Effects of intimal hyperplasia and vascular remodeling on vascular restenosis after balloon injury

    HAN Yaª²Ling, WANG Xiaoª²Zeng, KANG Jian, MENG Ziª²Min

    Department of Cardiovasology, Shenyang General Hospital of Chinese PLA, Shenyang 110016, China

    ¡¾Abstract¡¿ AIM: To explore the role of intimal hyperplasia and vascular remodeling in the formation of vascular restenosis. METHODS: The model of vascular restenosis established by balloon injury of rat carotid arteries was used and pathologic changes of the arterial wall at different times after balloon injury were observed by microscopy and computer image analyzing system. RESULTS: The proliferation of vascular smooth muscle cell (VSMC) was spotted on the surface of vascular lumen at 3 d after balloon injury, and at 7 d after injury, the neointima formed and continuously thickened. At 28 d after injury, the thickness and the area of the neointima reached their maximal, but at 35 d after injury, they were smaller than those at 28 d after injury. The thickness of the media at different times after balloon injury had no significant change, but the area of the media at 35 d after injury was smaller than that at 28 d after injury, and the area in injured vessels was smaller than that in nonª²injured vessels. The lumen area slightly increased at 3 d after injury and decreased at 7 d after injury. At 28 to 35 d after injury, the lumen area obviously decreased, compared with the nonª²injured control vessels. The crossª²sectional area bounded by the external elastic lamina slightly increased at 3 to 7 d after injury, reaching maximal at 14 d after injury, but at 35 d after injury it was significantly smaller than that at 28 d after injury and that of nonª²injured control vessels. CONCLUSION: Intimal hyperplasia and vascular remodeling are important pathological factors in the pathogenesis of vascular restenosis. The balance of intimal hyperplasia and vascular remodeling are responsible for the formation of vascular restenosis and they together result in lumen narrowing. ......