Inhibition Mechanism of Acellular Dermal Matrix on Capsule Formation in Expander-Implant Breast Reconstruction After Postmastectomy Radiotherapy

Attenuating Chronic Fibrosis: Decreasing Foreign Body Response with Acellular Dermal Matrix

Surgical implants are increasingly used across multiple medical disciplines, with applications ranging from tissue reconstruction to improving compromised organ and limb function. Despite their significant potential for improving health and quality of life, biomaterial implant function is severely limited by the body's immune response to its presence: this is known as the foreign body response (FBR) and is characterized by chronic inflammation and fibrotic capsule formation. This response can result in life-threatening sequelae such as implant malfunction, superimposed infection, and associated vessel thrombosis, in addition to soft tissue disfigurement. Patients may require frequent medical visits, as well as repeated invasive procedures, increasing the burden on an already strained health care system. Currently, the FBR and the cells and molecular mechanisms that mediate it are poorly understood. With applications across a wide array of surgical specialties, acellular dermal matrix (ADM) has emerged as a potential solution to the fibrotic reaction seen with FBR. Although the mechanisms by which ADM decreases chronic fibrosis remain to be clearly characterized, animal studies across diverse surgical models point to its biomimetic properties that facilitate decreased periprosthetic inflammation and improved host cell incorporation. Impact Statement Foreign body response (FBR) is a significant limitation to the use of implantable biomaterials. Acellular dermal matrix (ADM) has been observed to decrease the fibrotic reaction seen with FBR, although its mechanistic details are poorly understood. This review is dedicated to summarizing the primary literature on the biology of FBR in the context of ADM use, using surgical models in breast reconstruction, abdominal and chest wall repair, and pelvic reconstruction. This article will provide readers with an overarching review of shared mechanisms for ADM across multiple surgical models and diverse anatomical applications.

Human-Mimic Submuscular and Premuscular Irradiated Rat Model: Histologic Characteristics of the Capsule Tissue in Contact with the Breast Implant

Background

In this study, we established two rat models that mimic human submuscular and premuscular breast reconstruction. We analyzed the capsule formation according to surgical techniques and adjacent tissues, including the chest wall tissues, such as the ribs and acellular dermal matrices (ADMs) that come in contact with silicone implants.

Methods

This study consisted of experiments on 12 Sprague-Dawley rats that underwent implant reconstruction using ADM. They were divided into two groups: rats that underwent dual-plane implantation (n = 6; group 1) and those that underwent premuscular implant insertion (n = 6; group 2). All rats were irradiated with 35 Gy of fractionated radiation. Three months after surgery, the histology and immunochemistry of the capsule tissues of the ADM, muscle, and chest wall were analyzed.

Results

Overall capsule thickness was thicker in group 1. Based on the tissue in contact with the silicone implant, ADM had a thinner capsule, less inflammation, less fibrosis, and less vascularization than the muscle and chest wall tissues.

Conclusions

This study described two rat models of clinically relevant implant-based breast reconstruction using a submuscular and premuscular plane, ADM, and irradiation. Overall, the premuscular implantation rat model was associated with a thinner capsule. The ADM in contact with the silicone implant, even after irradiation, had superior protection from radiation compared with the other tissues.

How Porcine Acellular Dermal Matrix Influences the Development of the Breast Capsule 1 Year after Implantation: A Histopathological Analysis

Background

In prepectoral breast reconstruction (PPBR) the acellular dermal matrix (ADM)'s integration capacity into the tissue is known. The aim of this study was to analyze the effect of the ADM on development and composition of the peri-implant breast capsule in a dynamic setting of breast tissue expansion during two-stage prepectoral breast reconstruction.

Methods

This is a prospective single-center study in which 50 patients who underwent mastectomy and breast reconstruction with prepectoral tissue expander and Braxon ADM (group A) and submuscular tissue expander (group B) were enrolled. One-year post implantation hematoxylin & eosin (H&E) staining and immunohistochemistry analyses were done on capsule tissue samples.

Results

The analysis conducted on H&E-stained samples showed a significant reduction of cellular density and a decrease of the cellular infiltration in capsules of ADM-covered expanders compared with naked expander capsules (P < 0.05). The immunohistochemical analyses showed that group A capsules presented significantly less M1 CD68+ macrophages (P < 0.05), lower alfa-SMA expression levels, and a lower number of myofibroblasts (P < 0.05) compared with group B capsules. Presence of lymphatic vessels was minimally detected in both groups.

Conclusions

The ADM presence around the prepectoral tissue expander influences the development of the peri-implant capsule, causing a significant reduction of the number of cells and inflammatory infiltrate, especially M1 macrophages and myofibroblasts. The ADM Braxon is therefore effective in creating a noninflamed capsule around the implant and in dynamic tissue conditions, and such an environment is maintained in time.

Difference in the Occurrence of Capsular Contracture According to Tissue Characteristics in an Irradiated Rat Model

BACKGROUND

This study was performed to evaluate the hypothesis that capsule formation varies according to the radiation dose in muscle tissues; chest wall tissues, including the ribs; and acellular dermal matrices (ADM) that are in contact with the silicone implant.

METHODS

In this study, 20 Sprague-Dawley rats underwent submuscular plane implant reconstruction using ADM. They were divided into four groups: an unradiated control group ( n = 5), nonfractionated radiation at a dose of 10 Gy ( n = 5), nonfractionated radiation at a dose of 20 Gy ( n = 5), and fractionated radiation at a dose of 35 Gy ( n = 5). Three months after surgery, hardness was measured, and histologic and immunochemical analyses of the capsule tissues of the ADM, muscle tissues, and chest wall tissues were analyzed.

RESULTS

As the radiation dose increased, the silicone implant became harder, but no significant difference in capsule thickness according to the radiation dose was observed. Based on the tissue in contact with the silicone implant, ADM had a thinner capsule thickness than the muscle tissues, as well as less inflammation and less neovascularization compared with the other tissues.

CONCLUSIONS

This study describes a new rat model of clinically relevant implant-based breast reconstruction using a submuscular plane and ADM with irradiation. The ADM in contact with the silicone implant, even after irradiation, was protected from radiation compared with the other tissues.

CLINICAL RELEVANCE STATEMENT

These research results could support the use of ADM in implant-based breast reconstruction for prevention of the capsular contracture, even after radiation.

Long-Term Ultrasonographic and Histologic Changes in Acellular Dermal Matrix in Implant-Based Breast Reconstructions

BACKGROUND

Acellular dermal matrix (ADM) is composed of extracellular matrix (ECM) and is widely used in implant-based breast reconstructions. However, long-term changes in the ADM around implants have not been established. This study aimed to investigate long-term changes in the ADM covering breast implants using serial ultrasound and histologic evaluations.

METHODS

The authors evaluated the ultrasound results of 145 patients who underwent implant-based breast reconstructions with ADM coverings. The ultrasound results obtained within 18 months of surgery and those obtained 5 years postoperatively were analyzed to determine the change in ADM thickness. For histologic analysis, the ADM was harvested from 30 patients who underwent secondary breast surgery. Histologic features of the ECM and cellular components within the ADM were compared at specific intervals from ADM implantation and the second operation (early ADM group, <18 months; late ADM group, >5 years postoperatively).

