Recent advances in the treatment of complex congenital diaphragmatic hernia-a narrative review.

Background and Objective: Congenital diaphragmatic hernia (CDH) is an anomaly of the cardiopulmonary system maturation process that results from both a global embryopathy and concomitant mechanical compression of the cardiopulmonary system from the abdominal contents during fetal maturation. This results in pulmonary hypertension, pulmonary hypoplasia, and cardiac dysfunction, requiring intense critical care management. The patients with highest risk CDH are the most challenging, resource-intensive, and bear most of the mortality. Advances at the basic, translational, and clinical research levels are leading to novel therapies and management strategies for complex, high-risk CDH. Our objective is to review novel approaches in thinking and management for the most complex and high-risk CDH patients. These include patients with prenatal and postnatal indicators of high-risk defects, those receiving extracorporeal life support (ECLS), and those with concomitant anomalies such as complex cardiac and/or chromosomal abnormalities. Methods: PubMed was searched in late 2022 and early 2023 to identify relevant evidence. Search terms included congenital diaphragmatic hernia (CDH)", "extracorporeal life support (ECLS)", "pulmonary hypertension", "dual-hit hypothesis", "risk reduction", "cardiac/chromosomal anomalies", and "novel therapies". We included trials, multicenter studies (prospective and retrospective), single-center reports, and review articles/expert opinion. Key Content and Findings: CDH is a congenital anomaly of the cardiopulmonary and diaphragmatic systems that represents a spectrum of disease. High-risk or complex patients are defined by prenatal/postnatal risk stratification, receipt of ECLS, and/or having concomitant anomalies, representing the severe end of that spectrum. Overall survival of high-risk CDH is about 50% and comprises the vast majority of mortality, mandating special emphasis. The development of risk-stratification processes, best practices or guidelines of management, and novel therapies is critical to optimize the care of these infants. Conclusions: CDH patients with high-risk disease remain a challenging subset of CDH patients. Increasing opportunities for survival are being realized with novel, investigational approaches.