Extracorporeal Membrane Oxygenation and Thoratec Pneumatic Ventricular Assist Devices as Double Bridge to Heart Transplantation

Extracorporeal Membrane Oxygenation and Thoratec Pneumatic Ventricular Assist Devices as Double Bridge to Heart Transplantation N.-K. Chou, J.-M. Luo, N.-H. Chi, I.-H. Wu, S.-C. Huang, Y.-S. Chen, H.-Y. Yu, C.-I. Tsao, W.-J. Ko, S.-H. Chu, and S.-S. Wang ABSTRACT Introduction. Ventricular assist devices have benefited patients with end-stage heart failure as a bridge to heart transplantation (HTx). We present our experiment of HTx using extracorporeal membrane oxygenation (ECMO) with Thoratec pneumatic ventricular assist device (TpVAD). Methods. From May 1996 to June 2011, among 410 patients who underwent HTx 23 required mechanical circulatory support (MCS) with implantation of the TpVAD and 15 (65%) of them received grafts. Results. The 23 patients included 4 female and 19 male patients of age range 10 to 80 years. Eighteen (78%) of them needed ECMO before TpVAD implantation. Twelve (67%) were implanted with a TpVAD double bridge to HTx. The demand for MCS among patients with acute hemodynamic collapse has led to major improvements in the existing systems such as ECMO with double bridge to TpVAD. Conclusion. We used ECMO as a rescue procedure for acute hemodynamic deterioration. However, during ECMO support, left ventricular afterload increased. If prolonged support is required, TpVAD might be required: 15 (65%) of patients supported by ECMO with TpVAD needed to a wait a suitable donor. We recommend the application of ECMO for short-term support (within 1 week), and TpVAD as a bridge for medium- or long-term support. URRENTLY, HEART TRANSPLANTATION (HTx) is the definite choice of treatment for end-stage heart disease.1–3 As waiting times continue to increase, various bridge techniques have been used to prolong recipient survival until a suitable heart is available. Both extracorporeal membrane oxygenation (ECMO) and ventricular-assist devices (VADs) have benefited patients with end-stage heart failure as a bridge to (HTx).4 –7 However, ECMO support is associated with a significantly increased morbidity and mortality especially when administered for more than 2 weeks.8,9 Serious complications of cerebral infarction, brain hemorrhage, renal dysfunction, or multiple organ failure are often fatal or preclude transplantation. However, VADs have been successfully used for longer support as a bridge to transplantation or as destination therapy.4 –7 VADs can be bridged for weeks or months, allowing the patient more time to a wait a suitable organ. We present our experience with HTx in the presence of ECMO hybridized with the Thoratec ventricular pneumatic assist device (TpVAD).

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MATERIALS AND METHODS The Thoratec VAD is engineered with a pulsatile design. It includes an internal pumping chamber with inflow and outflow valves that enable cyclic filling and emptying; pump activation is elicited either by a pneumatic or an electrical system. The VAD includes a right ventricular assist device, a left ventricular device, and a biventricular assist device. From May 1996 to June 2011, we performed 410 HTx among whom 23 required, mechanical circulatory support (MCS) with TpVAD and 15 (65%) received a suitable donor thereafter for orthotopic HTx. The patients’ ages ranged from 10 to 80 years old (mean ⫽ 43.7). Nineteen (83%) of patients maintained their circulation by ECMO From the Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan. This work was supported in part by the Department of Medical Research of National Taiwan University Hospital. Address reprint requests to Shoei-Shen Wang, MD, PhD, Department of Surgery, National Taiwan University Hospital, No. 7 Chung-Shan South Road, Taipei, Taiwan. E-mail: wangp@ ntu.edu.tw © 2012 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710 Transplantation Proceedings, 44, 878 – 880 (2012)

ECMO AND TPVAD AS DOUBLE BRIDGE

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before TpVAD implantation; 47% of the patients suffering acute renal failure and hemodialysis were supported with ECMO and continuous arteriovenous hemofiltration (CAVH). Fifteen (79%) patients required intra-aortic balloon pumping (IABP) together with ECMO.

