| Aortic dissection is an acute vascular disease with alarmingly high mortality. Without therapy 70% of the patients will die in 2 weeks.Currently, the medical antihypertensive therapy applied in the clinical treatment is able to reduce the rate of aortic rupture but impossible to improve the aortic branch ischemia. And the surgical operation is usually accompanied with big injures, which raises risks and surgical mortality.The interventional transluminal therapy to the aortic dissection indicated satisfying result with small injures and higher success. But aortic full - cycle stent - graft was likely to occlude the aortic branch so its application in aortic dissection DeBakey type I and II was limited.Therefore, the investigation started from three aspects; the preparation of aortic dissection animal model, the animal experimental investigation of the aortic half - cycle stent - graft and the clinical interventional therapy of the aortic dissection. The purpose was to explore how to improve the aortic dissection treatment, broaden the clinical indications of the aortic stent - graft and also observe the therapeutic effect and safety for the new type interventional therapeutic apparatus.Material and methods1. The preparation of the percutaneous transluminal aortic dissection animal model:(1) The in vitro part of the experiment: adopting 40 fresh in vitro canineaorta, the circulation in vitro was established with the help of PP - 6 pump; used self - made metal hook, through the iliac artery approach, with the light from lateral side to form injury in the descending aorta inner wall so to lure the intimal uncovered to form aortic dissection when water entered into the aorta. Then, observed the morphological characteristics of the aortic dissection by the spiral CT and MR scanning.(2) The in vivo part of the experiment: selecting 15 adult healthy hybrid dogs, through the femoral artery approach, used the aortic transluminal self -made metal hook or needle - tip catheter respectively to prepare for the aortic dissection. Under X - ray monitoring, metal hook cut the inner wall of the descending aorta; then with 5F catheter and guide wire, searched for the intimal injury spot, and broadened the tear of intimal to evoke the aortic dissection.Under X - ray monitoring, the needle - tip catheter was slipped through femoral artery to descending aorta, and inserted into the aortic wall. The diluted contrast agent mixed with elastase and heparin was infused so that affected by both the biological injury by the elastase and physical laceration by the pressure of the infused liquid the aortic dissection will appear. Got access to the aortogra-phy and CT scanning data, observed the prognosis of the animal model and finally acquired the aortic specimen and analyzed the images.2. Investigation on the biocompatibility and the exclusive effect of the self - made aortic half - cycle stent - graft(1) Preparation of the stent - graft: adopted domestic medical stainless steel wire to make " Z" shape stent, melted the metal mark and longitude stainless wire, then suture the domestic superslip artificial vascular graft on the outer surface of the stent to make the half - cycle stent - graft.(2) Grouping of the animals: 15 adult healthy hybrid dogs were divided into 5 groups with 3 dogs each group and killed after operation 1,4,8,12 and 16 weeks respectively for specimens.(3) The operation: Randomly selected to exclude either left or right renal artery. Carried out the abdominal aortography to indicate the opening in bilateral renal artery and reveal its relation to the adjacent artery branches. By means of rotating catheter or adjusting the angles between the animals and X - ray tubewhen making the aortography, determined the precise direction of the opening of the renal artery to be excluded. When planting the half - cycle stent - graft, by monitoring the metal marks on the stent ends, pinpoint the location of artificial vascular graft. Ascertained that the vascular graft did not o... |
PDF Full Text Request