Best Age for VSD, ASD and AV Canal Defect Surgery

The best age for VSD surgery depends on size: a large ventricular septal defect (VSD) is best closed at six to twelve months. Among the other common acyanotic defects, an atrial septal defect (ASD) is closed at three to four years, a complete atrioventricular (AV) canal defect at three to four months, and coarctation of the aorta at diagnosis, as is a patent ductus arteriosus (PDA) causing heart failure.

These are the timings Dr. Aseem R. Srivastava, Chief – Pediatric CTVS & Chief – Adult CTVS, Artemis Hospitals, Gurugram, India, set out for the "pink" (acyanotic) defects, the ones that do not usually make a child blue. These defects share a mechanism: blood takes a short cut from the left side of the heart to the right, or the left ventricle pumps against an obstruction. What separates them is how quickly that mechanism does harm, and so how long a referring doctor can safely wait; a PDA without heart failure symptoms, for example, can wait until about three months. The principle behind every timing below, and the full table across all conditions, is in the complete guide to the correct timing for congenital heart surgery.

Atrial septal defect: the one defect where waiting is right

An ASD is best closed at three to four years of age. It is a hole, or communication, between the two upper collecting chambers of the heart, the right and left atria. It is very common, simple and easily treatable, and it is the one condition in this masterclass for which Dr. Srivastava recommended waiting.

Why ASDs are best closed at three to four years

He gave three reasons for the age of three to four years:

1. No survival penalty before then. On the survival curves he presented, the line for children with an untreated ASD essentially matches the line for the general population for the first three to four years. Waiting during that period does not increase mortality.
2. Better tolerance of bypass. An older child tolerates the heart-lung machine better than an infant.
3. A normal life afterwards. Children treated at three to four years have essentially normal life expectancy and quality of life, with no adverse effect from the delay. They also have no memory of the operation, which spares them, and indirectly their families, a difficult experience.

What happens if an ASD is left too long

The benign phase does not last. Beyond three to four years, Dr. Srivastava said, the survival curve begins to fall, and by twenty years close to one in ten children with an untreated ASD have died. Over the following decades the shunt leads to atrial fibrillation and other supraventricular arrhythmias, which become common from middle age, and, in adult life, to right heart failure. The window for closure is therefore before the curve starts to slope.

Many secundum ASDs can be closed with a catheter-delivered device rather than open surgery, depending on the size and position of the defect and the rims of tissue around it. Dr. Srivastava put the average cost of ASD closure at approximately USD 5,500; indicative ranges are on the ASD closure cost page.

Best age for VSD surgery: size decides everything

A large VSD should be closed at six to twelve months, or at any age if medicines fail to control symptoms; small VSDs almost never need treatment. A VSD is a communication between the right and left ventricles, the main pumping chambers. VSDs are more morbid than ASDs because the high-pressure left ventricle drives blood through the hole into the lungs, which raises pulmonary artery pressure significantly and causes heart failure.

The 80% that close are the small ones

The conventional teaching is that most VSDs close with time, and Dr. Srivastava agreed that around 80% do. His caution was about which ones. The VSDs that close are mostly the small ones, which also make up the largest share of VSDs seen in practice. Two relationships govern the rest:

• The chance of spontaneous closure is inversely proportional to the size of the defect. Small VSDs tend to close; large ones rarely do.
• The risk of dying from a VSD is directly proportional to its size. The bigger the defect, the higher the chance the child dies from it.

A large VSD is therefore more likely to cause death from heart failure than to close on its own, and it is never appropriate to wait for spontaneous closure.

Timing by VSD size

Dr. Srivastava's practice divides VSDs into three groups:

• Small VSDs almost never need treatment.
• Moderate VSDs cause heart failure symptoms that are easily managed with medicines. In these children, waiting one to two years is acceptable.
• Large VSDs carry a mortality of about 9 to 10% by one year of age. The recommended age for surgery is six to twelve months, so that these deaths are prevented and repair is complete before the first birthday.

The six-to-twelve-month window applies only when symptoms are controlled with medicines. The usual regimen is simple: furosemide, spironolactone and digoxin. If those do not control breathlessness, poor feeding and failure to gain weight, VSD closure is recommended at any age, whether that is 15 days, one month or two months. In Dr. Srivastava's words, if symptoms cannot be controlled with medicines, send the child for closure.

