| ObjectiveTo assess the efficacy, tissue coverage, degradation and biocompatibility for closure of atrial septal defect(ASD) in an swine model.Methods The model of ASD was built under echocardiography’s guidance after thoracotomy.15 swines were involved.Swines were sacrificed at 1 month,3 months,6 months and 9 months after surgery. Doppler echocardiography was used to observe efficacy and measure diameter of occluder disc.Gross anatomy was done to assess tissue coverage and degration. Hematoxylin-eosin staining was done to observe inflammatory reaction. Enzyme-linked immunosorbent assay(ELISA) was used to test the level of serum interleukin-6(IL-6).Cells around the occluders were observed by SEM and TEM.CD34 that was marker of endothelial cells was detected by ICH.ResultsIn addition 3 swines died of modeling, 12 swines with ASD were built successfully and implanted with biodegradable ASD occluders.No infection or shedding of occluder were observed intraoperative and postoperative. Occluders were placed well and no residual shunt was observed by doppler echocardiography.Occluders’ surface was partly covered with neointima by gross anatomy at 1 month after surgery,while totally covered at 3,6,9 months. Compared with occluder’s area,coverage area at 1 month after surgery was smaller(P<0.05),while similar at 3,6,9 months(P>0.05). Compared with pre-operation,diameter B of occluder disc decreased at 1,3 and 6 months after surgery(P < 0.05) and decreased significantly with the extension of time(P < 0.05); compared with pre-operation,occluder height H decreased at 3 months, 6 months after surgery(P < 0.05),however,there was little change at 1 month after surgery(P < 0.05). Compared with pre-operation, double disc area of occulder decreased at 1,3,6 and 9 months after surgery(P < 0.05) and decreased significantly with the extension of time(P < 0.05). Compared with pre-operation, serum IL-6 level increased at 1 month,3 months and 6 months,and declined to normal at 9 months after surgery(P<0.05). Endothelial cell and fibrocyte were observed by SEM and TEM. Endothelial cells were stained with CD34 antibody by immunohistochemistry.ConclusionsThere were fine effectiveness and biocompatibility of the fully biodegradable ASD occluder on closure model of swine with ASD,so it is an ideal fully biodegradable ASD occluder. |
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