[Pre-clinical in vivo evaluation study on a new Chinese-made surgical biopatch for atrial septum]

Objective: To evaluate the safety and effectiveness of a new Chinese-made surgical biopatch for atrial septum under the establishment of atrial septal defect animal model in miniature pigs. Methods: From June 2018 to April 2019, 26 pigs were divided into experimental group (15 pigs) and the control group (11 pigs). Animal models of atrial septal defect were established by traditional surgical methods. The to-be-evaluated and listed surgical biological patches (with a diameter of 10 mm) were implanted in the experimental group and the control group to repair the atrial septal defect. Cardiac ultrasound and blood examination of all animals were performed before and at 7, 30, 90, 180 days after operation, the results were analyzed with repetitive measurement and analysis of variance. At 90 days and 180 days after the operation, tissue samples were taken from animals after euthanasia. Pathological examination of heart and major organs were conducted. The independent sample t test and rank sum test were used to compare the data between the two groups, and the nonparametric was used to compare the patch calcification score between the two groups. Results: In total of 26 animals, 14 animals in the experimental group(6 at 90 days, 8 at 180 days) and 9 animals in the control group(4 at 90 days, 5 at 180 days) reached the end of the experiment. The other 3 animals (1 in the experimental group and 2 in the control group) died of arrhythmia, whole heart failure and right heart failure, the results of pathological examination showed that the causes of death were unrelated to the experimental materials. Cardiac ultrasound showed no patch leakage in all animals. There was no statistically significant difference in cardiac ultrasound and blood examination between the two groups at different time points after operation (all P>0.05). The pathological results showed that all the implants were intact and had good biocompatibility. There was no significant difference in the mean endothelialization rate between the experimental group and the control group at 90 and 180 days after operation ((80.8±29.1)% vs. (82.5±23.6)%, t=0.095, P=0.927; (78.8±36.4)% vs. (82.0±19.2)%, t=0.182, P=0.859) on 90 and 180 days, there was no significant difference in the patch calcification score between the two groups (1.00(1.25) vs. 2.00(0.75), Z=6.500, P=0.214; 0(0.75) vs. 1.00(2.00), Z=12.000, P=0.139). Conclusion: The new Chinese-made surgical biopatch for atrial septum has comparable safety and efficacy to that of the marketable patch in miniature pig atrial septal defect animal model.