Dual lumen cannulas (DLCs) for venovenous extracorporeal membrane oxygenation (ECMO) therapy are introduced in the right internal jugular vein, passing through the superior vena cava and the right atrium (RA) down to the inferior vena cava. The correct placement is challenging and needs careful positioning to limit mechanical complications. The outflow port needs to be located in the RA and directed toward the tricuspid valve (TV) to optimize therapy and reduce recirculation rate. Transesophageal echocardiography (TEE) is considered the standard to monitor insertion and optimal placement of this type of cannula. In addition to TEE 2D imaging, confirmation of optimal positioning is possible after ECMO initiation using color Doppler in a bicaval view to visualize the reinfusion jet located in the RA and pointing toward the TV.

We present an example of DLC implantation where correct positioning was confirmed before ECMO initiation using a microbubbles contrast technique. Using TEE 2D imaging, in a bicaval (Figure 1, A and B) and modified bicaval view (Figure 1, C and D), we depict the contrast obtained while flushing the reinjection port of the DLC with saline, simulating the reinfusion jet adequately directed toward the TV (arrows in Figure 1, B and D). We use a 50 cc catheter tip syringe (conical tip) with 0.9% saline to rapidly flush the DLC. The turbulences and bubbles created provide sufficient contrast.