RESULTS

The ADM thickness on ultrasound examination was significantly decreased in the late ADM group compared with that in the early ADM group ( P < 0.001). Histologic analyses revealed that the late ADM group had less thickness with lower ECM levels versus the early ADM group. Increased infiltration of host cells, such as vascular endothelial cells, myofibroblasts, and immune cells, occurred in the late ADM group.

CONCLUSIONS

Implanted ADMs underwent gradual thinning over time, in addition to ECM reduction and infiltration of host cells. These findings are useful in understanding the natural course of ADMs currently used in implant-based breast reconstructions.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Postoperative Complications Following Prepectoral Versus Partial Subpectoral Implant-Based Breast Reconstruction Using ADM: A Systematic Review and Meta-analysis

BACKGROUND

There is a paucity of evidence comparing the safety of prepectoral and partial subpectoral implant-based breast reconstruction using acellular dermal matrices (ADM). We performed a meta-analysis to evaluate the postoperative complications of the two approaches.

METHODS

PubMed, EMBASE, Web of Science and Cochrane Library were searched to retrieve relevant articles. The rates of the complications were, respectively, pooled, and relative risk (RR) was estimated with 95% confidence intervals (CIs) to compare the incidence between the two cohorts.

RESULTS

Ten articles reporting on 2667 breast reconstructions were eligible. The hematoma rate was lower in the prepectoral group (RR  =  0.590, 95% CI 0.351-0.992). No significant difference was observed in terms of seroma (RR = 1.079, 95% CI 0.489-2.381), skin flap necrosis (RR = 0.936, 95% CI 0.587-1.493), infection (RR = 0.985, 95% CI 0.706-1.375), tissue expander/implant explantation (RR  =  0.741, 95% CI 0.506-1.085), wound dehiscence (RR = 1.272, 95% CI 0.605-2.673), capsular contracture (RR = 0.939, 95% CI 0.678-1.300) and rippling (RR = 2.485, 95% CI 0.986-6.261). The RR of animation deformity for the prepectoral group compared with the subpectoral group was 0.040 (95% CI, 0.002-0.853).

CONCLUSIONS

This systematic review suggested that with appropriate patient selection, prepectoral breast reconstruction could avoid animation deformity without incurring higher risk of early wound complications, capsular contracture or rippling than partial subpectoral breast reconstruction. Plastic surgeons should complete a comprehensive assessment of the patients before choosing appropriate surgical approaches in clinical practice.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

COVID-19 Vaccination Status and Capsular Contracture Following Prosthetic Breast Reconstruction: A Retrospective, Multicenter Nested Case-Control Study

BACKGROUND

Capsular contracture (CC) is a common long-term complication following prosthetic-based breast reconstruction (PBBR). Seven cases of CC following mRNA vaccination for coronavirus 2019 (COVID-19) are reported in the literature.

OBJECTIVES

The aim of this study was to determine whether receiving the COVID-19 vaccine was associated with CC development following PBBR.

METHODS

A retrospective, multicenter nested case-control study was performed from January 2014 to July 2022 of adult female patients who underwent PBBR with acellular dermal matrix placement. Cases of CC were selected if no adjuvant radiation was received and they presented for follow-up between December 2020 and July 2022. Controls included patients who met inclusion criteria but who did not experience CC in either breast. Patient demographics, breast cancer characteristics, reconstructive surgery details, postoperative complications, and COVID-19 exposure details were analyzed and correlated with CC development.

RESULTS

Of a total of 230 patients (393 breasts) who received PBBR, 85 patients (135 breasts) met inclusion criteria, of whom 12 patients (19 breasts) developed CC and 73 patients (116 breasts) did not. At the time of median follow-up of 18.1 months (n = 85; interquartile range, 12.2-33.6 months), no statistically significant differences were observed between the short- or long-term complications in cases or controls. There were no significant differences in COVID-19 vaccination status, number of vaccine doses, or vaccination type between cases and controls. Vaccination status was not associated with greater odds of CC development (odds ratio, 1.44; 95% CI, 0.42-5.37; P > .05).

CONCLUSIONS

Direct association between CC and COVID-19 vaccination is difficult to prove. Given the known risk of severe COVID-19 infection among immunocompromised patients, those with breast cancer who undergo PBBR should be properly counseled on the benefits and risks of vaccination.

LEVEL OF EVIDENCE: 4

Implantation and tracing of green fluorescent protein-expressing adipose-derived stem cells in peri-implant capsular fibrosis

BACKGROUND

Adipose-derived stem cells (ASCs) have been reported to reduce fibrosis in various tissues. In this study, we investigated the inhibitory role of ASCs on capsule formation by analyzing the histologic, cellular, and molecular changes in a mouse model of peri-implant fibrosis. We also investigated the fate and distribution of ASCs in the peri-implant capsule.

METHODS

To establish a peri-implant fibrosis model, customized silicone implants were inserted into the dorsal site of C57BL/6 wild-type mice. ASCs were harvested from the fat tissues of transgenic mice that express a green fluorescent protein (GFP-ASCs) and then injected into the peri-implant space of recipient mice. The peri-implant tissues were harvested from postoperative week 2 to 8. We measured the capsule thickness, distribution, and differentiation of GFP-ASCs, as well as the cellular and molecular changes in capsular tissue following ASC treatment.

RESULTS

Injected GFP-ASCs were distributed within the peri-implant capsule and proliferated. Administration of ASCs reduced the capsule thickness, decreased the number of myofibroblasts and macrophages in the capsule, and decreased the mRNA level of fibrogenic genes within the peri-implant tissue. Angiogenesis was enhanced due to trans-differentiation of ASCs into vascular endothelial cells, and tissue hypoxia was relieved upon ASC treatment.

CONCLUSIONS

We uncovered that implanted ASCs inhibit capsule formation around the implant by characterizing a series of biological alterations upon ASC treatment and the fate of injected ASCs. These findings highlight the value of ASCs for future clinical applications in the prevention of capsular contracture after implant-based reconstruction surgery.

The influence of synthetic and biologic matrices on the choice of the implant plane during breast reconstruction. The modern state of the problem

Immediately after silicone implants were described, the technique of prepectoral implant placement dominated in breast reconstructive surgery. However, this plane soon had to be abandoned due to the high frequency of complications, such as infection, capsular contracture, explantation. For these reasons, surgeons soon had to switch to the subpectoral plane. Several decades later, thanks to the discovery of synthetic and biological meshes, surgeons returned to the prepectoral plane, but at a technically new level.

The purpose of this review was to analyze the role of biological and synthetic matrices as factors influencing the choice of the implant plane in one-stage breast reconstruction.

