Meeting Reviews
Session VII: Recent Innovations in Congenital Cardiac Care
By Meghan Whitley, DO, FAAP
Session VII moderated by our incoming CCAS President Mark D. Twite, MD, BCh - University of Colorado School of Medicine - Children’s Hospital of Colorado, concluded the Annual Meeting with two very interesting lectures discussing advances in the care of congenital cardiac patients as our field continues to evolve.
Clinical Innovations that Could Turn into Better Congenital Cardiac Care
James A. DiNardo, MD, FAAP
The first presentation was given by Dr. Jim DiNardo (Chief of the Division of Cardiac Anesthesia - Boston Children’s Hospital) discussing advances in the treatment of tracheobronchial lesions. Dr. DiNardo pointed out that, while the types of vascular rings have not changed with time, there have been new advances in identifying the role that a significant Kommerell diverticulum may play in persistent compression after ductal ligation. As a result, the surgical repair has also advanced to complete resection of the diverticulum and reimplantation of the aberrant left subclavian artery as a practice at some institutions, including Ann & Robert H. Lurie Children’s Hospital and Boston Children’s Hospital.
Dr. DiNardo outlined the multi-specialty collaboration between otolaryngology, general surgery and cardiothoracic surgery to accomplish this, with the addition of rigid bronchoscopy utilizing a three phase airway evaluation to assess the dynamic nature of compression. The components of this exam were described including a period of shallow spontaneous breathing, a cough under direct visualization, and mechanical distention of the airway using positive pressure to assess for other structures or lesions present - including aberrant bronchi, tracheal diverticulum or tracheoesophageal fistulas. While the anesthetic management is lesion dependent, Dr. DiNardo described that ketamine boluses are used frequently to accomplish this evaluation in the operating room immediately prior to surgery.
The operative repair typically involves an anterior aortopexy to create space in the superior mediastinum, a posterior tracheopexy, and mobilizing the esophagus laterally. Patients with Tetralogy of Fallot with absent pulmonary valve may require cardiopulmonary bypass and possibly regional perfusion in the case of a circumflex aorta given the complexity of the necessary repair. Dr. DiNardo described that if there is any suggestion that a diverticulum will cause residual compression, then it is resected at his institution.
The second topic discussed was the management of lymphatic dysfunction in single ventricle patients. Given that the lymphatic system is recognized as an increasing factor associated with morbidity in this patient group, an overview of the pathophysiology behind lymphatic dysfunction was reviewed. Dr. DiNardo presented a multimodal analysis showing Fontan patients having lower contractile force in the lymphatic system but at a higher rate. As a result, it was hypothesized that the increased chronotropic potential in their lymphatic vasculature may be a compensatory strategy for lymphatic dysfunction.
The nomenclature of lymphatic dysfunction was further discussed, including Pulmonary Lymphatic Perfusion Syndrome (PLPS) and the less well-defined and more devastating Central Lymphatic Flow Disorder (CFLD), which is typically associated with thoracic duct absence, obstruction or ligation. However, Dr. DiNardo cautioned that these classifications may change as technology and our understanding of lymphatic dysfunction improves.
With respect to the lymphatic interventions currently offered, Dr. DiNardo described how femoral lymphatic nodes are accessed percutaneously using ultrasound guidance and injected with contrast followed by MRI imaging. Following diagnostics, patients are moved to a procedure suite to attempt occlusion of lymphatic channels. Surgical options which were also described involve translocation of the thoracic duct via the innominate vein to the left atrial appendage or using a graft to connect the innominate vein to the right or common atrium.
Finally, Dr. DiNardo shared how lymphatic failure protocols are evolving to help identify and treat lymphatic failure in subsets of single ventricle patients. An important component of these protocols includes the above-mentioned MRI lymphatic imaging.
A question was raised in the later Q&A discussion regarding upper extremity central lines in patients with known lymphatic abnormalities. Dr. DiNardo stated the decision to place central access in this patient group is likely an institutional decision; however, there should be strict adherance to aseptic technique, limiting the time central access is used, and consideration to the size of the catheter in relation to the size of the internal jugular vein.
Scientific Innovations that Could Turn into Better Congenital Cardiac Care
David Faraoni, MD, PhD, FAHA
The second presentation was by Dr. David Faraoni (The Hospital for Sick Children, CCAS Research Committee Chair), who focused on three research topics which may be important in the upcoming years with respect to further improving care and outcomes in congential cardiac patients.
To start, Dr. Faraoni highlighted that significant advances have already been made in the care of congenital cardiac patients over time. Recent publications have shown the number of patients with congenital heart disease has significantly increased and is projected to increase further in the coming decades. Given improved mortality, congenital heart disease should now be thought of more as a chronic lifelong condition requiring continued medical care and we should be prepared to manage congenital heart disease patients as they continue to age.
Dr. Faraoni asserted that, as a result of improved mortality rates, it is no longer a relevant research endpoint and the focus of research should shift to morbidity and quality of life endpoints, including neurologic outcomes. A multicenter collaborative registry involving nine programs (Outcomes and Heath Care Resource Utilization in Patients with Congenital Heart Disease Undergoing Noncardiac Procedures) was highlighted which focuses on better understanding outcomes and hopes to improve risk stratification in these patients. The Cardiac Neurodevelopmental Outcome Collaborative (CNOC) was also mentioned as a resource for those interested in improving neurologic outcomes.
The second focus for research mentioned was improving data collection and data analysis. The standard use of the electronic medical record now affords clinicians and researchers the opportunity to collect, store, and process a large amount of patient-specific data. Dr. Faraoni cautioned it is important to extract this data in a meaningful way and cited articles showing how such information could be analyzed. Such analysis may also help guide patient care in the future. Real-time high frequency physiologic data, including waveform analysis, could allow clinicians to better identify impending issues and allow prompt intervention. Machine learning could also evolve as a bedside tool to better predict patient outcomes, based on imported patient data, to better counsel patients and families.
The final research priority Dr. Faraoni emphasized was how precision medicine would continue to evolve. Precision medicine could be used in the future to improve our understanding of how genes are interfering with cardiac disease in order to better design therapies, or even prevent diseases or complications from occuring. Dr. Sano’s work involving stem cell therapy to improve heart function and heart disease was highlighted as an example of ongoing research in the field of regenerative medicine. Dr. Faraoni concluded that the notion of “one size fits all” medicine would continue to shift towards individualized patient care as these exciting research topics continue to be explored.
