Accessing Extracorporeal Membrane Oxygenation Circuits to Perform Emergent Interventional Cardiac Catheterization

Background
Complications associated with cardiac catheterization during extracorporeal membrane oxygenation (ECMO) are not uncommon and often related to the access site. We report a straightforward technique for accessing the ECMO circuit to perform an emergent cardiac catheterization.

Methods
The patient is positioned head to toe inverted for easier access to the cannulas in the neck. After sterile preparation of the ECMO tubing the circuit is punctured with a needle (Figure). Next, using a Seldinger method, a short 4 Fr sheath is introduced into the circuit, aiming in the direction of flow. Once the procedure is finished, two clamps are placed on the arterial line, one on the arterial cannula just distal to the tip of the sheath, the second on the tubing proximal to the sheath’s entrance point. For a brief moment, the ECMO flow is ceased, and the tubing is cut proximal to the sheath entrance and reconnected to the arterial cannula.

Results
This has become our standard approach to diagnostic catheterization on ECMO over the last 2 years (n=6). More recently we have used this technique in two patients with hypoplastic left heart syndrome decompensated after Norwood I, due to presumed systemic-to-pulmonary artery shunt obstruction. In one patient, a successful balloon dilatation was performed and a coronary stent was placed in another patient with acute thrombotic occlusions of their systemic to pulmonary arterial shunts.

Conclusions
Direct Seldinger access to ECMO circuits is a potentially safe and effective alternative to percutaneous approach for performing an emergent interventional and diagnostic cardiac catheterization.