The Physiology of Microaxial Ventricular Assist Devices

At present, the Impella range of devices (Abiomed) are the only percutaneous transvalvular microaxial pumps that are approved for clinical use in the United States and Europe. The Impella 2.5 device was the first percutaneous transvalvular microaxial pump to be approved for use in 2008, primarily to support revascularization procedures. Advances over the last 15 years, most notably in the range of microaxial flow pumps and developments in controller software have improved device management and expanded the indications for Impella devices. The use of percutaneous microaxial flow pump devices have increased sharply over this period and are now widely incorporated into management protocols in cardiogenic shock. A recent randomized trial support the use of Impella in cardiogenic shock due to acute myocardial infarction. This chapter describes the physiology of transvalvular microaxial pumps and the practical management of these devices.