Ann Thorac Surg 2008;86:1677-1679. doi:10.1016/j.athoracsur.2008.04.101
© 2008 The Society of Thoracic Surgeons
Case Reports
Successful Conversion of TandemHeart Left Ventricular Assist Device to Right Ventricular Assist Device After Implantation of a HeartMate XVE
Masami Takagaki, MD, PhD,
Chris Wurzer, CCP,
Richard Wade, CCP,
Richard Lee, MD,
Sukit Chris Malaisrie, MD,
Patrick M. McCarthy, MD,
Edwin C. McGee, Jr, MD*
Division of Cardiothoracic Surgery, Bluhm Cardiovascular Institute, Northwestern University's Feinberg School of Medicine, Chicago, Illinois
Accepted for publication April 25, 2008.
* Address correspondence to Dr McGee, Heart Transplantation and Mechanical Assistance, Bluhm Cardiovascular Institute, Northwestern University Feinberg School of Medicine, 201 East Huron St, Suite 11-140, Chicago, IL 60611 (Email: emcgee{at}nmh.org).
| Dr McGee discloses that he has a financial relationship with Cardiac Assist Inc.
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Abstract
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A 60-year-old man with end-stage ischemic cardiomyopathy (ejection fraction, 10%) was admitted in cardiogenic shock, which was unresponsive to maximum inotropes and an intraaortic balloon pump. The TandemHeart (TH) left ventricular assist device (Cardiac Assist Inc, Pittsburgh, PA) was placed in the standard percutaneous transseptal configuration with improved hemodynamics. The HeartMate XVE (Thoratec Corp, Pleasanton, CA) implantation was performed as a bridge to transplant 5 days after TandemHeart insertion. The TandemHeart was converted to a temporary right ventricular assist device during the HeartMate XVE (Thoratec Corp) implantation due to right ventricular failure. The right ventricular assist device was weaned 3 days later. This strategy was useful, technically easy, and cost effective.
Right ventricular (RV) failure is a well-described complication of left ventricular assist device (LVAD) implantation [1]. Experience has shown that RV failure can be temporary and that the right ventricle can recover with temporary mechanical assistance.
The TandemHeart (TH) LVAD (Cardiac Assist Inc, Pittsburgh, PA) is typically configured as an LVAD with transeptal left atrial inflow and femoral artery outflow. It can be deployed open or percutaneously. The TandemHeart (TH) LVAD (Cardiac Assist Inc) has been used for ventricular assistance during complicated interventional procedures [2], cardiogenic shock [3], and postcardiotomy cardiac failure [4]. It can also be configured to support the right ventricle as a right ventricular assist device (RVAD) [5]. We are currently using this device as a bridge to an implantable LVAD for patients in cardiogenic shock who do not improve with inotropes or an intra-aortic balloon pump.
A 60-year-old man with end-stage ischemic cardiomyopathy (ejection fraction, 10%) was admitted due to severe left ventricular failure and respiratory distress. He had undergone coronary artery bypass grafting in 1987. Right heart catheterization revealed pulmonary hypertension (systolic pressure, 68 mm Hg) with high pulmonary vascular resistance (PVR) (417 dyn · s/cm5) with minimal reversibility. Despite inotropes and an intra-aortic balloon pump, his cardiac index remained low (1.8 L/min/m2). The patient developed acute on chronic oliguric renal failure.
A TH was placed to allow his condition to stabilize. He improved after TH support with increased cardiac index (2.4 L/min/m2), decreased Cr (2.2 mg/dL), and improved urine output. We believe that an isolated LVAD was his best option as that it could potentially lower his PVR to a level suitable for transplantation. To that end, we implanted the HeartMate XVE LVAD (Thoratec Corp, Pleasanton, CA) as a bridge to transplant 5 days after TH insertion.
The HeartMate outflow graft (Thoratec Corp) was anastomosed to the ascending aorta with a partial occlusion clamp. The TH was turned off and the outflow of the TH was clamped distal to the 3/8 inch x 3/8 inch connector as cardiopulmonary bypass was instituted with aortic and bi-caval cannulation. The TH inflow cannula was pulled to the inferior vena cava. As we believe the patient was at high risk for RV failure, we wanted to keep the TH available for possible RV assistance post-LVAD implantation. To prevent stasis in the circuit, the TH pump was re-circulated, with inflow from the IVC cannula, and outflow to the reservoir of the cardiopulmonary bypass circuit, using a perfusion adaptor (1/4 inch x male luer) placed at the luer port on the TH outflow cannula (3/8 inch x 3/8 inch) connector. The TH outflow was then directed to the cardiotomy reservoir using vacuum assisted drainage. The TH pump was not powered up, so a formal flow reading was not available; however, the pump head was visibly in motion and blood was flowing in both the inflow and outflow cannulas (Fig 1).
