Beier J P, Hess A, Loew J, Heinrich J, Boos A M, Arkudas A, Polykandriotis E, Bleiziffer O, Horch R E, Kneser U
Department of Plastic and Hand Surgery, University Hospital of Erlangen, Erlangen, Germany.
Eur Surg Res. 2011;46(3):148-55. doi: 10.1159/000324408. Epub 2011 Mar 4.
BACKGROUND/AIMS: The aim of this study was to generate an axially vascularized bone substitute. The arteriovenous (AV)-loop approach in a large-animal model was applied in order to induce axial vascularization in a clinically approved processed bovine cancellous bone (PBCB) matrix of significant volume with primary mechanical stability and to assess the course of increasing axial vascularization.
PBCB constructs were implanted into 13 merino sheep together with a microsurgically created AV loop in an isolation chamber. The vascularization process was monitored by sequential magnetic resonance imaging (MRI) scans. Explants were subjected to micro-computed tomography (micro-CT) analysis, histomorphometry and immunohistochemistry for CD31 and CD45.
Increasing axial vascularization in PBCB constructs was quantified by histomorphometry and visualized by micro-CT scans. Intravital sequential MRI scans demonstrated a significant progressive increase in perfused volume within the matrices. Immunohistochemistry confirmed endothelial lining of newly formed vessels.
This study demonstrates successful axial vascularization of a clinically approved, mechanically stable bone substitute with a significant volume by a microsurgical AV loop in a large-animal model. Thus microsurgical transplantation of a tissue-engineered, axially vascularized and mechanically stable bone substitute with clinically relevant dimensions may become clinically feasible in the future.
背景/目的：本研究的目的是生成一种轴向血管化的骨替代物。在大型动物模型中应用动静脉（AV）袢方法，以诱导具有主要机械稳定性的大量临床认可的加工牛松质骨（PBCB）基质中的轴向血管化，并评估轴向血管化增加的过程。
将PBCB构建体与通过显微外科手术创建的AV袢一起植入13只美利奴绵羊的隔离室中。通过连续磁共振成像（MRI）扫描监测血管化过程。对植入物进行微计算机断层扫描（micro-CT）分析、组织形态计量学分析以及针对CD31和CD45的免疫组织化学分析。
通过组织形态计量学对PBCB构建体中轴向血管化的增加进行了量化，并通过微CT扫描进行了可视化。活体连续MRI扫描显示基质内灌注体积有显著的逐步增加。免疫组织化学证实了新形成血管的内皮衬里。
本研究表明，在大型动物模型中，通过显微外科AV袢可成功实现对具有大量体积、临床认可且机械稳定的骨替代物的轴向血管化。因此，未来临床上移植具有临床相关尺寸的组织工程化、轴向血管化且机械稳定的骨替代物可能会变得可行。
