Deconstructing Allograft Adipose and Fascia Matrix: Fascia Matrix Improves Angiogenesis, Volume Retention, and Adipogenesis in a Rodent Model.

BACKGROUND: Autologous fat grafting is commonly used for soft-tissue repair (approximately 90,000 cases per year in the United States), but outcomes are limited by volume loss (20% to 80%) over time. Human allograft adipose matrix (AAM) stimulates de novo adipogenesis in vivo, but retention requires optimization. The extracellular matrix derived from superficial fascia, interstitial within the adipose layer, is typically removed during AAM processing. Thus, fascia, which contains numerous important proteins, might cooperate with AAM to stimulate de novo adipogenesis, improving long-term retention compared to AAM alone. METHODS: Human AAM and fascia matrix proteins (back and upper leg regions) were identified by mass spectrometry and annotated by gene ontology. A three-dimensional in vitro angiogenesis assay was performed. Finally, AAM and/or fascia (1 mL) was implanted into 6- to 8-week-old male Fischer rats. After 8 weeks, the authors assessed graft retention by gas pycnometry and angiogenesis (CD31) and adipocyte counts (hematoxylin and eosin) histologically. RESULTS: Gene ontology annotation revealed an angiogenic enrichment pattern unique to the fascia, including lactadherin, collagen alpha-3(V) chain, and tenascin-C. In vitro, AAM stimulated 1.0 ± 0.17 angiogenic sprouts per bead. The addition of fascia matrix increased sprouting by 88% (2.0 ± 0.12; P < 0.001). A similar angiogenic response (CD31) was observed in vivo. Graft retention volume was 25% (0.25 ± 0.13) for AAM, significantly increasing to 60% (0.60 ± 0.14) for AAM/fascia ( P < 0.05). De novo adipogenesis was 12% (12.4 ± 7.4) for AAM, significantly increasing to 51% (51.2 ± 8.0) for AAM/fascia ( P < 0.001) by means of adipocyte quantification. CONCLUSIONS: Combining fascia matrix with AAM improves angiogenesis and adipogenesis compared to AAM alone in rats. These preliminary in vitro and pilot animal studies should be further validated before definitive clinical adoption. CLINICAL RELEVANCE STATEMENT: When producing an off-the-shelf adipose inducing product by adding a connective tissue fascial component (that is normally discarded) to the mix of adipose matrix, vasculogenesis is increased and, thus, adipogenesis and graft survival is improved. This is a significant advance in this line of product.

Fluidic Device System for Mechanical Processing and Filtering of Human Lipoaspirate Enhances Recovery of Mesenchymal Stem Cells.

BACKGROUND: Adipose tissue is an easily accessible source of stem and progenitor cells that offers exciting promise as an injectable autologous therapeutic for regenerative applications. Mechanical processing is preferred over enzymatic digestion, and the most common method involves shuffling lipoaspirate between syringes and filtering to produce nanofat. Although nanofat has shown exciting clinical results, the authors hypothesized that new device designs could enhance recovery of stem/progenitor cells through optimization of fluid dynamics principles, integration, and automation. METHODS: The authors designed and fabricated the emulsification and micronization device (EMD) and the filtration device (FD) to replace the manual nanofat procedures. Using human lipoaspirate samples, the EMD and the FD were optimized and compared to traditional nanofat using ex vivo measurements of cell number, viability, and percentage of mesenchymal stem cells and endothelial progenitor cells. RESULTS: The EMD produced results statistically similar to nanofat, and these findings were confirmed for a cohort of diabetic patients. Combining the FD with the EMD was superior to manually filtered nanofat in terms of both recovered cell percentages (>1.5-fold) and numbers (two- to three-fold). Differences were statistically significant for total mesenchymal stem cells and a DPP4 + /CD55 + subpopulation linked to improved wound healing in diabetes. CONCLUSIONS: The new EMD and the FD improved mechanical processing of human lipoaspirate in terms of mesenchymal stem cell enrichment and number compared to traditional nanofat. Future work will seek to investigate the wound healing response both in vitro and in vivo, and to refine the technology for automated operation within clinical settings. CLINICAL RELEVANCE STATEMENT: The new devices improved mechanical processing of human lipoaspirate in terms of stem cell enrichment and number compared to traditional methods. Future work will seek to validate wound healing response and refine the technology for automated operation within clinical settings.

Historical Tools of Anthropometric Facial Assessment: A Systematic Raw Data Analysis on the Applicability of the Neoclassical Canons and Golden Ratio.