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Fig 1. Recirculation circuit. The outflow graft to the femoral artery has been clamped distal to the 3/8 connector. Outflow is directed to the cardiotomy reservoir. Inflow is from the inferior vena cava. (CPB = cardiopulmonary bypass; FV = femoral vein; RA = right atrium.)
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The aorta was cross clamped, and the cavae were occluded. The right atrium was opened. The defect in the interatrial septum was closed followed by the right atrium. The HeartMate XVE LVAD (Thoratec Corp) was implanted in the standard configuration. RV function was extremely poor with low LVAD filling, and we were not able to wean from cardiopulmonary bypass, despite nitric oxide and inotropic support. We decided to use the TH as a temporary RVAD. A 10-mm Vascutek graft (Vascutek, a Terumo Company, Scotland, UK) was anastomosed to the main pulmonary artery. The recirculation of the TH was discontinued, and the outflow of the pump was directed into the graft using a 23-French aortic cannula. The graft had been secured about the cannula with multiple ligatures (Fig 2). Cardiopulmonary bypass was weaned and the TH RVAD and LVAD were initiated. With the TH flow of more than 4.0 L/min, LVAD flows of greater than 2 L/min/m2 were achieved. We kept the chest open on that day, and the patient went back to the intensive care unit with stable pump flows. Anticoagulation with heparin (partial thromboplastin time 50 to 60 seconds) was introduced at approximately 48 hours, when the patient was no longer bleeding. At 24 hours of RVAD support, the right ventricle began to recover as noted by a pulsatile pulmonary artery trace. The RVAD was successfully weaned on postoperative day 3. The inflow cannula was withdrawn from the femoral vein, which was repaired. The graft to the pulmonary artery was divided and ligated. The chest was closed with good pump flows (> 2.2 L/min/m2). All inotropes were weaned and the patient was weaned from the ventilator, but he required a tracheostomy for secretion management. His course was complicated by dialysis dependent renal failure. The patient eventually succumbed to necrotizing pneumonia 6 months after pump placement. Throughout his convalescence, he maintained pump flows in excess of 2.2 L/min/m2 while on no inotropic support, indicating acceptable RV function.
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Fig 2. Right ventricular support using TandemHeart left ventricular assist device (Cardiac Assist Inc, Pittsburgh, PA). The inflow cannula has been placed in the right atrium. Outflow is directed into the main pulmonary artery to which a graft has been sewn. (CPB = cardiopulmonary bypass; FV = femoral vein; PA = pulmonary artery; RA = right atrium.)
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Comment
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We found the strategy of converting a pre-existing TH LVAD to a temporary RVAD useful, technically easy, and cost effective.
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References
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- Ochiai Y, McCarthy PM, Smedira NG, et al. Predictors of severe right ventricular failure after implantable left ventricular assist device insertion: analysis of 245 patients Circulation 2002;106(12 Suppl 1):I198-I202.[Medline]
- Kar B, Butkevich A, Civitello AB, et al. Hemodynamic support with a percutaneous left ventricular assist device during stenting of an unprotected left main coronary artery Texas Heart Inst J 2004;31:84-86.[Medline]
- Thiele H, Sick P, Boudriot E, Diederich KW, Hambrecht R, Niebauer J, Schuler G. Randomized comparison of intra-aortic balloon support with a percutaneous left ventricular assist device in patients with revascularized acute myocardial infarction complicated by cardiogenic shock Eur Heart J 2005;26:1276-1283.[Abstract/Free Full Text]
- Pitsis AA, Dardas P, Mezilis N, Nikoloudakis N, Filippatos G, Burkhoff D. Temporary assist device for postcardiotomy cardiac failure Ann Thorac Surg 2004;77:1431-1433.[Abstract/Free Full Text]
- Rajdev S, Benza R, Misra V. Use of Tandem Heart as a temporary hemodynamic support option for severe pulmonary artery hypertension complicated by cardiogenic shock J Invasive Cardiol 2007;19:E226-E229.[Medline]
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Abstract
Introduction
