><th></th><th></th><th>Inferior</th><th>Superior</th></tr></thead><tbody><tr><td rowspan="10">Surgeon</td><td>1</td><td>150</td><td>&lt;0.0001</td><td>1</td><td></td><td></td></tr><tr><td>2</td><td>97</td><td>&lt;0.0001</td><td>4.645</td><td>2.108</td><td>10.233</td></tr><tr><td>3</td><td>157</td><td>0.109</td><td>0.521</td><td>0.235</td><td>1.157</td></tr><tr><td>4</td><td>50</td><td>0.156</td><td>2.015</td><td>0.766</td><td>5.299</td></tr><tr><td>5</td><td>124</td><td>0.722</td><td>1.153</td><td>0.527</td><td>2.524</td></tr><tr><td>6</td><td>88</td><td>0.820</td><td>1.102</td><td>0.476</td><td>2.550</td></tr><tr><td>7</td><td>70</td><td>&lt;0.0001</td><td>5.746</td><td>2.368</td><td>13.940</td></tr><tr><td>8</td><td>17</td><td>0.005</td><td>6.280</td><td>1.758</td><td>22.434</td></tr><tr><td>9</td><td>33</td><td>0.157</td><td>2.222</td><td>0.735</td><td>6.714</td></tr><tr><td>10</td><td>63</td><td>&lt;0.0001</td><td>6.109</td><td>2.522</td><td>14.799</td></tr><tr><td>11</td><td>4</td><td>0.912</td><td>0.866</td><td>0.068</td><td>11.067</td></tr><tr><td rowspan="5">Years</td><td>2019</td><td>167</td><td>0.809</td><td>1</td><td></td><td></td></tr><tr><td>2020</td><td>128</td><td>0.953</td><td>0.980</td><td>0.501</td><td>1.916</td></tr><tr><td>2021</td><td>187</td><td>0.900</td><td>0.958</td><td>0.494</td><td>1.860</td></tr><tr><td>2022</td><td>178</td><td>0.483</td><td>1.305</td><td>0.621</td><td>2.740</td></tr><tr><td>2023</td><td>193</td><td>0.726</td><td>0.873</td><td>0.407</td><td>1.872</td></tr><tr><td rowspan="3">Mastectomy</td><td>NSM</td><td>451</td><td>0.996</td><td>1</td><td></td><td></td></tr><tr><td>SSM</td><td>397</td><td>0.931</td><td>0.962</td><td>0.400</td><td>2.313</td></tr><tr><td>Standard</td><td>5</td><td>0.994</td><td>0.989</td><td>0.062</td><td>15.738</td></tr><tr><td rowspan="8">Incision</td><td>axillar</td><td>41</td><td>&lt;0.0001</td><td>1</td><td></td><td></td></tr><tr><td>areolar</td><td>18</td><td>&lt;0.0001</td><td>0.022</td><td>0.004</td><td>0.122</td></tr><tr><td>central</td><td>376</td><td>&lt;0.0001</td><td>0.010</td><td>0.002</td><td>0.047</td></tr><tr><td>previous</td><td>16</td><td>&lt;0.0001</td><td>0.011</td><td>0.002</td><td>0.069</td></tr><tr><td>inversed T</td><td>27</td><td>&lt;0.0001</td><td>0.014</td><td>0.0022</td><td>0.079</td></tr><tr><td>areolar +</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>radial</td><td>137</td><td>&lt;0.0001</td><td>0.012</td><td>0.003</td><td>0.049</td></tr><tr><td>radial</td><td>14</td><td>&lt;0.0001</td><td>0.013</td><td>0.002</td><td>0.094</td></tr><tr><td>inferior fold</td><td>224</td><td>&lt;0.0001</td><td>0.008</td><td>0.002</td><td>0.031</td></tr></tbody></table>

Legend: BC: breast cancer, NSM: Nipple-sparing mastectomy, SSM: Skin-sparing mastectomy, SLNB: sentinel lymph node biopsy, ALND: axillary lymph node dissection, BMI: body mass index.

### 3.3. Length of Postoperative Stay (LOS)

The median LOS was 1 day and was significantly lower with prepectoral implant placement (Table 2). Regression analysis was evaluated for LOS < or >2 days. Prepectoral implant placement was not significantly associated with longer LOS. A significant association with longer LOS was observed for prophylactic mastectomy and mastectomy weight > 300 gr. Shorter LOS was observed in the years 2020 to 2023 compared to the year 2019 (Table 6).

<table><caption>**Table 6.** Regression analysis for length of post-operative stay (LOS) ≤ or >2 days.</caption><thead><tr><th colspan="6">LOS ≤ versus >2 Days: Regression</th></tr><tr><th></th><th>Nb</th><th>p</th><th>OR</th><th colspan="2">CI 95%</th></tr><tr><th></th><th></th><th></th><th></th><th>Inferior</th><th>Superior</th></tr></thead><tbody><tr><td rowspan="3">BMI</td><td>≤24.9</td><td>626</td><td>0.083</td><td>1</td><td></td><td></td></tr><tr><td>25–29.99</td><td>188</td><td>0.117</td><td>0.613</td><td>0.332</td><td>1.130</td></tr><tr><td>≥30</td><td>39</td><td>0.251</td><td>1.642</td><td>0.704</td><td>3.829</td></tr><tr><td>Mesh</td><td>Yes vs. No</td><td>185/668</td><td>0.599</td><td>0.786</td><td>0.320</td><td>1.930</td></tr><tr><td rowspan="3">Indication</td><td>Primary BC</td><td>633</td><td>0.004</td><td>1</td><td></td><td></td></tr><tr><td>Recurrence</td><td>67</td><td>0.671</td><td>1.197</td><td>0.521</td><td>2.750</td></tr><tr><td>Prophylactic</td><td>153</td><td>0.001</td><td>2.557</td><td>1.463</td><td>4.469</td></tr><tr><td rowspan="5">Years</td><td>2019</td><td>167</td><td>&lt;0.0001</td><td>1</td><td></td><td></td></tr><tr><td>2020</td><td>128</td><td>&lt;0.0001</td><td>0.213</td><td>0.099</td><td>0.455</td></tr><tr><td>2021</td><td>187</td><td>&lt;0.0001</td><td>0.264</td><td>0.129</td><td>0.543</td></tr><tr><td>2022</td><td>178</td><td>0.001</td><td>0.276</td><td>0.125</td><td>0.607</td></tr><tr><td>2023</td><td>193</td><td>0.014</td><td>0.382</td><td>0.178</td><td>0.820</td></tr><tr><td rowspan="3">Mastectomy</td><td>NSM</td><td>451</td><td>0.559</td><td>1</td><td></td><td></td></tr><tr><td>SSM</td><td>397</td><td>0.494</td><td>0.705</td><td>0.258</td><td>1.922</td></tr><tr><td>Standard</td><td>5</td><td>0.543</td><td>2.125</td><td>0.187</td><td>24.163</td></tr><tr><td>Implant position</td><td>Pre vs. Sub</td><td>324/529</td><td>0.202</td><td>0.629</td><td>0.309</td><td>1.282</td></tr></tbody></table>
<table><caption>**Table 6.** *Cont.*</caption><thead><tr><th colspan="2">LOS ≤ versus >2 Days: Regression</th><th rowspan="2">p</th><th rowspan="2">OR</th><th colspan="2">CI 95%</th></tr><tr><th></th><th>Nb</th><th>Inferior</th><th>Superior</th></tr></thead><tbody><tr><td rowspan="8">incision</td><td>inferior fold</td><td>224</td><td>0.379</td><td>1</td><td></td></tr><tr><td>axillar</td><td>41</td><td>0.466</td><td>1.395</td><td>0.570</td><td>3.415</td></tr><tr><td>areolar</td><td>18</td><td>0.225</td><td>2.158</td><td>0.623</td><td>7.472</td></tr><tr><td>central</td><td>376</td><td>0.683</td><td>0.794</td><td>0.262</td><td>2.408</td></tr><tr><td>previous</td><td>16</td><td>0.697</td><td>1.339</td><td>0.308</td><td>5.823</td></tr><tr><td>inversed T</td><td>27</td><td>0.246</td><td>1.936</td><td>0.633</td><td>5.917</td></tr><tr><td>areolar +</td><td>137</td><td>0.358</td><td>0.705</td><td>0.335</td><td>1.485</td></tr><tr><td>radial</td><td>14</td><td>0.883</td><td>0.882</td><td>0.166</td><td>4.693</td></tr><tr><td>Mastectomy weight</td><td>&gt; vs. ≤300 gr</td><td>448/405</td><td>0.001</td><td>2.315</td><td>1.398</td><td>3.833</td></tr></tbody></table>

Legend: BC: breast cancer, NSM: Nipple-sparing mastectomy, SSM: Skin-sparing mastectomy, BMI: body mass index.

