Objective To investigate the feasibility of percutaneous valved stent implantation above the coronary ostia as a transitional treatment for acute aortic valve rupture.
Background In recent years, some experimental and clinical studies about percutaneous aortic valve replacement has been conducted. Under current conditions, the risk of this technique is still high. aortic valved stent implantation above the coronary ostia might avoid blocking the coronary ostia.
Method Fresh pig pericardia were procured and processed to make artificial valves, and then mounted on tubular braided stents to make valved stents. Twenty healthy dogs weighing 17.7±3.1 kg were selected to establish a canine model of acute aortic valve rupture. The dogs were randomly divided into two groups: the rupture group without any treatment and the valved stent group with percutaneous valved stent implantation above the coronary ostia. The two groups of animals were followed up for 3 months. Echocardiography and other tests were performed to assess aortic regurgitation and ventricular function.
Results Acute aortic valve rupture models were successfully established in 16 of 20 dogs. In the rupture group, the mean aortic regurgitation was 6.8±1.9 ml/s, only three of eight animals survived for 3 months. In the valved stent group, the mean aortic regurgitation was 7.0±2.1 ml/s, valved stents were successfully implanted above the coronary ostia in eight animals. Instant post-implantation anatomy showed that the stents were located appropriately. Seven dogs survived for 3 months. Reduced aortic regurgitation was detected by colour Doppler echocardiography and no valved stent dislocation was found by 64-slice CT scan.
Conclusion Percutaneous valved stent implantation above the coronary ostia is feasible and effective as a transitional treatment for acute aortic valve rupture.