Mechanical Circulatory Support for Right Heart Failure: Current Technology and Future Outlook

Abstract

The increasing global prevalence of congestive heart failure is a major healthcare concern, accounting for a high morbidity rate worldwide. In particular, isolated right heart dysfunction after cardiotomy has a poor prognosis and is associated with a high mortality rate. The occurrence of postoperative right heart failure may develop in more than 40% of patients undergoing implantation of a left ventricular assist device (LVAD) and cardiac transplantation. To date, mechanical cardiac assistance in the form of VADs has become accepted as a therapeutic solution for end-stage patients when a donor heart is not available. However, right ventricular (RV) assistance is still in the early phase of development when compared with LVAD technology. State-of-the-art RVADs, both in clinical use and under development, are reviewed in this manuscript. Clinical RVADs include the extracorporeal pulsatile Abiomed BVS 5000 and AB5000, Thoratec PVAD, MEDOS VAD, BerlinHeart Excor, the percutaneous continuous flow CentriMag and TandemHeart systems, and the implantable Thoratec IVAD. Devices on the horizon, including the wear-free implantable DexAide and the minimally invasive Impella RD, are additionally reviewed. In addition to the current status of RV assistance, as well as the device categorization, the outlook and considerations for successful development of future RVADs were discussed.

Devices in Heart Failure

“…[85][86][87] Mechanical circulatory assist devices can be used with the inflow cannula in the RA or RV and out to the pulmonary artery or via venous-venous bypass if extracorporeal oxygenation is to be given. Such RV assist devices (RVAD) work at 4 L/min at 40 mmHg pulmonary pressure, 88 and include extracorporeal, paracorporeal, and implantable devices. Extracorporeal devices include the Abiomed BVS 5000, CentriMag systems.…”

“…90 The Thoratec PVAD (percutaneous VAD) has 5-6.5 L/min of pulsatile flow and is a pneumatic device. 88 The Thoratec IVAD (implantable VAD) can provide intermediate or longterm support. It is a pneumatic pump that can provide pulsatile flow between 4 and 7 L/min.…”

Mechanical circulatory support for the right ventricle in the setting of a left ventricular assist device

“…It is a pulsatile device that has been used for left, right and biventricular intermediate-to long-term support [29]. Before the introduction of continuous-flow devices, Farrar and associates conducted a multi-center study, including 213 patients receiving Thoratec paracorporeal ventricular assist device as bridge to transplant.…”

“…The Abiomed BVS 5000 (Abiomed, Inc., Danvers, MA) is a pulsatile device that is pneumatically driven and was the first FDA-approved device for postcardiotomy RV failure [29]. Morgan et al reported its use in 30 patients as RVADs, and of those, 21 (70%) survived support with nine recovery, five as bridge-to-bridge and one received a transplant [30].…”

Tissue Engineering by Intrinsic Vascularization in an <em>In Vivo</em> Tissue Engineering Chamber

“…1,2 Many approaches to engineer new and healthy tissue for the replacement of injured tissue or defective organs have been developed, 3-6 experimentally in small animal models with promising clinical potential. 7,8 However, vascularization remains one of the great challenges for tissue engineering limiting its potential to grow tissues of clinically relevant size.…”