What is complex biventricular repair?
Complex biventricular repair is a potential treatment option for children who were born with borderline single ventricle heart defects. These are heart conditions where the ventricles, the heart’s two lower chambers, aren’t large or strong enough to work correctly.
Most patients with borderline single ventricle heart defects traditionally undergo single ventricle palliation, but that procedure might not be the only option for your child.
A full biventricular repair is a procedure that creates two functioning ventricles similar to what’s found in a fully formed heart. In some situations where the small side of the heart can’t handle full circulation, a one-and-a-half ventricle repair is an option that reduces the heart’s workload by diverting some of the blood directly into the lungs (known as bidirectional Glenn).
Patients who have had previous single ventricle heart surgery, such as a Norwood, Glenn, or Fontan operation, can sometimes switch over to a biventricular repair strategy.
Still, if the small right or left heart is too small for biventricular repair, the small ventricle may first need to be rehabilitated through a series of procedures called staged ventricular recruitment. The ultimate goal of staged ventricular recruitment is to help the small side of the heart grow so that biventricular or one-and-a-half ventricle repair is possible.
The exact type and number of surgeries and procedures your child will need to achieve biventricular circulation depends on their heart condition and unique heart anatomy.
Learn about how we treat these conditions in our Complex Biventricular Repair Program
Why consider biventricular repair instead of a single ventricle palliation?
Most children with a single ventricle heart defect have a series of three heart surgeries, called single ventricle palliation, consisting of the Glenn, Norwood, and Fontan procedures. These surgeries allow the two ventricles to work together to pump oxygenated blood out to the body, and leave the deoxygenated blood to travel into the lungs without a pump.
While the Fontan procedure works well for some children, it isn’t right for every child. Common scenarios include:
- Single ventricle palliation is not possible or advisable because of individual circumstances. For example, single ventricle palliation may not be recommended for patients with Down syndrome, lung disease, or pulmonary vein stenosis. In these cases, the only options are to maintain the current circulation, or to proceed with a biventricular repair.
- Some children are good candidates for single ventricle palliation, but after considering both possible strategies (single ventricle vs. biventricular repair), we may recommend a biventricular repair because of the complications of the Fontan circulation of blood.
Children may experience long-term problems with Fontan circulation as they become adults, including high pressures in the veins and lymphatic system. The veins carry deoxygenated blood back to the heart. The lymphatic system is a series of vessels that connect the lymph nodes together and distributes white blood cells around the body. High pressures in the veins and lymphatic system can result in numerous complications, such as long-term liver disease, gastrointestinal tract disease, kidney disease, and problems with other organs.
To avoid complications of Fontan circulation, our team will often perform a two-ventricle (biventricular) heart repair. The aim is to improve a child’s long-term quality of life; we believe that many patients have benefited from these techniques.
Not all children are candidates for biventricular repair, and there are risks involved with this type of approach. That’s why it is important for your child to have a dedicated team of heart specialists evaluating your child and carefully monitoring outcomes.
Complex Biventricular Repair | Types of Biventricular Repairs
Double-switch operation for congenitally corrected transposition of the great arteries (cTGA)
A double-switch operation is used to correct congenitally corrected transposition of the great arteries, often referred to as L-TGA or CC-TGA. In this situation, both the ventricles and great arteries (aorta and pulmonary trunk) are transposed, meaning they are on the opposite side. Since this makes the right ventricle (instead of the left ventricle) the main pumping chamber, over time it can become strained and lead to heart failure. Some doctors will recommend leaving the right ventricle pumping blood to the body (conventional repair) because either no surgery is needed, or the surgery may be less complicated. Double-switch operations (anatomic repair) are designed to restore a normal anatomical arrangement where the right ventricle pumps deoxygenated blood to the lungs and the left ventricle pumps oxygenated blood to the body. The goal is to preserve ventricular function through anatomic repair, with the hope a near-normal functioning heart will improve a child’s quality of life.
Ventricular septation for double-inlet right or left ventricle
To treat double-inlet left ventricle or double-inlet right ventricle, we may perform a series of surgeries known as ventricular septation to create more efficient blood flow through a child’s heart. The first surgery begins to separate the ventricles, with the goal of streaming low-oxygen blood through one side of the heart to the lungs, and high-oxygen blood through the other side of the heart to the body. We typically perform ventricular septation in stages during early childhood. Sometimes ventricular septation involves maintaining a Glenn circulation of blood, which is similar to a one-and-a-half ventricle repair.
Staged ventricular recruitment for treatment of hypoplastic left heart syndrome (HLHS)
The goal of this series of procedures is to help “grow” a small, or borderline, left ventricle so that an infant’s heart strengthens enough to someday undergo a complete biventricular repair. The process consists of repairing the heart’s valves, closing a hole in the wall that separates the heart’s chambers (atrial septation), and enhancing blood flow to the lungs. Follow-up testing is typically performed some time in the next one to two years to see if the left ventricle has responded enough to undergo a biventricular repair.