### 3.4. Adjuvant Therapy

NAC was administered in 13.5% of patients (115/853) with a significantly higher rate in the prepectoral implant M-IBR group (Table 1). Adjuvant chemotherapy was administered in 19.86% of patients (139/700), with a significantly higher rate in the subpectoral implant M-IBR group (Table 1). Twenty-five percent of patients received PMRT, with no significant difference between subpectoral and prepectoral implant-M-IBR (Table 1). Sixty-two percent of primary BC patients received endocrine therapy, with no significant difference between subpectoral and prepectoral implant-M-IBR (Table 1).

The median time interval between surgery and adjuvant treatment was 48 days (mean: 54.6; CI 95%: 50.4–58.7; range: 11–291): 47 days (mean: 54.7; CI 95%: 48.9–60.6; range: 15–291) in the subpectoral implant group (129 patients) and 49 days (mean: 54.6; CI 95%: 49.1–60.1; range: 11–131) in the prepectoral implant group (75 patients) (p = 0.993).

The occurrence of complications did not affect the median time interval to adjuvant therapy: it was 48 days (mean: 55.0; CI 95%: 50.3–59.7; range: 11–291), 47 days (mean: 52.3; CI 95%: 43.6–61.0; range: 11–130), 48 days (mean: 54.0; CI 95%: 49.5–58.5; range: 11–291) and 55.5 days (mean: 59.2; CI 95%: 47.3–71.1; range: 27–130) in patients without no complication (171 patients), one complication of any grade (34 patients), no complication of grade 2–3 (183 patients) and one complication of grade 2–3 (22 patients), respectively (p = 0.451).

The median time interval between surgery and adjuvant chemotherapy (125 patients) was 43 days (mean: 45.1; CI 95%: 42.1–48.1; range: 11–122) and was 60 days (mean: 69.9; CI 95%: 61.0–78.7; range: 29–291) between surgery and PMRT (79 patients) (p < 0.0001).

### 3.5. Satisfaction

Good or very good satisfaction was observed in 74.2% (633/853) and failure-bad-medium satisfaction in 25.8% (220/853) (Table 1), with significant differences according to several factors: complications of all grades (p < 0.0001), grade 2–3 complications (p < 0.0001), indication (p < 0.0001), years (p < 0.0001), mastectomy weight (p = 0.030), axillary surgery (p = 0.016), previous radiotherapy (p < 0.0001) and smoking status (p = 0.029).

Patient satisfaction appeared to be independent of the surgeon (p = 0.070), the type of mastectomy (p = 0.093), the type of implant (p = 0.059), ASA status (p = 0.054), the implant size (p = 0.387), BMI (p = 0.693), incisions (p = 0.115), the breast cup size (p = 0.216), NAC (p = 0.333), previous ipsilateral surgery (p = 0.353), the implant position (p = 0.207), the mesh (p = 0.296) and age (p = 0.057).

In regression analysis, factors significantly associated with lower satisfaction (failure-bad-medium) were the year 2020 and grade 2–3 complications (Table 7).
<table><caption>**Table 7.** Factors associated with less satisfaction (failure-bad-medium) versus good and very good satisfaction: regression analysis.</caption><thead><tr><th colspan="2">Satisfaction: Regression</th><th>Nb</th><th>p</th><th>OR</th><th colspan="2">CI 95%</th></tr><tr><th></th><th></th><th></th><th></th><th></th><th>Inferior</th><th>Superior</th></tr></thead><tbody><tr><td rowspan="3">Indication</td><td>Primary BC</td><td>633</td><td>0.512</td><td>1</td><td></td><td></td></tr><tr><td>Recurrence</td><td>67</td><td>0.615</td><td>1.300</td><td>0.468</td><td>3.608</td></tr><tr><td>Prophylactic</td><td>153</td><td>0.361</td><td>0.755</td><td>0.413</td><td>1.380</td></tr><tr><td rowspan="5">Years</td><td>2019</td><td>167</td><td>&lt;0.0001</td><td>1</td><td></td><td></td></tr><tr><td>2020</td><td>128</td><td>0.017</td><td>1.916</td><td>1.121</td><td>3.275</td></tr><tr><td>2021</td><td>187</td><td>0.277</td><td>1.319</td><td>0.801</td><td>2.174</td></tr><tr><td>2022</td><td>178</td><td>0.041</td><td>0.550</td><td>0.310</td><td>0.975</td></tr><tr><td>2023</td><td>193</td><td>0.325</td><td>0.767</td><td>0.453</td><td>1.300</td></tr><tr><td>Mastectomy weight</td><td>&gt; vs. ≤300 gr</td><td>448/405</td><td>0.425</td><td>1.150</td><td>0.816</td><td>1.622</td></tr><tr><td rowspan="3">Axillary surgery</td><td>No</td><td>340</td><td>0.189</td><td>1</td><td></td><td></td></tr><tr><td>SLNB</td><td>438</td><td>0.068</td><td>1.506</td><td>0.970</td><td>2.338</td></tr><tr><td>ALND</td><td>75</td><td>0.365</td><td>1.368</td><td>0.694</td><td>2.694</td></tr><tr><td>Previous radiotherapy</td><td>Yes vs. No</td><td>85/768</td><td>0.108</td><td>2.113</td><td>0.849</td><td>5.258</td></tr><tr><td>Smoker</td><td>Yes vs. No</td><td>148/705</td><td>0.292</td><td>1.260</td><td>0.820</td><td>1.937</td></tr><tr><td>G 2-3 complication</td><td>Yes vs. No</td><td>94/759</td><td>&lt;0.0001</td><td>6.230</td><td>3.858</td><td>10.060</td></tr></tbody></table>

Legend: BC: breast cancer, SLNB: sentinel lymph node biopsy, ALND: axillary lymph node dissection.

### 3.6. Cost Evaluation

The median cost was 4178 Euros (mean: 4342; CI 95%: 4240–4444; range: 2788–14849): 3560 Euros (mean: 4236; CI 95%: 4101–4371; range: 2828–14849) for a subpectoral implant and 4426 Euros (mean: 4515; CI 95%: 4360–4670; range: 2788–12166) for a prepectoral implant.

For the prepectoral implant position, the median cost was 3305 Euros (mean: 3876; CI 95%: 3668–4085; range: 2788–9032) without a mesh and 4567 Euros (mean: 5053; CI 95%: 4859–5246; range: 4178–12166) with a mesh.

While the cost of a pre-pectoral implant procedure was 255 euros less expensive than a subpectoral implant procedure (−7.7%), the addition of mesh to the pre-pectoral implant procedure increased the cost by 1262 euros (38.2%).

In regression analysis, factors significantly associated with a cost higher than the median cost (4178 Euros) were: subpectoral placement (OR: 1.603, CI95% 1.070–2.400, *p* = 0.022) and mesh use (OR: 234.7, CI95% 55.7–989.9, *p* < 0.0001), while SLNB, on the other hand, generated a lower cost than no axillary surgery (OR: 0.557, CI95% 0.399–0.777, *p* = 0.001) (no significant difference between ALND and no axillary surgery: OR: 0.701, CI95% 0.378–1.301, *p* = 0.2660). Breast cup size had no significant effect on costs. Taking into account the shorter LOS for the prepectoral implant, it resulted in lower costs than the subpectoral implant and higher costs than the prepectoral implant IBR with a mesh.

### 3.7. Scores

The calculation of predictive scores for any complication or grade 2–3 complication using the ORs of significant factors from the regression analysis isolated four and five risk groups, respectively. A higher score predicted a higher risk of events, but with a low AUC value (<0.70).