Postmastectomy Radiation Therapy in the Setting of Two-Stage Retropectoral Implant-Based Breast Reconstruction: Should It be Delivered Before or After Implant Exchange? A Retrospective Analysis on 183 Patients

INTRODUCTION

Postmastectomy radiation therapy (PMRT) has a primary role in the treatment of locally advanced breast cancer; however, the most appropriate timing of irradiation in immediate tissue expander breast reconstruction (ITEBR) still remains unknown.

METHODS

A retrospective review was performed on all women undergoing mastectomy and retropectoral ITEBR at Campus Bio-Medico University Hospital in Rome, Italy, between 2010 and 2019. The patients were categorized into three cohorts: patients undergoing PMRT with the tissue expander (TE) in situ, patients with PMRT delivered to the permanent implant (PI), patients who were not administered RT. Complications and failure rates were analysed and compared. Potential predictors of adverse outcomes were analysed.

RESULTS

Over 10 years, 183 patients underwent retropectoral ITEBR (55 PMRT-TE, 50 PMRT-PI, 78 no-PMRT). The three groups were well matched with respect to patient- and treatment-related factors (p > 0.05), with the exception of neoadjuvant chemotherapy and irradiation. The mean follow-up was, respectively, 4.58, 7 and 5.75 years. Radiotherapy either to the TE or to the PI was independently associated with failure and conversion to autologous procedures (p < 0.0001). Failure rate was significantly higher when TE was irradiated (p = 0.03). PMRT was associated with severe capsular contracture development (p < 0.00001), the odds being higher when irradiation was delivered after implant exchange (p = 0.04). Increased BMI was significantly associated with failure.

CONCLUSIONS

When PMRT is delivered to the TE, the risk of failure is higher (OR 2.77); when the PI is irradiated, reconstruction will more likely be affected by severe capsular contracture (OR 2.7). However, considering that the overall risk of severe capsular contracture correlated to PMRT is higher than failure, we believe that irradiation should be delivered to the TE. Performing a proper capsuloplasty at the time of implant exchange, indeed, allows to correct the deformities related to radiation-induced capsular contracture. Patients with unfavourable outcomes after TE placement and RT, instead, can be directly switched to autologous reconstruction.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Braxon®-assisted prepectoral breast reconstruction: A decade later

We are sitting on the cusp of the bioengineered breast era, in which implant-based breast reconstruction is seeing a growing trend and biotechnology research progressively empowers clinical practice. As never before, the choice of biomaterials has acquired great importance for achieving reconstructive outcomes, and the increase in the use of acellular dermal matrices (ADMs) in the field of senology tells us a story of profound upheaval and progress. With the advent of prepectoral breast reconstruction (PPBR), plenty of devices have been proposed to wrap the silicone prosthesis, either completely or partially. However, this has caused a great deal of confusion and dissent with regard to the adoption of feasible reconstructive strategies as well as the original scientific rationale underlying the prepectoral approach. Braxon^® is the very first device that made prepectoral implant positioning possible, wrapping around the prosthesis and exerting the proven ADM regenerative potential at the implant–tissue interface, taking advantage of the body's physiological healing mechanisms. To date, the Braxon^® method is among the most studied and practiced worldwide, and more than 50 publications confirm the superior performance of the device in the most varied clinical scenarios. However, a comprehensive record of the working of this pioneering device is still missing. Therefore, our aim with this review is to lay a structured knowledge of surgery with BRAXON^® and to provide a decision-making tool in the field of PPBR through a complete understanding on the very first device for prepectoral, one decade after its introduction.

Acellular Dermal Matrix Mimicking a New Retroareolar Mass After Central Pillar Neonipple Reconstruction

ABSTRACT

Acellular dermal matrix (ADM) is an increasingly popular alloplastic cadaveric dermis used to enhance postmastectomy reconstruction. Acellular dermal matrix can be used as a nipple-shaped cylinder in central pillar nipple reconstruction to help maintain long-term projection. We report a unique presentation of ADM mimicking a retroareolar mass after central pillar neonipple reconstruction. A 49-year-old woman with a history of invasive ductal carcinoma underwent delayed nipple reconstruction after lumpectomy and oncoplastic closure using an inframammary V-Y advancement flap.The nipple reconstruction was performed using pretattoo and articulated tab flaps. A rolled tube of acellular dermal matrix was placed in the central aspect of the neonipple reconstruction for projection. At 4 months postoperative, a screening mammogram and ultrasound noted a new retroareolar mass classified as BIRADS 4 necessitating a breast biopsy. Biopsy revealed portions of fibrous connective tissue consistent with partially incorporated acellular dermal matrix allograft. There was no evidence of malignancy. To mitigate the risk of future radiographic or clinical misinterpretation of ADM in nipple reconstruction, the placement of radiopaque markers such as microclips on the ADM implant could be a useful adjunct. Radiologists and surgeons should include ADM artifact in their differential diagnosis of radiologic imaging when evaluating a new mass in the proximity of prior ADM placement in neonipple reconstruction of the breast.

Biological Cover Mitigates Disruption of the Dermal Structure in Mechanically Expanded Skin in a Porcine Model

Tissue expansion is an integral procedure of the vast majority of breast reconstruction and has a significant impact on the final clinical outcomes. Therefore, technological advances leading to a fewer number of unfavorable outcomes and a decrease in complication rates are imperative. In this study, using a porcine model, we investigated an effect of acellular dermal matrix (ADM) used as a tissue expander cover on the dermal changes induced by mechanical forces during tissue expansion. After 14 days of expansion, skin samples were collected from one animal, while the second animal underwent radiation, and tissue was collected 8 weeks later. Tissue expanded without the use of ADM and unexpanded skin served as the controls. Collected skin biopsies were used for histological and immunohistochemical evaluation, and for gene expression analysis. We revealed that the biological cover incorporation into host tissue is facilitated by macrophages without inducing a broad inflammatory response. The utilization of ADM mitigated disruption in the dermal structure, excessive collagen deposition, and capsule formation in non-irradiated expanded skin. The protective effect was not fully maintained in irradiated skin. These results demonstrate that tissue expansion might be improved by using the tissue expander cover.

The Role of Premastectomy Mastopexy and Breast Reduction in the Reconstruction of the Enlarged or Ptotic Breast

BACKGROUND

The indications for nipple-sparing mastectomy have broadened over time. Patients undergoing nipple-sparing mastectomy who have enlarged or ptotic breasts are at risk for skin flap and/or nipple-areola complex necrosis. Premastectomy mastopexy or breast reduction may reduce the risk for these complications.

METHODS

A retrospective review was undertaken in a series of patients who underwent premastectomy reduction mammaplasty or mastopexy followed by nipple-sparing mastectomy and immediate staged tissue expander/implant-based breast reconstruction. In each case, a subnipple biopsy was performed at the premastectomy procedure to clear it of any potential malignant involvement. In addition, the area under the areola was undermined to maximize the effect of the delay phenomenon on the eventual survival of the nipple-areola complex. Final reconstruction involved tissue expander exchange for a permanent implant with associated fat grafting. Data regarding surgical timing and selected postoperative complications were recorded.

