During recent years, we have predominantly used extracorporeal membrane oxygenation (ECMO) as a bridge to cardiac transplantation in children with dilated cardiomyopathy. With urgent listing for transplantation, waiting time on support has been short (less than 3 weeks), with low mortality and excellent posttransplant survival.1,2 There has been, however, significant morbidity related to the use of EMCO and the mandatory intensive care stay, and this morbidity increases with the duration of support. Therefore, if a long period of support becomes necessary, alternative forms of cardiac assistance have to be considered.
A 2-year-old, previously fit girl presented to her local hospital with a 3-day history of malaise. Dilated cardiomyopathy was diagnosed, and her condition deteriorated rapidly. She required inotropic support and intubation, at which time she suffered a 20-minute cardiac arrest. The patient was urgently transferred to our institution. Cardiac echocardiographs taken on arrival showed a structurally normal heart and a very dilated left ventricle with very poor contractility (fractional shortening 5–10%), and a provisional diagnosis of acute myocarditis was made. She was immediately cannulated for venoarterial ECMO via the neck vessels. This was followed by blade atrial septostomy for decompression of the left side of the heart during the same session.
No improvement in cardiac performance was seen on serial echocardiography over the next few days. On day 8, an attempt to reduce ECMO support under inotropic support failed and she was listed for urgent cardiac transplantation. A repeat stress test performed 2 days later again failed. The patient was hemodynamically stable on ECMO with mechanical ventilation and sedation. The ECMO system required three pumphead changes because of hemolysis, and on day 16 the circuit was changed because of ongoing growth of pseudomonas in blood cultures and the ECMO circuit. On day 20 she was successfully weaned off ECMO and decannulated; however, ventricular function remained severely impaired on echocardiography.
For the next 2 days the patient’s condition appeared stable on inotropic support, but then progressive low cardiac output with end-organ failure developed. Four days later she required repeat ECMO cannulation via the neck and received several days of dialysis until renal function recovered. From 10 days into the second ECMO run, increasing problems with bleeding and breakdown of the neck cannulation site occurred. Because cardiac function remained very poor with otherwise recovered end-organ function, the decision was made to change over to a long-term cardiac assist device. On day 19, a Berlin Heart left ventricular assist device (LVAD) was implanted between the left ventricular apex and ascending aorta. Right heart function appeared adequate on low-dose inotropic support.
The patient was hemodynamically stable on the LVAD and tolerated weaning from long-term sedation and ventilation. She was finally extubated 23 days after implantation of the Berlin Heart LVAD. Rehabilitation was commenced and she transferred to the high-dependency unit. There were no device-related complications. Native cardiac function continued to be very poor and cardiac biopsies revealed end-stage dilated cardiomyopathy.
The patient underwent a successful orthotopic cardiac transplantation after 67 days on the Berlin Heart LVAD. She was extubated on postoperative day 2 and discharged home 4 weeks later after a hospital stay of 137 days. The cumulative time on mechanical cardiac support was 106 days.
Until recently, only a very limited range of cardiac assist devices was available for children. In our institution we have extensive experience with the use of ECMO for respiratory assistance, and therefore preferred to use this device for cardiac support. Furthermore, in the United Kingdom, children on mechanical cardiac support can be urgently listed for transplantation (equivalent to United Network for Organ Sharing status lA in the United States), and a donor organ is usually available within 3 weeks.
Using this strategy in our institution over the last few years, more than 80% of children on cardiac ECMO have been successfully bridged to transplantation and over 75% have survived to hospital discharge.1,2 However, there has been significant morbidity related to long-term intensive care stay, sedation, and ventilation while on ECMO, with resultant extended hospital stay after transplantation. Importantly, most patients ultimately make an excellent recovery; in particular, the incidence of neurologic complications in the patients supported on ECMO has been very low. In contrast, neurologic deficit is one of the most common complications reported after the use of a paracorporeal device in children,3,4 which is another reason why we have been reluctant to use a different type of cardiac support.
In our patient, no suitable organ became available in the first few weeks after listing, and complications related to the cannulation site forced us to look for another mode of cardiac support. In our first experience with the Berlin Heart LVAD, we encountered no device-related complications. In addition, the patient could be extubated and started on a rehabilitation program, which no doubt contributed to her rapid recovery after transplantation.
In conclusion, ECMO provides excellent short-term mechanical assistance, but change over to a long-term device is necessary for extended periods of support.
1. McMahon A-M, van Doorn C, Burch M, et al: Improved early outcome for end-stage dilated cardiomyopathy in children. J Thorac Cardiovasc Surg
126: 1781–1787, 2003.
2. Goldman AP, Cassidy J, de Leval M, et al: The waiting game: Bridging to paediatric heart transplantation. Lancet
362: 1967–1970, 2003.
3. Hetzer R, Loebe M, Potapov EV, et al: Circulatory support with pneumatic paracorporeal ventricular assist device in infants and children. Ann Thorac Surg
66: 1498–1506, 1998.
4. Konertz W, Hotz H, Schneider M, et al: Clinical experience with the MEDOS HIA-VAD system in infants and children: A preliminary report. Ann Thorac Surg
63: 1138–1144, 1997.