### 3.8. Satisfaction and Complications According to Score Groups

In patients scored by the “any complication score”, good-very good satisfaction was reported by 77.7% (209/269), 75.2% (261/347), 67.9% (72/106) and 69.5% (91/131) in groups 1 to 4, respectively (*p* = 0.132). In group 3, 55.6% (20/36) of patients with a subpectoral implant were satisfied, compared with 74.3% (52/70) of those with a prepectoral implant (*p* = 0.042) (Table 8).
<table><caption>**Table 8.** Satisfaction and complications according to pre-pectoral or sub-pectoral implant placement and with or without a mesh in each group at risk of complications.</caption><thead><tr><th></th><th></th><th colspan="2">Satisfaction</th><th>Chi2</th><th colspan="2">Complications</th><th>Chi2</th></tr><tr><th></th><th></th><th>Nb</th><th>%</th><th>p</th><th>Nb</th><th>%</th><th>p</th></tr></thead><tbody><tr><td rowspan="5">Score all complications</td><td></td><td colspan="2">Good-very good</td><td></td><td colspan="2">All complications</td><td></td></tr><tr><td rowspan="4">Score 1</td><td>Sub-pectoral</td><td>175/230</td><td>76.1</td><td rowspan="4">0.087</td><td>(27/230)</td><td>11.7</td><td rowspan="4">0.510 *</td></tr><tr><td>Pre-pectoral</td><td>34/39</td><td>87.2</td><td>(5/39)</td><td>12.8</td></tr><tr><td>Pre-pectoral without mesh</td><td>34/39</td><td>87.2</td><td>(5/39)</td><td>12.8</td></tr><tr><td>Pre-pectoral with mesh</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td rowspan="5">Score 2</td><td>Sub-pectoral</td><td>189/256</td><td>73.8</td><td rowspan="5">0.195</td><td>(38/256)</td><td>14.8</td><td rowspan="5">0.525 *</td></tr><tr><td>Pre-pectoral</td><td>72/91</td><td>79.1</td><td>(13/91)</td><td>14.3</td></tr><tr><td>Pre-pectoral without mesh</td><td>72/91</td><td>79.1</td><td>(13/91)</td><td>14.3</td></tr><tr><td>Pre-pectoral with mesh</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Pre-pectoral</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td rowspan="5">Score 3</td><td>Sub-pectoral</td><td>20/36</td><td>55.6</td><td rowspan="5">0.042</td><td>(11/36)</td><td>30.6</td><td rowspan="5">0.126 *</td></tr><tr><td>Pre-pectoral</td><td>52/70</td><td>74.3</td><td>(13/70)</td><td>18.6</td></tr><tr><td>Pre-pectoral without mesh</td><td>(10/18)</td><td>55.6</td><td>(7/18)</td><td>38.9</td></tr><tr><td>Pre-pectoral with mesh</td><td>42/52</td><td>80.8</td><td>(6/52)</td><td>11.5</td></tr><tr><td>Pre-pectoral</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td rowspan="5">Score 4</td><td>Sub-pectoral</td><td>(3/7)</td><td>42.9</td><td rowspan="5">0.127</td><td>(5/7)</td><td>71.4</td><td rowspan="5">0.027 *</td></tr><tr><td>Pre-pectoral</td><td>88/124</td><td>71.0</td><td>(35/124)</td><td>28.2</td></tr><tr><td>Pre-pectoral without mesh</td><td>88/124</td><td>71.0</td><td>(35/124)</td><td>28.2</td></tr><tr><td>Pre-pectoral with mesh</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Pre-pectoral</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td rowspan="5">Score Grade 2-3 complications</td><td></td><td colspan="2">Good-very good</td><td></td><td colspan="2">Grade 2-3 complications</td><td></td></tr><tr><td rowspan="4">Score 1</td><td>Sub-pectoral</td><td>249/315</td><td>79.0</td><td rowspan="4">0.254</td><td>(21/315)</td><td>6.7</td><td rowspan="4">0.229 *</td></tr><tr><td>Pre-pectoral</td><td>99/120</td><td>82.5</td><td>(5/120)</td><td>4.2</td></tr><tr><td>Pre-pectoral without mesh</td><td>76/94</td><td>80.9</td><td>(5/94)</td><td>5.3</td></tr><tr><td>Pre-pectoral with mesh</td><td>23/26</td><td>88.5</td><td>(0/26)</td><td>0</td></tr><tr><td rowspan="5">Score 2</td><td>Sub-pectoral</td><td>108/160</td><td>67.5</td><td rowspan="5">0.044</td><td>(17/160)</td><td>10.6</td><td rowspan="5">0.425</td></tr><tr><td>Pre-pectoral</td><td>90/116</td><td>77.6</td><td>(14/116)</td><td>12.1</td></tr><tr><td>Pre-pectoral without mesh</td><td>30/37</td><td>81.1</td><td>(5/37)</td><td>13.5</td></tr><tr><td>Pre-pectoral with mesh</td><td>60/79</td><td>75.9</td><td>(9/79)</td><td>11.4</td></tr><tr><td>Pre-pectoral</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td rowspan="5">Score 3</td><td>Sub-pectoral</td><td>25/40</td><td>62.5</td><td rowspan="5">0.240</td><td>(7/40)</td><td>17.5</td><td rowspan="5">0.393</td></tr><tr><td>Pre-pectoral</td><td>49/69</td><td>71.0</td><td>(15/69)</td><td>21.7</td></tr><tr><td>Pre-pectoral without mesh</td><td>(8/14)</td><td>57.1</td><td>(4/14)</td><td>28.6</td></tr><tr><td>Pre-pectoral with mesh</td><td>41/55</td><td>74.5</td><td>(11/55)</td><td>20.0</td></tr><tr><td>Pre-pectoral</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td rowspan="5">Score 4</td><td>Sub-pectoral</td><td>(1/8)</td><td>12.5</td><td rowspan="5">0.190</td><td>(4/8)</td><td>50.0</td><td rowspan="5">0.611 *</td></tr><tr><td>Pre-pectoral</td><td>(6/15)</td><td>40.0</td><td>(7/15)</td><td>46.7</td></tr><tr><td>Pre-pectoral without mesh</td><td>(2/2)</td><td>100</td><td>(0/2)</td><td>0</td></tr><tr><td>Pre-pectoral with mesh</td><td>(4/13)</td><td>30.8</td><td>(7/13)</td><td>53.8</td></tr><tr><td>Pre-pectoral</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td rowspan="5">Score 5</td><td>Sub-pectoral</td><td>(4/6)</td><td>66.7</td><td rowspan="5">0.548</td><td>(3/6)</td><td>50.0</td><td rowspan="5">0.452 *</td></tr><tr><td>Pre-pectoral</td><td>(2/4)</td><td>50.0</td><td>(1/4)</td><td>25.0</td></tr><tr><td>Pre-pectoral without mesh</td><td>(0/1)</td><td>0</td><td>(1/1)</td><td>100</td></tr><tr><td>Pre-pectoral with mesh</td><td>(2/3)</td><td>66.7</td><td>(0/3)</td><td>0</td></tr><tr><td>Pre-pectoral</td><td>0</td><td>0</td><td>0</td><td>0</td></tr></tbody></table>

Legend: *: Fisher test.

In patients scored by the “grade 2–3 complication score”, good-very good satisfaction was reported by 80.0% (348/435), 71.7% (198/276), 67.9% (74/109), 30.4% (7/23) and 60.0% (6/10) in groups 1 to 5, respectively (p < 0.0001). In group 2, 67.5% (108/160) of patients with a subpectoral implant were satisfied compared to 77.6% (90/116) of those with a prepectoral implant (p = 0.044) (Table 8).

In patients with an “any grade complication” score rating of 4, those with a prepectoral implant had significantly fewer complications than those with a subpectoral implant. Prepectoral implant mesh patients with an “any grade complication” score rating of 3 had a significantly lower risk of experiencing complications than patients with a score of 3, patients with a prepectoral implant without a mesh. In patients scored with the “grade 2–3 complications” score, no significant difference was observed (Table 8).