RESULTS

In total, 39 implant-based reconstructions were performed in 20 patients. There were no cases of mastectomy flap necrosis, and partial necrosis of the nipple-areola complex with delayed wound healing was seen in two breasts in the same patient. All patients eventually completed the reconstructive process successfully.

CONCLUSION

Premastectomy mastopexy or breast reduction may afford a protective effect against mastectomy flap or nipple-areola complex necrosis in patients with large or ptotic breasts who subsequently undergo nipple-sparing mastectomy with immediate breast reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Pre-Pectoral One-Stage Breast Reconstruction with Anterior Coverage Using Superior Anterior Biological Acellular Dermal Matrix (ADM) and Inferior Anterior Dermal Sling Support

The use of acellular dermal matrix (ADM) implants has enhanced breast reconstruction. ADM is a biotechnologically designed human tissue of bovine or porcine origin in which tissue processing removes cellular antigens. In this case report, we describe the use of ADM in one-stage prepectoral breast reconstruction. Skin-reduction breast reconstruction with a prepectoral implant was performed. We created a combined dermal pocket using the inferior dermal flap, sutured with a patch of acellular dermal matrix to continue its extension until the upper pole, to cover the implant. This technique offers single-stage immediate reconstruction, with a decreased requirement for ADM and increased use of vascularized tissue and implant support. Additionally, in the pre-pectoral space, decreased pain postoperatively and less anatomic disruption is offered.

The Impact of Radiotherapy on Patient-reported Outcomes of Immediate Implant-based Breast Reconstruction With and Without Mesh

OBJECTIVE

To explore the impact of PMRT on PROs of IBBR performed with and without mesh.

SUMMARY OF BACKGROUND DATA

PMRT is increasingly given to improve breast cancer outcomes but can adversely impact complications after IBBR.Little; however, is known about the impact of PMRT on the PROs of IBBR, especially when mesh is used.

METHODS

The implant Breast Reconstruction evAluation prospective cohort study recruited consecutive women undergoing immediate IBBR from 81 UK breast and plastic surgical units. Demographic, operative, oncological, and 3-month complication data were collected, and patients consented to receive validated PRO questionnaires at 18-months. The association between IBBR, PMRT, and PROs were investigated using mixed-effects regression models adjusted for clinically-relevant confounders and including a random-effect to account for potential clustering by center.

RESULTS

A total of 1163 women consented to receive 18-month questionnaires of whom 730 (63%) completed it. Patients undergoing PMRT (214 patients) reported worse PROs in 3 BREAST-Q domains: satisfaction with breasts [-6.27 points, P = 0.008, 95% confidence interval (CI) (-10.91, -1.63)], satisfaction with outcome [-7.53 points, P = 0.002, CI (-12.20, -2.85)] and physical well-being [-6.55 points, P < 0.001, CI (-9.43, -3.67)]. Overall satisfaction was worse in the PMRT group [OR 0.497, P = 0.002, CI (0.32, 0.77)]. These effects were not ameliorated by mesh use.

CONCLUSIONS

PMRT may adversely affect PROs after IBBR irrespective of whether mesh is used. These findings should be discussed with all patients considering IBBR and when indications for PMRT are borderline to enable informed decision-making regarding oncological and reconstructive treatment options.

TRIAL REGISTRATION

ISRCTN37664281.

Prevention of Abdominal Bulging Using Onlay Dermal Autografts from Discarded Zone IV TRAM Flap Tissue

While the transverse rectus abdominis myocutaneous (TRAM) flap is a popular option for abdominal-based breast reconstruction, abdominal wall morbidities such as bulging or hernia remain a concern. Here, we introduced a surgical technique for reinforcing the abdominal wall using an onlay autograft obtained from discarded zone IV tissue following a primary closure. We compared abdominal wall morbidities between patients receiving an onlay graft and those receiving primary closure only. We retrospectively reviewed the medical charts of patients who underwent breast reconstruction using a TRAM flap between December 2018 and May 2021. Additionally, we assessed donor-site morbidities based on physical examination. Of the 79 patients included, 38 had received a dermal graft and 41 had not. Donor-site morbidities occurred in 10 (24.5%) and 1 (2.6%) patients, and bulging occurred in 8 (19.5%) and 1 (2.6%) patients in the primary closure and dermal autograft groups, respectively. A statistically significant difference in the incidence of bulging was observed between the groups (p = 0.030). In conclusion, the introduction of a dermal autograft after primary closure can successfully ameliorate morbidities at the TRAM flap site.

Submuscular Implant-Based Breast Reconstruction Using a Musculofascial Pocket Formed by the Pectoralis Major Muscle and the Serratus Anterior Muscle Fascia: A Novel Surgical Approach

BACKGROUND

Subpectoral implant-based breast reconstruction following mastectomy commonly severs the inferior border of the pectoralis major muscle for better projection of the lower pole. This can affect a patient's postoperative motor function and result in animation deformity. Implant-based breast reconstruction using partial muscle coverage with an acellular dermal matrix (ADM) can be costly. There is an unmet clinical need for a novel surgical method for submuscular implant-based breast reconstruction.

METHODS

We describe an innovative technique for submuscular implant-based breast reconstruction following mastectomy. The approach utilizes the serratus anterior muscle fascia connected to the lateral margin of the pectoralis major muscle to form a lateral tissue pocket for implant coverage. This method preserves the inferior border of the pectoralis major muscle and minimizes the size of ADM coverage. Patient satisfaction on the BREAST-Q Reconstruction Module and complications were assessed 12 months after surgery.

RESULTS

The novel surgical design was safe and used minimal ADM (6 × 5cm²). Mean satisfaction with breasts was 61 ± 4.7 (range, 48-73), mean psychosocial well-being was 66 ± 10 (range, 50-93), and mean sexual well-being was 47 ± 7.8 (range, 27-70). Animation deformity was avoided by preserving the inferior border of the pectoralis major muscle. Rates of revision (7.6%) and postsurgical seroma (3.4%) were low, and capsular contracture was minimal.

CONCLUSIONS

Submuscular implant-based breast reconstruction following mastectomy utilizing the serratus anterior muscle fascia connected to the lateral margin of the pectoralis major muscle to form a lateral tissue pocket for implant coverage is safe, feasible, and generates good aesthetic outcomes.

Abnormal Ultrasonographic Findings of Acellular Dermal Matrix in Implant-Based Breast Reconstruction: Correlations with Histopathology

Background: Acellular dermal matrix (ADM) in implant-based breast reconstruction can show various ultrasound (US) findings. However, there are limited reports on the US features of the ADM. The aims of this study were to evaluate US findings of the ADM in implant-based breast reconstruction and correlate them with histopathological findings. Methods: Between January 2015 and August 2020, 250 women who underwent implant-based breast reconstruction with ADM and a breast US examination at 6 months to 1 year after reconstruction were retrospectively analyzed. Abnormal US findings were classified as type 1 (focal thickening with decreased echogenicity), 2 (diffusely hyperechoic), or 3 (bright echogenic spots). ADM biopsy was performed in 33 patients who underwent second stage or revisional surgeries. Results: In total, 176 consecutive women with 207 US findings were analyzed. The US findings were normal in 52.2% of the women. The percentages of type 1, 2, and 3 patients were 13.5%, 11.1%, and 23. 2%, respectively. These patients had microscopic findings that showed patchy areas with chronic inflammatory infiltrates, dense collagen bundles without degenerative or inflammatory changes, and empty spaces or degenerated foci unaccompanied by inflammation. Conclusion: Knowing the various ADM presentations on US can help avoid unnecessary invasive procedures.

