Use of adipose tissue and stromal vascular fraction in hand surgery

Efficacy and safety of stromal vascular fraction on scar revision surgery: a prospective study

BACKGROUND

Cell-based therapies are popular in the field of reconstructive surgery. The stromal vascular fraction (SVF), comprised of mature adipocytes or blood, reportedly has a regenerative effect; however the mechanism remains unclear. This study aimed to prove the viability and effectiveness of using SVF in scar treatment.

METHODS

This prospective double-blind study involved 20 patients who visited an outpatient clinic for 2 years, from July 2016 to July 2018, and underwent scar revision for traumatic or surgical scars. After scar revision surgery performed by a single surgeon, patient scars were divided into experimental and control sides. The subcutaneous layer of the experimental and control sides were injected with 0.1 mL/cm of SVF and normal saline, respectively. Each side was evaluated using the Patient and Observer Scar Assessment Scale (POSAS) before and six months after the surgery.

RESULTS

Of the 20 patients who underwent scar revision surgery and SVF treatment, 4 dropped out for personal reasons. In 11 of 12 POSAS items, the experimental side showed significant improvements compared to the control side.

CONCLUSIONS

Although more research is needed, autologous SVF is a valuable source of regenerative medicine that can be swiftly and inexpensively prepared from human fat tissue.

Novel therapies and innovation for systemic sclerosis skin ulceration

Skin ulceration is an important cause of morbidity in systemic sclerosis and can occur at anytime during disease progression. Incident disease cohorts are important for understanding whether skin ulceration represents active vasculopathy versus resultant damage. Biomarkers for skin ulcer pathogenesis, both serum and imaging, are under investigation to elucidate the functional consequences of the structural abnormalities. Novel therapeutics for the treatment of vasculopathy benefit from reliable biomarkers able to predict the disease evolution remains an important unmet need. Nonetheless, a diagnostic approach that captures early skin ulceration and treatments that restore vascular and immune homeostasis is critical for effective systemic sclerosis (SSc) vasculopathy management.

Injectable Prevascularized Mature Adipose Tissues (iPAT) to Achieve Long-Term Survival in Soft Tissue Regeneration

Soft tissue regeneration remains a challenge in reconstructive surgery. So far, both autologous fat implantations and artificial implants methods used in clinical applications lead to various disadvantages and limited lifespan. To overcome these limitations and improve the graft volume maintenance, reproducing a mature adipose tissue already including vasculature structure before implantation can be the solution. Therefore, injectable prevascularized adipose tissues (iPAT) are made from physiological collagen microfibers mixed with human mature adipocytes, adipose-derived stem cells, and human umbilical vein endothelial cells, embedded in fibrin gel. Following murine subcutaneous implantation, the iPAT show a higher cell survival (84% ± 6% viability) and volume maintenance after 3 months (up to twice heavier) when compared to non-prevascularized balls and liposuctioned fat implanted controls. This higher survival can be explained by the greater amount of blood vessels found (up to 1.6-fold increase), with balanced host anastomosis (51% ± 1% of human/mouse lumens), also involving infiltration by the lymphatic and neural vasculature networks. Furthermore, with the cryopreservation possibility enabling their later reinjection, the iPAT technology has the merit to allow noninvasive soft tissue regeneration for long-term outcomes.

The Effects of Shear Force-Based Processing of Lipoaspirates on White Adipose Tissue and the Differentiation Potential of Adipose Derived Stem Cells

Autologous lipotransfer is a promising method for tissue regeneration, because white adipose tissue contains a heterogeneous cell population, including mesenchymal stem cells, endothelial cells, immune cells, and adipocytes. In order to improve the outcome, adipose tissue can be processed before application. In this study, we investigated changes caused by mechanical processing. Lipoaspirates were processed using sedimentation, first-time centrifugation, shear-force homogenization, and second-time centrifugation. The average adipocyte size, stromal vascular cell count, and adipocyte depot size were examined histologically at every processing step. In addition, the adipose derived stem cells (ADSCs) were isolated and differentiated osteogenically and adipogenically. While homogenization causes a disruption of adipocyte depots, the shape of the remaining adipocytes is not changed. On average, these adipocytes are smaller than the depot adipocytes, they are surrounded by the ECM, and therefore mechanically more stable. The volume loss of adipocyte depots leads to a significant enrichment of stromal vascular cells such as ADSCs. However, the mechanical processing does not change the potential of the ADSCs to differentiate adipogenically or osteogenically. It thus appears that mechanically processed lipoaspirates are promising for the reparation of even mechanically stressed tissue as that found in nasolabial folds. The changes resulting from the processing correspond more to a filtration of mechanically less stable components than to a manipulation of the tissue.

Update on the Basic Science Concepts and Applications of Adipose-Derived Stem Cells in Hand and Craniofacial Surgery

SUMMARY

Adipose-derived stem cell therapy offers plastic surgeons a novel treatment alternative for conditions with few therapeutic options. Adipose-derived stem cells are a promising treatment because of their broad differentiation potential, capacity for self-renewal, and ease of isolation. Over the past decade, plastic surgeons have attempted to harness adipose-derived stem cells' unique cellular characteristics to improve the survival of traditional fat grafting procedures, a process known as cell-assisted lipotransfer. However, the full implications of cell-assisted lipotransfer in clinical practice remain incompletely understood, stressing the urgent need to assess the scientific evidence supporting adipose-derived stem cell-based interventions. Furthermore, with the strict regulatory climate surrounding tissue explantation therapies, reviewing the safety and efficacy of these treatments will clarify their regulatory viability moving forward. In this report, the authors provide a comprehensive, up-to-date appraisal of best evidence-based practices supporting adipose-derived stem cell-derived therapies, highlighting the known mechanisms behind current clinical applications in tissue engineering and regenerative medicine specific to plastic and reconstructive surgery. The authors outline best practices for the harvest and isolation of adipose-derived stem cells and discuss why procedure standardization will elucidate the scientific bases for their broad use. Finally, the authors discuss challenges posed by U.S. Food and Drug Administration oversight of these cell-based therapies and examine the role of adipose-derived stem cell-based applications in the future of plastic surgery.