## 4. Discussion

M-IBR has increased in recent years, particularly implant IBR [18] and, more recently, prepectoral implant M-IBR has shown a rapid adoption, as reported by Chinta et al. [45]. We reported a significant increase in prepectoral M-IBR since the year 2021 but with significant variation in practice between surgeons. The use of mesh also increased in 2021–2022 (92% and 85% for prepectoral implant-M-IBR), but sharply decreased in 2023 (6.7%).
4.1. Complications

We report a high rate of skin and NAC complications, no doubt related to the high rate of NSM (52.9%). There is a balance between the risks of breast recurrence, complications, and final cosmetic results. The more fat tissue that remains, the lower the complication rate and the better the cosmetic result will be, but conversely, the more breast tissue that remains, the higher the risk of local recurrence [46]. Sixty to eighty percent of local recurrences have been reported to be located within the skin, the nipple-areolar complex (NACx) and subcutaneous tissue [47,48]. In MRI studies, the rate of residual glandular tissue reached 20%, higher in NSM than in SSM [49]. The thickness of the skin flap is of paramount importance. Andersson et al. [50] reported residual glandular tissue after prophylactic mastectomy in 6.9% of skin flaps ≤ 5 mm and 37.5% of skin flaps > 5 mm (OR 3.07; *p* = 0.005) with a significant increase when the flap thickness exceeded 7 mm (more than 40%). Consequently, complete breast tissue removal is required but at the cost of an increased risk of ischemic mastectomy flaps: a flap thickness of less than 5 or 8 mm has been reported as an independent predictor of ischemic complications [51,52] with odds of skin necrosis six times higher in skin flaps ≤ 5 mm compared to >5 mm [53]. Locoregional recurrence after NSM has been reported to be 0–11.7% and recurrence within the NAC itself has been reported at 0–5% [54]. In a recent systematic review [55], including 19 studies with 1917 implant M-IBR, local recurrence rates were localized in 4.7% of the cases in the skin, 0.4% in the chest wall and 0.4% in the NACx. The context of the mastectomy is also important. The local recurrence rate was found at 7.9% to 11.4% after therapeutic mastectomy [56,57] and 0 to 1.6% after prophylactic mastectomy [46,47,58–62]. The reported local recurrence rate within the NACx is very low and the rate of NACx necrosis is usually less than 11% [19,24,63–65]. The timing of breast reconstruction (immediate or delayed) [66,67], breast reconstruction per se [68] and implant location [69] did not affect local recurrence rates.

We observed an “any grade” complication rate of 17.2% which favorably compares with the literature data in which complication rates range from 19% to 42% depending on the implant-based reconstruction method (mesh or no mesh, NSM or SSM) [70–74]. In univariate analysis, the “any grade” complication rate was higher with prepectoral implants but was no longer significant in multivariate analysis. As we reported, prepectoral implants were associated with the use of a mesh in 54.3% of the cases (in contrast to subpectoral implants where a mesh was used in only 1.7% of patients). It has been reported that the use of a mesh has a significant and negative impact on the complication rate. As a result, the use of a mesh has dramatically fallen. In fact, a recent meta-analysis of 17 studies, evaluated complication rates comparing the acellular dermal matrix (ADM), a synthetic absorbable mesh, a synthetic non-absorbable mesh and no matrix [75]. The infection rate was higher for ADM, the seroma rate was lower for the synthetic absorbable matrix (OR: 0.2) and the synthetic non-absorbable matrix (OR: 0.1 compared to ADM). However, clinically significant complications (grade 2 and 3) did not differ between patients who received prepectoral or subpectoral implants [75]. In the above meta-analysis, major complications were similar whether or not a mesh was used. In another recent meta-analysis including 31 studies, there was no significant difference in overall complications and implant loss between subpectoral implantation without a mesh and a xenograft acellular dermal matrix (OR: 0.63) and synthetic mesh (OR: 0.77) [76]. On the other hand, areolar incisions and inverted T-incisions were significantly associated with a higher risk of overall complications, mirroring a report by Frey et al. [77] with a lower risk of mastectomy flap necrosis for inframammary fold incisions. Due to the small number of PMRT, we were not able to compare the effect in prepectoral versus subpectoral implants, but early literature data seems to favor the prepectoral position with less capsular contracture, probably due to a lower inflammation burden [78–81]. In addition, other studies have reported that neither neoadjuvant nor adjuvant chemotherapy was associated with the likelihood of complications in patients undergoing implant reconstruction, regardless of the implant position [82,83]. Finally, we defined different complication risk scores to compare mastectomy and reconstruction techniques in the hope of facilitating comparisons
between centers and studies. The key issue in clinical practice is the occurrence of grade 2–3 complications, which significantly increase with the risk group, but with a low predictive value (0.678).

To summarize, implant positioning (prepectoral or subpectoral) has no effect on the clinically relevant complication rate; only mesh use, smoking status and incision type (areolar and inverted T) had a negative effect. Moreover, the thickness and quality of perfusion of the skin flap are major factors in skin necrosis and implant loss and are the main criteria for deciding on prepectoral implantation [84,85]. Careful patient selection is therefore an important factor in minimizing complications. Obesity, smoking and diabetes are all known to be associated with complications [86–88] and the iBRA study confirmed the link between infection, previous radiation, prolonged operative time and the need for reoperation [39]. Complication risk scores may help to select patients for whom implant M-IBR is proposed.

## 4.2. Time to Adjuvant Therapies

Interestingly, the occurrence of complications, even grade 2–3 complications, did not significantly affect the time to start adjuvant treatment. The median time interval between surgery and adjuvant chemotherapy was 43 days and 60 days for PMRT. In a meta-analysis, Cook et al. reported an increase mean time to chemotherapy of 3.50 days, from 40.38 days after surgery to 43.56 days for mastectomy without IBR and with IBR, respectively, without clinical significance [89]. O’Connell et al. reported that major complications significantly increased treatment delays [90], with no significant effect on BC recurrence and death rates [91].

## 4.3. Patients’ Satisfaction, Length of Surgery and Costs

Patient satisfaction was independent of the implant location but strongly associated with the occurrence of complications (p < 0.0001). The use of mesh did not change this measure.

As reported by others [45], prepectoral implants shortened the duration of surgery (OR = 0.410, *p* = 0.002). Although the operative time was shorter for prepectoral implantation, Chinta et al. found no significant difference in cost between prepectoral and subpectoral implants in a multivariate analysis. In the regression analysis, we reported higher costs for subpectoral implantation (OR: 1.603) and for mesh use (OR: 234.7). Prepectoral reconstruction was associated with higher operative costs, undoubtedly due to the additional cost of the ADM [84]. However, the use of mesh has gradually decreased over the years in our practice and prepectoral M-IBR without mesh use cost 25% less than subpectoral placement in a comparative study [92]. Moreover, cost evaluation with percentage differences between different techniques seems to be more accurate than the quantitative value, as the coverage of the cost of interventions varies between countries and the economic models.

## 4.4. Limitations

Our study has several limitations. First, the retrospective nature of the study with potential biases despite multivariate analysis and a single-center study the results of which may not be generalizable to other teams. Second, only the short-term outcomes were examined. Thirdly, the relevance of the cost analysis to the particular center, as the cost calculation would vary from center to center/country to country. Finally, satisfaction was assessed without pre- and post-operative quality of life evaluation with the same follow-up. Future studies including several centers are needed and we plan a multicenter study with a larger number of patients, different practices and the use of different mesh types.

# 5. Conclusions

The results of our study provide further evidence that prepectoral implants do not lead to higher complication rates, are shorter and less expensive, provided that no mesh is used. Furthermore, compared with previous studies, we showed that the time to adjuvant
therapy does not differ from subpectoral implants and patient satisfaction remains similar. Prepectoral implantation can be considered a good and safe technique. A complication risk score may help in the decision to implant-M-IBR and may help to compare results between different teams and studies. These results need to be confirmed in other centers, and the predictive score for complications needs to be improved, in particular through a larger multicenter study that is currently underway.

**Author Contributions:** Conceptualization: G.H.; Methodology: G.H.; Formal analysis: G.H.; Validation: G.H., A.T., M.C., M.B. (Marie Bannier) and A.d.N.; Investigation: G.H.; Data Curation: G.H., C.B., M.C., M.B. (Marie Bannier), C.T. (Camille Tallet), L.S., C.T. (Charlène Teyssandier), A.C., A.B., A.V.T. and M.B. (Max Buttarelli); Writing—Original Draft Preparation: G.H., A.T., M.C., M.B. (Marie Bannier) and A.d.N.; Writing—Review & Editing: G.H., A.T., M.C., M.B. (Marie Bannier) and A.d.N.; Supervision: G.H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Institutional Review Board (or Ethics Committee) of Paoli Calmettes Institute (M-IBR-PPRP-IPC 2022-014 and approved in April 2022).

**Informed Consent Statement:** Patient consent was waived due to retrospective study with all criteria recorded for clinical practice.

**Data Availability Statement:** Data supporting reported results can be found in Paoli Calmettes Institute breast cancer data base.