Nanofibrillar Collagen Scaffold Enhances Edema Reduction and Formation of New Lymphatic Collectors after Lymphedema Surgery

BACKGROUND

Treatment of secondary lymphedema remains challenging, with suboptimal rates of edema reduction following physiologic procedures (i.e., lymphaticovenous anastomosis and vascularized lymph node transfer). The objective of this study was to investigate the long-term effect of a nanofibrillar collagen scaffold on edema reduction in lymphedema patients treated with lymphaticovenous anastomosis or vascularized lymph node transfer.

METHODS

A retrospective cohort study was performed, comparing stage 1 to 3 lymphedema patients who underwent lymphaticovenous anastomosis and/or vascularized lymph node transfer with or without delayed implantation of nanofibrillar collagen scaffold (BioBridge) from 2016 to 2019. The primary endpoint was excess volume reduction. Indocyanine green lymphatic mapping was performed to evaluate superficial lymphatic flow.

RESULTS

Edema reduction was significantly greater for the BioBridge cohort (12-month follow-up, n = 18) compared to controls (18.2-month follow-up, n = 11) (111.5 ± 34.5 percent versus 70.0 ± 19.0 percent; p = 0.0004). This held true in lymphaticovenous anastomosis and vascularized lymph node transfer subgroup analysis. The average rate of edema reduction increased by 3.5-fold in lymphaticovenous anastomosis and 7.6-fold in vascularized lymph node transfer following BioBridge placement. Eighty-eight percent of patients with concurrent liposuction and BioBridge implantation maintained normal volumes at 13 months postoperatively. Lymphatic mapping following BioBridge placement showed significantly more new lymphatic collectors and decreased dermal backflow. The majority of patients (77.8 percent) achieved and maintained normal limb volume at an average total follow-up of 29 months.

CONCLUSION

Nanofibrillar collagen scaffold implantation enhances overall effectiveness of physiologic procedures, even in the presence of liposuction, and is a promising adjunct therapy for treatment of lymphedema.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Acellular Dermal Matrix-Associated Contracture: A Clinical and Histologic Analysis of Patients Undergoing Prosthetic Breast Reconstruction

BACKGROUND

Capsular contracture is a well-recognized complication following prosthetic breast reconstruction. It has been the authors' observation that some patients undergoing breast reconstruction experience contracture specifically of the acellular dermal matrix placed at the time of their tissue expander insertion. The goal of the authors' study was to identify clinical and histologic findings associated with the development of acellular dermal matrix-associated contracture.

METHODS

The authors performed a retrospective cohort study of all patients undergoing bilateral implant-based breast reconstruction performed by the senior author (M.S.A.). Patients were excluded if they had radiation therapy to the breast. Patients with suspected acellular dermal matrix-associated contracture were identified by clinical photographs and review of operative notes. Histologic analysis was performed on specimens taken from two patients with acellular dermal matrix contracture.

RESULTS

The authors included a total of 46 patients (92 breasts), of which 19 breasts had suspected acellular dermal matrix-associated contracture. Acellular dermal matrix contracture was less common in direct-to-implant reconstruction (4.2 percent versus 26.5 percent; p = 0.020) and more common in breasts that had seromas (0 percent versus 15.8 percent; p = 0.001) or complications requiring early expander replacement. Contracted acellular dermal matrix had less vascularity and a lower collagen I-to-collagen III ratio, and was twice as thick as noncontracted acellular dermal matrix.

CONCLUSIONS

The authors have described a distinct phenomenon of acellular dermal matrix-associated contracture that occurs in a small subset of breasts where acellular dermal matrix is used. This merits further investigation. Future work will be required to better characterize the clinical factors that make acellular dermal matrix-associated contracture more likely to occur.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Direct comparison of CGCRYODERM and DermACELL in the same patient for outcomes in bilateral implant-based breast reconstruction: a retrospective case series

Background

The use of acellular dermal matrix (ADM) has been popularized in implant-based breast reconstruction (IBR). However, it is still controversial if ADM-associated complication rates differ with varying types of ADM products. The aim of this study was to compare postoperative complications between CGCRYODERM and DermACELL.

Methods

A retrospective chart review was performed on 32 patients (64 breasts) who underwent bilateral prosthetic breast reconstruction between June 2015 and December 2019. All patients received two different ADMs in each breast during the surgery. Demographic variables, operative characteristics, and postoperative outcomes were compared between the cryopreserved and pre-hydrated ADM.

Results

The overall major and minor postoperative complications developed in 7 and 1 out of 32 patients, respectively. Seroma and infection were the most common complications. There were no cases that infection and/or seroma involved both breasts in one individual. No significant differences were observed in terms of seroma, infection, hematoma, mastectomy flap necrosis, or drainage period between the CGCRYODERM and DermACELL groups (P=0.5637, 0.1797, 1.0000, 0.3173, and 0.2925, respectively). There was no case of reconstruction failure leading to explantation.

Conclusions

There were no statistically significant differences in postoperative complications between the two breasts reconstructed with CGCRYODERM and DermACELL in the same patient who underwent bilateral IBR. This is the first study to compare cryopreserved and pre-hydrated ADMs. We suggest that CGCRYODERM is a suitable option with a comparable safety profile for IBR.

Review of Outcomes in Prepectoral Prosthetic Breast Reconstruction with and without Surgical Mesh Assistance

BACKGROUND

In the past decade, surgeons have increasingly advocated for a return to prepectoral breast reconstruction with claims that surgical mesh (including acellular dermal matrix) can reduce complication rates. However, numerous surgical and implant advancements have occurred in the decades since the initial prepectoral studies, and it is unclear whether mesh is solely responsible for the touted benefits.

METHODS

The authors conducted a systematic review of all English language articles reporting original data for prepectoral implant-based breast reconstruction. Articles presenting duplicate data were excluded. Complications were recorded and calculated on a per-breast basis and separated as mesh-assisted, no-mesh prior to 2006, and no-mesh after 2006 (date of first silicone gel-filled breast implant approval). Capsular contracture comparisons were adjusted for duration of follow-up.

RESULTS

A total of 58 articles were included encompassing 3120 patients from 1966 to 2019. The majority of the included studies were retrospective case series. Reported complication outcomes were variable, with no significant difference between groups in hematoma, infection, or explantation rates. Capsular contracture rates were higher in historical no-mesh cohorts, whereas seroma rates were higher in contemporary no-mesh cohorts.