BACKGROUND: The fundamental tenets of facial aesthetic surgery education have not changed in centuries. Research is beginning to demonstrate that the Neoclassical Canons and the Golden Ratio, Phi, have limited utilization in populations other than those of White European extraction. OBJECTIVES: The purpose of this study was to analyze comparable raw data in the literature to determine (1) if there is interethnic variability in Neoclassical Canon and Phi measurements, and (2) if the measurements in these representative samples differ from the "ideal." METHODS: A PubMed/Scopus search was performed. Manuscripts with raw data and individuals aged ≥16 were included. Measurements were extracted and employed to calculate the Neoclassical Canons and Phi. One-way analysis of variance (ANOVA) tests were conducted to compare mean measurements across 6 ethnic groups (P < 0.05). RESULTS: Twenty-seven articles were included. Every continent was represented except Antarctica and Australia. Men were less commonly studied than women. Participant ages ranged from 16 to 56. Averaged Canons 2, 6-8 measurements had significant interethnic differences in males, whereas Canons 5-8 had significant differences across ethnicities in females. For men, there was significant interethnic variability in measurements of Phi 2, 5, 8, 10, and 17. For women, Phi 1, 2, 5, 8, 10, and 17 varied across ethnicities. No ethnic/gender group showed consistent approximation of the "ideal" for both the Neoclassical Canons and Phi. CONCLUSIONS: Today, the utility of the Neoclassical Canons and Phi is limited. It is incumbent on our field to systematically study and define the anthropometric measures that define the "ideal."

Improving In Vitro Cartilage Generation by Co-Culturing Adipose-Derived Stem Cells and Chondrocytes on an Allograft Adipose Matrix Framework.

BACKGROUND: Microtia is an inherited condition that results in varying degrees of external ear deformities; the most extreme form is anotia. Effective surgical reconstruction techniques have been developed. However, these usually require multistage procedures and have other inherent disadvantages. Tissue engineering technologies offer new approaches in the field of external ear reconstruction. In this setting, chondrocytes are cultured in the laboratory with the aim of creating bioengineered cartilage matrices. However, cartilage engineering has many challenges, including difficulty in culturing sufficient chondrocytes. To overcome these hurdles, the authors propose a novel model of cartilage engineering that involves co-culturing chondrocytes and adipose-derived stem cells on an allograft adipose-derived extracellular matrix scaffold. METHODS: Auricular chondrocytes from porcine ear were characterized. Adipose-derived stem cells were isolated and expanded from human lipoaspirate. Then, the auricular chondrocytes were cultured on the allograft adipose matrix either alone or with the adipose-derived stem cells at different ratios and examined histologically. RESULTS: Cartilage induction was most prominent when the cells were co-cultured on the allograft adipose matrix at a ratio of 1:9 (auricular chondrocyte-to-adipose-derived stem cell ratio). Furthermore, because of the xenogeneic nature of the experiment, the authors were able to determine that the adipose-derived stem cells contributed to chondrogenesis by means of a paracrine stimulation of the chondrocytes. CONCLUSIONS: In this situation, adipose-derived stem cells provide sufficient support to induce the formation of cartilage when the number of auricular chondrocytes available is limited. This novel model of cartilage engineering provides a setting for using the patient's own chondrocytes and adipose tissue to create a customized ear framework that could be further used for surgical reconstruction.

Ten-Year experience with vertical rectus abdominis myocutaneous flap for reconstruction of abdominoperineal resection defects.

PURPOSE: We evaluate outcomes of our single center using vertical rectus abdominis myocutaneous (VRAM) flaps for reconstruction after abdominoperineal resection (APR). Our goal was to analyze factors that may affect perineal wound healing, a problematic complication with APR reconstructions due to location and high frequency of neoadjuvant chemoradiation. METHODS: This single-center, retrospective study analyzed all VRAM flap perineal reconstruction patients after APR defect over a 10-year period (from July 2008 to June 2018). Outcome measures focused on factors that may affect perineal wound healing complication rates: cancer stage (I/II vs III/IV), neoadjuvant chemoradiation, surgeon's years in practice (<5 years vs >5 years), and pelvic closed suction drain use. RESULTS: Twenty-eight patients met inclusion criteria. The overall major perineal wound complication rate was 14.3% (4 patients). Lack of perioperative closed suction pelvic drain use was associated with a significantly higher rate of major perineal wound complications (28.6% vs 0% and p = 0.031). All four major wound complications occurred in patients who did not have a pelvic drain. The major perineal wound complication rate for patients who underwent neoadjuvant chemoradiation was 22% vs 0% with no neoadjuvant chemoradiation (p = 0.107). CONCLUSION: While our cohort represents a relatively small single-center study, our 14.3% rate of major perineal wound complications is consistent with previous studies in the literature. Our findings show that perioperative pelvic closed suction drain use is associated with a lower rate of perineal wound complications. While neoadjuvant chemoradiation trended toward a higher incidence of perineal wound complications, it did not reach statistical significance.

