Cannulation configuration and recirculation in venovenous extracorporeal membrane oxygenation

Abstract

Venovenous extracorporeal membrane oxygenation is a treatment for acute respiratory distress syndrome. Femoro-atrial cannulation means blood is drained from the inferior vena cava and returned to the superior vena cava; the opposite is termed atrio-femoral. Clinical data comparing these two methods is scarce and conflicting. Using computational fluid dynamics, we aim to compare atrio-femoral and femoro-atrial cannulation to assess the impact on recirculation fraction, under ideal conditions and several clinical scenarios. Using a patient-averaged model of the venae cavae and right atrium, commercially-available cannulae were positioned in each configuration. Additionally, occlusion of the femoro-atrial drainage cannula side-holes with/without reduced inferior vena cava inflow (0–75%) and retraction of the atrio-femoral drainage cannula were modelled. Large-eddy simulations were run for 2-6L/min circuit flow, obtaining time-averaged flow data. The model showed good agreement with clinical atrio-femoral recirculation data. Under ideal conditions, atrio-femoral yielded 13.5% higher recirculation than femoro-atrial across all circuit flow rates. Atrio-femoral right atrium flow patterns resembled normal physiology with a single large vortex. Femoro-atrial cannulation resulted in multiple vortices and increased turbulent kinetic energy at > 3L/min circuit flow. Occluding femoro-atrial drainage cannula side-holes and reducing inferior vena cava inflow increased mean recirculation by 11% and 32%, respectively. Retracting the atrio-femoral drainage cannula did not affect recirculation. These results suggest that, depending on drainage issues, either atrio-femoral or femoro-atrial cannulation may be preferrable. Rather than cannula tip proximity, the supply of available venous blood at the drainage site appears to be the strongest factor affecting recirculation.

Hemodynamic and recirculation performance of dual lumen cannulas for venovenous extracorporeal membrane oxygenation

“…Whilst being zero at 2 and 4 L/min, at 6 L/min increased slightly to 3.0–6.2%. Compared to data from SLCs in atrio-femoral and femoro-atrial configurations, using the same patient-averaged model 10 , DLC at the baseline position was much lower (Fig. 2 A) with the exception of 2 L/min where both cannula strategies have near-zero recirculation.…”

“…Two commonly used DLC designs, the Maquet Avalon Elite® (Getinge, Rastatt, Germany) and MC3 Crescent® (Medtronic International Trading Sàrl, Tolochenaz, Switzerland) were sectioned manually with a blade, measured with vernier calipers, and reconstructed into accurate 3D CAD geometries. Following the same methodology, as previously used by us with SLCs 10 , we positioned 3D reconstructions of each device in the patient-averaged model following venous centrelines, also modelling them as rigid-wall. A 27Fr cannula size was selected for the patient-averaged model mimicking a reasonable clinical choice of cannula size.…”

“…1 . Comparisons to SLCs reference our previous publication 10 where we inserted a 25Fr Maquet HLS Multistage drainage cannula and 19Fr Medtronic Bio-Medicus return cannula in atrio-femoral (drainage in the SVC) and femoro-atrial (drainage in the IVC) configurations, using the same patient-averaged model.

Figure 1 The patient-averaged right atrium, superior (SVC) and inferior vena cava (IVC) model with the dsAvalon inserted in the baseline position (left).

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“…The CFD model follows the same setup used previously 8 – 10 . Briefly, it is a large Eddy simulation (LES) with wall-adapting local-eddy viscosity (WALE) model and an all y+ wall function 13 .…”

“…We have developed a computational fluid dynamics (CFD) model of the right atrium (RA) and venae cavae 8 , tested its sensitivities 9 , and validated it against clinical data 10 . The model serves as a platform to investigate the impact of VV ECMO cannulation variables on performance.…”