The Comparison of Breast Reconstruction Using Two Types of Acellular Dermal Matrix after Breast-Conserving Surgery

Imaging Surveillance After Breast-Conserving Surgery for Cancer With Acellular Dermal Matrix Reconstruction

OBJECTIVE

The aim of this study was to investigate postoperative imaging findings of patients who underwent breast-conserving surgery for cancer and reconstruction with MegaDerm® (sheet-type and pellet-type), analyzing false positives and recurrences, using multi-modality images.

MATERIALS AND METHODS

This study included 201 women (age range: 28-81 years, mean age ± standard deviation: 53.2 ± 8.6 years) who underwent breast-conserving surgery and immediate reconstruction with MegaDerm®. Post-surgery, each patient underwent at least one mammography (MG), ultrasonography (US), and MRI, totaling 713 MG, 1063 US, and 607 MRI examinations. Postoperative images were reviewed separately for the two types of MegaDerm®, and suspicious imaging findings (false positives and recurrences) were analyzed, with a particular focus on the findings in direct contact with MegaDerm®.

RESULTS

MegaDerm® appeared as a circumscribed mass with homogeneous iso- or high density on MG, posterior shadowing on US, and no enhancement on MRI. Calcification was more common and increased in size in sheet-type MegaDerm®, while pellet-type often exhibited irregular margins. Nine out of 17 false positives had suspicious findings in direct contact with MegaDerm®, and six out of nine recurrences showed similar findings. Common suspicious findings included calcifications, asymmetries, and MegaDerm® irregularities on MG; masses and MegaDerm® irregularities on US; and enhancing masses and MegaDerm® irregularities with enhancement on MRI. Notably, MegaDerm® irregularity with calcification was observed on MG and US in only one recurrence case. In 44.4% (4/9) of false-positives in direct contact with MegaDerm®, suspicious findings showed no change or resolution on follow-up.

CONCLUSION

Suspicious imaging findings in direct contact with MegaDerm® may be associated with false positives or recurrences. Therefore, it is essential to recognize these characteristic findings and review the patient's history of MegaDerm® insertion when in doubt.

Decellularized Extracellular Matrix Scaffolds for Soft Tissue Augmentation: From Host-Scaffold Interactions to Bottlenecks in Clinical Translation

Along with a paradigm shift in looking at soft tissue fillers from space-filling to bioactive materials, decellularized extracellular matrix (DEM) fillers have gained more attention considering their superior bioactivity. However, the complex mechanisms that govern the interaction between host tissues and DEMs have been partially understood. This review first covers the mechanisms that determine immunogenicity, angiogenesis and vasculogenesis, and recellularization and remodeling after DEM implantation into host tissue, with a particular focus on related findings from filler materials. Accordingly, the review delves into the dual role of macrophages and their M1/M2 polarization paradigm to form both constructive and destructive immune responses to DEM implants. Moreover, the contribution of macrophages in angiogenesis has been elucidated, which includes but is not limited to the secretion of angiogenic growth factors and extracellular matrix (ECM) remodeling. The findings challenge the traditional view of immune cells as solely destructive entities in biomaterials and indicate their multifaceted roles in tissue regeneration. Furthermore, the review discusses how the compositional factors of DEMs, such as the presence of growth factors and matrikines, can influence angiogenesis, cell fate, and differentiation during the recellularization process. It is also shown that the biomechanical properties of DEMs, including tissue stiffness, modulate cell responses through mechanotransduction pathways, and the structural properties of DEMs, such as scaffold porosity, impact cell-cell and cell-ECM interactions. Finally, we pointed out the current clinical applications, the bottlenecks in the clinical translation of DEM biomaterials into soft tissue fillers, as well as the naïve research areas of the field.

Volume replacement in tumor plastic surgery and breast-conserving surgery using 3D grid and strip‑shaped acellular dermal matrix: Two case reports

The present study was driven by the scarcity of suitable materials for mending partial breast defects and the imperative considerations of safety and durability. The current study presents findings from two female patients, aged 59 and 40, who underwent breast cancer treatment. Patient 1 underwent a mastectomy with a sentinel lymph node biopsy, while patient 2 underwent a partial mastectomy with axillary lymph node dissection. Core needle biopsy confirmed invasive ductal carcinoma in both cases. Breast ultrasound revealed hypoechoic lesions with smooth edges. The reconstruction of the breast defect employed an acellular dermal matrix, and the safety and cosmetic outcomes for each patient were analyzed. At 3 months post-radiotherapy, neither patient experienced significant complications. The preservation of breast contour and volume was satisfactory, with no postoperative tumor recurrences detected. In summary, utilizing an acellular dermal matrix with a three-dimensional grid design for partial breast defect reconstruction offers a viable alternative that aligns with oncological safety standards and provides good cosmetic results.

