Ann Thorac Surg 2009;88:1676-1678. doi:10.1016/j.athoracsur.2009.01.074
© 2009 The Society of Thoracic Surgeons
Case Reports
Parallel Application of Extracorporeal Membrane Oxygenation and the CardioWest Total Artificial Heart as a Bridge to Transplant
Eric Anderson,
Dawn Jaroszewski, MD, MBA*,
Christopher Pierce, MS, CCP,
Patrick DeValeria, MD,
Francisco Arabia, MD, MBA
Division of Cardiothoracic Surgery, Mayo Clinic, Phoenix, Arizona
Accepted for publication January 13, 2009.
* Address correspondence to Dr Jaroszewski, Department of Cardiothoracic Surgery, Mayo Clinic, 5777 E Mayo Blvd, Phoenix, AZ 85054 (Email: aroszewski.dawn{at}mayo.edu).
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Abstract
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Circulatory assist devices are an increasingly common method of treating patients with refractory cardiogenic shock. We describe a patient who was a heart transplant candidate with biventricular failure who underwent CardioWest total artificial heart-temporary (SynCardia Inc, Tucson, AZ) implantation with extracorporeal membrane oxygenation to manage the patient's subsequent respiratory failure. After respiratory and hemodynamic stabilization, the CardioWest total artificial heart-temporary served as a successful 62-day bridge-to-heart transplantation.
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Introduction
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Cardiogenic shock can be a lethal condition if it is not treated urgently. Aggressive medical intervention has reduced mortality, but for refractory cases, systemic circulatory support may be necessary [1]. The use of mechanical support devices, such as the ventricular assist device or total artificial heart-temporary (TAH-t) can facilitate normal systemic and pulmonary circulation until heart transplantation [1]. Extracorporeal membrane oxygenation (ECMO) is another short-term option, especially if pulmonary function is compromised. The use of ventricular assist devices and the TAH have been shown to increase rate of survival to transplantation for patients who do not receive immediate heart transplantation [2–5]. A case is presented of ECMO use to support a patient with respiratory failure after the implantation of a TAH-t.
A 58-year-old man presented for treatment of decompensated ischemic cardiomyopathy. The patient's history included myocardial infarction and prior coronary artery bypass surgery with defibrillator implantation. Echocardiography showed global hypokinesis and ejection fraction of < 15%. After evaluation, the patient was listed as status IB for heart transplantation. He continued to decline, despite multiple inotropes and placement of an intra-aortic balloon pump. The patient was at high risk for imminent death from irreversible biventricular cardiac failure and the CardioWest TAH-t (SynCardia Inc, Tucson, AZ) was elected as a bridge-to-heart transplantation.
The TAH-t was implanted as previously described [6]. The TAH-t was allowed to take over the patient's circulation while he was weaned off cardiopulmonary bypass. Within a few minutes, a significant amount of fluid was noted in the endotracheal tube, and the patient's arterial saturations dropped. Despite the addition of positive end-expiratory pressure and maximization of ventilation efforts, the patient continued with a PaCO2 of > 70 and PaO2 of < 40 mm Hg. A transesophageal echocardiogram confirmed adequate pulmonary vein drainage without left atrial cuff compression. Cardiopulmonary bypass was reinstituted. The flows of the TAH-t were re-evaluated; however, no direct cause of the severe pulmonary edema and respiratory failure other than reperfusion injury was discovered. Additional support of the patient with ECMO was decided. The patient was re-heparinized with 30,000 units of heparin. Systemic anticoagulation was necessary to decrease the risk of thrombosis with the reduced TAH-t rate. Extracorporeal membrane oxygenation circuitry was connected to the previously placed bypass with a 22-French aortic cannula and a 28-French right atrial cannula. The ECMO circuit consisted of a CentriMag Blood Pump (Levitronix, Waltham, MA) and a 1.8 m2 Quadrox D (Maquet Inc, Bridgewater, NJ) oxygenator (Fig 1). Extracorporeal membrane oxygenation support was run at 2.5 to 4 L/min with target TAH-t support of 1.5 to 2.0 L/min. Table 1
shows the hemodynamics and flows while balancing the TAH and ECMO. The sternum was left open with an Ioban (3M, St. Paul, MN) covering to allow evacuation of hematoma and prevent tamponade during heparinization.
