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DOI: 10.1055/s-0030-1269298
Novel treatment concept for acute severe pulmonary hypertension with right to left atrial shunting and veno-venous extracorporeal membrane oxygenation
Purpose: A considerable number of patients suffering from pulmonary hypertension die of right ventricular (RV) failure. One option is an atrial septostomy (AS), but this causes perilous hypoxemia. AS combined with veno-venous extracorporeal membrane oxygenation (VV ECMO) could be a novel therapy option.
Methods: Three large animal trials (male sheep, 59±3kg) were performed to evaluate hemodyamics and overall animal health using this technique. In all experiments a thoracotomy was performed and monitors placed to measure cardiac output (CO) and all relevant pressures. Pulmonary hypertension and right ventricular strain were simulated by banding the pulmonary artery (PA) up to total occlusion. Catheters were placed for VV gas exchange. The first acute experiment (n=10) utilized an extra-anatomic interatrial shunt to examine the effect of variable shunt flow, while the second acute experiment (n=12) utilized a more clinically relevant, 1cm AS. The third experiment examined 72h of support (n=5) in awake, extubated sheep.
Results: In all experiments normal, pre-PA banding CO was maintained during AS-ECMO support, up to total PA occlusion. Right ventricular, atrial and pulmonary artery pressures remained moderately elevated. Three animals with a 50% reduction in PA flow were supported awake and extubated for 72 hours, two animals died on support. VV ECMO preserved regular blood gases with mean oxygen saturations between 88–99% and effective CO2 elimination even with complete PA occlusion.
Conclusion: The combination of an AS with VV ECMO is effective at maintaining normal CO and could thus be a novel concept for pulmonary and right ventricular support.