Mechanical Right Ventricular Assistance – Past, Present, and Future

Abstract

The increasing global prevalence of congestive heart failure is a major healthcare concern. In particular isolated right heart dysfunction may develop in more than 40% post-cardiotomy patients that has a poor prognosis and is associated with a greater than 70% mortality rate. When heart failure has gone beyond the treatment capacity of drug therapy and heart transplantation, mechanical cardiac assistance in the form of ventricular assist devices (VADs) has become accepted as a therapeutic solution for end-stage patients. However, right ventricular assist devices (RVADs) are still in the early development phase when compared to left ventricular assistance. To date, most clinically available RVADs are extracorporeal and only available for short-term use. They are associated with complications such as poor blood compatibility and high infection rates. Some paracorporeal and implantable devices provide mid- to long-term support but the invasive procedure required means they are usually offered to the critically ill patients. Current RVAD systems are reviewed and categorised according to their functionality, type of support, and target therapies. Several evolving technologies in blood pump applications hold the potential to provide the best possible RVAD system are discussed, including foldable pump structure, miniature drive technology, contactless bearing system, transcutaneous energy supply, and adaptive physiological controller. There remains a definite need for a RVAD which can be implanted with minimally invasive (surgical and imaging) techniques to offer more flexible therapy for wider range of patients. In developing novel approaches to mechanically support the pulmonary circulation, criteria and aims to overcome the significant limitations and bridge the unmet needs of current RVAD technologies are identified. The successful fulfillment of the requirements will allow the augmentation of cardiovascular performance in order to allow recovery and offer a significant boost in quality of life.