RESULTS

The 23 patients included 4 female and 19 male patients of age range 10 to 80 years. Eighteen (78%) patients needed ECMO before TpVAD implantation. Among them, 12 subjects (67%) were implanted with a TpVAD double bridge to HTx (Table 1). The demand for MCS among patients with acute hemodynamic collapse has led to major improvements in the existing clinical systems such as ECMO with double bridge to TpVAD. The Thoratec VAD duration was 1 to 281 days (mean ⫽ 52). There was no significant difference between survivors and nonsurvivors in age, sex, pretransplantation diagnosis, IABP use, or duration of VAD treatment. The combination of CAVH during ECMO support was associated with a significantly higher mortality rate (77%). Fifteen (65%) of the 23 patients with MCS were successfully bridged to HTx. We used ECMO as a rescue procedure for patients with acute hemodynamic deterioration. Because of the high complication and morbidity rates of ECMO support when it is used for a long period, the VAD was implanted as a left VAD, bi-VAD, or right VSD for long-term support before HTx. Thirty-four (85%) of 40 circulatory patients received

ECMO support hybridized with VAD, including 30 patients with left VAD, three patients with bi-VAD, and one patient with right VAD for Epstein anomaly (Fig 1). Twenty (59%) of the 34 patients awaited a suitable donor for HTx having undergone implantation of the VAD as a double bridge to HTx. The demand for MCS among patients with acute hemodynamic collapse has led to major improvements in the systems such as ECMO with a double bridge to TpVAD. Temporary mechanical support with an IABP or ECMO was needed for life support. Bleeding and right ventricular failure often occur after HeartMate left LVAD implantation plus ECMO as a bridge to HeartMate left LVAD implantation. HeartMate left LVAD provides safe stable long-term circulatory support without the need for anticoagulation. Four of nine subjects remained on HeartMate left LVAD before undergoing successful HTx. These patients were ambulatory and could be discharged while awaiting transplantation. Heart function may recover after long-term ventricular unloading with the HeartMate left LVAD. One 37-year-old male patient with dilated cardiomyopathy combined with coronary artery disease suffered congestive heart failure undergoing VAD with HeartMate II implantation survived with no neurological sequelae. He is currently in New York functional class I and is a waiting HTx. In conclusion, ECMO and VAD have provided excellent MCS.4 –7 ECMO is usually used as a rescue procedure or

Table 1. ECMO with TpLVAD as Double Bridge to HTx: Patient Overview Case Number

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Sex

HTx Age

Blood Type

F M M M M M M M M M F M M M M M M M F M F M M

49 47 35 60 40 69 30 80 50 32 37 51 43 10 39 49 54 40 53 56 11 48 22

AB B A A B O O B O O A O AB O O A O A O A O B B

Diagnosis

ECMO

IABP

CAVH

TpVAD Used Days

HTx

Outcome

DCMP DCMP Ebstein anomaly ICMP ICMP AMI, cardiac arrest DCMP ICMP AMI, cardiac arrest DCMP Acute myocarditis DCMP ICMP DCMP DCMP DCMP AMI, cardiac arrest AMI, cardiac arrest DCMP AMI, cardiac arrest DCMP AMI, CHF Traumatic LAD transection, CHF

⫹ ⫹ ⫹ ⫹ ⫹ ⫹ — — ⫹ ⫹ ⫹ ⫹ ⫹ — ⫹ ⫹ ⫹ ⫹ ⫹ ⫹ — ⫹ ⫹

⫹ — — ⫹ ⫹ ⫹ ⫹ ⫹ ⫹ ⫹ ⫹ ⫹ ⫹ — ⫹ ⫹ ⫹ ⫹ ⫹ — — ⫹ —

— — ⫹ ⫹ ⫹ ⫹ — — — ⫹ — — ⫹ — — — ⫹ ⫹ — — — ⫹ —

7 55 23 1 7 9 281 221 38 143 48 14 10 53 42 13 19 40 23 18 86 7 40

⫹ ⫹ ⫹ — — — ⫹ — ⫹ — ⫹ ⫹ — ⫹ ⫹ ⫹ — ⫹ ⫹ ⫹ ⫹ — ⫹

2645 d 1674 d Survival Death Death Death 234 d Death Survival Death Survival Survival Death Survival Survival Survival Death Survival Survival Survival Survival Death Survival

AMI, acute myocardial ischemia; CAVH, continuous arteriovenous hemofiltration; DCMP, dilated cardiomyopathy; ECMO, extracorporeal membrane oxygenation; HTx, heart transplantation; IABP, intra-aortic balloon pump; ICMP, ischemic cardiomyopathy; TpVAD, Thoratec pneumatic ventricular assist device; CHF, congestive heart failure.

