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Ventricular assist as a bridge to heart transplantation
Ventricular Assist as a Bridge to Heart Transplantation S.-S. Wang, S.-H. Chu, W.-J. Ko, Y.-S. Chen, N.-K. Chou, C.-H. Tsai, and F.-Y. Lin
F
OR END-STAGE myocardial failure, heart transplantation is the treatment of choice whenever a donor heart is available.1–5 At present, mechanical cardiac assist is considered only as a bridge to transplantation at National Taiwan University Hospital (NTUH).1,6,7 The use of a device for staged heart transplantation continues to provide necessary support to individuals who would otherwise likely die awaiting a suitable donor heart.8 There have been many different devices of mechanical assist that have shown good clinical outcome.6 – 8 We present our experience with Thoratec ventricular assist devices (TVAD) as a bridge to heart transplantation.
MATERIALS AND METHODS From July 1987 to November 1997, 81 patients underwent heart transplantation for severe myocardial failure at NTUH. Three patients underwent orthotopic heart transplantation (OHT) after bridging with TVAD. The first was a 49-year-old female with end-stage dilated cardiomyopathy under high doses of catecholamine infusion.9 Because of pulseless ventricular tachycardia, she was resuscitated and resumed sinus rhythm. A total of 100 mg of bolus epinephrine was injected to maintain weak pulsation during 30 minutes of cardiopulmonary resuscitation. Extracorporeal membrane oxygenation (ECMO) was set up through the right femoral artery and vein at the bedside by the percutaneous route. Two days later, because of hemodynamic instability, she was shifted to biventricular assist with TVAD. After 8 days on TVAD, she underwent OHT uneventfully on May 24, 1996. The second case was a 47-year-old male with dilated cardiomyopathy. Because of rapid hemodynamic deterioration and instability, ECMO was initiated. Two days later, because of no improvement of cardiac function on ECMO, he was shifted to biventricular support with TVAD. After 55 days of TVAD support, he underwent OHT with complication on March 11, 1997. The third case was a 35-year-old male with cardiogenic shock from Ebstain’s anomaly after tricuspid valve replacement. After ECMO support for 6 days, because of no recovery of cardiac function, he was shifted to right ventricular assist with TVAD. After 48 days on TVAD, he underwent OHT on June 17, 1997. The procedure to insert TVAD was as usual. After initiation of cardiopulmonary bypass, the left ventricular apex was incised to insert the inlet cannula and the outlet cannula was anastomosed to the ascending aorta. The right ventricular assist system was established with drainage from right atrium and outlet to the pulmonary artery. The third case received right ventricular assist only. Because of inadequate drainage, he underwent the drainage from the right ventricle after right atrial drainage for 4 days. The procedure of
OHT was also as usual, except the removal of TVAD, and setting up the cardiopulmonary bypass via the femoral route.
RESULTS
The general condition was steadily improved on TVAD, although all three patients were noted to have elevated free hemoglobin. In the first patient, moderate hemolysis with free hemoglobin of 7.47 mg/dL was noted before OHT, which may have been due to high outlet suction pressure of the TVAD. No infection was noted during the whole courses. Bleeding requiring reoperation to check bleeding or remove pericardial blood clot was necessary in all three patients. During the waiting period, all patients could ambulate with the TVAD by themselves. In addition, all patients underwent OHT and survived well. Weaning off TVAD support was achieved after initiating cardiopulmonary bypass via the femoral route during OHT, but the removal of the TVAD was delayed in the second patient because of delayed sternal closure of a compromised donor and a profuse bleeding problem. The operation time from skin to skin was 240, 600, and 520 minutes (mean 453 minutes), respectively, which was significantly longer than that (mean 299 minutes, N 5 64) of normal transplantation without previous cardiac operation, but similar to that (mean 473 minutes, n 5 14) of our OHT of “redo” cases. The cardiopulmonary bypass times were 164, 256, and 177 minutes (mean 199 minutes), respectively, significantly longer than that (mean 127 minutes) of normal transplantation, but similar to that (mean 197 minutes) of redo cases. The ischemic times of the donor hearts were 130, 142, and 95 minutes (mean 122 minutes), respectively, similar to that (mean 109 minutes) of normal transplantation and that (mean 129 minutes) of redo cases. After transplantation, postoperative care was as usual,1–3 including triple therapy with cyclosporine, azathioprine, and steroid, and regular echocardiographic examination and endomyocardial biopsy. The posttransplantation courses were uneventful, except for the second patient, who required reoperation to close the sternum and remove the From the Department of Surgery, National Taiwan University, Taipei, Taiwan. Address reprint requests to Dr Shoei-Shen Wang, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei, Taiwan.
