Kim Kitae, Ehara Natsuhiko, Koyama Tadaaki, Furukawa Yutaka
Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, 2-1-1, Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan.
Department of Cardiovascular Surgery, Kobe City Medical Center General Hospital, 2-1-1, Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan.
Eur Heart J Case Rep. 2020 Nov 12;4(6):1-6. doi: 10.1093/ehjcr/ytaa410. eCollection 2020 Dec.
Apico-aortic conduit (AAC) which connects the left ventricular (LV) apex directly to the descending aorta through a valved conduit, is an alternative to surgical aortic valve replacement (AVR) for patients with aortic stenosis (AS) who are inoperable or high risk for surgical AVR and are not suitable candidates for transcatheter aortic valve implantation (TAVI).
An 84-year-old man with severe AS underwent an AAC combined with coronary artery bypass grafting 8 years earlier. A saphenous vein graft was anastomosed from the conduit to the left anterior descending artery. He had developed haemolytic anaemia requiring frequent blood transfusions. The stenosis at the anastomosis of the left ventricle and the conduit might be the cause of a turbulent flow and a shear stress which led to mechanical haemolysis. We expected that dilatation of native aortic valve would reduce the blood flow at the anastomosis site and thereby improve haemolytic anaemia. Since balloon aortic valvuloplasty improved haemolytic anaemia without exacerbation of myocardial ischaemia, transsubclavian TAVI was performed. After the TAVI, significant reductions in the pressure gradient between the left ventricle and the ascending aorta and that between the left ventricle and the conduit were achieved, and the patient remained clinically stable without the recurrence of haemolytic anaemia.
This is the first report regarding mechanical haemolytic anaemia after AAC which might result from a turbulence and a shear stress by the stenosis of the anastomosis of the LV apex and the conduit. A careful monitoring for conduit dysfunction should be made after AAC.
心尖 - 主动脉管道（AAC）通过带瓣管道将左心室（LV）心尖直接连接至降主动脉，对于无法进行手术主动脉瓣置换（AVR）或手术AVR风险高且不适合经导管主动脉瓣植入术（TAVI）的主动脉狭窄（AS）患者而言，是手术AVR的一种替代方案。
一名84岁重度AS男性患者于8年前接受了AAC联合冠状动脉旁路移植术。将大隐静脉移植物从管道吻合至左前降支动脉。他出现了溶血性贫血，需要频繁输血。左心室与管道吻合处的狭窄可能是导致血流紊乱和剪切应力从而引起机械性溶血的原因。我们预计扩张天然主动脉瓣会减少吻合部位的血流，从而改善溶血性贫血。由于球囊主动脉瓣成形术改善了溶血性贫血且未加重心肌缺血，因此进行了经锁骨下动脉TAVI。TAVI术后，左心室与升主动脉之间以及左心室与管道之间的压力梯度显著降低，患者临床情况保持稳定，溶血性贫血未复发。
这是关于AAC术后机械性溶血性贫血的首例报告，其可能由左心室心尖与管道吻合处狭窄导致的血流紊乱和剪切应力引起。AAC术后应密切监测管道功能障碍情况。