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Fig 1. The extracorporeal membrane oxygenation circuit consisted of a CentriMag blood pump (Levitronix, Waltham, MA) and a 1.8 m2 Quadrox D oxygenator (Maquet Inc, Bridgewater, NJ).
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The patient was supported with ECMO for 16 hours and 10 minutes before complete weaning off the ECMO occurred and adequate oxygenation was maintained. Venoarterial ECMO was used to maximize arterial oxygenation and minimize pulmonary artery pressure that could contribute to pulmonary edema. The TAH and ECMO flows were adjusted to maintain mixed venous O2 saturations of 70% to 80% as continuous pulmonary artery pressure measurements are not possible with a pulmonary artery catheter with the CardioWest TAH-t. The patient returned to the operating room for removal of the ECMO circuitry. Anticoagulation with heparin was reinstituted 24 hours later and was maintained until warfarin was initiated on postoperative day 6 and adequate internationalized ratio > 2.5 was reached. Aspirin was started on postoperative day 4. Dipyridamole was added on postoperative day 6. Using a thromboelastographic guide, the anticoagulants were administered and adjusted to maintain adequate anticoagulation. After recovery of end organs and rehabilitation, the patient was re-listed for heart transplantation. Sixty-two days after placement of the CardioWest TAH-t (SynCardia Inc) and after ECMO, the orthotopic heart transplantation was performed. The patient continues without evidence of rejection more than 1 year from treatment.
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Comment
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Refractory cardiogenic shock can be lethal without emergent circulatory support [7, 8]. Respiratory failure after placement of the TAH-t could not be explained on a technical basis. The preoperative presence of pulmonary edema combined with cardiopulmonary bypass may have contributed to further lung injury at the alveolar level. The use of ECMO for most cases of cardiogenic shock allows for complete cardiopulmonary bypass until recovery or an alternate clinical course can be taken. For emergent cases involving severe hemodynamic instability and biventricular failure, the TAH-t has been associated with survival to transplant in 79% of patients [5]. We believe that there are no reported cases with ECMO used to support a patient who had respiratory failure after the implantation of a TAH-t. This case suggests that the use of ECMO prior to or during orthotopic implantation of a TAH-t may improve patient outcomes by providing oxygenation and circulatory support in emergent cases of hemodynamic instability and respiratory failure.
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References
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- Potapov EV, Loforte A, Weng Y, et al. Experience with 1000 implanted ventricular assist devices J Cardiac Surg 2008;23:185-194.[Medline]
- Brunet D, Eltchaninoff H, Kerkeni M, et al. Mechanical circulatory assistance in myocardial infarction with refractory cardiogenic shock Arch Cardio Dis 2008;101:30-34.
- Pagani FD, Lynch W, Swaniker F, et al. Extracorporeal life support to left ventricular assist device bridge to heart transplant Circ 1999;100:II-206-II-210.
- Haddad M, Hendry PJ, Masters RG, et al. Ventricular assist devices as a bridge to cardiac transplantation: the ottawa experience Artif Organs 2004;28:136-141.[Medline]
- Copeland JG, Smith RG, Arabia FA, et al. Cardiac replacement with a total artificial heart as a bridge to transplantation N Engl J Med 2004;351:859-867.[Medline]
- Arabia FA, Copeland JG, Pavie A, Smith RG. Implantation technique for the CardioWest total artificial heart Ann Thorac Surg 1999;68:698-704.[Abstract/Free Full Text]
- Combes A, Leprince P, Luyt CE, et al. Outcomes and long-term quality-of-life of patients supported by ECMO for refractory cardiogenic shock Crit Care Med 2008;36:1404-1411.[Medline]
- Van Doorn C, Karimova A, Burch M, Goldman A. Sequential use of extracorporeal membrane oxygenation and the berlin heart left ventricular assist device ASAIO J 2005;51:668-669.[Medline]
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Abstract
Introduction
