VADs for children waiting for heart transplant

A ventricular assist device (VAD) is a mechanical device that helps a failing heart to function. The pump-like device can be for short term use only, such as those for patients recovering from heart surgery or those waiting for a heart donor, or they can be for long term use such as those for patients suffering from congestive heart failure or cardiomyopathy. The longest record of a surviving cardiac patient on VAD is 7 years, as reported by the Texas Heart Institute last year. VADs have saved many lives of patients whose hearts are not longer capable of efficiently pumping on their own. VADs are especially used in patients waiting for heart transplantation.

Unfortunately, most VADs are adult-sized and are only suitable to assist adult-sized hearts. But what about those little baby hearts that need help?

It seems that a miniaturized VAD that can be used for children is available in Europe. And pediatricians are hoping that the device will soon be available in the US market

Dr Sanjiv K Gandhi of St Louis Children’s Hospital in Montana reported how he and his colleagues successfully implanted VAD in several children awaiting heart transplant. The implants increased the chances of survival of the children as they wait for the right heart.

In the US, about 400 pediatric heart-transplantation procedures are performed every year. Of these, about 100 recipients are under the age of 1. Heart transplants statistics show that babies are 10 times more likely to die while waiting for a heart compared to adults. As many as 50 babies which are placed on the heart transplant waiting list every year do not survive the wait (Source: Curfman et al., 2008). The use of the miniaturized VAD can lengthen the waiting time while pediatric cardiac patienst await for a heart donor.

Gandhi explains that

“extracorporeal membrane oxygenation (ECMO) has remained the most common form of mechanical support available prior to ventricular assist devices, but the incidence of medium- and long-term bleeding and infectious complications is exceedingly high with ECMO, and neurological impairment is also common. ECMO also restricts patient mobility, impairing physical rehabilitation.”

A 2006 review of data from the Pediatric Heart Transplant Study (PHTS) database indicate that VAD seems to be more successful in patients with cardiomyopathy compared to congenital heart diseases. The bridging time using VAD ranged from 1 to 465 days and the age of the patients ranged from 2 days to almost 18 years old.

Currently, there is an FDA-sponsored study ongoing implanting these tiny devices in American and Canadian children. According to Gandhi, the 70% to 75% survival rate may not sound much but it is definitely better than zero. In many cases, VAD is the only thing that stands between life and death for these patients. However, the doctor laments the fact that a lot of bureaucratic problems in the US hinder fast procurement of the device. For some tiny patients, this delay can mean death.

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