Ventricular assist devices

Recent advances in technology as well as new indications for implantation have appeared in the field of ventricular assist devices. Progress has also been made in the understanding of the underlying mechanisms of myocardial recovery after ventricular assist device support. Technological progress includes the development of fully implantable pulsatile and continuous flow pumps, either axial flow or centrifugal, for left ventricular and total heart assistance. Among the new indications for ventricular assist device support, the most important is the use of the device as permanent treatment for end-stage cardiac failure patients. Increased knowledge has been acquired regarding the effects of mechanical assistance and of unloading of the heart on haemodynamics, as well as on the cellular, molecular and electrophysiological characteristics of the failing heart. All these findings suggest that depressed myocardial function can sometimes recover with ventricular assist device therapy. Ventricular assist device support, however, still carries a high rate of complications: the device itself can fail, bleeding and thromboembolism are common, immunity is disturbed and the incidence of infection remains high. In patients with end-stage heart failure, ventricular assist devices can be used as a bridge to transplantation or to recovery, but they are now also considered as a long-term myocardial replacement therapy. Which device is the most appropriate for each indication, however, remains to be defined. Even if the underlying mechanisms of myocardial recovery are progressively clarified, the use of ventricular assist devices as a bridge to recovery still has limited clinical success. Clinical trials with the fully implantable devices are in their early stages, but these pumps appear promising in terms of efficacy, reliability and complication rate, as well as being easy to implant. Because more patients will benefit from ventricular assist device placement in the future, anaesthesiologists must be prepared to manage patients undergoing ventricular assist device placement or presenting for noncardiac surgery while under ventricular assist device support.