Clinical Trials

Surgery Projects

Title:  Berlin Heart
Principal Investigator: Kirk Kanter, M.D.

Currently, available therapy to support children at high risk of death from heart failure is limited.  The current standard of care in the United States is Extracorporeal Membrane Oxygenation (ECMO).  A device called the Berlin Heart EXCOR® Pediatric (EXCOR Pediatric) VAD (ventricular assist device) has been studied in Europe. 

The Food and Drug Administration (FDA) has granted special permission for the device to be studied in the United States.  The primary goal of the study is to assess the device safety and probable benefit of the EXCOR Pediatric.  The secondary goals of the study will provide more information on the response to the therapy and device performance. The data collected from study subjects who have received the EXCOR Pediatric will be compared to the patients who were on ECMO. 

The EXCOR Pediatric is a device that is inserted in the operating room.  The EXCOR Pediatric is placed outside the body and connected to the heart by special tubes.  The device can be used on newborn to young adult patients. The device is an air driven, heart assist device and was designed to support the right and left side of the heart separately or at the same time.  The device can be used to assist the heart when the patient’s heart is unable to maintain normal blood flow and/or blood pressure to the body on its own.   

Berlin Heart was granted an unconditional Investigational Device Exemption (IDE) approval by the FDA for a formal IDE study to prove safety and probable benefit of the device. The data that is collected will be de-identified.  The data may be linked with other existing databases, such as the INTERMACS registry, the Pediatric Heart Transplant registry (PHTS), the Extracorporeal Life Support Organization (ELSO), and the Extracorporeal Membrane Oxygenation (ECMO) registry.

Title: Surgical Planning for Reconstruction of Complex Congenital Heart Defects
Principal Investigator:  Kirk Kanter, M.D.

In the United States, approximately 1 in 200 babies are born each year with harmful congenital heart defects (CHD) that require some form of medical management. Often, these defects consist of holes in the septum (the walls between the heart chambers) and/or abnormal development of the heart chambers or major blood vessels. Surgery is the primary treatment course for many of these patients and, through the use of patches and artificial vessels, it is often possible to repair the defects and recreate the normal blood flow path through the heart.

These techniques are not always simple, however, and the surgeon must take great care not to harm the pumping function of the heart. In more complex cases, the surgeon must decide between multiple repair strategies that will have a major effect on the long-term health of the patient. It would be helpful in such cases for the surgeon to be able to assess the repair options prior to the operation using virtual 3-dimensional representations of that patient’s anatomy. Having this ability would remove some of the uncertainty from the decision-making process by providing accurate predictions of post-surgical anatomy.

In fact, the technology exists to include such a surgical planning tool into the standard treatment course for these patients. Using 3D anatomical images, acquired from basic techniques such as magnetic resonance (MRI), computed tomography (CT or ‘Cat Scan’) and echocardiography, engineers at Georgia Tech have the ability to build accurate computer 3D models of patient anatomy, such as the heart. Using these models with a state-of-the-art graphics manipulation tool, surgeons would have the ability to virtually operate on the patient and select the optimal treatment approach, as previously discussed. Similar techniques have already been developed and used to plan surgeries for a limited subset of CHD patients with a single ventricle physiology.

The purpose of this study is to further develop these techniques and apply them to a broader range of CHD patients. To do this, patients undergoing an appropriate surgical repair will be recruited to participate in the study. Images obtained from pre-operative MRI, CT or echocardiography will be used to build the anatomical model.  The surgeon can then manipulate the model to test the different available options.  Currently this project is in the testing phase.   By successfully testing and eventually implementing these techniques in the standard of care for CHD patients, the optimal approach for reconstruction will be implemented more frequently, and thus patient outcomes will improve.

Title: Tricuspid Atresia Study
Principal Investigator: Kirk Kanter, M.D.

