PM Modi praises rare surgery at AIIMS: What’s this foetal procedure all about? What does it mean for congenital defects in new-borns?

WHAT IS BALLOON DILATION OF THE AORTIC VALVE?

Balloon dilation of the aortic valve is a fetal procedure used to widen a severely narrowed aortic valve opening, a condition known as aortic stenosis, to improve blood flow through the left side of the foetal heart. According to the team of doctors, some types of serious heart diseases can be diagnosed while the baby is in the mother’s womb. Sometimes, treating them in the womb may improve the outlook for the baby after birth and lead to near normal development. “The procedure is performed if the foetus has aortic stenosis that, without intervention, can progress to hypoplastic left heart syndrome (HLHS), a complex congenital heart defect that occurs when the left side of the heart does not form properly. Without intervention, the left ventricle in foetuses with aortic stenosis often stops growing, leaving it too small to function during the birthing progress. For some foetuses, intervention to dilate or widen the aortic valve may increase blood flow across the valve and allow the left side of the heart to continue growing so that it is better developed at birth. This can prevent deaths at birth,” says Dr Ramakrishnan.

Detailing the procedure, doctors from Texas Children’s say, “In most cases, balloon dilation of the aortic valve is recommended between 20 to 29 weeks of pregnancy. During that period, mother and baby will be closely monitored to determine optimal timing for the procedure.The day of the procedure, the mother will be admitted to the hospital. The procedure is typically performed with epidural anaesthesia, not general anaesthesia, for the mother. The epidural will be placed and an ultrasound will be performed to determine the position of the fetus.”

WHAT DID AIIMS DOCTORS DO?

The 29-year-old patient, who had a history of three miscarriages, was carrying a 28-week foetus when doctors detected complications and spoke to the parents about their unborn child’s heart condition. But the parents decided to continue with the current pregnancy. The mother consented to the procedure with a wish to improve the outcome. The surgery was done at the Cardiothoracic Sciences Centre, AIIMS, on January 25 and both the mother and child are doing fine. The baby is expected to be born in two weeks.

“Such surgeries have also been conducted in the past but this was the first time it was done at AIIMS. We are not sure how successful those surgeries were but in this case we took time before announcing it. The teams of doctors are monitoring the growth of the heart chambers to ultimately determine the baby’s future management,” says Dr Ramakrishnan.

The procedure was done under ultrasound guidance. “We placed a needle through the mother’s abdomen and uterus into the baby’s heart. Once it was in position, we used a balloon catheter, inflated it, enlarged the opening of the aortic valve and increased blood flow into the left ventricle. We then deflated the balloon and removed the wire and needle, all in 90 seconds. We expect that the baby’s heart will develop better and complications will be less severe at birth,” he explains.

“Such a procedure is very challenging as it can risk the foetus. Everything has to be done under all ultrasound guidance. We usually do other procedures under angiography but this can’t be done in such a manner. Besides, it has to be done very quickly because you’re going to puncture a major heart chamber. So if something goes wrong, the foetus will die. It has to be very quick; just shoot, dilate and come out,” Dr Ramakrishnan adds.

WHY COULD THE PROCEDURE NOT BE DONE AFTER BIRTH?

According to the doctors, the post-natal period would have been very challenging for the child as there was not much activity in the heart. “In the best case scenario, the child could have survived till 15 years of age. That too with three major open heart surgeries and a paediatric heart transplantation as well.” says Dr Ramakrishnan.

CAN EARLY INTERVENTIONS BETTER OUTCOMES?

If successful, the procedure increases the potential for the child to have a biventricular repair after birth, a procedure to ensure the two ventricles function and pump efficiently. If no intervention is performed, a serious condition requiring immediate intervention at birth could develop. “With fetal aortic valvuloplasty, the goal is to allow the left ventricle to stay sufficient size. Even with a successful valvuloplasty, most children will require either cardiac surgery or cardiac catheterisation after birth. The hope is that children with a biventricular repair will have better long-term outcomes,” says an update from Texas Children’s Hospital, US, which conducts such procedures.

WHAT ABOUT PREPPING THE FOETUS FOR THE PROCEDURE

Once the foetus is in the desired position, medication is given to prevent pain and limit movement.

WHAT ABOUT RISKS?

As with any surgical procedure, the risks could be pre-term labour, loss of pregnancy, damage to the foetus, fluid around the foetal heart, slowing of the fetal heart rate.

WHAT ABOUT POST INTERVENTION PROTOCOL FOR THE MOTHER?

According to Texas Children’s, “The typical hospital stay following a foetal balloon dilation of the aortic valve is 48 hours. During this time mother and unborn baby will be closely monitored. Upon discharge,the pregnancy will be carefully followed with regular checkups, including foetal ultrasounds and foetal echocardiograms to evaluate the baby’s development and heart condition. The goal is for the mother to carry the baby as close to full term as possible, giving the foetal lungs, brain and other vital organs a chance to mature as much as possible before delivery. This allows the child to become more stable before undergoing heart surgery after birth.”