Striving for physiologic coaptation: An experimental and innovative approach towards designing and implanting aortic neo-leaflets.

Aortic valve repair has emerged as the treatment of choice for congenital aortic valvular disease, avoiding the need for a reoperation associated with stented prosthesis overgrowth. The introduction of a leaflet implant represents a recent advancement in a field that originated early techniques, such as simple commissurotomies. In our experimental approach, we assessed two established leaflet-sizing techniques by analysing their resultant coaptation areas.

An intraoperative test device for aortic valve repair.

Objective: Aortic valve repair is currently in transition from surgical improvisation to a reproducible operation and an option for many patients with aortic regurgitation. Our research efforts at improving reproducibility include development of methods for intraoperatively testing and visualizing the valve in its diastolic state.

Methods: We developed a device that can be intraoperatively secured in the transected aorta allowing the aortic root to be pressurized and the closed valve to be inspected endoscopically.

In vivo tissue regeneration with robotic implants.

Robots that reside inside the body to restore or enhance biological function have long been a staple of science fiction. Creating such robotic implants poses challenges both in signaling between the implant and the biological host, as well as in implant design. To investigate these challenges, we created a robotic implant to perform in vivo tissue regeneration via mechanostimulation.

An Intracardiac Soft Robotic Device for Augmentation of Blood Ejection from the Failing Right Ventricle.

We introduce an implantable intracardiac soft robotic right ventricular ejection device (RVED) for dynamic approximation of the right ventricular (RV) free wall and the interventricular septum (IVS) in synchrony with the cardiac cycle to augment blood ejection in right heart failure (RHF). The RVED is designed for safe and effective intracardiac operation and consists of an anchoring system deployed across the IVS, an RV free wall anchor, and a pneumatic artificial muscle linear actuator that spans the RV chamber between the two anchors. Using a ventricular simulator and a custom controller, we characterized ventricular volume ejection, linear approximation against different loads and the effect of varying device actuation periods on volume ejection.

Myocardial rescue with autologous mitochondrial transplantation in a porcine model of ischemia/reperfusion.

Objective: To demonstrate the clinical efficacy of autologous mitochondrial transplantation in preparation for translation to human application using an in vivo swine model.

Methods: A left mini-thoracotomy was performed on Yorkshire pigs. The pectoralis major was dissected, and skeletal muscle tissue was removed and used for the isolation of autologous mitochondria.

Cardioscopic Tool-delivery Instrument for Beating-heart Surgery.

This paper describes an instrument that provides solutions to two open challenges in beating-heart intracardiac surgery - providing high-fidelity imaging of tool-tissue contact and controlling tool penetration into tissue over the cardiac cycle. Tool delivery is illustrated in the context of tissue removal for which these challenges equate to visualization of the tissue as it is being removed and to control of cutting depth. Cardioscopic imaging is provided by a camera and illumination system encased in an optical window.

Surgical repair of congenital aortic regurgitation by aortic root reduction: A finite element study.

During surgical reconstruction of the aortic valve in the child, the use of foreign graft material can limit durability of the repair due to inability of the graft to grow with the child and to accelerated structural degeneration. In this study we use computer simulation and ex vivo experiments to explore a surgical repair method that has the potential to treat a particular form of congenital aortic regurgitation without the introduction of graft material. Specifically, in an aortic valve that is regurgitant due to a congenitally undersized leaflet, we propose resecting a portion of the aortic root belonging to one of the normal leaflets in order to improve valve closure and eliminate regurgitation.

High level expression of bioactive recombinant human growth hormone in the milk of a cloned transgenic cow.

Transgenic farm animals have been proposed as an alternative to current bioreactors for large scale production of biopharmaceuticals. However, the efficiency of both methods in the production of the same protein has not yet been established. Here we report the production of recombinant human growth hormone (hGH) in the milk of a cloned transgenic cow at levels of up to 5 g l(-1).