Heart Transplant and Ventricular Assist: Cardiac Surgery and Heart Failure Perspective

For nearly 60 years, there have been two surgical treatment options for individuals with severe advanced heart failure: heart transplantation or implantation of a left ventricular assist device. As these fields have advanced in parallel, improvements in surgical technique, device development, and patient selection have improved outcomes for both therapies. Development of a comprehensive approach to the management of the most severe forms of advanced heart failure requires a deep understanding of both heart transplantation and durable ventricular assistance, including recent advancements in both fields. This article will review the substantial progress in the fields of heart transplantation and mechanical left ventricular assistance, including recent changes to organ allocation prioritization and left ventricular assist device evaluation, both of which have dramatically influenced practice in these fields.

Complications of Minimally Invasive Left Ventricular Assistance Device Implantation

Indication of Ventricular assistance is advanced cardiac failure with maximal medical and surgical treatment has been used. The ventricular assistance has two main purposes: first, to maintain circulation by discharging the ventricle (s) untill to recovery, or to ensure patient survival by replacing cardiac function permanently or transitionally for patients waiting for heart Transplantation. The encouraging results of the partial or total artificial heart and the miniaturization of these devices allow their use in permanent implantation for patients with heart failure that is not eligible for heart transplantation. In left mono-ventricular assistance, blood is taken from the apex of the left ventricle (LV) and reinjected in the ascending aorta. The classic surgical approach is a total median sternotomy. Other minimally invasive approaches for the implantation or explanation of left ventricular assist devices have been published and have shown encouraging results. These alternatives currently play an important role in certain indications and in patients with heavy medical history. Nevertheless, the complications of the ventricular assistance even by minimally invasive approaches might be serious and represent a turning point in the life of the patients. In this chapter, we describe the implantation technique of left ventricular assistance device (LVAD) and we discuss its advantages and disadvantages including possible complications.

Clinical trials in cardiac xenotransplantation: are we ready to handle ethical issues?

Heart allotransplantation has become one of the methods of choice in the treatment of severe heart failure. In the face of its difficulties, such as the unmet balance between organ supply and demand, the use of xenotransplantation might be an attractive option in the near future, even more with the ongoing progress achieved regarding the avoidance of hyperacute rejection and primary organ disfunction, maintenance of xenograft function and control of xenograft growth. To make possible this translational challenge, some points must be taken into account indeed, and they are the equipoise of human benefit and animal suffering, the risk of unknown infections, a well prepared informed consent, ethical and religious beliefs, and the role of cardiac xenotransplantation in a ventricular assistance device era.

Numerical study of shear-based hemolysis in aorta with left ventricular assistance device

Ventricular assistance devices (VADs) for heart failure treatment have been paid high attention among researchers for decades. However, the follow-up complications such as hemolysis and thrombosis require further optimization for this technique. Shear stress has been demonstrated to be significantly related to the hemolysis because of the rupture of red blood cells membrane with a leaking of hemoglobin in the plasma. This issue has already been investigated inside the pump of VAD, but estimations are still lacking regarding hemolysis generation in the aorta itself after VAD implantaion. Thus, the present study aims to evaluate the hemolysis in aorta through establishing the 3D numerical model of aorta with left ventricular assistance device (LVAD). Non-Newtonian Carreau model has been adopted. Comparisons of hemolysis evaluation have been made with two different mathematical models existing in literature. Moreover, the flow topology and hemodynamic variations have been studied. Different working conditions of LVAD have been considered corresponding to different heart failure severities. The results reveal a relatively low level of hemolysis risks in aorta. The thrombosis is more prone to occur in the case of severe heart failure condition.

Impact of ventricular assistance devices on patients submitted to heart transplantation

Background The introduction of veno-arterial extracorporeal life support (v-a ECLS) widens the spectrum of patients that can be included in the heart transplant program, some examples are extended myocardial infarction, fulminant myocarditis or advanced cardiac insufficiency. In addition to this, the implementation of extracorporeal cardiopulmonary resuscitation (ECPR) extends even more the range of patients that can be benefitted of this therapy as a bridge to transplant. Purpose Our objective is to describe the incidence of v-a ECLS in those patients submitted to a heart transplant and to establish whether or not this technique increases the risk of mortality in this population. Methods Retrospective and descriptive statistical analysis of 82 consecutive patients submitted to heart transplant between 2015 and 2019 in a High Technology University Hospital. Demographic and clinical data, extracorporeal life support, extracorporeal cardiopulmonary resuscitation and assistance device type, together with survival at 30 days and one year were collected. Results 82 patients were transplanted during the study period distributed as follows: 47 (51.69%) were elective and 35 (48.1%) emergent being 25 (30.12%) of grade 1A and 10 (12.19%) of grade 1B. 52% had prior intra-aortic balloon contrapulsation. Patients transplanted under ECLS were 80% men and average age of 53 (SD 15) years old. The most prevalent diagnosis was acute myocardial infarction Killip IV (32%), followed by terminal heart failure (28%). 32% of the patients were under peripheral ECMO, 36% under left ventricular assistance, 20% under biventricular assist device, and 12% required ECPR. 72% of devices were implanted in the operating room and 16% in the ICU. The one-year survival of the sample was 88%. 2 patients died after transplantation (8%) during the first month, and 1 patient died within the first year. All three patients had terminal heart failure and the VAD implant was inserted electively Conclusions ECLS prior to cardiac transplantation allow selected patients to arrive alive to the transplant. The choice among devices is related to the diagnosis and expected duration of the therapy but we have not found in our series effects on subsequent mortality. Survival at one year in the subjects analysed is greater than the national registry of the last 10 years, although the tendency is to improve every year. This new scenario implies an increment of the complexity in the management of these patients and requires an special effort in terms of staff ratio and training. In our centre, the implementation of ECLS resulted in an increment of our staff and formative sessions. Funding Acknowledgement Type of funding source: None