Early Clinical Application of Assisted Circulation

To the Editor: Today, the implantation of ventricular assist devices (VADs) is a well-established clinical procedure in its 2 applications: as a bridge to cardiac transplantation and as a bridge to myocardial recovery. I thought that your readers might enjoy an account of the earliest clinical applications of assisted circulation, as they occurred almost 4 decades ago. In July 1961, I left my association with Dr. Willem J. Kolff, who was then at the Department of Artificial Organs at the Cleveland Clinic, and arrived at Baylor University in Houston as a fellow in cardiovascular surgery. Dr. Michael E. DeBakey knew of our group's presentation at the ASAIO (American Society for Artificial Internal Organs) meeting in Atlantic City, in March l961. At that meeting, I had described 1 the implantation, in dogs, of 3 types of orthotopic total artificial hearts, each of which used a different source of external energy: an implantable electric motor; an implantable rotating pump with an external electric motor; and a pneumatic pump. It was the 1st time that a driven pneumatic system had been described. Dr. DeBakey asked me if I would agree to spend some time in the laboratory working on the total artificial heart project during my fellowship. At that time, there was nothing at Baylor to start with, except for Louis Feldman's enthusiasm. He was the engineer in charge of the machine shop. In those days, cases of post-cardiotomy cardiogenic shock, with stunning of potentially viable myocardial tissue, were not uncommon. Shortly after my arrival at Baylor, a cardiac surgery patient had to be supported for several hours postoperatively by means of a left ventricular bypass from the left atrium to the femoral artery with the aid of a roller pump. This short period of support had been unsuccessful, so it occurred to me, while I walked back to Baylor one evening in the fall of 1961, that a prolonged use (several days) of mechanical circulation might be the answer to support these patients. During 1961–62, our lab at Baylor developed a small, intrathoracic, pneumatic-driven pump that partly bypassed the left ventricle from the left atrium to the thoracic aorta. The pump's housing was made of Silastic reinforced with Dacron fabric (Fig. 1). 2,3 In May 1962, I presented this work at the Young Investigator's Award Competition of the American College of Cardiology, in Denver. Fig. 1 Drawing of the 19 July 1963 clinical prototype that was developed by Domingo Liotta at Baylor University, Houston. The pump is shown in diastole. The actual clinical prototype is at the Smithsonian Institution, Washington, DC. On 18 July 1963, one of Dr. E. Stanley Crawford's patients underwent an aortic valve replacement. The calcified stenotic valve was replaced with a Starr-Edwards prosthetic valve. Early the next morning, the patient had a cardiac arrest and was resuscitated by means of the open-chest technique. After the chest was closed, it was evident that severe brain damage had occurred. The patient remained in a coma, with low cardiac output and anuria. Subsequently, a rather severe pulmonary edema developed and was refractory to standard treatment. The 1st clinical VAD, bypassing the left ventricle from the left atrium to the descending aorta through a left thoracotomy, was implanted in this patient on the evening of 19 July by Dr. Crawford and me. The pump was regulated to bypass with 1,800 to 2,500 mL of blood per minute. Although the anuria that had been present since cardiac arrest persisted, the pulmonary edema cleared, as indicated by plain chest x–ray and auscultation. We discontinued mechanical support after 4 days of continuous use, but the patient remained in a coma and died. 4 At the beginning of 1966, Dr. DeBakey and I started implanting paracorporeal VADs at the Methodist Hospital. A patient from Mexico underwent a double valve replacement but could not be weaned from extracorporeal circulation. Then we implanted a paracorporeal VAD from the left atrium to the right subclavian artery. After support by the VAD for 10 days, at a flow rate up to 1,200 mL/min, the patient recovered, which made this the 1st successful use of a VAD for postcardiotomy shock. 5,6 Several years later, she died in Mexico in a car accident. The 1966 paracorporeal VADs were lined with Dacron velour to create a neoendocardium that would deter thromboembolism. 7 Everything that followed this early clinical research in the field of assisted circulation is well known and need not be repeated here.