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CHOU, LUO, CHI ET AL

Fig 1. Algorism of personalized mechanical circulatory support for hemodynamic collapse at National Taiwan University Hospital. ECMO, extracorporeal membrane oxygenation; F-VA, femoral vein outflow to ECMO and artery inflow from ECMO to femoral artery; HTx, heart transplantation; TpBVAD, Thoratec pneumatic biventricular assist device; TpLVAD, Thoratec pneumatic left ventricular assist device; TpRVAD, Thoratec pneumatic right ventricular assist device; B-LVAD, biopump left ventricular assist device; HLVAD; HeartMat left ventricular assist device.

device for acute hemodynamic deterioration. During ECMO support, left ventricular afterload increases and left ventricular failure may become more severe. To add support, we performed left ventricular drainage or left ventricular VAD. After ECMO was provided for acute circulatory collapse, pharmacological support may be added with a phosphodiesterase inhibitor and a catecholamine.8,9 With the circulatory support still limited, the high complication and morbidity rates of long-term ECMO use remain a problem.8,9 Thus, the double bridge from ECMO to TpVAD provides more circulatory support that is suitable for long-term hemodynamic maintenance. As a result, TpVAD can be considered when prolonged support is required for patients. From our experience, 20/34 (65%) patients who waited for a suitable donor for HTx were supported by ECMO with TpVAD. The waiting time for HTx after TpVAD implantation ranged from 7 to 281 days. With the increasing waiting time for HTx in Taiwan, we recommend the application of ECMO for short-term support within 1 week and TpVAD for long-term support as a bridge. ACKNOWLEDGMENTS The authors acknowledge the collaboration of organ transplantation team at the National Taiwan University Hospital.

REFERENCES 1. Canter CE, Shaddy RE, Bernstein D, et al: Indications for heart transplantation in pediatric heart disease. Circulation 115:65, 2007 2. Del Nido PJ, Armitage JM, Ficker FJ, et al: Extracorporeal membrane oxygenation support as a bridge to pediatric heart transplantation. Circulation 90:66, 1994 3. Gajarski RJ, Mosca RS, Ohye RG, et al: Use of extracorporeal life support as a bridge to pediatric cardiac transplantation. J Heart Lung Transplant 22:28, 2003 4. Reinhartz O, Keith FM, El-Banayosy A, et al: Multicenter experience with the Thoratec ventricular assist device in children and adolescents. J Heart Lung Transplant 20:439, 2001 5. Fiser WP, Yetman AT, Gunselman RJ, et al: Pediatric arteriovenous extracorporeal membrane oxygenation (ECMO) as a bridge to cardiac transplantation. J Heart Lung Transplant 22:770, 2003 6. Imamura M, Dossey AM, Prodhan P, et al: Bridge to cardiac transplant in children: Berlin heart versus extracorporeal membrane oxygenation. Ann Thorac Surg 87:1894, 2009 7. Frazier OH, Rose EA, Oz MC, et al: Multicenter clinical evaluation of the HeartMate vented electric left ventricular assist system in patients awaiting heart transplantation. J Thorac Cardiovasc Surg 122:1186, 2001 8. Chou NK, Chi NH, Wu IW, et al: Extracoporeal membrane oxygenation to rescue cardiopulmonary failure after heart transplantation: a single-center experience. Transplant Proc 42:943, 2010 9. Chou NK, Chi NH, Wu IW, et al: Extracoporeal membrane oxygenation hybrid with Thoratec ventricular-assist-devices as double bridge to heart transplantation. Transplant Proc 42:920, 2010