© 1998 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
0041-1345/98/$19.00 PII S0041-1345(98)01077-X
Transplantation Proceedings, 30, 3401–3402 (1998)
3401
3402
TVAD. All three patients were discharged in good condition, and are currently alive and well. DISCUSSION
Circulatory assist is required while irreversible hemodynamic deterioration occurs during the waiting period for a suitable donor for heart transplantation.8 The currently available clinical heart assist devices in Taiwan include the intraaortic balloon pump (IABP), ECMO, and VAD.1 Through diastolic augmentation and afterload reduction, IABP could be successfully weaned off in 63% of coronary artery bypass graft patients at NTUH.1 For both lung and heart failure, ECMO provides better support. However, during ECMO support, left ventricular afterload is increased. Also, complications such as infection and hemolysis increase as assist duration increases. About 50% of patients with cardiogenic shock resistant to IABP could be weaned off ECMO at NTUH.1,6,7 When prolonged ventricular assist is required, VAD is the method of choice. In all three patients, ECMO was first used to treat cardiogenic shock, and then VAD was applied. We applied ECMO first not only because ECMO could be set up quickly at bed-side within 30 minutes as a rescue procedure, but we also hoped that the hemodynamic deterioration could be recovered after short-term assist. Yet, none of the three transplant recipients could be weaned off the mechanical assist device. Therefore, as a bridge to heart transplantation, VAD is sufficient. Unless used as a bedside rescue, no ECMO is required for double bridges. Both the HeartMate ventricular assist system (VAS) and
WANG, CHU, KO ET AL
TVAD have been applied at NTUH.1 Because the former could only assist the left ventricle, another assist device was required for right ventricular assist. Therefore, we preferred the TVAD for biventricular assist, even though the last patient, with cardiogenic shock after tricuspid valve replacement for Ebstain’s anomaly, underwent only right ventricular support with TVAD. TVAD could actually be used as biventricular support, or as left or right ventricular support. At present, heart transplantation is a well-established procedure for treatment of end-stage cardiac disease. While a patient experiences irreversible hemodynamic instability during the wait for a suitable donor, successful application of TVAD for right ventricular assist or biventricular assist can lead to successful heart transplantation.
REFERENCES 1. Wang SS, Chu SH: Artif Organs 20:1325, 1996 2. Wang SS, Chu SH, Ko WJ: Transplant Proc 28:1733, 1996 3. Chu SH, Wang SS: Ann Thorac Cardiovasc Surg 2:104, 1996 4. Chu SH, Wang SS, Tsai CH, et al: J Cardiovasc Surg 36:449, 1995 5. Chu SH, Tsai CH, Wang SS, et al: Jpn Circ J 55:1, 1991 6. Wang SS, Chen YS, Ko WJ, et al: Artif Organs 20:1287, 1996 7. Ko WJ, Wang SS, Chen YS, et al: Transplant Proc 28:1735, 1996 8. Mehta SM, Aufiero TX, Pae WE, et al: J Heart Lung Transplant 14:585, 1995 9. Yu HY, Ko WJ, Wang SS, et al: Ann Thorac Cardiovasc Surg 3:125, 1997
F
OR END-STAGE myocardial failure, heart transplantation is the treatment of choice whenever a donor heart is available.1–5 At present, mechanical cardiac assist is considered only as a bridge to transplantation at National Taiwan University Hospital (NTUH).1,6,7 The use of a device for staged heart transplantation continues to provide necessary support to individuals who would otherwise likely die awaiting a suitable donor heart.8 There have been many different devices of mechanical assist that have shown good clinical outcome.6 – 8 We present our experience with Thoratec ventricular assist devices (TVAD) as a bridge to heart transplantation.
MATERIALS AND METHODS From July 1987 to November 1997, 81 patients underwent heart transplantation for severe myocardial failure at NTUH. Three patients underwent orthotopic heart transplantation (OHT) after bridging with TVAD. The first was a 49-year-old female with end-stage dilated cardiomyopathy under high doses of catecholamine infusion.9 Because of pulseless ventricular tachycardia, she was resuscitated and resumed sinus rhythm. A total of 100 mg of bolus epinephrine was injected to maintain weak pulsation during 30 minutes of cardiopulmonary resuscitation. Extracorporeal membrane oxygenation (ECMO) was set up through the right femoral artery and vein at the bedside by the percutaneous route. Two days later, because of hemodynamic instability, she was shifted to biventricular assist with TVAD. After 8 days on TVAD, she underwent OHT uneventfully on May 24, 1996. The second case was a 47-year-old male with dilated cardiomyopathy. Because of rapid hemodynamic deterioration and instability, ECMO was initiated. Two days later, because of no improvement of cardiac function on ECMO, he was shifted to biventricular support with TVAD. After 55 days of TVAD support, he underwent OHT with complication on March 11, 1997. The third case was a 35-year-old male with cardiogenic shock from Ebstain’s anomaly after tricuspid valve replacement. After ECMO support for 6 days, because of no recovery of cardiac function, he was shifted to right ventricular assist with TVAD. After 48 days on TVAD, he underwent OHT on June 17, 1997. The procedure to insert TVAD was as usual. After initiation of cardiopulmonary bypass, the left ventricular apex was incised to insert the inlet cannula and the outlet cannula was anastomosed to the ascending aorta. The right ventricular assist system was established with drainage from right atrium and outlet to the pulmonary artery. The third case received right ventricular assist only. Because of inadequate drainage, he underwent the drainage from the right ventricle after right atrial drainage for 4 days. The procedure of
OHT was also as usual, except the removal of TVAD, and setting up the cardiopulmonary bypass via the femoral route.
