Cardiac concerns are on the rise. Technology aiding in the prevention and treatment of heart issues has been in the spotlight for several decades. Often, cardiac problems occur due to the narrowing of arteries, and stents are often the treatment of choice. Stents are small, extendable devices that are placed at the site of the narrowing and help keep the arteries open for normal blood flow to continue. However, the use of stents can be challenging in small children with congenital heart disease. As the child keeps growing, so do the vessels, and many cardiac interventionists are against the use of stents in growing children. Thus, for paediatric patients, it is imperative to use stents that can be further dilated overtime to prevent restenosis.
In the past few years, a hybrid-cell-design redilatable stent has become available. This stent is redilatable in later life and has shown promising results for treatment in congenital heart disease cases.
Dr CS Muthukumaran, Paediatric Interventional Cardiologist, Apollo Children’s Hospitals, Chennai, talked to us regarding one of his cases involving a baby girl who was successfully treated by implanting a redilatable stent.
Twins, Naina and Nivya, were born prematurely to Sunita and Raj (all names changed) at 35 weeks of gestation. While Nivya seemed to be perfectly healthy, Naina was observed to have some difficulty breathing, with a weak pulse in the lower part of the body. An aortic coarctation was suspected and an echo was done to confirm the diagnosis. On day 1 of her life, Naina was diagnosed with coarctation, a defect in which the aorta is narrower than usual and often requires immediate surgical intervention. Since Naina weighed only 1.5 kgs, and was too small for any surgical intervention, she was first treated with prostaglandin to help keep the tube open. Prostaglandin, however, cannot be given endlessly. Since a baby’s arteries are small and a long-term continuous IV can result in infections, this can only be a short-term treatment. Therefore, even though Naina had not gained much more weight, by day 12 of life, as per procedure, an adult coronary balloon was introduced through Naina’s femoral artery. The balloon was dilated, the obstruction was relieved, and once her health recovered, Naina was discharged from the hospital in 10 days.
During follow-up, it was noticed that the arteries were narrowing again. At 4 months 7 days, 3.8 kgs, doctors considered ballooning again. However, there was a risk that this procedure would be required again and again as Naina grew. They, therefore, discussed using a permanent stent to prevent the arteries from collapsing again. In the second procedure, the doctors inserted a redilatable stent into the femoral artery. This stent was dilated to 6 mm diameter, which should be good for the first 1-2 years of life. The advantage of the stent is that it can be dilated up to 18 mm, the adult size. According to Dr Muthukumaran, ‘Redilatation will probably be required at least a couple of times before Naina is an adult. However, this is a short, 30-minute procedure with very little risk.’
This is the first time that such a procedure was done in a pre-term baby. Normally, anastomosis, a surgical repair, is done via the chest in cases of aortic coarctation in newborn children. However, there may be long term consequences such as infections, prolonged use of ventilators, and chances of the arteries narrowing again. Even though it is not a permanent treatment, surgery is also likely to leave a permanent scar.
As of the latest follow-up, Naina was doing well and had achieved a decent weight of 4.2 kgs.
Thus, the use of redilatable stents is a good option for treating congenital aortic coarctation. ‘With about 8 out of 1,000 babies being born with heart defects and coarctation being one of the most common, this promising treatment would help many in the future’, says Dr Muthukumaran.