Beurteilung der Lebensfähigkeit der Menschen Fat Injektion in Nacktmäusen mit Micro-Computertomographie
Summary
Fat grafting is an essential technique for reconstructing soft tissue deficits. However, it remains an unpredictable procedure characterized by variable graft survival. Our goal was to devise a mouse model that utilizes a novel imaging method to compare volume retention between differing techniques of fat graft preparation and delivery.
Abstract
Fetttransfer ist ein wichtiges Instrument in der Chirurg Rüstzeug für die Behandlung von Weichgewebedefizite im ganzen Körper. Fett ist der ideale Weichgewebe Füllstoff, wie es ist leicht verfügbar, leicht zu erhalten, kostengünstig und von Natur aus biokompatibel. 1 Doch trotz seiner wachsenden Popularität, wird Fetttransplantation von unvorhersehbaren Ergebnissen und variable Transplantatüberleben behindert, mit veröffentlichten Abscheideraten im Bereich irgendwo von 10 -80%. 1-3
Um Untersuchungen an Fetttransplantation zu erleichtern, haben wir deshalb entwickelte ein Tiermodell, das für Echtzeitanalyse des eingespritzten Fett Volumenretention ermöglicht. Kurz gesagt, wird ein kleiner Schnitt in der Kopfhaut eines CD-1-Nacktmaus vorgenommen und 200-400 ul verarbeitet lipoaspirate über dem Schädel plaziert. Die Kopfhaut wird als Empfängerstelle wegen seiner Abwesenheit Mutterunterhautfett gewählt und wegen der ausgezeichneten Hintergrund Kontrast von der Schädeldach vorgesehen, die hilftder Analyseprozess. Mikrocomputertomographie (Mikro-CT) verwendet wird, um das Transplantat an der Grundlinie und danach alle zwei Wochen zu scannen. Die CT-Bilder rekonstruiert und eine Imaging-Software wird verwendet, um Transplantatmengen zu quantifizieren.
Traditionell Techniken, um Fetttransplantat Volumen beurteilen haben erforderte euthanizing die Studie Tier nur eine einzige Bewertung des Transplantats Gewicht und Volumen von physikalischen Mess ex vivo liefern. Biochemische und histologische Vergleiche sind ebenfalls erforderlich, die Studie Tier eingeschläfert werden. Diese beschriebenen Abbildungstechnik bietet den Vorteil der Visualisierung und objektiv zu quantifizieren Volumen zu mehreren Zeitpunkten nach der ersten Transplantation, ohne die Studie Tier zu opfern. Die Technik wird durch die Größe des Transplantats in der Lage, wie größere Transplantate Risiko Haut und Fettnekrose injiziert werden begrenzt. Diese Methode hat einen Nutzen für alle Studien, die Fetttransplantat Lebensfähigkeit und Volumenretention. Es ist besonders gut geeignet, um die OEMng eine visuelle Darstellung der Fett-Transplantate und nach Volumenänderungen im Laufe der Zeit.
Introduction
Soft tissue defects arise from a variety of causes including trauma, tumor resection, aging, and congenital anomaly. They can be debilitating for patients, and represent one of the most common, yet challenging problems for reconstructive surgeons. Many methods exist for addressing soft tissue deficiencies, such as local and free flaps, collagen injections, and synthetic fillers.4-8 However, since its first documented use by Neuber in 18931, autologous fat transfer remains the gold standard for the repair of soft tissue deficits, as it is ready available, easy and safe to harvest, and naturally compatible.1,2
Despite these advantages, autologous fat grafts suffer from unpredictable and variable survival, with retention rates ranging anywhere from 10-80% over time.1-3,9 In order to account for this expected loss of volume and symmetry, surgeons must often overcorrect when filling soft tissue defects, or perform multiple follow-up procedures.
