Evolution in Tissue Expander Design for Breast Reconstruction: Technological Innovation to Optimize Patient Outcomes

The current use of tissue expanders in breast reconstruction: device design, features, and technical considerations

INTRODUCTION

The use of tissue expanders (TE) in post-mastectomy breast reconstruction is a widely accepted practice, especially in patients desiring implant-based breast reconstruction. It has become the standard of care to perform a two-staged breast reconstruction using tissue expanders for the past 50 years due to its reliability, safety, cost-effectiveness, and versatility. Due to its popularity, there are numerous types and features of breast tissue expanders and various surgical approaches available for plastic surgeons.

AREAS COVERED

In this article, we will review the role of tissue expanders in breast reconstruction, the types and features of breast tissue expanders, and technical considerations.

EXPERT OPINION

The use of tissue expanders in breast reconstruction offers significant advantages of preserving the breast skin envelope and reestablishing the breast mound. With evolving approaches to breast reconstruction, tissue expander design, and application underwent several refinements and modifications. Due to these advances, studies on its long-term efficacy and safety profile typically fall behind and more studies with higher levels of evidence are needed to better evaluate the efficacy and safety profile of tissue expanders. With increased understanding, reconstructive surgeons can minimize complications and maximize reconstructive, aesthetic outcomes with high patient satisfaction.

Imaging of the Reconstructed Breast

The incidence of breast cancer and, therefore, the need for breast reconstruction are expected to increase. The many reconstructive options available and the changing aspects of the field make this a complex area of plastic surgery, requiring knowledge and expertise. Two major types of breast reconstruction can be distinguished: breast implants and autologous flaps. Both present advantages and disadvantages. Autologous fat grafting is also commonly used. MRI is the modality of choice for evaluating breast reconstruction. Knowledge of the type of reconstruction is preferable to provide the maximum amount of pertinent information and avoid false positives. Early complications include seroma, hematoma, and infection. Late complications depend on the type of reconstruction. Implant rupture and implant capsular contracture are frequently encountered. Depending on the implant type, specific MRI signs can be depicted. In the case of myocutaneous flap, fat necrosis, fibrosis, and vascular compromise represent the most common complications. Late cancer recurrence is much less common. Rarely reported late complications include breast-implant-associated large cell anaplastic lymphoma (BIA-ALCL) and, recently described and even rarer, breast-implant-associated squamous cell carcinoma (BIA-SCC). In this review article, the various types of breast reconstruction will be presented, with emphasis on pertinent imaging findings and complications.

Same-Day Mastectomy and Immediate Prosthetic Breast Reconstruction: A 12-Year National Database Analysis and Early Postoperative Outcomes

BACKGROUND

Coronavirus disease of 2019 and rising health care costs have incentivized shorter hospital stays after mastectomies with immediate prosthetic reconstruction. The purpose of this study was to compare postoperative outcomes following same-day and non-same-day mastectomy with immediate prosthetic reconstruction.

METHODS

A retrospective analysis of the American College of Surgeons National Surgical Quality Improvement Program database from 2007 to 2019 was performed. Patients who underwent mastectomies and immediate reconstruction with tissue expanders or implants were selected and grouped based on length of stay. Univariate analysis and multivariate regression were performed to compare 30-day postoperative outcomes between length-of-stay groups.

RESULTS

A total of 45,451 patients were included: 1508 had same-day surgery (SDS) and 43,942 were admitted for 1 or more night (non-SDS). There was no significant difference in overall 30-day postoperative complications between SDS and non-SDS following immediate prosthetic reconstruction. SDS was not a predictor of complications (OR, 1.1; P = 0.346), whereas tissue expander reconstruction decreased odds of morbidity compared with direct-to-implant reconstruction (OR, 0.77; P < 0.001). Among patients who had SDS, smoking was significantly associated with early complications on multivariate analysis (OR, 1.85; P = 0.010).

