Commentary: No one-size-fits-all approach to extracorporeal membrane oxygenation

Justin H. Berger, MD, PhD, and Katsuhide Maeda, MD, PhD

Central Message.

Supporting a child with right heart failure due to severe pulmonary hypertension is challenging. An approach should be determined based on a careful assessment of RV and pulmonary function.

See Article page 452.

Supporting children with complex congenital heart disease by mechanical circulatory support requires innovative approaches. When coupled with pulmonary hypertension (PH), mortality can exceed 50%.¹ In this issue of the Journal, Stephens and colleagues² described a novel approach for central venoarterial extracorporeal membrane oxygenation (ECMO) cannulation in a child with d-transposition of the great arteries who had undergone an arterial switch procedure with the Lecompte maneuver.² The patient was in right heart failure due to severe PH. Cannulation was performed via the right pulmonary artery (PA) and ascending aorta via a short tube graft using Berlin EXCOR cannulae. We commend the authors for successfully supporting this patient to lung transplant, and, more importantly, sharing their thoughtful approach to mechanical support in PH with right ventricle (RV) failure.

To support decompensating patients with PH, 4 classic approaches can be considered, taking into account a careful assessment of RV and pulmonary function. For complete RV and lung support, standard venoarterial ECMO strategies may be employed to unload the RV and successfully bridge to transplant and/or recovery.³ For lung support with reasonable RV function, venovenous ECMO with or without atrial septal defect creation should be considered. To support a failing RV with relatively good lung function, a Potts shunt with PA-to-descending aorta connection with or without one-way valve may be a better option.⁴ For lung support with depressed RV function, a PA-to-left-atrium shunt with artificial membrane decreases RV afterload and supports oxygenation.⁵

The new approach by Stephens and colleagues² can also decrease the PA pressure, with a theoretical benefit of afterload reduction to the decompressed RV. This benefit needs to be confirmed in future reports/research. In addition, the described use of ventricular assist device (VAD)-style central cannulation improves stability, allowing for increased mobility and rehabilitation while on support. If aiming for extubated and mobile ECMO, the child's developmental state and temperament should be taken into account in choosing a cannulation strategy.

This report also highlights the complications that unusual anatomy—in this case, severe right ventricular dilation and anterior draping of the pulmonary arteries over the aorta—pose in central cannulation for ECMO. Berlin cannula offer technical advantages in unusual cardiac anatomy. We have frequently added short interposition grafts, as done here, to allow for better geometry or access to distant structures (eg, left atrium via a trans-right atrial graft to an enlarged patent foramen ovale) when placing VADs. Unlike the range of devices available for adult-sized patients with 2-ventricle circulation, small children are limited to a single Food and Drug Administration–approved device, the Berlin EXCOR VAD. With the recent removal of the HeartWare HVAD from the market, the ability to implant a durable and dischargeable device in a medium-sized child has disappeared. Given the anatomic variety we work with, there will never be a “one-size-fits-all” approach. Consequently, innovative surgical strategies for both ECMO and VAD support are required, as novel methods in one form of mechanical circulatory support will inform new, iterative approaches in the other, and vice versa.