CONCLUSIONS

Limited data exist to understand the benefits of surgical mesh devices in prepectoral breast reconstruction. Level I studies with an appropriate control group are needed to better understand the specific role of mesh for these procedures. Existing data are inconclusive but suggest that prepectoral breast reconstruction can be safely performed without surgical mesh.

Biological and synthetic mesh assisted breast reconstruction procedures: Joint guidelines from the Association of Breast Surgery and the British Association of Plastic, Reconstructive and Aesthetic Surgeons

These guidelines have been produced with the involvement of the Association of Breast Surgery and the British Association of Plastic, Reconstructive and Aesthetic Surgeons. Recommendations have been derived after a review of published data regarding the use of acellular dermal matrix (ADM), biological and synthetic mesh in breast reconstruction. The guidelines represent a consensus opinion on the optimal management of patients having biological or synthetic mesh assisted breast reconstruction informed by peer-review publications. The Guidelines should be used to inform clinical decision making. Ultimately, members of the MDT remain responsible for the treatment of patients under their care.

Compact Fat Grafting: A Novel Method to Improve Graft Retention Through Modulation of Adipocyte Size

BACKGROUND

The viable zone where adipocytes and/or adipose-derived stem cells survive is present at the surface of graft fat tissue; however, there is controversy regarding the zone thickness. Graft retention could be improved if more adipocytes are included in the zone.

OBJECTIVES

We hypothesize that a temporary reduction in adipocyte size prior to grafting could increase the number of adipocytes in the viable zone. We reduced the adipocyte size by treatment with MLN4924, which controls lipid accumulation in adipocytes, and investigated the histological and microenvironmental changes in grafted fat.

METHODS

Subcutaneous fat harvested from wild-type C57BL/6J mice was chopped into small pieces; treated with dimethyl sulfoxide (control group), 0.25 μM MLN4924, or 0.5 μM MLN4924 for 4 days; and grafted into recipient C57BL/6J mice at the supraperiosteal plane of the skull.

RESULTS

The reduced adipocyte size in response to MLN4924 treatment was restored within 8 weeks after fat grafting. The MLN4924-treated groups exhibited substantially greater graft volume, lower tissue hypoxia, and higher production of M2 macrophages compared with the control group.

CONCLUSIONS

Grafting with compact fat that had smaller adipocytes improved the microenvironment by modulating tissue hypoxia and macrophage polarization, leading to improved graft retention. Therefore, compact fat grafting may offer a new clinical strategy without the need for stem cell manipulation.

Epidemiology and Prevention of Breast Prosthesis Capsular Contracture Recurrence

INTRODUCTION

Baker grade III and IV breast prosthesis capsular contractures represent a major problem for patients undergoing mammoplasties. The risk factors involved in recurrence are debated, and the best surgical approach for their prevention is not established. The objective was to identify these.

MATERIALS AND METHODS

We carried out a retrospective study of patients operated on for capsular contracture at the Saint-Louis Hospital in Paris from 2012 to 2014. The characteristics at inclusion were compared so as to determine the risk factors of recurrence. The surgical approaches were compared between the patients with recurrence and those without at 5 years.

RESULTS

Of the 100 patients included, 24 had a recurrence. The minimal follow-up was 5 years. No risk factors of recurrence of capsular contracture were identified. The surgical approach associated with the lowest rate of recurrence was anterior capsulectomy [OR total capsulectomy = 2.36 (0.73; 8.037) OR capsulotomy = 4.33 (1.37; 14.81)] (p < 0.040) with alteration of the volume of the implant, whether greater or less than initially [OR greater volume = 0.30 (0.096; 0.83); OR smaller volume = 0.14 (0.008; 0.85)] (p < 0.018).

CONCLUSION

The occurrence of capsular contracture is a major problem with prosthetic breast surgery. The main risk factors identified to date are essentially in regard to the occurrence of a first episode. No significant risk factors for recurrence were identified. The best prevention appears to be an anterior capsulectomy with reducing the volume of the implant.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 . IV.

Use of a Bioabsorbable Implant-Acellular Dermal Matrix Construct to Facilitate Oncoplastic Breast-conserving Surgery

Supplemental Digital Content is available in the text.

Deformity after partial mastectomy for breast cancer is not uncommon. The immediate replacement of breast volume by a bioabsorbable implant has been shown to facilitate tissue ingrowth, maintain breast contour, reduce scarring and fibrosis, and preserve cosmesis. Soft tissue coverage is critical to minimize palpability and to prevent infection and extrusion of this device, especially after radiotherapy. This coverage is often not possible after significant oncological resection or in leaner patients. Here, we describe the use of a bioabsorbable implant-acellular dermal matrix construct in patients with insufficient soft tissue coverage after wide local excision.

Comparison of irradiated and non-irradiated acellular dermal matrices in breast reconstruction under radiotherapy

Background

Acellular dermal matrices (ADMs) have become an essential material for implant-based breast reconstruction. No previous studies have evaluated the effects of sterility of ADM under conditions of radiation. This study compared sterile (irradiated) and aseptic (non-irradiated) ADMs to determine which would better endure radiotherapy.

Methods

Eighteen male Balb/C mice were assigned to the control group with no irradiation (group 1) or one of two other groups with a radiation intensity of 10 Gy (group 2) or 20 Gy (group 3). Both sterile and aseptic ADMs were inserted into the back of each mouse. The residual volume of the ADM (measured using three-dimensional photography), cell incorporation, α-smooth muscle actin expression, and connective tissue growth factor expression were evaluated. The thickness and CD3 expression of the skin were measured 4 and 8 weeks after radiation.

Results

In groups 2 and 3, irradiated ADMs had a significantly larger residual volume than the non-irradiated ADMs after 8 weeks (P<0.05). No significant differences were found in cell incorporation and the amount of fibrosis between irradiated and non-irradiated ADMs. The skin was significantly thicker in the non-irradiated ADMs than in the irradiated ADMs in group 3 (P<0.05). CD3 staining showed significantly fewer inflammatory cells in the skin of irradiated ADMs than in non-irradiated ADMs in all three groups after 4 and 8 weeks (P<0.05).

Conclusions

Under radiation exposure, irradiated ADMs were more durable, with less volume decrease and less deposition of collagen fibers and inflammatory reactions in the skin than in non-irradiated ADMs.

Acute Postoperative Complications in Prepectoral versus Subpectoral Reconstruction following Nipple-Sparing Mastectomy

BACKGROUND

Nipple-sparing mastectomy is associated with improved aesthetics and oncologic safety. Recently, there has been a resurgence in prepectoral reconstruction. Because of limited data comparing complication rates on patients undergoing prepectoral breast reconstruction, this study compared 30-day postoperative complications by plane of prosthetic placement.

