Medical device innovation has accelerated at an unprecedented pace over the past 50 years, leading to less invasive and more durable interventions for patients suffering from a variety of ailments. This is especially true in the cardiac realm. However, the vast majority of this innovation has been focused in areas that affect the adult population. Therefore, meaningful advancement in therapeutics for the pediatric population is largely the result of off-label use of medical devices originally intended for other purposes. Common examples include use of endovascular stents originally intended for biliary interventions, use of vascular plugs to close a patent ductus arteriosus in small infants, and use of transcatheter aortic valves in the pulmonary position.
So what are the reasons for this? Largely this boils down to economics and risk. Medical device companies are searching for the largest potential market for a new product in order to maximize return on investment. Breakthroughs in treatment of common adult problems such as coronary vascular disease or aortic valve disease are understandably more attractive to companies given the inherently higher number of affected patients and higher potential for profit. The logic follows that there should be some reasonable expectation of recovery of the enormous cost of product development and clinical trials for these companies. There is also the possibility that ethical concerns regarding clinical trials in children and enrolment in randomized, blinded studies are barriers to interest by the industry.
Understandably there are inherent challenges in the development of medical devices for children. The devices need to be designed for small patient size, need the ability to be “up-sized” when necessary, and need to be durable for the lifetime of the patient. Percutaneously deployed devices need to be low profile for use through small vascular access sheaths, and much progress has been made in miniaturization of many tools used in the cardiac catheterization laboratory. Progress has also been made with endovascular stent technology, allowing stents to be deployed at a relatively small diameter and later further dilated to full adult size for that vessel. Significant limitations remain not only in stent technology for small patients, but also devices for closure of septal defects, percutaneous valve replacement, and electrophysiologic intervention to name a few. It remains to be seen how resorbable materials, stem cell utilization, targeted payload delivery, or nanotechnology may augment our efforts at cardiac interventions in children.
What is needed is continued innovation and development, and an understanding that there may be unrecognized opportunity through this process. Structural heart disease offers a prime example of unexpected benefit from a device originally designed for a congenital purpose, but was later found to have a much larger market that conveyed financial benefit to the company. The Amplatzer septal occluder was designed for percutaneous closure of an atrial septal defect (ASD), mostly in children. It was later modified slightly to close a patent foramen ovale (PFO) in selected adult patients with stroke-like symptoms which was a much larger market. There are certain to be other similar instances as more devices are designed and put into the clinical realm.
As a medical community, we need to encourage research and investment into development of medical devices specifically designed for use in children. Solutions to these problems are multivariate and complex, and will require persistent effort by all involved. Some have suggested enhanced public–private partnership initiatives which would help minimize the risk of initial investment in product development by medical device companies. Other than standard research grants, there may be ways to subsidize medical device development specific to the pediatric and congenital patients. Staged incentives at predetermined benchmarks up to and including pre-market approval would certainly aid in offsetting cost of product development. There may also be ways to encourage the medical industry to focus in the congenital area through some sense of altruism or contributing to the common good. This sounds rather idealistic, but when combined with a shared risk model which includes government support this may be achievable.
Science and technology will undoubtedly continue to change the landscape of medicine at a rapid rate. And while children with congenital disease often present some of the most complex clinical problems, they can achieve the most benefit in terms of patient years saved and lifetime productivity. It is imperative that we continue to focus on this vulnerable segment of our society, and promote innovation of medical devices specifically designed for their needs.