The Molecular Pathogenesis of Dupuytren Disease: Review of the Literature and Suggested New Approaches to Treatment.

BACKGROUND: Ever since the classification of Dupuytren disease into the proliferative, involutional, and residual stages, extensive research has been performed to uncover the molecular underpinnings of the disease and develop better treatment modalities for patients. The aim of this article is to systematically review the basic science literature pertaining to Dupuytren disease and suggest a new approach to treatment. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a systematic review was conducted using the MEDLINE database to identify basic science literature on Dupuytren pathophysiology falling under 1 or more of the following categories: (1) Molecular alterations, (2) Structural alterations, and (3) Genetic predisposition. RESULTS: A total of 177 articles were reviewed of which 77 studies met inclusion criteria. Articles were categorized into respective sections outlined in the study methods. CONCLUSION: The pathophysiological changes involved in Dupuytren's disease can be divided into a number of molecular and structural alterations with genetic predisposition playing a contributory role. Understanding these changes can allow for the development of biologics which may disrupt and halt the disease process.

Micro/nanobubbles: Improving Pancreatic Islet Cell Survival for Transplantation.

PURPOSE: The preservation of transplantable tissue is directly tied to and limited by the ischemia time. Micro/nanobubbles (MNBs) are miniature gaseous voids that allow for the oxygenation of tissue given their high oxygen-carrying capacity. One of the current limitations of islet cell transplantation for type 1 diabetes is poor islet survival, caused by hypoxia, after harvesting the cells from pancreata. As such, the purpose of this study was to elucidate whether MNBs, when added to standard culture medium, improve islet cell survival postharvest. MATERIALS AND METHODS: Islet cells were harvested from Sprague-Dawley rat pancreas tissue via a standard collagenase digestion and gradient purification. To create the MNB solution, a shear-based generation system was used to produce both air- and oxygen-filled MNBs in standard Connaught Medical Research Laboratories (CMRL) medium. Four groups, consisting of 500 islet equivalents, were cultured with either the standard CMRL medium, macrobubble-CMRL, MNB (air)-CMRL, or MNB (O2)-CMRL, and they were incubated at 37°C. Each treatment solution was replenished 24 hours postincubation, and after 48 hours of culture, dithizone staining was used to determine the islet cell counts, and the viability was assessed using Calcein AM/propidium iodide staining. RESULTS: Islet cells that were preserved in macrobubble-CMRL, MNB (air)-CMRL, and MNB (O2)-CMRL conditions showed an increased survival compared with those cultured with standard CMRL. The islet cells cultured in the MNB (air)-CMRL condition demonstrated the greatest cell survival compared with all other groups, including the pure oxygen-carrying MNBs. None of the MNB treatments significantly altered the viability of the islet cells compared to the control condition. CONCLUSIONS: The addition of MNBs to culture medium offers an innovative approach for the oxygenation of transplantable tissue, such as islet cells. This study demonstrated that MNBs filled with air provided the most optimal addition to the islet cell culture medium for improving islet cell survival amongst the treatment groups we tested. Given these findings, we hypothesize that MNBs may also improve the oxygenation and survival of a variety of other tissues, including fat grafts from lipoaspirate, chronic wounds, and solid organs.

Adipose-derived stem cell extracellular vesicles: A systematic review✰.

INTRODUCTION: Extracellular vesicles (EVs) are cell-secreted packages that deliver cargo to target cells to effect functional and phenotypic changes. They are secreted by many different cell types, including adipose-derived stem cells (ADSCs), which are a promising field of study in regenerative medicine. Our aim was to perform a systematic review of the literature to summarize the scientific work that has been conducted on ADSC EVs to date. METHODS: The Pubmed database was queried with keywords (and variations of) "adipose derived stem cell," "stromal vascular fraction," and "extracellular vesicles." We excluded review papers, then manually screened articles based on title and abstract. Full-text articles were assessed for eligibility to include in final review. RESULTS: While an extensive body of research exists on EVs, a much smaller proportion of that is original research on ADSC EVs. Of 44 manuscripts that met our database search criteria, 21 articles were selected for our systematic review. CONCLUSION: ADSC EVs were found to exert effects on angiogenesis, cell survival and apoptosis, inflammation, tissue regeneration, and reduction of disease pathology. Further studies examine characteristics of ADSC EVs. Future work should aim to further detail the safety profiles of ADSC EVs given their potential for cell-based therapies. The body of research studies characterizing ADSC EVs continues to expand, and much work remains to be done before human pilot studies can be considered. To our knowledge, we offer the first systematic review summarizing the research on ADSC EVs and their determined roles to date.

