Li Tao, Bao Xianhao, Feng Jiaxuan, Li Zhenjiang, Liu Junjun, Zhao Yuxi, Wu Mingwei, Zeng Zhaoxiang, Feng Rui, Zhou Jian, Jing Zaiping
Endovascular Diagnosis and Treatment Center for Heart Valvular Diseases, and Endovascular Diagnosis and Treatment Center for Aortic Dissection, Changhai Hospital, Navy Medical University, Shanghai, China.
Heart Surg Forum. 2019 Sep 16;22(5):E380-E384. doi: 10.1532/hsf.2585.
To explore the feasibility of endovascular reconstruction of aortic root including aortic valve, sinus of valsalva and ascending aorta by a single stent-graft, a novel valved stent-graft with two fenestrae for preserving the coronary arteries was designed and performed in-vitro on a pig heart based circulation simulating system.
Pig hearts were harvested from 30 healthy adult female pigs weighing between 60-65 kilograms. Before sacrifice, all the pigs received aortic computed tomography angiography (CTA) examinations and morphologic parameters of aortic root were measured. Then we customized the valved stent-grafts according to the CTA measurements. After the pig heart was fixed on the special platform according to the original orientation and connected to the circulation system, the stent graft was delivered through transapical access and covered the segment from aortic annulus to proximal part of aortic arch under DSA (digital subtraction angiography) guidance. Then changes of coronary flow before and after the procedure and fenestration alignment with coronary ostia were analyzed.
The overall technical success rate was 100%. The valve functions tested by ultrasound were in good condition under 120 mmHg circulation pressure. The flow of left coronary artery (LCA) did not decrease, but increased after the stent-graft implantation (340 ± 2.06 mL/min versus 288 ± 5.29 mL/min, P < .05). Similarly, the flow of right coronary artery (RCA) also increased (392 ± 9.17 mL/min versus 348 ± 8.01 mL/min; P < .05). The final angiography confirmed that both coronary arteries were patent. When generally observed from outer wall of valsalva sinus, both RCA and LCA orifices were aligned with the fenestrae. In 4 cases, the autologous valve leaflets blocked nearly 20% of the LCA fenestra's area, but the flow did not significantly decrease in these cases.
Stimulated on a pig heart-based circulation simulation system, the one-piece valved-fenestrated stent graft with a branch could be delivered via the transapical access and deployed accurately, which achieved endovascular reconstruction of aortic valve, sinus of valsalva and ascending aorta while preserving the coronary artery perfusion by fenestrations. More in-vivo experiments on animal models are mandatory to further verify its efficacy and safety.
探讨采用单一支架型人工血管进行主动脉根部（包括主动脉瓣、主动脉窦和升主动脉）血管腔内重建的可行性，设计了一种新型的带有两个用于保留冠状动脉的开窗的带瓣支架型人工血管，并在猪心体外循环模拟系统上进行了实验。
从30只体重在60 - 65千克的健康成年雌性猪身上获取心脏。在处死前，所有猪均接受主动脉计算机断层扫描血管造影（CTA）检查，并测量主动脉根部的形态学参数。然后根据CTA测量结果定制带瓣支架型人工血管。将猪心按原方向固定在特殊平台上并连接到循环系统后，在数字减影血管造影（DSA）引导下经心尖途径输送支架型人工血管，覆盖从主动脉瓣环到主动脉弓近端的节段。然后分析手术前后冠状动脉血流的变化以及开窗与冠状动脉口的对齐情况。
总体技术成功率为100%。在120 mmHg循环压力下，经超声检测瓣膜功能良好。支架型人工血管植入后左冠状动脉（LCA）血流未减少，反而增加（340±2.06 mL/min对288±5.29 mL/min，P <.05）。同样，右冠状动脉（RCA）血流也增加（392±9.17 mL/min对348±8.01 mL/min；P <.05）。最终血管造影证实两支冠状动脉均通畅。从主动脉窦外壁总体观察时，RCA和LCA口均与开窗对齐。4例中，自体瓣膜叶几乎阻塞了LCA开窗面积的20%，但这些病例中血流未显著减少。
在猪心体外循环模拟系统上进行实验，带有分支的一体式带瓣开窗支架型人工血管可经心尖途径输送并准确植入，实现了主动脉瓣、主动脉窦和升主动脉的血管腔内重建，同时通过开窗保留了冠状动脉灌注。需要在动物模型上进行更多的体内实验以进一步验证其有效性和安全性。
