Πώς δουλεύει η συσκευή impella

The Impella device is a percutaneous, catheter-based microaxial flow pump that provides active mechanical circulatory support by directly unloading the ventricle, thereby supporting systemic circulation in patients with impaired native cardiac output.

This device is positioned across the aortic valve into the left ventricle (LV) where it aspirates blood through an inlet near the ventricular apex and expels it into the ascending aorta via an outlet above the aortic valve. This mechanism reduces LV end-diastolic pressure and wall stress, decreases myocardial oxygen demand, and improves coronary perfusion by increasing aortic root diastolic pressure, ultimately lessening ventricular workload and facilitating myocardial recovery NICE CG187 Bandini et al. 2026.

The Impella operates via a microaxial pump motor that draws blood from the LV and propels it into the arterial circulation at flow rates varying by device type, with some models delivering up to 5.5 L/min. Its pump mechanism generates rotary force creating negative pressure to aspirate blood and then actively move it forward, functioning similarly to an Archimedes’ screw Tetaj et al. 2026.

This active ventricular unloading interrupts the vicious cycle of cardiogenic shock, characterized by reduced cardiac output, compensatory neurohormonal activation, increased wall stress, and progressive myocardial injury, by mechanically supporting circulation and reducing LV pressures Bandini et al. 2026 NICE CG187.

Impella devices are available for both left and right ventricular support. Left-sided devices (e.g., Impella CP and Impella 5.5) are introduced typically through femoral or surgical axillary/subclavian access and positioned retrogradely across the aortic valve. For right ventricular support, the Impella RP is inserted venously and advanced into the pulmonary artery, facilitating unloading of the right ventricle (RV) by aspirating blood from the inferior vena cava and ejecting it into the pulmonary artery NICE CG187 Bandini et al. 2026.

The functional impact of Impella support includes significant hemodynamic improvements such as reduction in left ventricular stroke work and pulmonary capillary wedge pressure, alongside increases in mean arterial pressure and peripheral organ perfusion. Early studies also demonstrate improvements in right ventricular-pulmonary artery hemodynamics after left-sided Impella 5.5 placement, even in patients with compromised RV function Daso et al. 2026.

The device's continuous flow contributes to left ventricular unloading by actively reducing preload and afterload, which contrasts with indirect methods like the intra-aortic balloon pump (IABP). This direct unloading reduces LV volume and pressure more effectively, which can improve myocardial energetics and systemic perfusion Tetaj et al. 2026 NICE CG187.

Overall, the Impella device functions as a temporary mechanical ventricular assist that actively aspirates blood from the ventricle and delivers it into the arterial system, thereby reducing ventricular wall stress and myocardial oxygen consumption while maintaining or augmenting systemic cardiac output Bandini et al. 2026 NICE CG187.