**Conflicts of Interest:** The authors declare no conflicts of interest.

## References

1. Sung, H.; Ferlay, J.; Siege, R.L.; Laversanne, M.; Soerjomataram, I.; Jemal, A.; Bray, F. Global cancer statistics2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. *CA Cancer J. Clin.* **2021**, *71*, 209–249. [CrossRef] [PubMed]

2. Van Maaren, M.C.; de Munck, L.; de Bock, G.H.; Jobsen, J.J.; van Dalen, T.; Linn, S.C.; Poortmans, P.; Strobbe, L.J.A.; Siesling, S. 10 year survival after breast-conserving surgery plus radiotherapy compared with mastectomy in early breast cancer in the Netherlands: A population-based study. *Lancet Oncol.* **2016**, *17*, 1158–1170. [CrossRef]

3. De Boniface, J.; Frisell, J.; Bergkvist, L.; Andersson, Y. Breast-conserving surgery followed by whole-breast irradiation offers survival benefits over mastectomy without irradiation. *Br. J. Surg.* **2018**, *105*, 1607–1614. [CrossRef]

4. Hofvind, S.; Holen, Å.; Aas, T.; Roman, M.; Sebuødegård, S.; Akslen, L.A. Women treated with breast conserving surgery do better than those with mastectomy independent of detection mode, prognostic and predictive tumor characteristics. *Eur. J. Surg. Oncol.* **2015**, *41*, 1417–1422. [CrossRef]

5. Agarwal, S.; Pappas, L.; Neumayer, L.; Kokeny, K.; Agarwal, J. Effect of breast conservation therapy vs mastectomy on disease-specific survival for early-stage breast cancer. *JAMA Surg.* **2014**, *149*, 267–274. [CrossRef]

6. Krag, D.N.; Anderson, S.J.; Julian, T.B.; Brown, A.M.; Harlow, S.P.; Costantino, J.P.; Ashikaga, T.; Weaver, D.L.; Mamounas, E.P.; Jalovec, L.M.; et al. Sentinel-lymph-node resection compared with conventional axillary-lymph-node dissection in clinically node-negative patients with breast cancer: Overall survival findings from the NSABP B-32 randomised phase 3 trial. *Lancet Oncol.* **2010**, *11*, 927–933. [CrossRef]

7. Houvenaeghel, G.; Cohen, M.; Raro, P.; De Troyer, J.; de Lara, C.T.; Gimbergues, P.; Gauthier, T.; Faure-Virelizier, C.; Vaini-Cowen, V.; Lantheaume, S.; et al. Overview of the pathological results and treatment characteristics in the first 1000 patients randomized in the SERC trial: Axillary dissection versus no axillary dissection in patients with involved sentinel node. *BMC Cancer* **2018**, *18*, 1153. [CrossRef]

8. Matala, C.M.; McIntosh, S.A.; Purushotham, A.D. Immediate breast reconstruction after mastectomy for cancer. *Br. J. Surg.* **2000**, *87*, 1455–1472. [CrossRef]

9. Kummerow, K.L.; Du, L.; Penson, D.F.; Shyr, Y.; Hooks, M.A. Nationwide trends in mastectomy for early-stage breast cancer. *JAMA Surg.* **2015**, *150*, 9–16. [CrossRef]

10. Houvenaeghel, G.; Lambaudie, E.; Cohen, M.; Classe, J.-M.; Reyal, F.; Garbay, J.-R.; Giard, S.; Chopin, N.; Martinez, A.; Rouzier, R.; et al. Therapeutic escalation—De-escalation: Data from 15.508 early breast cancer treated with upfront surgery and sentinel lymph node biopsy (SLNB). *Breast* **2017**, *34*, 24–33. [CrossRef]

11. De Boniface, J.; Szulkin, R.; Johansson, A.L.V. Survival After Breast Conservation vs Mastectomy Adjusted for Comorbidity and Socioeconomic Status: A Swedish National 6-Year Follow-up of 48,986 Women. *JAMA Surg.* **2021**, *156*, 628–637. [CrossRef]
12. Xu, F.; Lei, C.; Cao, H.; Liu, J.; Li, J.; Jiang, H.; Chinese Society of Breast Surgery. Multi-center investigation of breast reconstruction after mastectomy from Chinese Society of Breast Surgery: A survey based on 31 tertiary hospitals (CSBrS-004). *Chin. J. Cancer Res.* **2021**, *33*, 33–41. [CrossRef]

13. Jeevan, R.; Mennie, J.C.; Mohanna, P.N.; O'Donoghue, J.M.; Rainsbury, R.M.; A Cromwell, D. National trends and regional variation in immediate breast reconstruction rates. *Br. J. Surg.* **2016**, *103*, 1147–1156. [CrossRef]

14. Morante, L.; Rua, S.; Cohen, M.; Sabiani, L.; Martino, M.; Buttarelli, M.; Van Troy, A.; Gonçalves, A.; Tallet, A.; Coudray, A.J.; et al. Outcome and Impact on Adjuvant Treatment Processing Time after Mastectomy with or without Immediate Breast Reconstruction on a Large Cohort and Determination of a Postoperative Complications Predictive Score. *Arch. Clin. Med Case Rep.* **2023**, *7*, 390–408. [CrossRef]

15. Nègre, G.; Balcaen, T.; Dast, S.; Sinna, R.; Chazard, E. Breast reconstruction in France, observational study of 140,904 cases of mastectomy for breast cancer. *Ann. Chir. Plast. Esthet.* **2020**, *65*, 36–43. [CrossRef]

16. Panchal, H.; Matros, E. Current trends in postmastectomy breast reconstruction. *Plast. Reconstr. Surg.* **2017**, *140*, 7S–13S. [CrossRef]

17. Mylvaganam, S.; Conroy, E.; Williamson, P.R.; Barnes, N.L.; Cutress, R.I.; Gardiner, M.D.; Jain, A.; Skillman, J.M.; Thrush, S.; Whisker, L.J.; et al. Variation in the provision and practice of implant-based breast reconstruction in the UK: Results from the iBRA national practice questionnaire. *Breast* **2017**, *35*, 182–190.

18. Nelson, J.A.; Voineskos, S.H.; Qi, J.; Kim, H.M.; Hamill, J.B.; Wilkins, E.G.; Pusic, A.L. Elective revisions after breast reconstruction: Results from the mastectomy reconstruction outcomes consortium. *Plast. Reconstr. Surg.* **2019**, *144*, 1280–1290. [CrossRef]

19. Houvenaeghel, G.; Cohen, M.; Dammacco, M.A.; D'Halluin, F.; Regis, C.; Gutowski, M.; Acker, O.; Fournier, M.; Bannier, M.; Lusque, A.; et al. Prophylactic nipple-sparing mastectomy with immediate breast reconstruction: Results of a French prospective trial. *Br. J. Surg.* **2021**, *108*, 296–301. [CrossRef]

20. Smith, B.L.; Tang, R.; Rai, U.; Plichta, J.K.; Colwell, A.S.; Gadd, M.A.; Specht, M.C.; Austen, W.G.; Coopey, S.B. Oncologic safety of nipple-sparing mastectomy in women with breast cancer. *J. Am. Coll. Surg.* **2017**, *225*, 361–365. [CrossRef]

21. Li, M.; Chen, K.; Liu, F.; Su, F.; Li, S.; Zhu, L. Nipple sparing mastectomy in breast cancer patients and long-term survival outcomes: An analysis of the SEER database. *PLoS ONE* **2017**, *12*, e0183448. [CrossRef]

22. Muller, T.; Baratte, A.; Bruant-Rodier, C.; Bodin, F.; Mathelin, C. Oncological safety of nipple-sparing prophylactic mastectomy: A review of the literature on 3716 cases. *Ann. Chir. Plast. Esthet.* **2018**, *63*, e6–e13. [CrossRef]

23. Quilichini, O.; Barrou, J.; Bannier, M.; Rua, S.; Van Troy, A.; Sabiani, L.; Lambaudie, E.; Cohen, M.; Houvenaeghel, G. Mastectomy with immediate breast reconstruction: Results of a mono-centric 4-years cohort. *Ann. Med. Surg.* **2020**, *61*, 172–179. [CrossRef]

24. Wu, Z.-Y.; Kim, H.-J.; Lee, J.-W.; Chung, I.-Y.; Kim, J.-S.; Lee, S.-B.; Son, B.-H.; Eom, J.-S.; Kim, S.-B.; Gong, G.-Y.; et al. Breast Cancer Recurrence in the Nipple-Areola Complex After Nipple-Sparing Mastectomy With Immediate Breast Reconstruction for Invasive Breast Cancer. *JAMA Surg.* **2019**, *154*, 1030–1037. [CrossRef]

