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INTRODUCTION: Vascularized Composite Allografts (VCA) are usually performed in a full major histocompatibility complex mismatch setting, with a risk of acute rejection depending on factors such as the type of immunosuppression therapy and the quality of graft preservation. In this systematic review, we present the different immunosuppression protocols used in VCA and point out relationships between acute rejection rates and possible factors that might influence it. METHODS: This systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We systematically searched Medline (PubMed), Embase, and The Cochrane Library between November 2022 and February 2023, using following Mesh Terms: Transplant, Transplantation, Hand, Face, Uterus, Penis, Abdominal Wall, Larynx, and Composite Tissue Allografts. All VCA case reports and reviews describing multiple case reports were included. RESULTS: We discovered 211 VCA cases reported. The preferred treatment was a combination of antithymocyte globulins, mycophenolate mofetil (MMF), tacrolimus, and steroids; and a combination of MMF, tacrolimus, and steroids for induction and maintenance treatment, respectively. Burn patients showed a higher acute rejection rate (P = 0.073) and were administered higher MMF doses (P = 0.020). CONCLUSIONS: In contrast to previous statements, the field of VCA is not rapidly evolving, as it has encountered challenges in addressing immune-related concerns. This is highlighted by the absence of a standardized immunosuppression regimen. Consequently, more substantial data are required to draw more conclusive results regarding the immunogenicity of VCAs and the potential superiority of one immunosuppressive treatment over another. Future efforts should be made to report the VCA surgeries comprehensively, and muti-institutional long-term prospective follow-up studies should be performed to compare the number of acute rejections with influencing factors.
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Background: Thermography can be used in pre-operative planning of free perforator flap surgeries. Thermography assesses skin temperature by measuring the quantity of infrared radiation observed. In this meta-analysis, authors assess the sensitivity of smartphone-based thermal imaging (SBTI) in the detection of perforators and analyze the difference between static and dynamic imaging. Materials and methods: Authors followed the PRISMA guidelines for systematic reviews and meta-analyses. The meta package in R was used to conduct the meta-analysis. The "metaprop" function was used to calculate the overall sensitivity estimate and 95% confidence interval. The "metaprop.one" function was used to calculate subgroup estimates for static and dynamic study types. The "metareg" function was used to conduct meta-regression analyses to explore sources of heterogeneity. Results: This study includes seven articles with 1429 perforators being evaluated. The overall proportion of the sensitivities was estimated to be 0.8754 (95% CI: 0.7542; 0.9414) using a random effects model. The heterogeneity of the studies was high, as indicated by the tau^2 value of 1.2500 (95% CI: 0.4497; 8.4060) and the I^2 value of 92.6% (95% CI: 88.1%; 95.4%). The pooled sensitivity for static imaging was 0.8636 (95%CI: 0.6238-0.9603) with a tau^2 of 2.0661 and a tau of 1.4374, while the pooled sensitivity for dynamic imaging was slightly higher (p = 0.7016) at 0.8993 (95%CI: 0.7412-0.9653) with a smaller tau^2 of 0.8403 and a tau of 0.9167. Conclusion: Further studies need to confirm that SBTI is a reliable and convenient technique for detecting perforators for the pre-operative planning of free perforator flap surgeries.
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Background and Objective: Mastectomy is a primary treatment for breast cancer patients, and both autologous and implant-based reconstructive techniques have shown excellent results. In recent years, advancements in bioengineering have led to a proliferation of innovative approaches to breast reconstruction. This article comprehensively explores the promising perspectives offered by bioengineering and tissue engineering in the field of breast reconstruction. Methods: A literature review was conducted between April and June 2023 on PubMed and Google Scholar Databases. All English and French articles related to bioengineering applied to the field of breast reconstruction were included. We used the Evidence-Based Veterinary Medicine Association (EBVM) Toolkit 14 checklist for narrative reviews as a quality assurance measure and the Scale for the Assessment of Narrative Review Articles (SANRA) tool to self-assess our methodology. Key Content and Findings: Over 130 references related to breast bioengineering were included. The analysis revealed four key applications: enhancing the quality of the skin envelope, improving the viability of fat grafting, creating breast shape and volume via bio-printing, and optimizing nipple reconstruction through engineering techniques. The primary identified approaches revolved around establishing structural support and enhancing cellular viability. Structural techniques predominantly involved the implementation of 3D printed, decellularized, or biocompatible material scaffolds. Meanwhile, promoting cellular content trophicity primarily focused on harnessing the regenerative potential of adipose-derived stem cells (ADSCs) and increasing the tissue's survivability and cell trophicity. Conclusions: Tissue and bioengineering hold immense promise in the field of breast reconstruction, offering a diverse array of approaches. By combining existing techniques with novel advancements, they have the potential to significantly enhance the therapeutic options available to plastic and reconstructive surgeons.