Nov. 26, 2020
In the 65 years since the first use of cardiopulmonary bypass at Mayo Clinic for the repair of a ventricular septal defect, the field of congenital cardiac surgery has reached a summit unimaginable at the time of the specialty's inception, tackling challenges in anatomy, physiology and technology that once appeared insurmountable.
The care that Mayo Clinic's congenital cardiac surgery specialty is currently able to provide for people with congenital heart disease (CHD) from the cradle — and even the womb — to the grave has been revolutionized in recent decades. While the present is bright for those with CHD, with new technology and innovations on the horizon, the future is even brighter. This article briefly highlights the current state of care and looks to the future within various realms of CHD.
Changing paradigm for health care
Health care as a whole in society continues to evolve. Today it is largely reactive and symptom based; in the next decade it will be preemptive and molecular based. While greatly improved compared with those of previous decades, the interventions used by Mayo Clinic's congenital cardiac surgery specialists are usually late stage, corrective and expensive, but they are evolving to early stage, curative and affordable. These interventions are frequently invasive, but are moving toward becoming less invasive and increasingly utilizing technology such as robotics. These changes are fueled by surgical, technological and process innovations.
Imaging and diagnostics
Imaging and diagnostic capabilities have revolutionized the capacity to care for patients of all ages with CHD. Increasingly the diagnosis of CHD is made during gestation. With increased resolution in imaging, identification of certain features, such as a restrictive or intact atrial septum in hypoplastic left heart syndrome, can be anticipated and intervened on soon after delivery at centers with expertise in this area, improving outcomes.
Advances in imaging and systematic study of quantified parameters, such as indexed right ventricular volumes on magnetic resonance imaging, have helped define thresholds for surgical intervention and improved outcomes. Development of diagnostic parameters such as liver stiffness has assisted the ability to evaluate patients for sequelae of CHD.
Additionally, 3D modeling now aids in preoperative planning for patients with complex lesions. This modeling can be particularly helpful in adult patients with CHD who have had multiple previous repairs, not infrequently involving surgical techniques that are now extinct.
Virtual reality opens another world of possibility in both preoperative planning and education. The complex 3D structure of congenital heart defects can be more completely understood by walking through them and examining every angle. Diagnostic capabilities will also improve with increasing use of molecular and genetic markers, allowing earlier detection and earlier intervention when appropriate. Such advances will make possible personalized treatment based on the molecular fingerprint of the patient's disease process.
Devices and technology
Current state-of-the-art care of CHD includes a close collaboration between surgeons and interventional cardiologists, with transcatheter interventions assisting before and after surgical interventions, as well as being performed with surgery in hybrid procedures.
Advances in devices and technology for transcatheter approaches now allow ductal stents as opposed to surgical shunts, percutaneous closure of certain atrial septal defects and percutaneous valve replacements in select patients.
Refinement of cardiopulmonary bypass machines, including alterations in oxygenators, safety alarms, and tubing and priming to minimize systemic response to bypass, have improved outcomes.
Ventricular assist devices have progressed to become smaller and optimize long-term support, and they are now available for children and even infants. Technological innovations have also led to minimal access surgery and robot-assisted surgery that can be applied in certain teenagers and adults with CHD. Now more than ever a multidisciplinary approach is needed for the care of patients with CHD, with a team of specialists determining the best combination of treatment strategies.
On the horizon are further advances in the areas of devices and technology. A subset of CHD progresses during gestation, worsening the severity of the condition and the prognosis for the baby after birth. Fetal cardiac intervention, however, gives the opportunity to stop or slow such progression, thereby improving the patient's overall prognosis.
With technological advancements and refinement of interventional techniques such as ex utero intrapartum treatment, a subset of patients with hypoplastic left heart syndrome has undergone fetal cardiac interventions with evidence of improvement compared with similar patients without intervention.
Other congenital cardiac anomalies have the potential of benefiting from fetal cardiac intervention with further study and experience in this burgeoning realm.
Other technology and device developments are on the horizon with the potential to significantly improve the ability to care for patients:
- Refinement in transcatheter technology will enable smaller delivery systems — particularly important in small patients with CHD.
- Biomaterials development will lead to implanted materials with fewer issues related to clotting and scarring, with the potential for drug elution technology for specific diseases.
- Tissue engineering also is on the horizon, including biodegradable scaffolds and materials with the potential to grow with the patient.
- Robot-assisted technology will continue to evolve, allowing the potential for use in smaller patients and even in remote surgeries.
- Continued development in assist devices will create implantable devices (as opposed to extracorporeal devices) and smaller devices for the unique CHD anatomy and physiology.
Increasingly the world is generating large amounts of data. Patient care is no exception. In recent years advancements in the ability to monitor patients has led to a body of research on patient management based on a constellation of parameters. Such data integration is currently impacting perioperative care. Other process innovation has included implementation of algorithms and protocols; as variability decreases, the quality of care increases. Such measures decrease length of hospital stays, decrease complications and improve outcomes.
Data related to health care will only increase in ensuing years. Artificial intelligence and machine learning will be critical in optimizing the use of such data in the care of patients. In the near future, real-time analysis of patient-specific data will alert physicians of impending physiological compromise before hemodynamic change is apparent to the patient or the physician. Artificial intelligence and machine learning will also become fundamental in the diagnosis of conditions. Remote monitoring, both for perioperative care that decreases hospital stays and in the intermittent or continuous monitoring and management of chronic conditions, will become routine.
Progress in the field of CHD has enabled Mayo Clinic's congenital cardiac surgery subspecialists to conquer many challenges and correct many anomalies. What was once thought to be impossible has now become routine. Mayo Clinic is now able to provide hope to patients with the most severe forms of CHD. The vast majority receive corrective as opposed to palliative repairs and live with an excellent quality of life into adulthood. But loftier heights remain ahead, and with continuous surgical, technological and process innovations, that goal of nearing perfection is getting closer every day.