METHODS

A retrospective review was conducted on all consecutive patients undergoing nipple-sparing mastectomy with implant-based reconstruction with either prepectoral or subpectoral placement from 2014 to 2018. The primary outcome was a composite, acute 30-day postoperative complication, including nipple-areola complex necrosis, mastectomy flap necrosis, wound dehiscence, infection, hematoma, and seroma. Secondary outcomes included nipple loss and rates of unintended reoperations. Univariate and mixed effects multivariate logistic regression were used to compare outcomes.

RESULTS

A total of 228 patients and 405 breasts were included in the final cohort, with 202 in the subpectoral cohort and 203 in the prepectoral cohort. The overall complication rate was 7.65 percent, with no significant difference between subpectoral and prepectoral cohorts (9.41 percent versus 5.91 percent, respectively; p = 0.148). Prepectoral reconstruction was associated with significantly reduced ischemic complications, including nipple loss because of necrosis (2.97 percent versus 0.49 percent, respectively; p = 0.015) and mastectomy flap necrosis (5.45 percent versus 0 percent; p = 0.003). There were no significant differences in rates of infection, hematoma, seroma, or implant loss/exchange.

CONCLUSIONS

Prepectoral reconstruction is associated with similar overall 30-day postoperative complications and reoperations compared to traditional subpectoral implants. However, prepectoral reconstruction was associated with significantly decreased ischemic complications, including mastectomy flap necrosis and nipple-areola complex loss because of necrosis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Hypofractionated Radiotherapy With Volumetric Modulated Arc Therapy Decreases Postoperative Complications in Prosthetic Breast Reconstructions: A Clinicopathologic Study

Background

Emerging radiation technologies are expected to provide a positive impact on the reduction in postoperative complications in patients receiving prosthetic breast reconstruction. This study aimed to determine whether hypofractionated radiation therapy(RT) with volumetric modulated arc therapy(VMAT) is superior to conventional RT in the setting of prosthetic reconstruction.

Methods

From retrospective data collections, postoperative complications were compared for all patients with mastectomy and staged prosthetic reconstruction without RT, with hypofractionation using 40 Gy in 15 fractions with VMAT (Hypo-VMAT) or conventional RT (50 Gy over 5 weeks). After harvesting subpectoral capsules from patients with informed consents, histologic analysis including immunohistochemistry and immunofluorescence for collagen type I, α-smooth muscle actin, CD34 and CD31 expression was performed.

Results

A total of 288 reconstructions without RT, 55 reconstructions with Hypo-VMAT, and 29 reconstructions with conventional RT were examined. During average follow-up period of 34.8 months, rates of overall complications were 6.3% in the no-radiation group, 18.2% in Hypo-VMAT group and 44.8% in conventional-RT group with significant differences (no-RT vs Hypo-VMAT: p=0.006; Hypo-VMAT vs conventional-RT: p=0.012). Levels of myofibroblasts and tissue fibrosis were lower in the Hypo-VMAT group than in conventional-RT group (p=0.016 and p=0.040, respectively), while those of progenitor cells and microvessel density were higher in the Hypo-VMAT group than in conventional-RT group (p<0.001 and p<0.001, respectively).

Conclusion

We demonstrated that hypofractionated RT with VMAT served to reduce radiation-related morbidities in prosthetic reconstruction from a clinicopathologic perspective, compared to conventional RT. It may offer a practical strategy to mitigate radiation-related complications in clinical settings.

Outcomes of Immediate Alloplastic Breast Reconstruction in Patients Receiving Post-Mastectomy Radiotherapy

Background:

Immediate alloplastic breast reconstruction is traditionally avoided in patients who require post-mastectomy radiation therapy (PMRT). However, a subset of patients who undergo alloplastic reconstruction may unpredictably require adjuvant radiation. The purpose of this study was to compare outcomes and complications in patients at our institution who had undergone immediate alloplastic breast reconstruction and received PMRT to either the permanent implant or temporary tissue expander.

Materials and Methods:

A retrospective cohort study was performed looking at patients who underwent immediate alloplastic breast reconstruction over a 10-year period (2009-2019) at our regional breast centre. All patients who underwent immediate alloplastic breast reconstruction and had PMRT were included in the study. Major (wound dehiscence with device exposure, or reconstructive failure) and minor (infection, capsular contracture, revision surgery) complication rates between those patients receiving radiation to a tissue expander versus implant were compared using Fisher exact test ( P < .05).

Results:

Six-hundred ninety-two patients were identified, and 43 patients met inclusion criteria. Of this group, 29 received PMRT to implants and 14 received PMRT to tissue expanders. Complication rates were similar between groups for superficial wound infection (3.4% vs 7.1%), periprosthetic infection (3.4% vs 7.1%), capsular contracture (41.4% vs 21.4%), revision surgery for aesthetics (41.4% vs 21.4%), wound dehiscence and device exposure (3.4% vs 21.3%), and reconstructive failure (10.3% vs 6.7%). Total complication rates were similar between groups (51.7% vs 42.9%).

Discussion:

Overall 6.4% of patients who underwent immediate alloplastic breast reconstruction required PMRT over a 10-year period. Complication rates for infection, capsular contracture, revision surgery, wound dehiscence and device exposure, and reconstructive failure were similar between both groups. Total complication rates were similar between groups. This information will help to inform decision-making regarding immediate alloplastic reconstruction and expected complications when PMRT is needed.

A Comparative Analysis between Subpectoral versus Prepectoral Single Stage Direct-to-Implant Breast Reconstruction

Background and objectives: Until now subpectoral breast reconstruction (SBR) has been the predominant form; however, it can present with pectoralis muscle contraction and animation deformity. To avoid these complications, surgeons have begun placing breast implants in the same anatomic space as the breast tissue that was removed. We report a comparative analysis of prepectoral breast reconstruction (PBR) versus subpectoral breast reconstruction to analyze their differences. Materials and Methods: Direct-to-implant (DTI) reconstruction using acellular dermal matrix (ADM) performed from February 2015 to February 2020 were retrospectively reviewed. We then compared the clinical course and postoperative outcomes of the two groups (prepectoral vs. subpectoral) based on the overall incidence of complications, pain scale, and the duration of drainage. Results: A total of 167 patients underwent unilateral DTI, with SBR 114 (68.3%) and PBR 53 (31.7%). Patient demographics were similar between the two groups. There was no statistically significant difference in rates of seroma, infection (requiring intravenous antibiotics), hematoma, and skin necrosis. Implant loss rates in the SBR 6.1% (n = 7) and PBR 9.4% (n = 5) were also not statistically significant (p = 0.99). The hemovac duration period was significantly longer in the SBR (14.93 ± 5.57 days) group than in the PBR group (11.09 ± 4.82 days) (p < 0.01). However, post-operative pain scores are similar between two groups, although it is not clear whether this was due to the effect of postoperative patient-controlled analgesia. Conclusions: A SBR is a commonly used procedure with various advantages, but there are many problems due to damage to the normal pectoralis major muscle. According to the results of our study, the PBR group had a shorter hemovac duration period compared to the SBR group, although there was no significant difference in complication rate. A PBR is a simple and safe technique allowing early discharge without increasing the incidence of long-term complications.

