Safety and Feasibility Study of a Novel Stent-Graft for Thoracic Endovascular Aortic Repair: a Canine Model Experiment

Abstract Objective: To evaluate the safety and feasibility of a novel stent-graft for thoracic endovascular aortic repair (TEVAR) in a canine model, 9 adult hybrid dogs were used for the experiment. Methods: All animals were implanted with a novel thoracic aortic stent-graft via femoral artery. Blood sample was collected at pre-operation and 1, 2, 4, 8 and 12 weeks after implantation for hematological examination. Moreover, tissues from randomly selected 4 dogs were subjected to histopathological analysis with the optical microscope after stent-grafts were implanted for 3, 6, 9, and 12 months respectively. The experimental period lasted for more than 2 years. Results: A total of 9 stent-grafts were successfully implanted in the canine thoracic aortas and no migration or deformation occurred. Related indicators of blood routine, inflammatory factors, and immunology changes were not significantly (P>0.05), except the white blood cell (WBC) counts in the first week. Moreover, abnormal morphology was not found in all thoracic aortas via histopathological examination. Additionally, all stent-grafts were patent and did not migrate, and there was no thrombus in the lumens of stent-grafts. Conclusion: The novel thoracic aortic stent-graft made in China was safe and feasible for thoracic endovascular aortic repair in a canine model.

摘要
研究目的：评估一款新型胸主动脉覆膜支架用于胸主动脉腔内修复术（thoracic endovascular aortic repair, TEVAR）的安全性与可行性，本实验选用9只成年杂交犬作为实验对象。
方法：所有实验动物均经股动脉途径植入新型胸主动脉覆膜支架。分别于术前及术后1、2、4、8、12周采集血液样本，进行血液学检查。此外，分别于覆膜支架植入后3、6、9、12个月，随机选取4只犬获取组织样本，采用光学显微镜开展组织病理学分析。本实验周期超过2年。
结果：共计9枚覆膜支架成功植入犬胸主动脉，未发生移位或变形。除术后第一周的白细胞（white blood cell, WBC）计数外，血常规、炎症因子及免疫学相关指标均无显著差异（P>0.05）。组织病理学检查显示所有受试犬胸主动脉均未出现形态异常。此外，所有覆膜支架均保持通畅，未发生移位，支架内腔无血栓形成。
结论：国产新型胸主动脉覆膜支架应用于犬模型的胸主动脉腔内修复术，具备良好的安全性与可行性。