title: Early feasibility testing and engineering development of the transapical approach for the HeartWare MVAD ventricular assist system.
abstract: 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.
authors.affiliation: 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.
authors.forename: Daniel
authors.initials: D
authors.lastname: Tamez
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: LaRose
authors.forename: Charles
authors.initials: C
authors.lastname: Shambaugh
authors.forename: Katherine
authors.initials: K
authors.lastname: Chorpenning
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Soucy
authors.forename: Michael A
authors.initials: MA
authors.lastname: Sobieski
authors.forename: Leslie
authors.initials: L
authors.lastname: Sherwood
authors.forename: Guruprasad A
authors.initials: GA
authors.lastname: Giridharan
authors.forename: Gretel
authors.initials: G
authors.lastname: Monreal
authors.forename: Steven C
authors.initials: SC
authors.lastname: Koenig
authors.forename: Mark S
authors.initials: MS
authors.lastname: Slaughter
mesh_terms: D000818:Animals; D002102:Cadaver; D013504:Cardiovascular Surgical Procedures / Q000379:methods*; D002417:Cattle; D004195:Disease Models, Animal; D005240:Feasibility Studies; D006353:Heart-Assist Devices; D006439:Hemodynamics; D006801:Humans; D008422:Materials Testing; D008904:Miniaturization; D011474:Prosthesis Design