A surgical cure, not just survival

The aim of VSD closure today, Dr. Srivastava said, is a surgical cure, which he defined as a child who is alive long after the operation with near-normal pulmonary artery pressures. Repair at six months gives a 95% or greater chance of that cure. Repair at four years rarely achieves it, because by then the high flow has already damaged the pulmonary arteries. Late repair of a large VSD may close the hole without restoring normal lungs, and a large VSD left long enough can become inoperable altogether. The VSD closure cost page gives indicative costs.

AV canal defect: repair at three to four months

An atrioventricular canal defect (also called an atrioventricular septal defect, AVSD) combines an ASD, a VSD and a single common valve between the atria and the ventricles in place of the separate mitral and tricuspid valves. It is a much more morbid condition than an isolated VSD, and it is commonly associated with Down syndrome.

Why the window is so short

In an AV canal defect, pulmonary artery pressures are much higher than with a VSD, the risk of death in the first months of life is very high, and the defect never closes on its own. The lungs are damaged quickly, and Dr. Srivastava gave the limits plainly: a child with a complete AV canal defect is more likely to be inoperable than operable if treatment is delayed beyond nine to twelve months of age. In children with Down syndrome the change comes earlier, typically by six to nine months.

Timing in practice

The recommended age for repair of a complete AV canal defect is three to four months. Until about three months, the breathlessness, chest infections and difficulty feeding these babies experience can usually be controlled with medicines. If they cannot, repair is brought forward. The earliest his team has operated is at about six weeks, and it can be done earlier still when symptoms are not controlled. Indicative costs are on the AV canal defect repair cost page.

For referring doctors, the practical rule is that a baby with Down syndrome and a complete AV canal defect should be referred well before the three-to-four-month repair window, not once the child has "grown a little".

Patent ductus arteriosus: symptoms set the timing

The ductus arteriosus is a blood vessel that connects the pulmonary artery to the aorta before birth and normally closes in the first days of life. In a PDA it remains open, and a large left-to-right shunt causes heart failure symptoms, failure to thrive and shortness of breath.

Dr. Srivastava's timing depends on whether those symptoms are present:

• With heart failure symptoms, closure is recommended at diagnosis, whatever the child's age or weight, because the mortality of surgical or device closure is very small compared with the risk of continued heart failure. In this situation his team goes for surgical closure.
• Without heart failure symptoms, or with symptoms controlled by medicines, his team closes the PDA with a catheter-delivered device at around three months of age.

PDAs also behave differently from other shunt lesions when they present late: as the guide to timing congenital heart surgery explains, a late-presenting PDA is usually still operable.

Coarctation of the aorta: surgery at diagnosis

In coarctation of the aorta, the aorta is narrowed at the junction of the aortic arch and the descending thoracic aorta. The left ventricle has to pump against a very high afterload, the resistance created by the narrowing.

Two reasons not to wait

Dr. Srivastava recommended surgery immediately after diagnosis, for two reasons.

The first is survival. The risk of dying from coarctation is about 30% by one year of age. Children who survive infancy adapt partly to the narrowing, but they continue to carry a smaller annual risk of death from its complications.

The second is blood pressure. Coarctation causes hypertension in the upper body, and if it is not treated in time, that hypertension tends to persist. Children treated early are less likely to have hypertension late after the operation. Children treated late are likely to stay on antihypertensive medicines, probably for life.

A referral checklist for acyanotic defects

Taken together, Dr. Srivastava's timings give referring doctors a clear order of urgency:

1. Coarctation of the aorta, and a PDA with heart failure: refer at diagnosis.
2. Any VSD or AV canal defect whose symptoms are not controlled with furosemide, spironolactone and digoxin: refer at once, at any age.
3. Complete AV canal defect: plan repair at three to four months, earlier if symptoms are poorly controlled; with Down syndrome, inoperability can set in by six to nine months.
4. Large VSD: plan repair at six to twelve months.
5. PDA without symptoms: device closure at about three months.
6. Moderate VSD: medical treatment, with a decision within one to two years.
7. ASD: elective closure at three to four years, before the survival curve begins to fall.

Children who present after these windows are not automatically beyond help; cardiac catheterisation decides operability, as the pillar guide sets out. The cyanotic and newborn-critical conditions, where the timing is measured in days and weeks, are covered in TGA, tetralogy of Fallot, TAPVR and truncus: timing of surgery.