25. Simon, P.; Barrou, J.; Cohen, M.; Rua, S.; Lambaudie, E.; Houvenaeghel, G. Types of Mastectomies and Immediate Reconstructions for Ipsilateral Breast Local Recurrences. *Front. Oncol.* **2020**, *10*, 567298. [CrossRef]

26. Wei, C.H.; Scott, A.M.; Price, A.N.; Miller, H.C.; Klassen, A.F.; Jhanwar, S.M.; J Mehrara, B.K.; J Disa, J.J.; McCarthy, C.; Matros, E.; et al. Psychosocial and sexual well-being following nipple-sparing mastectomy and reconstruction. *Breast J.* **2016**, *22*, 10–17. [CrossRef]

27. Moyer, H.R.; Ghazi, B.; Daniel, J.R.; Gasgarth, R.; Carlson, G.W. Nipple-sparing mastectomy: Technical aspects and aesthetic outcomes. *Ann. Plast. Surg.* **2012**, *68*, 446–450. [CrossRef]

28. Gerber, B.; Krause, A.; Dieterich, M.; Kundt, G.; Reimer, T. The oncological safety of skin sparing mastectomy with conservation of the nipple-areola complex and autologous reconstruction: An extended follow-up study. *Ann. Surg.* **2009**, *249*, 461–468. [CrossRef]

29. Agha, R.A.; Al Omran, Y.; Wellstead, G.; Sagoo, H.; Barai, I.; Rajmohan, S.; Borrelli, M.R.; Vella-Baldacchino, M.; Orgill, D.P.; Rusby, J.E. Systematic review of therapeutic nipple-sparing versus skin-sparing mastectomy. *BJS Open* **2018**, *3*, 135–145. [CrossRef]

30. Weber, W.P.; Haug, M.; Kurzeder, C.; Bjelic-Radisic, V.; Koller, R.; Reitsamer, R.; Fitzal, F.; Biazus, J.; Brenelli, F.; Urban, C.; et al. Oncoplastic Breast Consortium consensus conference on nipple sparing Mastectomy. *Breast Cancer Res. Treat.* **2018**, *172*, 523–537. [CrossRef]

31. Manning, A.T.; Wood, C.; Eaton, A.; Capko, D.; Pusic, A.; Morrow, M.; Sacchini, V. Nipple-sparing mastectomy in patients with BRCA1/2 mutations and variants of uncertain significance. *Br. J. Surg.* **2015**, *102*, 1354–1359. [CrossRef]

32. Jakub, J.W.; Peled, A.W.; Gray, R.J.; Greenup, R.A.; Kiluk, J.V.; Sacchini, V.; McLaughlin, S.A.; Tchou, J.C.; Vierkant, R.A.; Degnim, A.C.; et al. Oncologic safety of prophylactic nipple-sparing mastectomy in a population with BRCA mutations: A multi-institutional study. *JAMA Surg.* **2018**, *153*, 123–129. [CrossRef]

33. Houvenaeghel, G.; Cohen, M.; Sabiani, L.; Van Troy, A.; Quilichini, O.; Charavil, A.; Buttarelli, M.; Rua, S.; Tallet, A.; de Nonneville, A.; et al. Mastectomy and Immediate Breast Reconstruction with Pre-Pectoral or Sub-Pectoral Implant: Assessing Clinical Practice, Post-Surgical Outcomes, Patient's Satisfaction and Cost. *J. Surg. Res.* **2022**, *5*, 500–510. [CrossRef]

34. King, C.A.; Bartholomew, A.J.; Sosin, M.; Avila, A.; Famiglietti, A.L.; Dekker, P.K.; Perez-Alvarez, I.M.; Song, D.H.; Fan, K.L.; Tousimis, E.A. A Critical Appraisal of Late Complications of Prepectoral versus Subpectoral Breast Reconstruction Following Nipple-Sparing Mastectomy. *Ann. Surg. Oncol.* **2021**, *28*, 9150–9158. [CrossRef]
35. Lai, H.-W.; Toesca, A.; Sarfati, B.; Park, H.S.; Houvenaeghel, G.; Selber, J.C.; Cheng, F.; Kuo, W.; Peradze, N.; Song, S.; et al. Consensus Statement on Robotic Mastectomy—Expert Panel From International Endoscopic and Robotic Breast Surgery Symposium (IERBS) 2019. *Ann. Surg.* **2020**, *271*, 1005–1012. [CrossRef]

36. Lai, H.W.; Chen, S.T.; Mok, C.W.; Lin, Y.J.; Wu, H.K.; Lin, S.L.; Chen, D.R.; Kuo, S.J. Robotic versus conventional nipple sparing mastectomy and immediate gel implant breast reconstruction in the management of breast cancer—A case control comparison study with analysis of clinical outcome, medical cost, and patient-reported cosmetic results. *J. Plast. Reconstr. Aesthetic Surg.* **2020**, *73*, 1514–1525. [CrossRef]

37. Houvenaeghel, G.; Barrou, J.; Jauffret, C.; Rua, S.; Sabiani, L.; Van Troy, A.; Buttarelli, M.; Blache, G.; Lambaudie, E.; Cohen, M.; et al. Robotic Versus Conventional Nipple-Sparing Mastectomy with Immediate Breast Reconstruction. *Front. Oncol.* **2021**, *11*, 637049. [CrossRef]

38. Toesca, A.; Sangalli, C.M.; Maisonneuve, P.; Massari, G.; Girardi, A.; Baker, J.L.; Lissidini, G.; Invento, A.; Farante, G.; Corso, G.; et al. A Randomized Trial of Robotic Mastectomy versus Open Surgery in Women with Breast Cancer or BRCA Mutation. *Ann. Surg.* **2021**, *276*, 11–19. [CrossRef]

39. Potter, S.; Conroy, E.J.; I Cutress, R.; Williamson, P.R.; Whisker, L.; Thrush, S.; Skillman, J.; Barnes, N.L.P.; Mylvaganam, S.; Teasdale, E.; et al. Short-term safety outcomes of mastectomy and immediate implant-based breast reconstruction with and without mesh (iBRA): A multicentre, prospective cohort study. *Lancet Oncol.* **2019**, *20*, 254–266. [CrossRef]

40. Sewart, E.; Turner, N.L.; Conroy, E.J.; Cutress, R.I.; Skillman, J.; Whisker, L.; Thrush, S.; Barnes, N.; Holcombe, C.; Potter, S.; et al. Patient-reported outcomes of immediate implant-based breast reconstruction with and without biological or synthetic mesh. *BJS Open* **2021**, *5*, zraa063. [CrossRef]

41. Sorkin, M.; Qi, J.M.; Kim, H.M.S.; Hamill, J.B.; Kozlow, J.H.M.; Pusic, A.L.M.; Wilkins, E.G.M. Acellular dermal matrix in immediate expander/implant breast reconstruction: A multicenter assessment of risks and benefits. *Plast. Reconstr. Surg.* **2017**, *140*, 1091–1100. [CrossRef]

42. Gschwantler-Kaulich, D.; Schrenk, P.; Bjelic-Radisic, V.; Unterrieder, K.; Leser, C.; Fink-Retter, A.; Salama, M.; Singer, C. Mesh versus acellular dermal matrix in immediate implant-based breast reconstruction—A prospective randomized trial. *Eur. J. Surg. Oncol.* **2016**, *42*, 665–671. [CrossRef]

43. McCarthy, C.; Lee, C.; Halvorson, E.G.; Riedel, E.; Pusic, A.L.; Mehrara, B.J.; Disa, J.J. The use of acellular dermal matrices in two-stage expander/implant reconstruction: A multicenter, blinded randomised controlled trial. *Plast. Reconstr. Surg.* **2012**, *130* (Suppl. S2), 57–66. [CrossRef]

44. Clavien, P.A.; Barkun, J.; de Oliveira, M.L.; Vauthey, J.N.; Dindo, D.; Schulick, R.D.; de Santibañes, E.; Pekolj, J.; Slankamenac, K.; Bassi, C.; et al. The Clavien-Dindo Classification of Surgical Complications: Five-Year Experience. *Ann. Surg.* **2009**, *250*, 187–196. [CrossRef]

45. Chinta, S.; Koh, D.J.; Sobti, N.; Packowski, K.; Rosado, N.; Austen, W.; Jimenez, R.B.; Specht, M.; Liao, E.C. Cost analysis of pre-pectoral implant-based breast reconstruction. *Sci. Rep.* **2022**, *12*, 17512. [CrossRef]