Efficacy of Acellular Dermal Matrix in Capsular Contracture of Implant-Based Breast Reconstruction: A Single-Arm Meta-analysis

BACKGROUND

A large number of clinical studies have suggested that acellular dermal matrix (ADM) can decrease the incidence of capsular contracture in implant-based breast reconstruction. Yet, there is currently no high-level epidemiological evidence to prove this. The goal of this meta-analysis was to clarify the efficacy of ADM in capsular contracture, and provide a reference value for plastic surgeons.

METHODS

We systematically performed a search on PubMed, EMBASE, and the Cochrane Library to identify eligible studies from inception up to October 1, 2019. A random-effects model was used to obtain a pooled incidence rate. We conducted subgroup analysis according to geographic region, type of ADM, body mass index (BMI), duration of follow-up, and proportion of participants who have received radiotherapy.

RESULTS

A total of 18 studies involving 2941 cases were included. Overall, the pooled incidence rate of capsular contracture was 2.4% (95% CI 1.2-3.9%). The results from subgroup analyses indicated an even lower incidence in North America (1.6%, 95% CI 0.5-3.3%) and in human-derived ADM (HADM) (1.2%, 95% CI 0.2-3.0%). In addition, the results showed that the patients with BMI < 24, or who have received radiotherapy, were more prone to capsular contracture.

CONCLUSION

The application of ADM can effectively reduce the incidence of capsular contracture in implant-based breast reconstruction. And we infer that it might also apply to breast augmentation. However, additional high-quality trials are warranted to corroborate the findings of this meta-analysis.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Acellular Dermal Matrix Performance Compared with Latissimus Dorsi Myocutaneous Flap in Expander-Based Breast Reconstruction

Latissimus dorsi myocutaneous flap (LDMF) with tissue expander provides excellent results in breast reconstruction. Acellular dermal matrix (ADM) has been used in expander-based reconstruction (EBR) with good results. This study assesses how ADM compares to LDMF in EBR.

Methods

The cohorts comprised 124 patients (218 breasts) who had EBR using ADM between 2006 and 2012, and 242 patients (266 breasts) who had EBR using LDMF between 1994 and 2012. Postoperative complications, reoperations, Breast-Q scores, and objectively assessed aesthetic outcomes were compared.

Results

Median age was 55 years for both ADM (range 23-84) and LDMF (range 26-88) groups. No statistically significant differences were noted between the groups in the rates of major postoperative complications (P > 0.3). Forty-nine of the 218 (22.5%) in the ADM group and 67 of 266 (25.2%) in the LDMF group had a total of 63 and 84 reoperations, respectively (P = 0.52), with no significant differences in the reoperations rate (P > 0.3). No significant differences were observed in the Breast-Q scores. Some categorical differences were noted in the aesthetic outcomes; however, the difference between the overall outcomes was not significant (P = 0.54).

Conclusion

Our study revealed no statistically significant differences in the complications or reoperation rates, patient satisfaction, or overall aesthetic outcomes when comparing the use of ADM to LDMF in EBR. In conclusion, this study supports the hypothesis that ADM performs as well as LDMF in EBR.

Wise Pattern Direct Implant Breast Reconstruction: A Review and Improved Outcomes Using Dermal Matrix

The inverted T (Wise pattern) mastectomy for patients with macromastia or significant breast ptosis has evolved along with generalized techniques for breast reconstruction. We present a review of Wise pattern breast reconstruction along with our technique for direct to implant reconstruction using dermal matrix.

Prepectoral breast reconstruction

Implant-based breast reconstruction is the most commonly used reconstruction technique after mastectomy. This is because skin-sparing mastectomy has become possible with advancements in oncology. In addition, the development of breast implants and the advent of acellular dermal matrices have reduced postoperative complications and resulted in superior cosmetic results. The most frequently performed surgical breast reconstruction procedure for the past 20 years was the insertion of an implant under the pectoralis major muscle by means of the dual plane approach. However, some patients suffered from pain and animation deformity caused by muscle manipulation. Recently, a prepectoral approach has been used to solve the above problems in select patients, and the results are similar to subpectoral results. However, this technique is not always chosen due to the number of considerations for successful surgery. In this article, we will discuss the emergence of prepectoral breast reconstruction, indications and contraindications, surgical procedures, and outcomes.

Acellular Dermal Matrix Reduces Myofibroblast Presence in the Breast Capsule

Background

Capsular contracture remains a common complication after implant-based breast reconstruction. Previous work has suggested that the use of acellular dermal matrix (ADM) reduces the rate of capsular contracture, though little is understood about the underlying mechanism. As myofibroblasts are believed to be the key cells implicated in contracture formation, we hypothesized that ADM would result in a reduction in periprosthetic myofibroblast concentration.

Methods

Five patients who underwent immediate prepectoral tissue expander placement with anterior ADM coverage and an inferior cuff were included. At the second stage, tissue samples were obtained of both ADM and capsule from each reconstructed breast. Samples were then prepared for hematoxylin and eosin staining and immunohistochemistry for myofibroblast identification (alpha smooth muscle actin and vimentin positive and desmin negative) and analysis. Experimental values are presented as mean ± SD unless otherwise stated. Statistical significance was determined using unpaired t test.

Results

Successful incorporation of ADM was noted in all cases. A significant reduction in myofibroblast concentration was noted in the ADM versus the capsule (P = 0.0018). This was paralleled by significantly thicker periprosthetic capsule formation overlying the formerly raw pectoralis major muscle, that is, not covered by ADM (P < 0.0001).

Conclusions

In the presence of ADM, there are significantly fewer myofibroblasts in breast capsules and thinner capsules on histology. Given the central role of myofibroblasts in the development of clinically significant capsular contracture, this study unmasks a possible mechanism for the protective effect of ADM with respect to capsular contracture development.

The role of fat grafting in prepectoral breast reconstruction

Prepectoral breast reconstruction has reemerged as a promising alternative to submuscular implants, as they place the patient at lower risk for pain, muscular impairment, and animation deformity. However, the thinner amount of overlying tissue in prepectoral reconstruction presents its own unique set of challenges. A "rippling" deformity is seen in some prepectoral patients, which is typically corrected with fat grafting. This report details our recommended technique for fat grafting in the prepectorally implanted patient.

[Mastectomy and immediate reconstruction: Indications, techniques and decision algorithm]

Immediate breast reconstruction indications extend to infiltrating carcinomas, due to new matrix implant coverage techniques and the development of perforator flaps. These techniques allow adjuvant treatments. However, the decision of immediate reconstruction must be discussed with the oncological multidisciplinary team and the benefits/risks must also be evaluated in relation to the morphology of the patients and their co-morbidities. The chosen type of mastectomy: conventional or skin sparing and/or nipple sparing depends on the shape and volume of the breast, the localization of the tumor in the breast and the distance from the nipple areola complex (NAC). We describe an algorithm to allow, in the case of therapeutic mastectomy with or without adjuvant radiotherapy, an immediate reconstruction with implants or free or pedicled flaps.