Westaby S, Katsumata T, Evans R, Pigott D, Taggart D P, Jarvik R K
Oxford Heart Centre, Oxford, United Kingdom.
J Thorac Cardiovasc Surg. 1997 Sep;114(3):467-74. doi: 10.1016/S0022-5223(97)70195-8.
We developed a system for mechanical circulatory support based on the Jarvik 2000 intraventricular axial flow impeller pump (Jarvik Research, Inc., New York, N.Y.) and percutaneous electric power. The adult pump provides flow at a rate up to 10 L/min with an energy requirement of 7 to 10 watts. The device was implanted into the apex of the left ventricle through a left thoracotomy without cardiopulmonary bypass. A Dacron graft conveyed blood to the descending thoracic aorta. In patients, we will use a skull-mounted carbon pedestal to transmit fine electric wires through the scalp skin. Being highly vascular, the scalp skin is resistant to infection.
We tested 16 adult systems and one pediatric system in 17 adult ewes weighing between 60 and 90 kg. Five died of perioperative complications. Twelve survived between 3 and 198 days (mean 44 days) with a functioning device. None of the sheep could receive adequate anticoagulation with warfarin (INR 1.0 to 1.5). Acute thrombotic occlusion occurred after a 3-hour power loss in one device (46 days) but was cleared with streptokinase. In a second animal with endocarditis, the pump inflow became occluded with vegetations. No other device-related problems or important hemolysis developed despite pump speeds between 10,000 and 18,000 rpm. Renal function remained normal in all animals. Autopsy studies showed no pannus ingrowth at the device inflow despite the restrictive left ventricular cavity size. No sign of thromboembolism could be detected in the brains or kidneys.
Our findings indicate the Jarvik 2000 Oxford System to be a safe and effective circulatory assist device. Potential uses include permanent circulatory support, bridge to transplantation, or bridge to myocardial recovery in acute or chronic left ventricular failure.
我们基于Jarvik 2000型心室内轴流叶轮泵（Jarvik研究公司，纽约州纽约市）和经皮电力开发了一种机械循环支持系统。成人泵的流量可达10升/分钟，能量需求为7至10瓦。该装置通过左胸廓切开术在无体外循环的情况下植入左心室心尖。一条涤纶移植物将血液输送至降主动脉。在患者中，我们将使用安装在颅骨上的碳基座通过头皮皮肤传输细电线。头皮皮肤血管丰富，抗感染能力强。
我们在17只体重60至90千克的成年母羊身上测试了16个成人系统和1个儿科系统。5只因围手术期并发症死亡。12只存活3至198天（平均44天），装置功能正常。所有绵羊使用华法林均无法达到足够的抗凝效果（国际标准化比值1.0至1.5）。一台装置（46天）在断电3小时后发生急性血栓性阻塞，但用链激酶清除。在第二只患有心内膜炎的动物中，泵的流入道被赘生物阻塞。尽管泵速在10000至18000转/分钟之间，但未出现其他与装置相关的问题或严重溶血。所有动物的肾功能均保持正常。尸检研究显示，尽管左心室腔尺寸受限，但装置流入道处无血管翳长入。在大脑或肾脏中未检测到血栓栓塞迹象。
我们的研究结果表明Jarvik 2000牛津系统是一种安全有效的循环辅助装置。其潜在用途包括永久性循环支持、移植桥梁或急性或慢性左心室衰竭时心肌恢复的桥梁。