46. Deutschmann, C.; Singer, C.F.; Gschwantler-Kaulich, D.; Pfeiler, G.; Leser, C.; Baltzer, P.A.T.; Helbich, T.H.; Kraus, C.; Korbatits, R.; Marzogi, A.; et al. Residual fibroglandular breast tissue after mastectomy is associated with an increased risk of a local recurrence or a new primary breast cancer. *BMC Cancer* **2023**, *23*, 281. [CrossRef]

47. Kaas, R.; Senno Verhoef, S.; Wesseling, J.; Rookus, M.A.; Oldenburg, H.S.A.; Vrancken Peeters, M.-J.; Rutgers, E.J.T. Prophylactic mastectomy in BRCA1 and BRCA2 mutation carriers: Very low risk for subsequent breast cancer. *Ann. Surg.* **2010**, *251*, 488–492. [CrossRef]

48. Heemskerk-Gerritsen, B.A.; Brekelmans, C.T.; Menke-Pluymers, M.B.; van Geel, A.N.; Tilanus-Linthorst, M.M.; Bartels, C.C.; Tan, M.; Meijers-Heijboer, H.E.; Klijn, J.G.; Seynaeve, C. Prophylactic mastectomy in BRCA1/2 mutation carriers and women at risk of hereditary breast cancer: Longterm experiences at the Rotterdam Family Cancer Clinic. *Ann. Surg. Oncol.* **2007**, *14*, 3335–3344. [CrossRef]

49. Woitek, R.; Pfeiler, G.; Farr, A.; Kapetas, P.; Furtner, J.; Bernathova, M.; Schöpf, V.; Clauser, P.; Marino, M.A.; Pinker, K.; et al. MRI-based quantification of residual fibroglandular tissue of the breast after conservative mastectomies. *Eur. J. Radiol.* **2018**, *104*, 1–7. [CrossRef]

50. Andersson, M.N.; Sund, M.; Svensson, J.; Björkgren, A.; Wiberg, R. Prophylactic mastectomy—Correlation between skin flap thickness and residual glandular tissue evaluated postoperatively by imaging. *J. Plast. Reconstr. Aesthetic Surg.* **2022**, *75*, 1813–1819. [CrossRef]

51. Frey, J.D.; Salilian, A.A.; Choi, M.; Karp, N.S. Mastectomy flap thickness and complications in nipplesparing mastectomy: Objective evaluation using magnetic resonance imaging. *Plast. Reconstr. Surg. Glob. Open* **2017**, *5*, e1439. [CrossRef]

52. De Vita, R.; Zoccali, G.; Buccheri, E.M.; Costantini, M.; Botti, C.; Pozzi, M. Outcome evaluation after 2023 nipple-sparing mastectomies: Our experience. *Plast. Reconstr. Surg.* **2017**, *139*, 335e–347e. [CrossRef]

53. Wiberg, R.; Andersson, M.N.; Svensson, J.; Rosén, A.; Koch, F.; Björkgren, A.; Sund, M. Prophylactic mastectomy: Postoperative skin flap thickness evaluated by MRT, ultrasound and clinical examination. *Ann. Surg. Oncol.* **2020**, *27*, 2221–2228. [CrossRef]

54. Adam, H.; Bygdeson, M.; de Boniface, J. The oncological safety of nipple-sparing mastectomy—A Swedish matched cohort study. *Eur. J. Surg. Oncol.* **2014**, *40*, 1209–1215. [CrossRef]

55. Joo, J.H.; Ki, Y.; Kim, W.; Nam, J.; Kim, D.; Park, J.; Kim, H.Y.; Jung, Y.J.; Choo, K.S.; Nam, K.J.; et al. Pattern of local recurrence after mastectomy and reconstruction in breast cancer patients: A systematic review. *Gland. Surg.* **2021**, *10*, 2037–2046. [CrossRef]
56. Al-Himdani, S.; Timbrell, S.; Tan, K.; Morris, J.; Bundred, N. Prediction of margin involvement and local recurrence after skin-sparing and simple mastectomy. *Eur. J. Surg. Oncol.* **2016**, *42*, 935–941. [CrossRef]

57. De La Cruz, L.; Moody, A.M.; Tappy, E.E.; Blankenship, S.A.; Hecht, E.M. Overall survival, disease-free survival, local recurrence, and nipple-areolar recurrence in the setting of nipple-sparing mastectomy: A meta-analysis and systematic review. *Ann. Surg. Oncol.* **2015**, *22*, 3241–3249. [CrossRef]

58. Mutter, R.W.; Frost, M.H.; Hoskin, T.L.; Johnson, J.L.; Hartmann, L.C.; Boughey, J.C. Breast cancer after prophylactic mastectomy (bilateral or contralateral prophylactic mastectomy), a clinical entity: Presentation, management, and outcomes. *Breast Cancer Res. Treat.* **2015**, *153*, 183–190. [CrossRef]

59. Rebbbeck, T.R.; Friebel, T.; Lynch, H.T.; Neuhausen, S.L.; Veer, L.V.; Garber, J.E.; Evans, G.R.; Narod, S.A.; Isaacs, C.; Matloff, E.; et al. Bilateral prophylactic mastectomy reduces breast cancer risk in BRCA1 and BRCA2 mutation carriers: The PROSE study group. *J. Clin. Oncol.* **2004**, *22*, 1055–1062. [CrossRef]

60. Domchek, S.M.; Friebel, T.M.; Singer, C.F.; Evans, D.G.; Lynch, H.T.; Isaacs, C.; Garber, J.E.; Neuhausen, S.L.; Matloff, E.; Eeles, R.; et al. Association of risk-reducing surgery in BRCA1 or BRCA2 mutation carriers with cancer risk and mortality. *JAMA* **2010**, *304*, 967–975. [CrossRef]

61. Heemskerk-Gerritsen, B.A.; Menke-Pluijmers, M.B.; Jager, A.; Tilanus-Linthorst, M.M.; Koppert, L.B.; Obdeijn, I.M.; van Deurzen, C.H.; Collée, J.M.; Seynaeve, C.; Hooning, M.J. Substantial breast cancer risk reduction and potential survival benefit after bilateral mastectomy when compared with surveillance in healthy BRCA1 and BRCA2 mutation carriers: A prospective analysis. *Ann. Oncol.* **2013**, *24*, 2029–2035. [CrossRef]

62. Skytte, A.-B.; Crüger, D.; Gerster, M.; Laenkholm, A.-V.; Lang, C.; Brøndum-Nielsen, K.; Andersen, M.; Sunde, L.; Kølvraa, S.; Gerdes, A.-M. Breast cancer after bilateral risk-reducing mastectomy. *Clin. Genet.* **2011**, *79*, 431–437. [CrossRef]

63. Petit, J.Y.; Veronesi, U.; Orecchia, R.; Rey, P.; Martella, S.; Didier, F.; Viale, G.; Veronesi, P.; Luini, A.; Galimberti, V.; et al. Nipple sparing mastectomy with nipple areola intraoperative radiotherapy: One thousand and one cases of a five years experience at the European institute of oncology of Milan (EIO). *Breast Cancer Res. Treat.* **2009**, *117*, 333–338. [CrossRef]

64. Lago, V.; Maisto, V.; Gimenez-Climent, J.; Vila, J.; Vazquez, C.; Estevan, R. Nipple-sparing mastectomy as treatment for patients with ductal carcinoma in situ: A 10-year follow-up study. *Breast J.* **2018**, *24*, 298–303. [CrossRef]

65. Metere, A.; Fabiani, E.; Lonardo, M.T.; Giannotti, D.; Pace, D.; Giacomelli, L. Nipple-Sparing Mastectomy Long-Term Outcomes: Early and Late Complications. *Medicina* **2020**, *56*, 166. [CrossRef]

66. Shen, Z.; Sun, J.; Yu, Y.; Chiu, C.; Zhang, Z.; Zhang, Y.; Xu, J. Oncological safety and complication risks of mastectomy with or without breast reconstruction: A Bayesian analysis. *J. Plast. Reconstr. Aesthetic Surg.* **2021**, *74*, 290–299. [CrossRef]

67. Bargon, C.A.; Young-Afat, D.A.; Ikinci, M.; Braakenburg, A.; Rakhorst, H.A.; Mureau, M.A.; Verkooijen, H.M.; Doeksen, A. Breast cancer recurrence after immediate and delayed postmastectomy breast reconstruction—A systematic review and meta-analysis. *Cancer* **2022**, *128*, 3449–3469. [CrossRef]

