Proper patient selection and timing of intervention are two of the most important factors in predicting a successful outcome for the patient who requires a TAH. The main indication for the use of TAH is in patients who are heart transplant candidates with severe biventricular failure in imminent risk of death and a suitable donor heart is not available. LVADs have proven very effective in either bridging patients to heart transplantation or as destination therapy in those patients who are not candidates [4, 5]. LVADs outcomes have continued to improve over the years and some patient subgroups experience near transplant survival outcomes. However, heart transplantation still has a better survival outcome over LVADs [6]. Furthermore, the use of isolated LVADs has unmasked a patient population that continues to experience right ventricular failure with an incidence approaching 40% [7]. There are several ventricular assist devices (VAD’s) that have been utilized for temporary right ventricular (RV) support with the intent of providing support to the RV. However, the need for a right ventricular assist device (RVAD) identifies a patient population that has worse outcomes [8].

The TAH continues to be used as a BTT in patients with severe biventricular failure, i.e., INTERMACS profile 1 and primarily profile 2 [9, 10]. However, the last few years has seen an increase in its use and better understanding for the indications for its use. Many potential indications for the use of a TAH have been conceptualized for many years; however, it has been in recent times that the TAH has been utilized for these very ill patients. For this reason, few of these cases have reached the medical literature and others are too early to report.

The need for re-transplantation is essential to provide long term survival for a heart transplant recipient who is experiencing graft failure that is not responding to conventional therapy. In cases of severe and diffuse coronary artery vasculopathy not amenable to percutaneous interventions or coronary artery bypass grafting, retransplantation is the only definite therapy in a viable patient. If a donor has not become available and the patient is experiencing hemodynamic instability despite inotropic support, temporizing measures that will provide more time include the use of ECMO or biventricular support. The role of the TAH in this particular patient population provides several advantages as long as the TAH is implanted prior to total cardiovascular collapse and end-organ damage. The TAH allows for immunosuppression to be discontinued and potentially lowers the increased risk of infection and kidney damage. Furthermore, it allows the patient to be ambulatory and potentially the benefit of being discharged home [11]. The use of the TAH for this indication is associated with a survival rate of 47%. However, the use of the TAH for hemodynamic collapse in the onset of acute rejection has not been described. This will probably be associated with a high rate of complications and poor outcomes. The role of the TAH in the chronic graft failure scenario will probably continue to increase as the transplant population has a mean survival of approximately 10 years and the donor shortage continues [12, 13].

The use of the TAH in the pediatric population with advanced heart failure as the result of an idiopathic, viral or congenital structural abnormality provides significant advantages. In addition to correction of hemodynamic deterioration, it provides a surgical scenario that allows for the correction of some of the congenital abnormalities at the time of TAH implantation and prior to the time of transplantation. The 50 cc SynCardia™ TAH has been developed for this smaller body-size patient population [14–17]. If successful, it will further expand the use of this technology in children and small adults with a BSA as low as 1.0 m². Approximately 30 patients with congenital heart disease had been implanted with the Syncardia™ TAH by the end of 2013. The majority of these patients were implanted in the last few years and in multiple centers. Some of the congenital abnormalities in these patients include corrected transposition of the great vessels and single ventricle. Although reports are just starting to be reported, some of these patients are experiencing altered hemodynamics and a failing Fontan. It is the expectation that the next few years will provide more evidence-based medicine regarding the management in this complex population with the TAH. The implantation of the SynCardia™ TAH or any newer TAH in patients with congenital heart disease will challenge surgeons to develop surgical modifications to the conventional implantation of the device as the cardiac abnormalities dictate modification and design.

The outcome of the patient with a primary cardiac malignancy is usually dismal. Although the majority of cardiac tumors are benign, a malignant tumor carries a fatal prognosis if unresectable. Diagnosis of these malignant tumors usually includes a biopsy at the time of presentation or occurs at the time of an optimistic but failed surgical resection. Imaging studies (echocardiography, computerized tomography, and MRI) are usually helpful but in some if not most instances failed to accurately delineate the extent of the disease [18]. Chemotherapy and radiation therapy have been utilized in unresectable cases. Heart transplantation has been utilized to treat selected patients with cardiac malignancies, however, several studies have shown poor outcomes. The use of ventricular assist devices has been reported and more recently the use of the HeartMate II LVAD used in the TAH configuration was described in a patient. A very small number of patients with cardiac tumors have received the Syncardia™ TAH. It is doubtful that there will be enough scientific information to make any prediction on outcomes. The use of the TAH in this population will generate controversy in the medical field. However, long-term use of the TAH followed by transplantation may one day play a role.

Acquired or ischemic ventricular septal defect (VSD) as a complication of myocardial infarction remains a condition with significant morbidity. Surgical correction is the most common therapy that carries a significant morbidity and mortality [19]. The use of MCS has been reported in the management of ischemic VSDs [20]. The successful use of the Syncardia™ TAH has also been reported [21]. A very small number of patients have been done for this indication to have a series of patients. The procedure probably will continue to have a significant morbidity and mortality as these patient populations have significant hemodynamic and physiologic impairment.

The patient populations experiencing infiltrative (i.e., amyloid) or hypertrophic cardiomyopathy are ideal candidates for the use of a TAH as this therapy eliminates the effect of the disease process in both affected ventricles. Although the use of left ventricular assist devices (LVAD) have been reported [22], the utilization of the TAH continues to increase in this population. Another population that benefit from the TAH technology are those patients who experience ventricular tachycardia (VT) storm or malignant arrhythmias despite multiple ablations. Although LVAD’s have also been used in this setting, the TAH continues to find a role in this group of patients. However, medical reporting in these two populations will increase in the next few years.

LVAD’s have been extremely successful in the management of congestive heart failure both in the BTT and destination therapy who are failing medical therapy. However, despite the best management, a number of BTT patients who have received LVADs continue to or relapse with right ventricular failure (RVF). The TAH has been successful in re-bridging these patients and eliminating the effects of RVF despite LVAD support [23]. However, this has not been tested in the destination (DT) population.

The conventional median sternotomy incision is performed and the pericardium is opened to expose the native heart. The drivelines for the prosthetic ventricles are then pulled outwards via a chest tube through pre-cut wounds under the left costal margin. Aortic and bicaval cannulations are performed, cardiopulmonary bypass is performed after appropriate heparinization, the heart is fibrillated and the aorta is cross-clamped. The patient is cooled to 32° F. The heart is then excised, starting with a ventriculectomy from right to left. Both native heart atria are left in place, as well a small amount of ventricle along with 1–2 mm of mitral and tricuspid valve tissue attached to the annulus.

The left atrial quick connect is placed through the mitral valve annulus and sutured to the left atrial cuff and the remnant ventricular muscle. The right atrial quick connect is placed through the tricuspid valve annulus and sutured in a similar way. The arterial conduits are then anastomosed to their respective arteries (see Fig. 17.5). At this stage, the suture lines are checked for leaks and if applicable, Coseal (Baxter Healthcare, Los Angeles, CA) or Bioglue (CryoLife, Kennesaw, GA) can be used to further secure the suture lines. A sheet of ePTFE-membrane is secured to the posterior pericardium for the purpose of minimizing adhesions at the time of the explantation. Rewarming usually begins at this point.