RESULTS
The general condition was steadily improved on TVAD, although all three patients were noted to have elevated free hemoglobin. In the first patient, moderate hemolysis with free hemoglobin of 7.47 mg/dL was noted before OHT, which may have been due to high outlet suction pressure of the TVAD. No infection was noted during the whole courses. Bleeding requiring reoperation to check bleeding or remove pericardial blood clot was necessary in all three patients. During the waiting period, all patients could ambulate with the TVAD by themselves. In addition, all patients underwent OHT and survived well. Weaning off TVAD support was achieved after initiating cardiopulmonary bypass via the femoral route during OHT, but the removal of the TVAD was delayed in the second patient because of delayed sternal closure of a compromised donor and a profuse bleeding problem. The operation time from skin to skin was 240, 600, and 520 minutes (mean 453 minutes), respectively, which was significantly longer than that (mean 299 minutes, N 5 64) of normal transplantation without previous cardiac operation, but similar to that (mean 473 minutes, n 5 14) of our OHT of “redo” cases. The cardiopulmonary bypass times were 164, 256, and 177 minutes (mean 199 minutes), respectively, significantly longer than that (mean 127 minutes) of normal transplantation, but similar to that (mean 197 minutes) of redo cases. The ischemic times of the donor hearts were 130, 142, and 95 minutes (mean 122 minutes), respectively, similar to that (mean 109 minutes) of normal transplantation and that (mean 129 minutes) of redo cases. After transplantation, postoperative care was as usual,1–3 including triple therapy with cyclosporine, azathioprine, and steroid, and regular echocardiographic examination and endomyocardial biopsy. The posttransplantation courses were uneventful, except for the second patient, who required reoperation to close the sternum and remove the From the Department of Surgery, National Taiwan University, Taipei, Taiwan. Address reprint requests to Dr Shoei-Shen Wang, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei, Taiwan.
© 1998 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
0041-1345/98/$19.00 PII S0041-1345(98)01077-X
Transplantation Proceedings, 30, 3401–3402 (1998)
3401
3402
TVAD. All three patients were discharged in good condition, and are currently alive and well. DISCUSSION
Circulatory assist is required while irreversible hemodynamic deterioration occurs during the waiting period for a suitable donor for heart transplantation.8 The currently available clinical heart assist devices in Taiwan include the intraaortic balloon pump (IABP), ECMO, and VAD.1 Through diastolic augmentation and afterload reduction, IABP could be successfully weaned off in 63% of coronary artery bypass graft patients at NTUH.1 For both lung and heart failure, ECMO provides better support. However, during ECMO support, left ventricular afterload is increased. Also, complications such as infection and hemolysis increase as assist duration increases. About 50% of patients with cardiogenic shock resistant to IABP could be weaned off ECMO at NTUH.1,6,7 When prolonged ventricular assist is required, VAD is the method of choice. In all three patients, ECMO was first used to treat cardiogenic shock, and then VAD was applied. We applied ECMO first not only because ECMO could be set up quickly at bed-side within 30 minutes as a rescue procedure, but we also hoped that the hemodynamic deterioration could be recovered after short-term assist. Yet, none of the three transplant recipients could be weaned off the mechanical assist device. Therefore, as a bridge to heart transplantation, VAD is sufficient. Unless used as a bedside rescue, no ECMO is required for double bridges. Both the HeartMate ventricular assist system (VAS) and
WANG, CHU, KO ET AL
TVAD have been applied at NTUH.1 Because the former could only assist the left ventricle, another assist device was required for right ventricular assist. Therefore, we preferred the TVAD for biventricular assist, even though the last patient, with cardiogenic shock after tricuspid valve replacement for Ebstain’s anomaly, underwent only right ventricular support with TVAD. TVAD could actually be used as biventricular support, or as left or right ventricular support. At present, heart transplantation is a well-established procedure for treatment of end-stage cardiac disease. While a patient experiences irreversible hemodynamic instability during the wait for a suitable donor, successful application of TVAD for right ventricular assist or biventricular assist can lead to successful heart transplantation.
REFERENCES 1. Wang SS, Chu SH: Artif Organs 20:1325, 1996 2. Wang SS, Chu SH, Ko WJ: Transplant Proc 28:1733, 1996 3. Chu SH, Wang SS: Ann Thorac Cardiovasc Surg 2:104, 1996 4. Chu SH, Wang SS, Tsai CH, et al: J Cardiovasc Surg 36:449, 1995 5. Chu SH, Tsai CH, Wang SS, et al: Jpn Circ J 55:1, 1991 6. Wang SS, Chen YS, Ko WJ, et al: Artif Organs 20:1287, 1996 7. Ko WJ, Wang SS, Chen YS, et al: Transplant Proc 28:1735, 1996 8. Mehta SM, Aufiero TX, Pae WE, et al: J Heart Lung Transplant 14:585, 1995 9. Yu HY, Ko WJ, Wang SS, et al: Ann Thorac Cardiovasc Surg 3:125, 1997