Implantation of ventricular assist devices (VADs) for the treatment of end-stage heart failure (HF) falls decidedly short of clinical demand, which exceeds 100,000 HF patients per year. Ventricular assist device implantation often requires major surgical intervention with associated risk of adverse events and long recovery periods. To address these limitations, HeartWare, Inc. has developed a platform of miniature ventricular devices with progressively reduced surgical invasiveness and innovative patient peripherals. One surgical implant concept is a transapical version of the miniaturized left ventricular assist device (MVAD). The HeartWare MVAD Pump is a small, continuous-flow, full-support device that has a displacement volume of 22 ml. A new cannula configuration has been developed for transapical implantation, where the outflow cannula is positioned across the aortic valve. The two primary objectives for this feasibility study were to evaluate anatomic fit and surgical approach and efficacy of the transapical MVAD configuration. Anatomic fit and surgical approach were demonstrated using human cadavers (n = 4). Efficacy was demonstrated in acute (n = 2) and chronic (n = 1) bovine model experiments and assessed by improvements in hemodynamics, biocompatibility, flow dynamics, and histopathology. Potential advantages of the MVAD Pump include flow support in the same direction as the native ventricle, elimination of cardiopulmonary bypass, and minimally invasive implantation.
From the *HeartWare, Inc., Miami Lakes, Florida; †Division of Thoracic and Cardiovascular Surgery, Cardiovascular Innovation Institute, University of Louisville, Louisville, Kentucky; ‡Department of Bioengineering, University of Louisville, Louisville, Kentucky; and §Research Resources Facilities (RRF), University of Louisville, Louisville, Kentucky.
Submitted for consideration July 2013; accepted for publication in revised form November 2013.
Disclosure: Funding for this study was supported by NIH SBIR phase I grant number 1R43HL103014-01A1 (PI: Dan Tamez). Daniel Tamez, Jeffrey A. LaRose, Charles Shambaugh, Katherine Chorpenning are employees of HeartWare. Mark Slaughter has received an education and training grant from HeartWare. For the remaining authors, no conflicts of interest were declared.
Reprint Requests: Mark S. Slaughter, MD, Division of Thoracic and Cardiovascular Surgery, University of Louisville, 201 Abraham Flexner Way, Suite 1200, Louisville, KY 40202. Email: Mark.firstname.lastname@example.org.