CONCLUSIONS

This study provides an up-to-date assessment of the safety of mastectomies with immediate prosthetic breast reconstruction that captures recent advancements. Postoperative complication rates are similar between same-day discharge and at least 1-night stay, suggesting that same-day procedures may be safe for appropriately selected patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Dosimetric characterization of single- and dual-port temporary tissue expanders for postmastectomy radiotherapy using Monte Carlo methods

Purpose

The aim of this work was two-fold: a) to assess two treatment planning strategies for accounting CT artifacts introduced by temporary tissue-expanders (TTEs); b) to evaluate the dosimetric impact of two commercially available and one novel TTE.

Methods

The CT artifacts were managed using two strategies. 1) Identifying the metal in the RayStation treatment planning software (TPS) using image window-level adjustments, delineate a contour enclosing the artifact, and setting the density of the surrounding voxels to unity (RS1). 2) Registering a geometry template with dimensions and materials from the TTEs (RS2). Both strategies were compared for DermaSpan, AlloX2, and AlloX2-Pro TTEs using Collapsed Cone Convolution (CCC) in RayStation TPS, Monte Carlo simulations (MC) using TOPAS, and film measurements. Wax slab phantoms with metallic ports and breast phantoms with TTEs balloons were made and irradiated with a 6 MV AP beam and partial arc, respectively. Dose values along the AP direction calculated with CCC (RS2) and TOPAS (RS1 and RS2) were compared with film measurements. The impact in dose distributions was evaluated with RS2 by comparing TOPAS simulations with and without the metal port.

Results

For the wax slab phantoms, the dose differences between RS1 and RS2 were 0.5% for DermaSpan and AlloX2 but 3% for AlloX2-Pro. From TOPAS simulations of RS2, the impact in dose distributions caused by the magnet attenuation was (6.4 ± 0.4) %, (4.9 ± 0.7)%, and (2.0 ± 0.9)% for DermaSpan, AlloX2, and AlloX2-Pro, respectively. With breast phantoms, maximum differences in DVH parameters between RS1 and RS2 were as follows. For AlloX2 at the posterior region: (2.1 ± 1.0)%, (1.9 ± 1.0)% and (1.4 ± 1.0)% for D1, D10, and average dose, respectively. For AlloX2-Pro at the anterior region (-1.0 ± 1.0)%, (-0.6 ± 1.0)% and (-0.6 ± 1.0)% for D1, D10 and average dose, respectively. The impact in D10 caused by the magnet was at most (5.5 ± 1.0)% and (-0.8 ± 1.0)% for AlloX2 and AlloX2-Pro, respectively.

Conclusion

Two strategies for accounting for CT artifacts from three breast TTEs were assessed using CCC, MC, and film measurements. This study showed that the highest differences with respect to measurements occurred with RS1 and can be mitigated if a template with the actual port geometry and materials is used.

The Impact of Aeroform Tissue Expanders on the Outcomes of Implant-Based Breast Reconstruction; A Systematic Review and Meta-Analysis

BACKGROUND

Breast reconstruction can improve the quality of patients' lives by restoring the breasts' natural appearance. Saline-based tissue expanders are associated with significant drawbacks. The current systematic review and meta-analysis aimed to reveal the usability, safety, and economic burden of AeroForm-based tissue expanders for breast reconstruction.

METHODS

An extensive systematic literature review was implemented from inception to 9 December 2021. All clinical studies that included women with breast cancer subjected to AeroForm-based tissue expansion for breast reconstruction were included in the study.

RESULTS

This systematic review included eleven articles consisting of 748 patients. There were 1220 reconstructed breasts in which 530 (43.44%) breasts were reconstructed using AeroForm devices. AeroForm-based tissue expanders were associated with shorter duration to complete breast expansion (MD-35.22; 95% -46.65, -23.78;P<0.001) and complete reconstruction (MD-30.511; 95% -54.659, -6.636;P=0.013). The overall satisfaction rate of the aesthetic results of the AeroForm expanders was 81.4% (95%CI; 60.3% to 92.6%,P=0.006) and 64.6% (95%CI; 53.8% to 74%,P=0.008) for patients and surgeons. Patients subjected to saline-based breast reconstruction were 1.17 times at high risk to develop breast-related adverse events (RR1.17; 95% 0.86, 1.58; P=0.31). This includes a high risk of mastectomy flap necrosis (RR1.91; 95% 1.03, 3.55;P=0.04) and post-operative wound infection (RR 1.63; 95% 0.91, 2.91;P=0.1).

