Influence of ECMO and IABP on coronary blood flow. Valuable combination or waste of resources?]

The treatment of patients in severe cardiogenic shock with an intra-aortic balloon pump (IABP) or extracorporeal membrane oxygenation (ECMO) is a common procedure to achieve stabilization. Only limited data are available on the simultaneous use of both systems. The aim of the present study was to assess the effect of the concomitant use of IABP and ECMO on coronary blood flow. In addition, the influence of antegrade and retrograde perfusion was evaluated. A median sternotomy was performed in adult pigs under general anesthesia. Arterial ECMO perfusion was realized through the ascending aorta or the femoral artery, and the IABP was implanted via the second femoral artery. Six measurements of arterial pressure in the left anterior descending artery (LAD) and in the left atrium were made at intervals of 2 min. In addition, lactate concentration and oxygen saturation in the coronary sinus were recorded. The ECMO support was either 100 or 50 % of cardiac output. Each experiment was carried out first without and then with additional IABP support. The simultaneous use of ECMO and IABP is feasible for antegrade perfusion, where the IABP leads to an increase of blood pressure in the coronary arteries. In addition, the myocardial oxygen supply improves. By contrast, the use of an IABP in retrograde perfusion leads to a reduction of blood pressure in the LAD and to a reduced oxygen supply. A comparison between antegrade and retrograde perfusion with IABP support showed significantly better mean arterial pressure in the LAD for antegrade perfusion. Without IABP, blood pressure in the LAD was better in retrograde perfusion. In antegrade perfusion the simultaneous use of IABP and ECMO is useful. In retrograde perfusion IABP impairs the mean arterial pressure and consequently the perfusion of the coronary arteries.