Poorly vascularized graft beds are partly to blame for this tissue resorption. Additionally, the lack of a benchmark analysis method to compare graft survival may also contribute to the inconsistency in reported results. A precise method for measuring graft volume would reduce measurement error when evaluating retention rates. This in turn would help researchers more accurately identify the causative factors that affect graft survival. Although many laboratory animal models have facilitated both quantitative and qualitative assessment of human fat graft survival, most are based on histological and biochemical means and require sacrificing the study animal to yield a single measurement.3,10-12 Little has been reported on the use of imaging techniques to enumerate fat graft volume retention in vivo.
A handful of clinical studies have shown more effective measurement techniques using imaging. Magnetic Resonance Imaging (MRI) was employed by Hörl et al. to measure fat graft survival13, and CT was utilized by Har-Shai et al. and Fontdevila et al. in their analyses of volume retention after grafting in patients who suffered from HIV.14,15 Employing three-dimensional (3D) imaging software, Meier et al. measured volume retention in humans after autologous fat grafting by comparing images from the preoperative and postoperative period.16
Yet, a standardized method employing imaging to measure fat graft survival is lacking in basic science research. A high resolution imaging approach for assessing the volumes of fat grafts would allow not only for accurate and reproducible volume measurements, but also for repeated measurements allowing visualization of the evolution of fat graft survival in a real time fashion.
Protocol
Representative Results
Discussion
Bis zu diesem Zeitpunkt haben die meisten Forscher auf nicht-bildgebenden Verfahren geltend gemacht, um die langfristige Überleben von Fett Transplantate zu quantifizieren, aber diese Methoden das Opfer der Studie Tier-und ergeben nur eine einzelne Messung. 3,10-12 Unsere Studie stellt eine verbesserte Analyseverfahren, die objektiv, Echtzeitquantifizierungs Fett Transplantatüberlebens in einem Maus-Modell ermöglicht.
Kritisch bei diesem Verfahren sicherzustellen, dass ausreich…
Divulgazioni
The authors have nothing to disclose.
Acknowledgements
Diese Studie wurde von der Oak Foundation, der Hagey Labor für Pädiatrische Regenerative Medizin und der National Institute of Health, Grants NIHR21DE019274, NIHR01DE019434, NIHR01DE021683 und NIHU01HL099776 zu MTLDCW unterstützt wurde von der ACS Franklin H. Martin Fakultät Forschungsstipendium, das Hagey unterstützt Labor für Pädiatrische Regenerative Medizin und der Stanford University Child Health Research Institute Fakultät Scholar Award. Mikro-CT wurde an der Stanford Center for Innovation in In-vivo-Imaging durchgeführt.
Materials
| Reagents and Materials | Manufacturer |
| SAL lipoaspirate | N/A |
| Centrifuge | Beckman Coulter, Inc., Pasadena, CA |
| 50 ml conical tubes | BD Biosciences, San Jose, CA |
| CD-1 nude mice (Crl:CD1-Foxn1nu) | Charles River Laboratories, Inc., Wilmington, MA |
| Isoflurane | Henry Schein, Dublin, OH |
| 2.5% Betadine | Purdue Pharma, L.P., Stamford, CT |
| 70% Ethanol solution | Gold Shield, Hayward, CA |
| 1cc luer-lock syringe | BD Biosciences, San Jose, CA |
| 14 gauge cannula | Shippert Medical, Centennial, CO |
| Forceps | Fine Science Tools, Heidelberg, Germany |
| Tenotomy scissors | Fine Science Tools, Heidelberg, Germany |
| 6-0 nylon suture | Ethicon, Blue Ash, OH |
| Phosphate buffered saline | Gibco, Carlsbad, CA |
| micro-CT scanner | Siemens Healthcare, Pleasanton, CA |
| Phantom | TriFoil Imaging, Northridge, CA |
| Imaging analysis software | IRW, Siemens Healthcare, Pleasanton, CA |
| Scale | Mettler-Toledo International, Inc., Columbus, OH |
Riferimenti
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