Overview of the Advances in Congenital Heart Disease Treatment
Congenital heart disease (CHD) is a term that refers to a wide range of structural defects that can involve the valves, blood vessels, and walls of the heart. This kind of heart abnormality will be present at birth and is the major cause of developmental defect-related deaths.
These heart defects result in obstructed or abnormal blood flow and thus require active treatment with complex surgeries. Novel surgeries and changes in therapeutics for CHD have led to striking improvements in the care of patients with CHD.
The developments in CHD surgery primarily focus on newer surgical techniques and advanced repair materials that are used during the operation. Recent years have also seen rapid progress in the fields of imaging, devices, and percutaneous interventions in various congenital cardiac lesions. Fortunately, due to these advancements in non-surgical and surgical care, the long-term outcomes have greatly improved in patients with CHD.
CHD - No Longer a Mere Pediatric Condition
With an increasing number of CHD patients being able to survive into their adulthood, research has evolved rapidly in the field of mechanical device support that helps address the needs of individuals with adult CHD. Ventricular assist devices (VAD) help the heart function better and improve quality of life.
Over the last thirty years, the field of pediatric cardiac catheterization has evolved rapidly and has been transformed from being a diagnostic tool to a modality of treatment. Newer endovascular techniques and management strategies are being applied. Sophisticated imaging techniques such as three-dimensional (3D) rotational angiography, 3D printing, multi-modal image fusion, and holographic imaging have facilitated accurate diagnosis and planning of surgical procedures. Improved designs of equipment have allowed reduction of radiation exposure.
Advances in Prenatal Imaging Have Increased the Rates of Fetal CHD Diagnosis
Fetal Interventions that may improve functions of the heart become possible because of a fetal CHD diagnosis. Currently, the cardiac lesions that can benefit from fetal interventions include fetal arrhythmias, hypoplastic left heart syndrome, and severe aortic or pulmonary stenosis. With improved outcomes, this has become an exciting advancement in the field of CHD treatment.
Ongoing developments in the field of imaging include:
- Three-dimensional Rotational Angiography and Fusion Imaging Techniques (3DRA): This is an emerging technology that can provide real-time 3D volume rendered, cross-sectional images, which help visualization of the complex anatomy of the heart during both diagnostic and interventional procedures. It is used to plan and guide the stent during cardiac interventions. Recent studies have reported the additional benefits of 3DRA compared to the 2D biplane angiography.
- Transthoracic echocardiography: This recent innovation includes various newly developed modalities such as tissue tracking, improved continuous-wave/pulsed wave Doppler and tissue Doppler techniques. These imaging techniques allow a better understanding of the underlying cause of CHD and non-invasive documentation.
Advancements in Surgical Treatment of CHD
- Cardiac Imaging-Based Operative Planning: Advancements in the field of cardiac imaging such as 3D reconstructions have led to better operative planning, simulation, and training.
- Closure of Patent Ductus Arteriosus (PDA) in pre-term and low-birth-weight infants: Recently, there has been supporting evidence for the feasibility and efficacy of percutaneous PDA closure in prematurely born infants weighing less than 6 kg. The success rate ranges between 88% and 94%. More recently, a new microvascular plug called MVPTM has been introduced. The advantages with this device include delivery through a microcatheter, a flexible delivery cable, a diskless design which reduces the risk of protrusion of the device to the aorta or the left pulmonary artery. Moreover, the PDA closure performed with MVPTM in an extremely premature infant showed good results.
- Right Ventricular Flow Tract (RVOT) Stenting in Fallot’s tetralogy: In order to enlarge the right ventricular outflow tract, stent implantation is being currently used as a bridging procedure. It relieves cyanosis and promotes pulmonary artery growth. Several studies have shown favorable outcomes with the use of RVOT stents alone since 2008.
- Advanced repair materials: During the repair of complex congenital cardiac defects, advanced patches and valves are being used to avoid reoperation and improve long-term outcomes. Recently, a patch called CorMatrix has been introduced, which is made up of decellularized porcine small intestinal submucosa extracellular matrix (SIS-ECM). The U.S. Food and Drug Administration (FDA) has approved the use of porcine SIS-ECM. Studies have confirmed that repair of CHD using SIS-ECM is safe and provides good results.
- Robotic cardiac surgery: Robotic systems are being successfully used to perform mitral valve repairs and atrial septal defect closures. The da VinciTM surgical system is the only U.S. FDA-approved robotic system to be used in cardiac surgery.
There has been enormous progress in the field of diagnosis, and treatment of complex CHD in the past two decades. With these technological advances; cardiac surgery has become minimally invasive, safe as well as efficacious.