Tricuspid Atresia (TA) is an abnormality of the heart valve and right side of the heart that occurs to a baby’s heart before birth. The normal opening between the right atrium (upper chamber of the heart) and the right ventricle (lower chamber of the heart) is called the tricuspid valve. When the tricuspid valve does not form during a baby’s development before it is born, blood is unable to flow between the two chambers. With the absence of this blood flow, the right lower chamber does not develop into a normal size. Blood is then forced to travel from the right upper chamber into the left upper chamber through a hole called the patent foramen ovale (PFO) a normal opening between the right and left upper chamber in the baby’s heart before it is born. After birth this hole should close on its own, but does not in this defect since the blood flow keeps it open. This opening allows blood that has been oxygenated by the lungs (red blood) to mix with the unoxygenated blood (blue blood) from the right upper chamber. This mixing causes the blood to have a lower oxygen content overall. This mixed blood is pumped into the left lower chamber. If there is a hole (ventricular septal defect) between the right and left lower chambers, then the mixed blood will travel to the lungs, through the small right lower chamber and the main vessel to the lungs (the Pulmonary Artery) as well as to the body via the left lower chamber and the main blood vessel to the body (the Aorta). Once the baby is born, it has the normal need for oxygen and relies on the lungs to perform the normal exchange of carbon dioxide and oxygen and to give the blood oxygen (red blood). Infants born with Tricuspid Atresia that do not have a hole between the two lower chambers have a small amount of blood flow to the lungs, provided by another small blood vessel called a patent ductus arteriosus (PDA). The PDA normally closes within a few hours up to a few days after the baby is born. This lack of red blood causes the baby to become slightly blue or cyanotic. The baby’s heart will beat faster to pump more blood to the lungs and the baby will begin to breathe faster trying to take in more air. The more work the heart and lungs do to increase the amount of red blood to the body, the more need there is for more red blood. This cycle will cause the baby’s body to release chemicals into the blood that will eventually cause the baby’s heart to stop beating. This could take as long as two weeks to happen if the heart defect is not found.

It usually takes three operations to fix a heart with this defect, with the first one as soon as possible after the defect is discovered. If there is a hole between the two lower chambers (ventricular septal defect), but without any narrowing of the pulmonary artery, a small band is placed around the pulmonary artery as a temporary procedure. This temporary procedure prevents too much blood from flowing to the lungs. If there is not enough blood flow to the lungs then a shunt is created, the shunt connects the blood flow from the aorta to the pulmonary artery to supply the lungs with blood. The size of the shunt is based on the infant’s size. The second operation is the Glenn anastomosis and is done when the infant is between four and six months of age. The superior vena cava is sewn to the right pulmonary artery increasing the blue blood flow to the lungs. The shunt is removed at this time. The final operation is the Fontan Procedure. The inferior vena cava is sewn to the junction of the right pulmonary artery and superior vena cava. A special fabric tube (Gore-Tex) is used to create a separation between the inferior vena cava and the heart.  The tissue (atrial septum) between the two upper chambers (right and left atriums) is removed. The heart now has a single atrium and a single ventricle and the blood flow to the lungs bypasses the heart completely.

Long-term outlook for the children will be the basis for this study. Most children have reasonably good exercise tolerance during their daily lives. Currently two areas of concern are serious heart beat irregularity and a breakdown of the normal protein in the child’s system. After the child is enrolled in the study, he or she will be followed for a period of at least five years with an annual phone survey. The questions included in the survey include the parent/legal guardian’s perception of the child’s health, current medications, level of energy, shortness of breath and a list of any other surgeries or hospitalizations the child has had over the previous year. Patient demographic and physician information will also be kept current to follow the child over this time period.

Title: Pulmonary Ventricle - Pulmonary Conduits in Infants and Young Children
Principal Investigator: Kirk Kanter, M.D.

Children born with the congenital heart disease known as Pulmonary Atresia or Pulmonary Stenosis (an absence of the Pulmonary artery or a severe narrowing of the Pulmonary artery) require intervention at a young age. This procedure involves the insertion of a conduit (or tube) connecting the right ventricle (Pulmonary Ventricle) to the right and left pulmonary arteries to allow blood flow to the lungs. Different types of conduits are available for use, dependant on the size and whether or not a valved conduit will be necessary. These tubes can be made from man-made material, such as Gore-Tex™, or bioprosthetic materials both human and animal. Due to the nature of the immune system and normal growth of these infants and young children these conduits become calcified or too small relatively quickly, requiring re-operation. One area of interest involves what the bioprosthetic conduits are treated with to prevent calcification of the conduit and valves. With each subsequent operation the patient is exposed to additional blood products and other normal surgical risks, therefore the impetus to postpone these procedures as long as possible is the common goal.

