Editorial on the Research TopicNeonatal ECMO in 2019: Where Are We Now? Where Next? Despite significant advances in neonatal intensive care, including neonatal ventilation in the current era, extracorporeal membrane oxygenation (ECMO) continues to play a crucial role in selected cases of severe cardio-respiratory failure, potentially reversible, but refractory to conventional ventilatory therapy and maximal pharmacological treatment (1).Our Research Topic attempted to focus on some of continuing challenges in neonatal ECMO. In this issue of Frontiers in Pediatrics, we have collected a wide range of manuscripts related to the use of ECMO in the neonatal period (Broman; Butt and Chiletti; Cashen et al.; Di Nardo et al.; Kersten et al.; Macchini et al.; Perez Ortiz et al.; Rafat and Schaible; Raffaeli et al.; Raffaeli et al.; Roeleveld and Mendonca; Schiller and Tibboel).Since the formation of the Extracorporeal Life Support Organization (ELSO) in 1989, 45,205 newborns have been supported on ECMO in 492 centers (www.elso.org) (2). Respiratory failure was the predominant reason for ECMO utilization in 33,400 newborns, whereas ECMO was used for cardiac failure in 9,561 newborns, and 2,244 were supported for refractory cardiac arrest-extracorporeal cardiopulmonary resuscitation (ECPR). Today, congenital diaphragmatic hernia (CDH) and meconium aspiration syndrome (MAS) are the exclusive neonatal diagnoses that alone represent about 46% of all cases of neonatal respiratory ECMO, reaching 92% of total ECMO if all "others" neonatal ECMO were added (2, 3). The classification of "others" includes all other diagnostic categories such as non-specific respiratory failure, congenital anomaly, pulmonary hypoplasia, hypoxic-ischemic encephalopathy, cardiorespiratory arrest, and inborn errors of metabolism (4). The mortality rate, however, varies significantly depending on the underlying respiratory disease. For instance, neonates with CDH and sepsis have higher mortality rates (47 and 49%, respectively) in contrast to those with MAS (9%) (2). Pulmonary hypertension and lung hypoplasia play a crucial role in determining survival in CDH (5). Neonates with prolonged ECMO run for >21 days have demonstrated higher mortality due to the increased risk of mechanical complications (6).Veno-arterial (V-A) ECMO still represents the support of choice in neonates, with more than 80% receiving V-A support (2). The vessel size is the most critical limiting factor in using the veno-venous (V-V) ECMO in neonates as the smallest double-lumen venous cannula currently commercially available is 13 Fr (3, 7). However, it should be noted that mortality is not significantly different between the two types of support. However, neurological complications are reported to be