What Should We Know in Postoperative Surveillance Imaging After Oncoplastic Breast-Conserving Surgery with Pellet-Type Acellular Dermal Matrix?

RATIONALE AND OBJECTIVES

The aim of this study was to evaluate the usual postoperative imaging findings among patients who underwent oncoplastic breast-conserving surgery (BCS) with acellular dermal matrix (ADM) and to assess the clinical utility of mammography (MG) and ultrasonography (US) in follow-ups.

MATERIALS AND METHODS

This retrospective review of our prospectively collected database of patients who underwent oncoplastic BCS with ADM was conducted with IRB approval and in HIPPA compliance. A total of 105 patients whose follow-up MG and US studies over 2years after surgery were available were included in this study. Postoperative imaging findings were analyzed based on sequential MG and US follow-ups. The clinical outcomes and pathological data were also reviewed. The diagnostic performance of MG and US for postoperative surveillance was assessed.

RESULTS

On MG, ADM presented as an oval (99/105, 94.3%), circumscribed/obscured (65/105, 61.9%), and high-density (56/105, 53.3%) mass with calcifications (54/105, 51.4%). On US, the ADM-filled cavity presented as an oval (93/105, 88.6%), circumscribed (70/105, 66.7%), heterogenous echoic (65/105, 61.9%) mass with marginal/posterior acoustic shadowing (95/105, 90.5%) on US. During the follow-up period (mean, 46.1months; range, 26-58 months), four tumor recurrences were diagnosed (4/105, 3.8%). One tumor recurrence detected on MG presented as microcalcifications (1/4, 25%), which were differentiated from benign postoperative calcifications due to their suspicious morphology and location. Two additional recurrences (2/4, 50%), which were MG-negative small masses or intraductal lesions, were detected on US. One tumor recurrence was missed on both MG+US and was detected by magnetic resonance imaging performed at clinician's request. The sensitivity and specificity of MG, US, and MG+US for postoperative surveillance were 25%, 50% and 75% and 100%, 98% and 98%, respectively.

CONCLUSION

Recognition and adequate interpretation of the usual findings after oncoplastic BCS with ADM insertion are important in postoperative imaging surveillance. The sole use of MG is not sufficient for the detection of mass-type tumor recurrence due to the density of inserted ADM fillers. Therefore, the combined use of MG+US could serve as a useful postoperative surveillance tool with increased sensitivity in this population.

Inflammation-mediated matrix remodeling of extracellular matrix-mimicking biomaterials in tissue engineering and regenerative medicine

Extracellular matrix (ECM)-mimicking biomaterials are considered effective tissue-engineered scaffolds for regenerative medicine because of their biocompatibility, biodegradability, and bioactivity. ECM-mimicking biomaterials preserve natural microstructures and matrix-related bioactive components and undergo continuous matrix remodeling upon transplantation. The interaction between host immune cells and transplanted ECM-mimicking biomaterials has attracted considerable attention in recent years. Transplantation of biomaterials may initiate injuries and early pro-inflammation reactions characterized by infiltration of neutrophils and M1 macrophages. Pro-inflammation reactions may lead to degradation of the transplanted biomaterial and drive the matrix into a fetal-like state. ECM degradation leads to the release of matrix-related bioactive components that act as signals for cell migration, proliferation, and differentiation. In late stages, pro-inflammatory cells fade away, and anti-inflammatory cells emerge, which involves macrophage polarization to the M2 phenotype and leukocyte activation to T helper 2 (Th2) cells. These anti-inflammatory cells interact with each other to facilitate matrix deposition and tissue reconstruction. Deposited ECM molecules serve as vital components of the mature tissue and influence tissue homeostasis. However, dysregulation of matrix remodeling results in several pathological conditions, such as aggressive inflammation, difficult healing, and non-functional fibrosis. In this review, we summarize the characteristics of inflammatory responses in matrix remodeling after transplantation of ECM-mimicking biomaterials. Additionally, we discuss the intrinsic linkages between matrix remodeling and tissue regeneration. STATEMENT OF SIGNIFICANCE: Extracellular matrix (ECM)-mimicking biomaterials are effectively used as scaffolds in tissue engineering and regenerative medicine. However, dysregulation of matrix remodeling can cause various pathological conditions. Here, the review describes the characteristics of inflammatory responses in matrix remodeling after transplantation of ECM-mimicking biomaterials. Additionally, we discuss the intrinsic linkages between matrix remodeling and tissue regeneration. We believe that understanding host immune responses to matrix remodeling of transplanted biomaterials is important for directing effective tissue regeneration of ECM-mimicking biomaterials. Considering the close relationship between immune response and matrix remodeling results, we highlight the need for studies of the effects of clinical characteristics on matrix remodeling of transplanted biomaterials.