New Mechanical Fat Separation Technique: Adjustable Regenerative Adipose-tissue Transfer (ARAT) and Mechanical Stromal Cell Transfer (MEST)

Background

Adipose tissue is not only a very important source of filler but also the body's greatest source of regenerative cells.

Objectives

In this study, adipose tissue was cut to the desired dimensions using ultra-sharp blade systems to avoid excessive blunt pressure and applied to various anatomical areas-a procedure known as adjustable regenerative adipose-tissue transfer (ARAT). Mechanical stromal cell transfer (MEST) of regenerative cells from fat tissue was also examined.

Methods

ARAT, MEST, or a combination of these was applied in the facial area of a total of 24 patients who were followed for at least 24 months. The integrity of the fat tissue cut with different diameter blades is shown histopathologically. The number and viability of the stromal cells obtained were evaluated and secretome analyses were performed. Patient and surgeon satisfaction were assessed with a visual analog scale.

Results

With the ARAT technique, the desired size fat grafts were obtained between 4000- and 200-micron diameters and applied at varying depths to different aesthetic units of the face, and a guide was developed. In MEST, stromal cells were obtained from 100 mL of condensed fat using different indication-based protocols with 93% mean viability and cell counts of 28.66 to 88.88 × 10⁶.

Conclusions

There are 2 main complications in fat grafting: visibility in thin skin and a low retention rate. The ARAT technique can be used to prevent these 2 complications. MEST, on the other hand, obtains a high rate of fat and viable stromal cells without applying excessive blunt pressure.

Level of Evidence 4

Segmental aponeurectomy with Z-Plasty as a treatment option in Dupuytren's disease: A retrospective cohort study

BACKGROUND

Aponeurectomy remains the reference standard treatment for digit tethering by palmar fascial cords in Dupuytren's disease but is associated with a substantial complication rate. An alternative technique decreases metacarpophalangeal joint (MCPJ) flexion contracture by combining palmar segmental aponeurectomy with Z-plasty skin closure. The primary objective of this study was to assess range of motion of the operated ray after the procedure. The secondary objectives were to assess the complication rate and to determine the recurrence rate after at least 1 year.

HYPOTHESIS

Palmar segmental aponeurectomy with Z-plasty closure may provide the advantages of aponeurectomy while decreasing the surgical risk and recurrence rate.

MATERIAL AND METHODS

A retrospective study was conducted in 16 patients with predominant MCPJ flexion contracture due to a well-defined palmar fascial cord. Anaesthesia was loco-regional. The Z-plasty design involved a longitudinal incision along the palmar cord with an oblique incision at each end at a 60° angle to the longitudinal incision. The length of the aponeurectomy was about 1.5cm, to allow full MCPJ extension.

RESULTS

In all, the 16 patients-13 males and 3 females-had 17 segmental palmar aponeurectomy procedures with Z-plasty closure. Mean operative time was 18minutes. Before surgery, mean loss of extension was 47° at the MCP joint and 15° at the corresponding proximal interphalangeal joint (PIPJ). Immediately after surgery, a 97% improvement in MCPJ extension was noted, leaving a mean extension deficit of 1.25°. Mean follow-up was 18.9 months. No complications occurred. Two patients experienced a recurrence.

DISCUSSION

Segmental palmar aponeurectomy as described by Moermans in 1991 improves extension similarly to extensive aponeurectomy but has a lower complication rate. Z-plasty provides good exposure of the pedicles and takes advantage of the greater pliability of the skin on either side of the cord to lengthen the skin by 75%, thereby limiting the risk of the complications seen with needle aponeurotomy. Segmental palmar aponeurectomy with Z-plasty has a role in the management of Dupuytren's disease with flexion contracture predominantly involving the MCPJ.

Friend or foe: Multiple roles of adipose tissue in cancer formation and progression

Obesity is well-known as the second factor for tumorigenesis after smoking and is bound up with the malignant progression of several kinds of cancers, including esophageal cancer, liver cancer, colorectal cancer, kidney cancer, and ovarian cancer. The increased morbidity and mortality of obesity-related cancer are mostly attributed to dysfunctional adipose tissue. The possible mechanisms connecting dysfunctional adipose tissue to high cancer risk mainly focus on chronic inflammation, obesity-related microenvironment, adipokine secretion disorder, and browning of adipose tissue, and so forth. The stromal vascular cells in adipose tissue trigger chronic inflammation through secreting inflammatory factors and promote cancer cell proliferation. Hypertrophic adipose tissues lead to metabolic disorders of adipocytes, such as abnormal levels of adipokines that mediate cancer progression and metastasis. Cancer patients often show adipose tissue browning and cancerous cachexia in an advanced stage, which lead to unsatisfied chemotherapy effect and poor prognosis. However, increasing evidence has shown that adipose tissue may display quite opposite effects in cancer development. Therefore, the interaction between cancers and adipose tissue exert a vital role in mediates adipose tissue dysfunction and further leads to cancer progression. In conclusion, targeting the dysfunction of adipose tissue provides a promising strategy for cancer prevention and therapy.