The New Frontier: A Review of Augmented Reality and Virtual Reality in Plastic Surgery.

Mixed reality, a blending of the physical and digital worlds, can enhance the surgical experience, leading to greater precision, efficiency, and improved outcomes. Various studies across different disciplines have reported encouraging results using mixed reality technologies, such as augmented and virtual reality. To provide a better understanding of the applications and limitations of this technology in plastic surgery, we performed a systematic review of the literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The initial query of the National Center for Biotechnology Information database yielded 2544 results, and only 46 articles met our inclusion criteria. The majority of studies were in the field of craniofacial surgery, and uses of mixed reality included preoperative planning, intraoperative guides, and education of surgical trainees. A deeper understanding of mixed reality technologies may promote its integration and also help inspire new and creative applications in healthcare.

Clinical Utility of Postoperative Computed Tomography Imaging in Orbital Floor Fracture Management.

BACKGROUND: Surgical repair of orbital floor fractures aims to improve visual function and appearance. Postoperative care often involves computed tomography (CT) imaging in addition to physical examination. It has yet to be investigated whether postoperative CT imaging influences treatment of orbital floor fractures. METHODS: A retrospective chart review was conducted for all patients who underwent orbital floor fracture repair at University of California, Irvine, from 2008 to 2017. Demographics, injury characteristics, and presurgical and postsurgical management were retrospectively extracted for 217 cases. Patients who experienced a change of care following postoperative CT (n = 6) were compared with the entire patient cohort. RESULTS: Postoperative CT imaging influenced orbital floor fracture management in 6 patients (7.2% of patients with imaging). The positive predictive value of a postoperative CT scan was 10.3%, compared with 17.6% for a physical examination. An estimated $2013.76 was spent to obtain a postoperative CT scan that revealed 1 additional patient who needed reoperation (number needed to treat = 14). A multivariate regression model demonstrated no association between postoperative CT scans and change in management (P = 0.995). CONCLUSIONS: In this patient cohort, postoperative CT imaging and its associated costs did not significantly benefit management of orbital floor fracture repair. Careful clinical physical examination should be emphasized over postoperative CT imaging to reliably determine the necessity for reoperation in orbital floor fracture management.

Mesenchymal stem cell dysfunction in diabetes.

Diabetes mellitus (DM) is a chronic disease that results in a variety of systemic complications. Recently, stem cell-based therapies have been proposed as potential modalities to manage DM related complications. Mesenchymal stem cell (MSC) based therapies are often considered as an ideal stem cell-based treatment for DM management due to their immunosuppressive characteristics, anti-inflammatory properties and differentiation potential. While MSCs show tremendous promise, the underlying functional deficits of MSCs in DM patients is not well understood. Using the MEDLINE database to define these functional deficits, our search yielded 1826 articles of which 33 met our inclusion criteria. This allowed us to review the topic and illuminate four major molecular categories by which MSCs are compromised in both Type 1 DM and Type II DM models which include: (1) changes in angiogenesis/vasculogenesis, (2) altered pro-inflammatory cytokine secretion, (3) increased oxidative stress markers and (4) impaired cellular differentiation and decreased proliferation. Knowledge of the deficits in MSC function will allow us to more clearly assess the efficacy of potential biologic therapies for reversing these dysfunctions when treating the complications of diabetic disease.

A Novel Innovation for Surgical Flap Markings Using Projected Stencils.

Despite the vast amount of technological advancement seen in the operating room, surgical markings are still drawn as "best estimates" the same way Susruta drew them in the sixth century BC. Many of the flaps used in plastic surgery have precise geometries that are hard to replicate by hand. In this article, the authors describe a novel approach in making surgical markings more accurate by using a pico-projector to project a prefabricated flap, designed on Google Sketchup, as a stencil. Projected and hand-drawn rhomboid and bilobed flaps were tested on cadavers, with both quantitative and qualitative outcomes favoring the projected flaps. This unique concept can not only be used in the operating room but also serve as an educational tool for training plastic and reconstructive surgeons. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Platelet-Rich Plasma, Adipose Tissue, and Scar Modulation.

