Implantation of the syncardia total artificial heart

In Vivo Biocompatibility of an Innovative Elastomer for Heart Assist Devices

Cardiac surgical approaches require the development of new materials regardless of the polyurethanes used for pulsatile blood pumps; therefore, an innovative biomaterial, a copolymer of poly(ethylene terephthalate) and dimer fatty acid (dilinoleic acid) modified with D-glucitol, hereafter referred to as PET/DLA, has been developed, showing non-hemolytic and atrombogenic properties and resistance to biodegradation. The aim of this work was to evaluate in vivo inflammatory responses to intramuscular implantation of PET/DLA biomaterials of different compositions (hard to soft segments). Two copolymers containing 70 and 65 wt.% of hard segments, as in poly(ethylene terephthalate) and dilinoleic acid in soft segments modified with D-glucitol, were used for implantation tests to monitor tissue response. Medical grade polyurethanes Bionate II 90A and Bionate II 55 were used as reference materials. After euthanasia of animals (New Zealand White rabbits, n = 49), internal organs and tissues that contacted the material were collected for histopathological examination. The following parameters were determined: peripheral blood count, blood smear with May Grunwald–Giemsa staining, and serum C-reactive protein (CRPP). The healing process observed at the implantation site of the new materials after 12 weeks indicated normal progressive collagenization of the scar, with an indication of the inflammatory–resorptive process. The analysis of the chemical structure of explants 12 weeks after implantation showed good stability of the tested copolymers in contact with living tissues. Overall, the obtained results indicate great potential for PET/DLA in medical applications; however, final verification of its applicability as a structural material in prostheses is needed.

Early LVAD Implantation in a Patient with Left Ventricular Failure after Aortic Dissection with Left Main Stem Involvement

Background: Coronary involvement in aortic dissection heralds a poor outcome. Involvement of the left main stem may lead to left ventricular (LV) failure requiring mechanical circulatory support.

Case Report: A staged approach was applied in a 24-year-old female who suffered extensive infarction due to aortic dissection with left main stem involvement. After replacement of the ascending aorta and grafting of the left internal thoracic artery to the left anterior descending artery following a failed attempt at reconstruction of the left coronary ostium, she failed to wean from cardiopulmonary bypass (CPB) and underwent implantation of an extracorporeal life support (ECLS) system as a bridge to decision. Subsequent implantation of a left ventricular assist device (LVAD) as a bridge to recovery/transplantation was followed by an uneventful further course.

Conclusions: Our experience suggests that early implantation of a ventricular assist device (VAD) as bridge to recovery/transplantation is an alternative to prolonged ECLS in patients who suffered extensive myocardial infarction in the course of aortic dissection.

The total artificial heart

The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.