Pediatric Heart Surgery | Specialists and Information

Information on pediatric cardiac surgery

Pediatric cardiac surgery, also known as children's heart surgery, includes all forms of surgical treatment for congenital heart defects. Just like heart surgery in general, it is still a relatively young medical specialty.

Pediatric heart surgery was revolutionized by the use of the heart-lung machine. However, it does not only take over the function of the heart and lungs during open heart surgery in pediatric surgery in order to maintain circulation. The heart-lung machine has become an integral part of everyday pediatric cardiac surgery.

However, other developments in pediatric heart surgery, such as new surgical techniques, better suture material and aseptic conditions, have further reduced the mortality rate of young patients. In general, doctors today tend to perform pediatric heart surgery at an early stage to correct congenital heart defects.

Heart defects are the most common congenital malformations in children. In Germany, around 5000 - 6000 newborns are affected every year. Although prenatal diagnosis has improved considerably, the number of children with heart defects cannot be reduced.

However, early diagnosis and birth and treatment plans optimized for the heart defect increase the chances of survival even in the case of the most severe heart defects. Pediatric heart surgery for congenital heart defects has become a real specialty within heart surgery.

There are several centers for pediatric heart surgery in Germany, but not every hospital offers such pediatric heart surgery.

Cardiac septal defects - common in pediatric cardiac surgery

Heart defects in the area of the cardiac septum are very often found in infants and children. These can be minor or major wall defects that lead to mixed blood forming in the atria or ventricles. Mixed blood because oxygen-poor blood from the body is mixed with oxygen-rich blood from the lungs via the defect.

Symptoms and indication for surgery

Depending on the size of the defect in the septum, symptoms of varying severity occur. Larger holes lead to mixed blood and thus to a reduced oxygen supply to the body. This manifests itself, for example, in a change in skin color and a lack of resilience.

Pediatric heart surgery can help here to surgically close the defect. Smaller defects, on the other hand, can remain undetected and unnoticed for years. Heart defects are usually diagnosed via ECG, cardiac catheterization or other imaging procedures.

The doctor can then discuss the best course of action with the parents. Not every heart defect is a case for pediatric heart surgery. Many of the smaller interventricular septal defects initially only require regular echocardiographic monitoring. In infants and children in particular, many of the "holes" in the septum between the right and left side of the heart close on their own and do not require pediatric cardiac surgery.

If a hole remains, this is usually not a problem either. Heart defects of this type can still be treated in infancy or adolescence without any great risk. However, if such a heart defect is not treated in time, there is a risk of serious complications, such as

• Inflammation,
• cardiac arrhythmias,
• valve diseases or
• permanent lung changes.

One of the more common wall defects is the septal defect between the right and left ventricle. The operation follows a standardized procedure and is characterized by a low risk of complications

Procedure for an interventricular septal defect operation

First, the chest is opened at the sternum. The heart-lung machine simultaneously takes over the circulation and replaces the heartbeat and breathing. The heart is stopped for the duration of the operation. The right atrium of the heart is opened and the doctor enters the ventricle via the heart valve there (tricuspid valve). The defect is closed using patches and several sutures.

This operation can also be used to treat and close other similar malformations. Depending on the location of the defect between the two chambers of the heart, pediatric heart surgery must have different ways of penetrating the heart. Alternative routes are via the left heart (pulmonary valve) or directly via the aortic valve from the large aorta into the left ventricle. In very rare cases, the right ventricle must also be opened via an incision close to the apex of the heart.

Following pediatric heart surgery, the operated child has a very good chance of leading a healthy life with a functioning heart. Nevertheless, a very close follow-up is still carried out at the beginning.

Correctable heart valve defects thanks to pediatric heart surgery

Severe heart disease usually has a negative effect on heart function. It is therefore very important to correct them as early as possible with the help of pediatric heart surgery. In the case of correctable heart defects, cardiac surgeons perform "curative surgery" within the first year of life. Depending on the heart defect, operations can now also be performed within the first 3 months of life.

As soon as the heart defect has been treated, this not only enables the child to develop almost normally both mentally and physically, but also prevents consequential damage caused by the serious heart defect.

If left untreated, there is a risk of heart failure and cardiac insufficiency, for example. In the worst case, the only option is an artificial heart, which can only remain in the body for a transitional period. Finding a suitable donor heart is often a lengthy and often futile process. Early correction of heart defects is therefore the better way for the child's future life.

One of the most common treatment options in pediatric heart surgery is heart valve surgery. Today, many difficult heart defects can be corrected by perfect reconstruction of the diseased areas of the heart (especially the heart valves) and by using the body's own tissue in a way that is durable and capable of growth.

The body's proportions and tissues still change significantly, especially in children and adolescents. Valve repair is therefore preferable to valve replacement. Most, if not all, clinics aim for reconstruction in valve operations. This has proven advantages for heart function and quality of life.

When replacing valves, personalized solutions often have to be sought and found, especially for young patients, as, for example, sporting activity, planned pregnancy or the need for care due to a physical/mental disability have an influence on the choice of prosthesis. Replacement valves obtained from autologous material are most frequently used for pulmonary valve replacement in pediatric heart surgery.

Aortic valve reconstruction and aortic valve replacement

There is also often a need to operate on the aortic valve. This also involves opening the chest along the sternum to expose the heart. Once the heart has stopped and the heart-lung machine has taken over, the aorta is opened. This incision allows the aortic valve in the left heart to be reached and repaired.

