The Section of Pediatric Cardiothoracic Surgery advances care for children with congenital heart disease and other conditions through a broad portfolio of clinical, translational, and data science driven research projects, spanning viral immunology, surgical innovation, and vascular biomechanics.
Over the past year, the section, led by Pirooz Eghtesady, MD, PhD, has published articles through leading medical journals, moving the needle toward clinical breakthroughs and life-saving innovations that improve the lives of patients.
A major stream of work is led by Mathieu Garand, PhD, co-investigator in the Eghtesady Lab, whose recent research has focused on viral co-infection, immune modulation, and computational tools for high-throughput analysis. His study, “Viral Co-infection in COVID-19: Prevalence and Clinical Associations of Human Pegivirus,” published in Next Research, examines how Human Pegivirus (HPgV) co-infection may influence the clinical course of COVID-19. By defining the prevalence of HPgV in patients with COVID-19 and analyzing associated clinical features, the study seeks to clarify how viral co-infections shape immune responses and clinical outcomes.
In parallel, Garand and colleagues recently published AxioParse in BioTechniques, introducing a Python-based pipeline built on the Dagster orchestration framework. AxioParse automates key analytical steps including data cleaning, taxonomic mapping, and downstream formatting, providing robust infrastructure for complex biological datasets and enabling more efficient, reproducible analyses across virology and immunology research.
Together, these efforts highlight the section’s broader strategy of integrating computational science with clinical investigation to accelerate discovery and translation.
Jacob Miller, MD, has also been very active in research efforts with the section. Miller and Eghtesady are providing clinical support on several clinical and translational projects, led by Edon Rabonowitz, MD, a pediatric cardiologist, which are aimed at improving surgical outcomes and rethinking reconstructive strategies in complex congenital heart disease. In a pilot study published in the Journal of the American Heart Association, the investigators evaluated the impact of vascular geometry on thrombosis in pediatric patients using modified Blalock-Taussig-Thomas shunt (mBTTS). The study showed that specific geometric features of the pulmonary artery, brachiocephalic, and subclavian arteries are significantly associated with shunt thrombosis, supporting the concept that vascular geometry plays a critical role in clot formation. These findings lay the groundwork for future hemodynamic modeling and may guide preoperative planning and shunt design to reduce life-threatening thrombosis in this vulnerable population.
The section is also pioneering new approaches to valve reconstruction in Tetralogy of Fallot (ToF). Congenital cardiac fellow Ayman Almousa, MD, Eghtesady, and colleagues reported on the “Use of Right Atrial Appendage Tissue for Pulmonary Valve Reconstruction in Tetralogy of Fallot” in Seminars in Thoracic and Cardiovascular Surgery. This work details the rationale, preclinical development, and early clinical outcomes of using right atrial appendage (RAA) tissue to create a pulmonary valve during ToF repair, with the goal of reducing early pulmonary regurgitation and providing a living, potentially growable valve substitute. In July, researchers in the section, assisted by general surgery resident Paighton Miller, MD, (PGY-2) also published an article titled “Right Atrial Appendage for Aortic Valve Reconstruction,” in the Annals of Thoracic Surgery. This study suggested that living RAA tissue can function in the aortic position, offering a possible new option for patients needing aortic valve interventions.
A companion case report, published in collaboration with pediatric cardiology, in The Journal of the American College of Cardiology: Case Reports further illustrates “Valve Creation from Atrial Appendage Tissue for Primary Repair of Tetralogy of Fallot in Infants,” highlighting feasibility and early outcomes in the most fragile age group.
The section’s transplant research also continues to gain national visibility. One project, co-authored by Garand and Eghtesady, alongside Lakshmi Gokanapudy Hahn, MD, a pediatric cardiologist, was selected for presentation in the “Immune Mechanisms of Heart Transplant Rejection” session at the International Society for Heart & Lung Transplantation (ISHLT) 2026 Annual Meeting and was named one of five finalists for the ISHLT/Enduring Hearts Pediatric Heart Transplantation Innovation Challenge Grant.
Additionally, WashU Medicine and St. Louis Children’s Hospital are among the few institutions nationally to perform heart valve transplants. Backed by the section’s rigorous research, this new treatment option is aimed at providing a valve with growth potential for pediatric patients who require valve replacement.
In multi-organ transplantation, the team has reported excellent outcomes with combined heart–liver transplantation (CHLT) in carefully selected patients with end-stage failure of both organs. In this series, most CHLTs were performed en bloc, with low perioperative mortality, no need for re-transplantation over a median follow-up of 37.5 months, and 1-, 3-, and 5-year patient and graft survival of 92%, reinforcing CHLT as a viable option in this high-risk cohort.
Taken together, the section’s work—from viral immunology and data science to vascular geometry, living valve reconstruction, and transplantation—reflects a comprehensive research strategy that integrates basic science, computational methods, and surgical innovation to improve outcomes for children with severe heart disease. The researchers in pediatric cardiothoracic surgery have several other projects pending publication, including further research into the mBTTS risk stratification and pulmonary valve creation for complex cardiac reconstruction.