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Endovascular Aneurysm Repair - part 4

Đó IS polyurethane bị suy thoái thủy phân [10], và thay thế bởi một polyurethane polycarbonate ổn định hơn đã-được để đề xuất [11]. Tiến bộ nén của các phương tiện truyền thông-lớp Nếu không có dấu hiệu rách WS cần chú ý trong nghiên cứu này. Nó là một, nhưng không đáng kể | The healing response towards polyurethane covered Wallstents I 37 that polyurethane is subjected to hydrolytic degradation 10 and replacement by a more stable polycarbonate polyurethane has been proposed 11 . Progressive compression of the tunica media without signs of laceration was noted in this study. It is a common yet insignificant finding in arterial stenting 18 19 . However there was an increasing amount of collagen representing scar tissue probably owing to the wall pressure of the devices. It is also worth mentioning that the tunica media of the aorta is predominantly elastic and does not have a lamina elastica interna. The latter is present in smaller muscular arteries such as the iliac renal and coronary arteries and contrary to simple medial compression laceration of this important structure by stent wires represents an important stimulus for neointimal proliferation 20 21 . Endothelialization is important for a thrombus-free luminal surface and long-term patency particularly in small vessels. Thrombus initially covering the luminal surface of the endoprostheses was subsequently replaced by a neointima with areas of endothelium. Animals have a higher potential for endothelialization than human beings 22 . Endothelium on the luminal surface of conventional and endovascular prostheses is experimentally proven by pannus ingrowth from the host intima across the anastomosis yet is limited to a length of 10-15 mm 5 . Indeed we observed endothelial covering of the anastomotic sites in all of the endoprostheses. Transmural ingrowth of microvessels from perigraft tissue towards the lumen is another mechanism discussed in the literature 23-25 . Finally fallout en-dothelialization of undifferentiated multipotential mononuclear cells from the blood can also occur 26 27 . In human beings the capacity for endo-thelialization of vascular prostheses is very limited and restricted to anastomotic ingrowth 22 28-30 . We used a spongy covering and observed pores on the .