Level of Evidence: 4.

Topical oxygen therapy & micro/nanobubbles: a new modality for tissue oxygen delivery.

Up to 15 billion dollars of US health care expenditure each year is consumed by treatment of poorly healing wounds whose etiologies are often associated with aberrancies in tissue oxygenation. To address this issue, several modes of tissue oxygen delivery systems exist, including Hyperbaric Oxygen Therapy (HBOT) and Topical Oxygen Therapy (TOT), but their efficacies have yet to be fully substantiated. Micro/nanobubbles (MNBs), which range anywhere from 100 µm to <1 µm in diameter and are relatively stable for hours, offer a new mode of oxygen delivery to wounds. The aim of this article is to systematically review literature examining the use of TOT for wound healing and use of MNBs for tissue oxygenation using the MEDLINE database. The search yielded 87 articles (12 MNB articles and 75 TOT articles), of which 52 met the inclusion criteria for this literature review (12 MNB articles and 40 TOT articles). Additionally, we present an analysis on the efficacy of our MNB generating technology and propose its use as a wound healing agent.

Adipose-Derived Tissue in the Treatment of Dermal Fibrosis: Antifibrotic Effects of Adipose-Derived Stem Cells.

Treatment of hypertrophic scars and other fibrotic skin conditions with autologous fat injections shows promising clinical results; however, the underlying mechanisms of its antifibrotic action have not been comprehensively studied. Adipose-derived stem cells, or stromal cell-derived factors, inherent components of the transplanted fat tissue, seem to be responsible for its therapeutic effects on difficult scars. The mechanisms by which this therapeutic effect takes place are diverse and are mostly mediated by paracrine signaling, which switches on various antifibrotic molecular pathways, modulates the activity of the central profibrotic transforming growth factor ß/Smad pathway, and normalizes functioning of fibroblasts and keratinocytes in the recipient site. Direct cell-to-cell communications and differentiation of cell types may also play a positive role in scar treatment, even though they have not been extensively studied in this context. A more thorough understanding of the fat tissue antifibrotic mechanisms of action will turn this treatment from an anecdotal remedy to a more controlled, timely administered technology.

Elucidating the Preadipocyte and Its Role in Adipocyte Formation: a Comprehensive Review.

Adipogenesis is a complex process whereby the multipotent adipose-derived stem cell is converted to a preadipocyte before terminal differentiation into the mature adipocyte. Preadipocytes are present throughout adult life, exhibit adipose fat depot specificity, and differentiate and proliferate from distinct progenitor cells. The mechanisms that promote preadipocyte commitment and maturation involve numerous protein factor regulators, epigenetic factors, and miRNAs. Detailed characterization of this process is currently an area of intense research and understanding the roles of preadipocytes in tissue plasticity may provide insight into novel approaches for tissue engineering, regenerative medicine and treating a host of obesity-related conditions. In the current study, we analyzed the current literature and present a review of the characteristics of transitioning adipocytes and detail how local microenvironments influence their progression towards terminal differentiation and maturation. Specifically, we detail the characterization of preadipocyte via surface markers, examine the signaling cascades and regulation behind adipogenesis and cell maturation, and survey their role in tissue plasticity and health and disease.

Deconstructing negative pressure wound therapy.

Since its introduction 20 years ago for the treatment of chronic wounds, negative pressure wound therapy use has expanded to a variety of other wound types. Various mechanisms of action for its efficacy in wound healing have been postulated, but no unifying theory exists. Proposed mechanisms include induction of perfusion changes, microdeformation, macrodeformation, exudate control and decreasing the bacterial load in the wound. We surmise that these different mechanisms have varying levels of dominance in each wound type. Specifically, negative pressure wound therapy is beneficial to acute open wounds because it induces perfusion changes and formation of granulation tissue. Post-surgical incisional wounds are positively affected by perfusion changes and exudate control. In the context of chronic wounds, negative pressure wound therapy removes harmful and corrosive substances within the wounds to affect healing. When skin grafts and dermal substitutes are used to close a wound, negative pressure wound therapy is effective in promoting granulation tissue formation, controlling exudate and decreasing the bacterial load in the wound. In this review, we elucidate some of the mechanisms behind the positive wound healing effects of negative pressure wound therapy, providing possible explanations for these effects in different wound types.