CONCLUSION

AeroForm-based tissue expanders represent a new era of breast reconstruction. These devices provided an earlier transition to exchange for the permanent implant with a convenient and comfortable expansion process. This was associated with a high satisfaction rate for patients and surgeons.

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 .

Safety of CPX4 Breast Tissue Expanders in Primary Reconstruction Patients

Background:

In the United States, 2-stage expander-to-implant–based breast reconstruction accounts for more than half of all breast reconstruction procedures. Tissue expansion technology has undergone significant advancements in the past few decades. Previous reports suggest that the most common perioperative complications associated with breast tissue expanders are infection and skin flap necrosis. However, little clinical data are available for CPX4 Breast Tissue Expanders. The aim of the study was to measure real-world outcomes related to safety and effectiveness of the tissue expansion process, in patients who underwent primary breast reconstruction following the use of CPX4 Breast Tissue Expanders.

Methods:

This was a single-arm retrospective cohort design looking at patients who underwent 2-stage, expander-to-implant–based primary breast reconstruction at a single site between April 2013 and December 2016 and who had a minimum of 2 years follow-up. Descriptive statistics were used to summarize baseline characteristics and safety outcomes.

Results:

A total of 123 patients were followed for an average of 3.73 ± 0.94 years. At least 1 complication during the time of tissue expansion, before the permanent implant, was reported in 39/123 (31.7%) patients [51/220 implants (23.2%)]. The most frequently reported complications were delayed wound healing (13.8%) and cellulitis/infection (9.7%).

Conclusion:

Analyses of real-world data from a single site provide further support for the safety and effectiveness of the CPX4 Breast Tissue Expander for women undergoing 2-stage expander-to-implant primary breast reconstruction.

Prepectoral Direct-to-Implant Breast Reconstruction: Safety Outcome Endpoints and Delineation of Risk Factors

BACKGROUND

Continued evolution of implant-based breast reconstruction involves immediate placement of the implant above the pectoralis muscle. The shift to prepectoral breast reconstruction is driven by goals of decreasing morbidity such as breast animation deformity, range-of-motion problems, and pain, and is made possible by improvements in mastectomy skin flap viability. To define clinical factors to guide patient selection for direct-to-implant prepectoral implant reconstruction, this study compares safety endpoints and risk factors between prepectoral and subpectoral direct-to-implant breast reconstruction cohorts. The authors hypothesized that prepectoral direct-to-implant breast reconstruction is a safe alternative to subpectoral direct-to-implant breast reconstruction.

METHODS

Retrospective chart review identified patients who underwent prepectoral and subpectoral direct-to-implant breast reconstruction, performed by a team of five surgical oncologists and two plastic surgeons. Univariate analysis compared patient characteristics between cohorts. A penalized logistic regression model was constructed to identify relationships between postoperative complications and covariate risk factors.

RESULTS

A cohort of 114 prepectoral direct-to-implant patients was compared with 142 subpectoral direct-to-implant patients. The results of the penalized regression model demonstrated equivalence in safety metrics between prepectoral direct-to-implant and subpectoral direct-to-implant breast reconstruction, including seroma (p = 0.0883), cancer recurrence (p = 0.876), explantation (p = 0.992), capsular contracture (p = 0.158), mastectomy skin flap necrosis (p = 0.769), infection (p = 0.523), hematoma (p = 0.228), and revision (p = 0.122).

CONCLUSIONS

This study demonstrates that prepectoral direct-to-implant reconstruction is a safe alternative to subpectoral direct-to-implant reconstruction. Given the low morbidity and elimination of animation deformity, prepectoral direct-to-implant reconstruction should be considered when the mastectomy skin flap is robust.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.