Study Of The Atheromatous Abdominal Aorta On Rabbits After Treated By HIFU

Background and Objective: The application of the technique of high-intensity focused ultrasound (HIFU) to treat the malignant tumor (especially deep malignant tumor) has gained notable clinical effects. To study the vascular safety during the treatment, we constructed a rabbit model of atheromatous abdominal aorta to investigate the effect of HIFU on vascular pathology and hemodynamics.1,Model construction and measurement of vascula boreModel constructionOne grade big New Zealand rabbits had been feed for 8 weeks with high fat food, and the food quantity was adjusted according to individual weight increase. Blood lipid, such as TC,TG,HDL-c were assessed before experiment and at the 4th, the 8th week after experiment respectively. At the same time, samples were randomly collected to observe the pathological changes by naked eyes and microscope, and the area of Atherosclerotic fibrous plaque was also disposed, which all together to judge the degree of the disease and to evaluate the construction of model.Measurement of the vascula bore of rabbit's abdominal aortaMethods: Randomly select ten rabbits from the research group(n=34)and the control group(n=34), The sample rabbits were continually perfused with 4% formaldehydum polymerisatum in vivo. After that, the vascula bore were measured by mean of slide gaud or were calculated from the perimeter, and the mean was calculated. Results: the vascula bore of rabbit's abdominal aorta was 2.1mm (No statistics difference was found between research group and control group). Conclusions: continued perfusion with 4% formaldehydum polymerisatum in vivo was a good method to preserve the vascula form to measure the bore.2,Pathological observation of the atheromatous abdominal aorta of rabbits treated by HIFUMethods: After subdivided into two groups, the research group and the control group were exposured in HIFU with different degree of 0.8MHz/10000w/cm2. Later, by means of HE staining and special elastic fibers staining, the change of morphology and Ultrastructure of vascula endothelial cells and smooth muscle cells were studied at the very day, the fifth day and the tenth day after exposured in HIFU respectively. Results: After exposured in HIFU, the vascula endothelial cells of abdominal aorta were damaged, or even disappeared. And derangement, breakage and solution had taken place to elastic fibers. Conclusions: Both the two different HIFU would result in coagulation necrosis to rabbit abdominal aorta to some degree. No statistics difference was found between the research group and the control group, so did that between the individual subgroups.3,Hemodynamics observation of the atheromatous abdomial aorta of rabbits treated by HIFUBlood stream Detect by color Doppler ultrasoundMethod: The technique of color Doppler ultrasound blood stream Detect was used to study the Hemodynamics change of the atheromatous abdominal aorta of rabbits at the day before exposure in HIFU, the very day, the fifth day and the tenth day after exposured in HIFU respectively. Results: Vmax and Vmin of the atheromatous abdominal aorta were significantly slow after exposured in either of the two sorts of different HIFU, and there were significant difference among every time groups. PI and RI of the atheromatous abdominal aorta were also significantly changed among all the time groups before and after treatment by HIFU.X-ray DSA detectMethod: By means of X-ray DSA, the atheromatous abdominal aorta of rabbits were detected at the day before exposure in HIFU, the very day, the fifth day and the tenth day after exposured in HIFU respectively. Results: After exposured in HIFU, the blood stream block, the blood filling delay as well as the Vascular wall defect were found in atheromatous abdominal aorta, but those Pathological changes would remised as the time passed. No Vascular embolism and Vascular rupture were found. Conclusion: Although HIFU would damaged 2.1mm atheromatous abdominal aorta of rabbits to some deg...