RESUMEN
BACKGROUND: Accelerated intimal hyperplasia (IH) is an important cause of morbidity and mortality in patients with atherosclerotic vascular disease treated with bypass vein grafts. We used an interposition vein graft model to determine the source of neointimal cells in a clinically relevant large animal model. METHODS: Jugular vein segments from sex-mismatched, MHC-in-bred pigs were implanted into common carotid arteries bilaterally and harvested up to 8 weeks postsurgery for stereological, histological, and immunofluorescence analyses. RESULTS: Progressive IH lesions contained macrophages and smooth muscle cells (SMC). Fluorescent in situ hybridization following grafting of female veins into male arteries revealed that only â¼10% of the SMC were male, confirming that the majority of intimal SMC derived from the local vessel wall. CONCLUSIONS: The majority of neointimal SMC in the IH seen after interposition vein grafting derive from the engrafted local vessel wall. These are the first results from a clinically relevant large animal model that confirm data from rodent models. They have implications for the utility of therapeutic stem cells in this type of intimal hyperplasia.