Title: AACOA study
Principal Investigator: Kirk Kanter, M.D.

Anomalous aortic origin of a coronary artery (AACOA) is a rare congenital anomaly in which one of the main arteries (a blood vessel that feeds the heart) is located in a different place than it is normally found.  AACOA is difficult to diagnose because the child usually shows no signs or symptoms of having a heart problem.  Children (and adults) with this anomaly, however, are at risk for sudden death, especially during or just after exercise.  Common symptoms are those that occur during or just after exertion and include chest pain, dizziness or syncope (passing out).  The diagnosis is usually made by echocardiography (ultrasound of the heart) with follow up tests including a heart catheterization, MRI (magnetic resonance imaging) or CT (‘Cat Scan’).

Once the diagnosis is made, cardiologists treat the patients in different ways.  Some cardiologists recommend that the child not exercise at all, while some recommend surgery.  Surgeons and cardiologists agree that if the child has symptoms, then surgery is needed at any age.  It remains unclear what to do if a child does not have symptoms.  Those without symptoms who are less than 30 years of age are at a higher risk of sudden death than those who are diagnosed later in life.

Variation in treatment plans is due to the fact that AACOA is very rare and no single institution has enough patients to study the best care. The purpose of this study is to develop and maintain multi-institutional registry of information on patients that have been evaluated and/or followed at any institution that participates in the Children’s Heart Surgeons Society.  A database will provide clinical data warehousing, interfacing with data analysis for critical program review and future access to clinical data for investigational purposes.  The objectives of this registry are (1) to determine the natural history of AACOA through examination of a large multi-center registry; (2) to determine the unnatural history of AACOA; (3) to develop clinically applicable models of the natural and unnatural histories; and (4) Obtain follow-up data to assess the long-term clinical outcomes.

Title: Pediatric Heart Transplant Study (Registry)
Principal Investigator: Kirk Kanter, M.D.

All children receiving a heart transplant will be entered into a national database. Several times a year, all participating physicians will enter information about follow-up care; therefore, more can be learned about how children react to transplantation surgery.

Title: Influence of Genetic Polymorphisms on Ventricular Structure and Function in Patients with Single Ventricle Anatomy
Principal Investigator: Paul Kirshbom, M.D.

In the Unites States, approximately 30,000 children are born with congenital heart disease every year. Between 1000 and 2000 of these children have some form of functional single ventricle anatomy, with variants of hypoplastic left heart syndrome (HLHS) comprising about half. Patients with functional single ventricle anatomy are born with a malformation that renders one of their ventricles unusable and surgically unrecoverable. In HLHS, for example, either the mitral or aortic valve can be absent or significantly stenotic, which is generally associated with marked hypoplasia of the left ventricle and the ascending aorta. Other common variants of single ventricle anatomy are tricuspid or pulmonary atresia, often associated with some degree of right ventricular hypoplasia, unbalanced atrioventricular defects, in which either ventricle can be unusable due to malposition of the interventricular septum, and the heterotaxy syndromes. All of these congenital cardiac anomalies, as well as several other less common variants, can be treated with a multi-stage surgical palliation that usually requires three surgical procedures during the first three years of life. At the completion of this series of palliative procedures the children are left with their single functional ventricle driving blood flow to the systemic circulation while their pulmonary circulation is derived from passive drainage of the systemic venous return into and through the pulmonary vasculature. This arrangement, the so-called “Fontan physiology”, can provide an excellent quality of life as these children grow and enter young adulthood; however, it is by no means a normal hemodynamic arrangement and a significant percentage of children with single ventricle anatomy will fail either during the early palliative steps or at some point after they achieve final Fontan palliation.

Failure of single ventricle patients to progress through the multi-stage palliation or late failure of patients after the Fontan procedure can result from a myriad of causes. While ventricular dysfunction is a common finding in failing single ventricle patients, an anatomic reason for their clinical failure, such as myocardial ischemia or ventricular outflow obstruction, often cannot be identified. Many of these patients subsequently die or require cardiac transplantation when their single ventricle fails. Because patient outcomes are highly variable despite similar anatomy and hemodynamics, it has been suggested that genetic variability may play a role in the ability of patients to tolerate long-term single ventricle palliation.