Abstract 2045: Mesothelial Cells for Myocardial Regeneration: Revival of the Omentum
Objectives In cellular cardiomyoplasty the mortality of implanted cells is important due to the reduced irrigation of infarcted scars. In the past, omentum flaps have been used to increase the vascularization of ischemic hearts. The goal of this study is to evaluate and to compare the histological and hemodynamic evolution of myocardial infarcts treated with mesothelial angiogenic cells (isolated from the omentum) with infarcts treated with skeletal myoblasts.
Methods In 22 sheep a LV myocardial infarction was created by surgical ligature of 2 coronary branches. Mesothelial cells were isolated from a laparoscopic biopsy of the omentum and myoblasts from a skeletal muscle biopsy. After 3 weeks of in vitro cell expansion, myocardial infarcted areas were treated with injections of culture medium (group 1 control), with mesothelial cells (group 2) and with myoblasts (group 3). After 3 months echocardiographic and histological studies were performed.
Results Five sheep (18%) died during the creation of infarction due to ventricular fibrillation. After 3 weeks of cultures, 80±14 million mesothelial cells and myoblasts were obtained. In both cell treated groups echocardiographic studies at 3 months showed significant limitation of ventricular dilatation and improvement of ejection fraction (Table⇓). In the group treated with mesothelial cells, histologic studies showed a significant angiogenesis and arteriogenesis (increased number of capillaries and arterioles) compared to control and myoblast groups.
Conclusions Mesothelial cells are mesenchymal progenitors of coronary arteries and secrete some growth factors (SDF, FGF and VEGF cytokines). They also present similar morphologic and functional characteristics as endothelial cells. In our study mesothelial cells limited postichemic LV remodeling, improved EF and induced neovascularization of infarcted areas. It could be proposed for the regeneration of hibernating and partially ischemic myocardium.