Cannulation strategies for percutaneous extracorporeal membrane oxygenation in adults

Abstract

Extracorporeal membrane oxygenation (ECMO) has revolutionized treatment of severe isolated or combined failure of lung and heart. Due to remarkable technical development the frequency of use is growing fast, with increasing adoption by interventional cardiologists independent of cardiac surgery. Nevertheless, ECMO support harbors substantial risk such as bleeding, thromboembolic events and infection. Percutaneous ECMO circuits usually comprise cannulation of two large vessels (‘dual’ cannulation), either veno-venous for respiratory and veno-arterial for circulatory support. Recently experienced centers apply more advanced strategies by cannulation of three large vessels (‘triple’ cannulation), resulting in veno-veno-arterial or veno-arterio-venous cannulation. While the former intends to improve drainage and unloading, the latter represents a very potent method to provide circulatory and respiratory support at the same time. As such triple cannulation expands the field of application at the expense of increased complexity of ECMO systems. Here, we review percutaneous dual and triple cannulation strategies for different clinical scenarios of the critically ill. As there is no unifying terminology to date, we propose a nomenclature which uses “A” and all following letters for supplying cannulas and all letters before “A” for draining cannulas. This general and unequivocal code covers both dual and triple ECMO cannulation strategies (VV, VA, VVA, VAV). Notwithstanding the technical evolution, current knowledge of ECMO support is mainly based on observational experience and mostly retrospective studies. Prospective controlled trials are urgently needed to generate evidence on safety and efficacy of ECMO support in different clinical settings.

Cannulation techniques for extracorporeal life support

“…A more advanced option is to upgrade veno-arterial to veno-venous-arterial configuration of ECMO circuit (VVA) inserting a second cannula for venous blood drainage (usually via internal jugular vein). The enhanced drainage reduces preload for LV, thus minimizing the risk of its distension (14).…”

“…Large bore cannulas (23-31 Fr) are used for venous drainage whereas smaller (15)(16)(17)(18)(19) are sufficient for venous return. The tips of the cannulas should be at the level of atrial-caval junctions (14). The correct position of the cannulas is very important to prevent recirculation of the oxygenated blood between two cannulas.…”

Veno-venous extracorporeal membrane oxygenation: cannulation techniques

“…Typically, the 23 Fr cannula allows a maximum flow of 3 L/min, the 27 Fr cannula is limited to 4.5 L/min, and the 31 Fr DLB cannula allows not more than 5 L/min. In these cases, hemolysis could occur if high flow rates are applied (45). Thus, it is strongly recommended to employ the largest cannula tolerated by the patient's anatomy, or, if the 60% of the estimated patient's CO cannot be achieved by the chosen cannula, the classic double femoro-jugular cannulation should be performed.…”

“…Echocardiographic and/or pulse contour methods can be used in these patients (30). The DLB cannulae that are currently available offer limited maximal blood flow (45). Typically, the 23 Fr cannula allows a maximum flow of 3 L/min, the 27 Fr cannula is limited to 4.5 L/min, and the 31 Fr DLB cannula allows not more than 5 L/min.…”

Triple Cannulation ECMO

“…As triple cannulation resulted in a confusing use of multiple abbreviations during clinical routine, we have recently proposed a unifying terminology of ECMO cannulation modes [6].…”