Objective:To assess the efficacy

tissue coverage

degradation and bio-compatibility for closure of atrial septal defect(ASD)in an swine model. Methods:The model of ASD was built under echocardiography’s guidance after thoracotomy. Fifteen swines were involved and all swines were sacrificed at 1

3

6

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. ELISA was used to test the level of IL-6. Results:Except 3 swines died of modeling

12 swines with ASD were built successfully and implanted with biodegradable ASD occluders.No infection or shedding of occluder was observed intra-operative and post-operative. 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 that of pre-operation

diameter of occluder disc decreased at 1

3

6 months after surgery(P <0.05) and decreased significantly with the extension of time(P<0.05);compared with that of pre-operation

occluders’ height decreased at 3 months

6months after surgery(P<0.05)

however

there was little change at 1 month after surgery(P >0.05). Compared with that pre-operation

double disc area of occluder decreased at 1

3

6

9 months after surgery(P<0.05)and decreased significantly with the extension of time(P<0.05). Compared with that pre-operation

serum IL-6 level increased at 3 months and 6 months(P<0.05)

and declined to normal at 9 months after surgery(P>0.05). Conclusion:With satisfactory effectiveness

bio-compatibility and degradation

the fully biodegradable ASD occluder is ideal for swine model of ASD.