Staged ventricular recruitment for unbalanced AV canal
This series of surgeries treats atrioventricular canal defect (AV canal). Typically in an unbalanced AV canal, blood flow is entering more into one ventricle than the other. The ventricle that is not receiving enough blood may become too small or underdeveloped to support a normal circulation. There can also be valve leakage that causes the ventricles to become overworked and fail.
The goal of staged recruitment for the unbalanced AV canal is to repair the AV valve in such a way that allows blood to be distributed proportionately between the two ventricles. This allows each ventricle to develop and grow properly. Sometimes, this can be completed in one surgery. For other cases, we prefer to stage the procedure to ensure each ventricle develops well after the initial valve surgery, and to make sure the valves are appropriately sized for biventricular circulation. Some children with unbalanced AV canal have biventricular repairs but eventually need more valve surgery or valve replacements. However, many of these patients need more valve surgery after the Fontan procedure anyway, because an AV canal defect can make the AV valve leak.
Biventricular repair for previously palliated single ventricle
We may recommend a change in strategy toward a biventricular repair for children who have already had a Norwood, Glenn, or Fontan procedure. The strategy aims to convert the ventricular arrangement into two pumping ventricles. A conversion to biventricular circulation from a Fontan is generally considered a big change in circulation, and may be more unpredictable than staged recruitment before the Fontan. If our team can choose the timing of biventricular repair, we typically recommend it after the Norwood or Glenn procedures but before the Fontan.
Complex baffle repairs for DORV and complex transposition
Many of the techniques mentioned above are used in the repair of double outlet right ventricle (DORV) and complex transposition of the great arteries (TGA). This anatomy often also requires a complex baffle repair to separate the right ventricle from the left ventricle, while also ensuring that blood has a clear pathway to exit each ventricle to its corresponding great artery outflow. We construct this pathway using a “ventricular baffle,” a patch that redirects bloodflow to its intended destination. Electrophsiology mapping is an important component in this procedure to ensure that the intricate placement of this baffle does not disrupt the heart’s conduction system.
One-and-a-half (1.5) ventricle repair for small right ventricle
When the right side of a child’s heart can’t handle the full volume of circulation, a one-and-a-half (1.5) ventricle repair, known as bidirectional Glenn, is a surgical option that reduces the heart’s workload by diverting some of the blood directly into the lungs.
'Reverse' double switch operation (rDSO) and reverse one-and-a-half (1.5) ventricle repair for small left ventricle
When the left side of a child’s heart is too small or can’t handle pumping blood to the while body, a “reverse” switch is a surgical option that reduces the heart’s left ventricle workload by allowing it to work under lower pressure by pumping blood only to the lungs. Meanwhile, the stronger right ventricle is left responsible for pumping blood to the body.
Complete biventricular repair
A single stage complete biventricular repair aims to fully reconstruct the underdeveloped pathways of complex congenital heart defects to give a child a normal, two-ventricle heart. It’s an innovative procedure that is performed in only one surgery.
Complex Biventricular Repair | Frequently Asked Questions
A complex biventricular repair can involve many surgeries and procedures (a process known as staged recruitment) over several months or years. Our team at the Complex Biventricular Repair Program performs the repair in several stages so we can carefully monitor your child’s heart and make sure it can tolerate each stage before we move forward with the next procedure.
The length of the repair process depends on your child’s specific heart condition, what types of surgeries they have already had, and their overall health.
Ideally, we prefer to begin the repair after a child has had a stage 1 procedure, around the time of their stage 2 bidirectional Glenn procedure, which usually occurs when they’re between 3 to 6 months old. We prefer to begin the repair before a child has had a Fontan procedure, but in some cases, we may consider a biventricular repair after the Fontan procedure.
Not all single ventricle patients are candidates for biventricular repair. If your child has one of the conditions we’ve mentioned, our team can review imaging of your child’s heart and offer an opinion. Submit a second opinion request.
The risks and complications of biventricular repair vary greatly and depend on the type of heart defect and your child’s overall health. Your cardiologist will discuss your child’s individual risks with you.
In some cases, a biventricular repair means more surgeries than the Fontan procedure. Sometimes additional surgeries may be required to repair or replace valves in the heart. There may be a risk of heart failure if the heart can’t tolerate the conversion to biventricular circulation. In some cases we perform the procedure in stages to minimize this risk, with an option to switch over to the Fontan procedure if biventricular staging doesn’t work as planned. Staging operations can allow us to make sure the heart can tolerate one procedure before we move onto the next step.
Children who have a biventricular repair will need to be followed and monitored throughout their lives by a cardiologist. We have treated many patients who had a complex biventricular repair because no other surgical options were available to them. We have also treated many patients who could have had a Fontan procedure, but instead had a biventricular repair. Many of these children are growing and thriving — and thanks to surgical innovations and more insight on how the heart develops, the long-term outlook for children who have these procedures only continues to improve.
