Pumpless arteriovenous extracorporeal membrane oxygenation for 2000 g newborns with respiratory failure: proof of principle data from a preterm lamb model

Background: Extracorporeal membrane oxygenation (ECMO) is a life-saving intervention for neonates with severe respiratory failure; however, its use in preterm infants is limited by anatomical and physiological constraints. We investigated the feasibility of pumpless arteriovenous ECMO (AV-ECMO) in sub-2000 g premature lambs unresponsive to mechanical ventilation. Methods: Nineteen preterm lambs at 119 days’ gestational age (mean birth weight 1.9 kg) were allocated to either a control group (n = 9) or an AV-ECMO group (n = 10). Physiological, biochemical, and ultrasound parameters were monitored over 48 h. Circuit flow rates and plasma biomarkers were assessed, and ductus arteriosus patency was evaluated using ultrasound. Results: Nine out of ten AV-ECMO animals that were unresponsive to ventilation support survived a predetermined planned 48-hour study period. AV-ECMO enabled successful withdrawal of mechanical ventilation while maintaining critical physiological parameters, including heart rate, mean arterial pressure, pH, and lactate levels. A strong positive correlation was observed between DA diameter and total circuit flow (r = 0.775, p < 0.001). Conclusions: This study demonstrates the feasibility of pulsatile, pumpless AV-ECMO using small catheters in premature lambs at or below 2 kg in weight with severe respiratory failure. Further studies are warranted to assess long-term outcomes. Impact: This study presents the first successful demonstration of pumpless arteriovenous ECMO using small catheters in premature lambs unresponsive to ventilation. This study demonstrates the feasibility of pump-free ECMO in neonates previously considered too small or fragile for conventional ECMO. Further refinement of this approach, along with additional trials, has the potential to improve survival in this vulnerable population.