68. Gieni, M.; Avram, R.; Dickson, L.; Farrokhyar, F.; Lovrics, P.; Faidi, S.; Sne, N. Local breast cancer recurrence after mastectomy and immediate breast reconstruction for invasive cancer: A meta-analysis. *Breast* **2012**, *21*, 230–236. [CrossRef]

69. Ha, J.H.; Cheun, J.-H.; Jung, J.-J.; Kim, H.-K.; Lee, H.-B.; Shin, H.-C.; Moon, H.-G.; Han, W.; Myung, Y.; Jeong, J.H.; et al. Impact of implant surface type on breast cancer relapse after breast reconstruction: Propensity score-matched study. *Br. J. Surg.* **2023**, *110*, 1288–1292. [CrossRef]

70. Karoobi, M.; Yazd, S.M.M.; Nafissi, N.; Zolnouri, M.; Khosravi, M.; Sayad, S. Comparative clinical outcomes of using three-dimensional and TIGR mesh in immediate breast reconstruction surgery for breast cancer patients. *J. Plast. Reconstr. Aesthetic Surg.* **2023**, *86*, 321–328. [CrossRef]

71. Lam, T.C.; Hsieh, F.; Salinas, J.; Boyages, J. Immediate and Long-term Complications of Direct-to-implant Breast Reconstruction after Nipple- or Skin-sparing Mastectomy. *Plast. Reconstr. Surg. Glob. Open* **2018**, *6*, e1977. [CrossRef] [PubMed]

72. Li, L.; Su, Y.; Xiu, B.; Huang, X.; Chi, W.; Hou, J.; Zhang, Y.; Tian, J.; Wang, J.; Wu, J. Comparison of prepectoral and subpectoral breast reconstruction after mastectomies: A systematic review and meta-analysis. *Eur. J. Surg. Oncol.* **2019**, *45*, 1542–1550. [CrossRef]

73. Mirhaidari, S.J.; Azouz, V.; Wagner, D.S. Prepectoral versus subpectoral direct to implant immediate breast reconstruction. *Ann. Plast. Surg.* **2020**, *84*, 263–270. [CrossRef]

74. Li, Y.; Xu, G.; Yu, N.; Huang, J.; Long, X. Prepectoral Versus Subpectoral Implant Based Breast Reconstruction: A Meta-analysis. *Ann. Plast. Surg.* **2020**, *85*, 437–447. [CrossRef]

75. Choi, Y.-S.; You, H.-J.; Lee, T.-Y.; Kim, D.-W. Comparing Complications of Biologic and Synthetic Mesh in Breast Reconstruction: A Systematic Review and Network Meta-Analysis. *Arch. Plast. Surg.* **2023**, *50*, 3–9. [CrossRef]

76. Murphy, D.M.; O'donnell, J.P.M.; Ryan, J.; O'Neill, B.L.; Boland, M.R.M.M.; Lowery, A.J.; Kerin, M.J.F.; McInerney, N.M. Immediate Breast Cancer Reconstruction with or without Dermal Matrix or Synthetic Mesh Support: A Review and Network Meta-Analysis. *Plast. Reconstr. Surg.* **2023**, *151*, 563e–574e. [CrossRef]

77. Frey, J.D.; Salibian, A.A.; Levine, J.P.; Karp, N.S.; Choi, M. Incision Choices in Nipple-Sparing Mastectomy: A Comparative Analysis of Outcomes and Evolution of a Clinical Algorithm. *Plast. Reconstr. Surg.* **2018**, *142*, 826e–835e. [CrossRef]

78. Zhu, L.; Liu, C. Postoperative Complications Following Prepectoral Versus Partial Subpectoral Implant-Based Breast Reconstruction Using ADM: A Systematic Review and Meta-analysis. *Aesthetic Plast. Surg.* **2023**, *47*, 1260–1273. [CrossRef]
79. Sigalove, S.; Maxwell, G.P.; Sigalove, N.M.; Storm-Dickerson, T.L.; Pope, N.M.; Rice, J.M.; Gabriel, A. Prepectoral Implant-Based Breast Reconstruction and Postmastectomy Radiotherapy: Short-Term Outcomes. *Plast. Reconstr. Surg. Glob. Open* **2017**, *5*, e1631. [CrossRef]

80. Sigalove, S. Prepectoral breast reconstruction and radiotherapy—A closer look. *Gland Surg.* **2019**, *8*, 67–74. [CrossRef]

81. Momoh, A.O.; Ahmed, R.; Kelley, B.P.; Aliu, O.; Kidwell, K.M.; Kozlow, J.H.; Chung, K.C. A Systematic Review of Complications of Implant-based Breast Reconstruction with Prereconstruction and Postreconstruction Radiotherapy. *Ann. Surg. Oncol.* **2014**, *21*, 118–124. [CrossRef]

82. Hart, S.E.; Brown, D.L.; Kim, H.M.; Qi, J.; Hamill, J.B.; Wilkins, E.G. Association of Clinical Complications of Chemotherapy and Patient-Reported Outcomes After Immediate Breast Reconstruction. *JAMA Surg.* **2021**, *156*, 847–855. [CrossRef]

83. Scardina, L.; Di Leone, A.; Biondi, E.; Carnassale, B.; Sanchez, A.M.; D'archi, S.; Franco, A.; Moschella, F.; Magno, S.; Terribile, D.; et al. Prepectoral vs. Submuscular Immediate Breast Reconstruction in Patients Undergoing Mastectomy after Neoadjuvant Chemotherapy: Our Early Experience. *J. Pers. Med.* **2022**, *12*, 1533. [CrossRef]

84. Long, C.; Kraenzlin, F.; Aravind, P.; Kokosis, G.; Yesantharao, P.; Sacks, J.M.; Rosson, G.D. Prepectoral breast reconstruction is safe in the setting of post-mastectomy radiation therapy. *J. Plast. Reconstr. Aesthetic Surg.* **2022**, *75*, 3041–3047. [CrossRef] [PubMed]

85. Sbitany, H. Important Considerations for Performing Prepectoral Breast Reconstruction. *Plast. Reconstr. Surg.* **2017**, *140*, 7S–13S. [CrossRef]

86. Salzberg, C.A.; Ashikari, A.Y.; Berry, C.; Hunsicker, L.M. Acellular dermal matrix-assisted direct-to-implant breast reconstruction and capsular contracture: A 13-year experience. *Plast. Reconstr. Surg.* **2016**, *138*, 329–337. [CrossRef]

87. Loo, Y.L.; Haider, S. The use of porcine acellular dermal matrix in single-stage, implant-based immediate breast reconstruction: A 2-center retrospective outcome study. *Plast. Reconstr. Surg. Glob. Open* **2018**, *6*, e1895. [CrossRef]

88. Ter Louw, R.P.; Nahabedian, M.Y. Prepectoral breast reconstruction. *Plast. Reconstr. Surg.* **2017**, *140*, 51S–59S. [CrossRef]

89. Cook, P.; Yin, G.; Ayeni, F.E.; Eslick, G.D.; Edirimanne, S. Does Immediate Breast Reconstruction Lead to a Delay in Adjuvant Chemotherapy for Breast Cancer? A Meta-Analysis and Systematic Review. *Clin. Breast Cancer* **2023**, *23*, e285–e295. [CrossRef]

90. O'connell, R.L.; Rattay, T.; Dave, R.V.; Trickey, A.; Skillman, J.; Barnes, N.L.P.; Gardiner, M.; Harnett, A.; Potter, S.; Holcombe, C. Breast Reconstruction Research Collaborative. The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: The iBRA-2 study. *Br. J. Cancer* **2019**, *120*, 883–895. [CrossRef]

91. Cui, W.; Xie, Y. Oncological results in women with wound complications following mastectomy and immediate breast reconstruction: A meta-analysis. *Int. Wound J.* **2023**, *20*, 1361–1368. [CrossRef] [PubMed]

92. Viezel-Mathieu, A.; Alnaif, N.; Aljerian, A.; Safran, T.; Brabant, G.; Boileau, J.-F.; Dionisopoulos, T. Acellular der- mal matrix– sparing direct-to-implant prepectoral breast reconstruction: A comparative study including cost analysis. *Ann. Plast. Surg.* **2020**, *84*, 139–143. [CrossRef]

**Disclaimer/Publisher's Note:** The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.