There are two different surgical procedures in pediatric heart surgery. In the Ross operation, the aortic valve is repaired using material from the pulmonary valve. The David operation, on the other hand, replaces the aortic root and preserves the aortic valve.

Aortic valve reconstruction generally has a good prognosis. Its durability depends on the complexity and outcome of the actual correction. It is most effective when the heart valve can be reconstructed in three segments, i.e. exactly like the original.

To prevent blood clots from forming after a heart valve operation, children are given an anticoagulant, usually aspirin (2mg/kg) for a period of three months.

If the valve is replaced mechanically (i.e. not with autologous or foreign donor material), there is on the one hand unlimited durability, but on the other hand lifelong blood clotting inhibition, as deposits can form on the artificial surfaces of the heart valve replacement. Over the years, there is a risk of bleeding or clot formation that should not be underestimated.

If the valve is replaced with a bioprosthesis, anticoagulation (usually with coumarin) is only necessary for a period of three months if the ventricular function and sinus rhythm are normal. However, young patients degrade these valves relatively quickly, which makes a new replacement and therefore a new operation necessary.

No anticoagulation is required after a Ross operation. In the medium term, the experience is also good in adulthood. In the long term, however, aortic valve insufficiency (autograft) often occurs again, so that pediatric heart surgery is consulted again.

One option for pediatric heart surgery that is currently still in the trial phase is the growing biologic valve. These valves are produced on the basis of cell-free homografts (human valves) and are currently still being tested. It is not yet possible to provide any information about their long-term success.

However, previous trials with pig valves as a biological substitute have shown a lower durability than homografts or other bio-flap systems. The use of such biologic valves that grow with the patient is one of the great visions for the future of pediatric heart surgery.

Mitral valve surgery and mitral valve replacement in pediatric heart surgery

This operation also involves opening the sternum to expose the heart. The heart-lung machine takes over the work of the immobilized heart and lungs to maintain circulation and breathing during paediatric heart surgery. The left atrium of the heart is opened during this pediatric heart surgery in order to treat the mitral valve.

If there is a narrowing (stenosis) in the area of the mitral valve, the surgeon will attempt to correct this narrowing by cutting or thinning out the leaflets.

An insufficiently functioning (insufficient) mitral valve must be replaced with a suitable implant or autograft. Mechanical prostheses are also suitable for mitral valve replacement in children.

Congenital heart defects in adolescents

The older a child gets, the more often a combination of a previously corrected heart defect and newly acquired defects can occur. This is why many children who have undergone surgery later have to undergo pediatric heart surgery again. Scarring and repeated stress on body and mind are a major challenge of modern pediatric heart surgery. This constantly growing and largest group of patients with congenital heart defects is not uniform.

In order to reduce the burden on children and adolescents, all atrial septal operations, for example, can now be performed as minimally invasive operations. For this purpose, the skin is incised on the right below the left breast and the hole in the septum is then repaired using catheters.

In infants and toddlers, the sternum can also be spared and only half opened. This form of pediatric heart surgery is particularly suitable for atrial septal defect, ventricular septal defect or AV canal correction, for example.

If severe heart defects are treated in infancy, it has been shown that the children can subsequently develop normally.

Transposition of the large outgoing vessels - the great art of pediatric heart surgery

In order to correct congenital heart defects in infancy, doctors need state-of-the-art surgical techniques and a great deal of experience.

A particular challenge is the transposition of the large vessels in the heart. The pulmonary artery (artery that branches off from the heart to the lungs ) and the aorta (large aorta) are "connected" in reverse: In these children, the pulmonary artery connects where the aorta should actually connect, while the aorta branches off into the lungs.

As a result, hardly any oxygen-rich blood reaches the body. Without pediatric heart surgery, these newborns would die shortly after birth. Without treatment, oxygen exchange in the first few days of life only takes place via postnatal shunt openings. These are windows or openings in the heart that only close some time after birth.

Transposition of the great vessels is nowadays corrected with a switch operation. This involves detaching the large artery in the body, the aorta, and the pulmonary artery, the pulmonary artery, from the heart, swapping them and suturing them back to the heart in their normal position.

But how is this difficult arterial switch operation performed?

During this pediatric heart surgery, the chest is opened along the sternum to expose the heart. After the heart has been stopped and the heart-lung machine maintains circulation, the pulmonary artery and aorta can be separated.

After swapping the vessels, the doctors immediately sew them back to the heart in the correct position. Furthermore, the outlets of the coronary arteries must also be observed and checked so that the heart muscle can later be nourished and supplied with oxygen.

This operation is a real milestone in pediatric heart surgery, as it makes an otherwise fatal malformation of the heart treatable.

Non-correctable heart defects - the limits of pediatric heart surgery?

In the case of particularly severe heart defects, corrective surgery with separate systemic and pulmonary circulation and two heart pumping chambers is impossible. In this case, the operation is performed in several stages in order to stabilize the patient and improve their quality of life.

First, the doctors ensure blood circulation in the body and lungs, usually through mixed blood and later without the corresponding heart chamber involvement.

The deoxygenated blood is fed directly from the large body veins into the pulmonary artery (= Fontan circulation). The heart is practically bypassed in order to relieve it or to avoid the ineffectiveness of the heart due to a serious heart defect. The blood is diverted from the inferior vena cava past the heart to the pulmonary artery.

The blood no longer flows directly through the heart. This may improve blood flow, resulting in fewer cardiac arrhythmias and a better quality of life.