Heart transplantation (HTx) is the final treatment for patients with advanced heart failure [1] . It is estimated that 26 million adults worldwide are living with heart failure (HF) [2] , costing roughly 1% - 2% of healthcare expenditures in Europe and North America [3] . In Korea, heart failure prevalence was estimated to be 1.53% in 2013 [4] . Heart failure is a serious and frequent pathology in Africa. It affects young and active subjects [5] . According to PIO et al. [5] in Togo, the prevalence of HFs was 28.6%. PIO found left ventricular systolic dysfunction in 213 patients (56.6%) [5] . Thiam [6] in Senegal reported a prevalence of 37.7%. In Côte d’Ivoire, according to Gnaba et al., HF accounted for 60 to 65% of hospitalized patients. The average left ventricular ejection fraction (LVEF) was 35.8 ± 13% [7] . The main identified causes of heart failure were ischemic heart disease (60%) and hypertensive heart disease (20%) [7] . Patients with end-stage heart failure and cardiomyopathies are candidates for heart transplantation. The first attempt was made 118 years ago, in 1905, by Alexis Carrel and Charles Guthrie at the University of Chicago. In 1967, Human-to-human heart transplantation, which is the replacement of a failing heart with one from a suitable donor, was first carried out by Dr Christian Barnard at the Groote Schuur Hospital in Cape Town, South Africa [8] . Since 1982, more than 14,000 heart transplants have been performed in pediatric patients worldwide [9] , which corresponds to around 10% of all heart transplants [10] . About 50% of pediatric patients received heart transplants due to CHD [9] , while this proportion is 2.2% in the adult comparison group [11] [12] . The indications ( Table 1 ) and contraindications ( Table 2 ) for heart transplantation according to the European Society of Cardiology (ESC) and American Heart Association (AHA) guidelines are varied. There are two surgical techniques used in cardiac transplantation: the right atrial (RA) technique and the bi-caval technique. The bi-caval anastomosis technique is currently used. This gesture is not practiced in Sub-Saharan Africa, due to the absence of laws in force and certain beliefs. Dilated cardiomyopathies with severe heart failure are on the rise in our countries.

We report the cases of 3 children who underwent successful heart transplants in pediatric cardiac surgery at Seoul National University Hospital from July to October 2024.

Heart transplantation (HTx) remains the last therapeutic resort for patients with advanced heart failure. The first clinical heart transplant was accomplished in an adult by Barnard in Cape Town, South Africa, in 1967 [13] . Thus, this first heart transplant in Africa has raised hope in the African population. But heart transplantation remains absent in sub-Saharan Africa. However, heart failure in the African working population is clearly on the rise. According to the Global Observatory of Donation and Transplantation 2017 database, Africa recorded only 14 heart transplants out of 7881 globally, representing 0.2% of the global total in 2016 [14] . Similarly, in 2022, the International Report on Organ Donation and Transplantation Activities recorded heart transplantations in only one country in Africa, Tunisia [15] .

During our internship in the Department of Pediatric Cardiac Surgery at Seoul National University Hospital, 3 males children whose ages were 3, 9 and 20 years old were operated on. The majority of pediatric transplant patients are those with pre- and postoperative complex CHDs and those with cardiomyopathies. In our study, One patient had ventricular septal disease operated on and two patients had cardiomyopathy. In the pediatric population, congenital heart disease accounts for about half of the indications; these are either non-repairable malformations or malformations operated on but resulting in terminal heart failure. The 3 patients had left ventricular dysfunction with an ejection function of 28% for case 1, 22.4% for case 2 and 26% - 29% for case 3. The alteration of left ventricular function required the implementation of left ventricular support for the 3 patients. This essential ventricular support allows patients to wait until they have a donor for a heart transplant. All 3 patients had left ventricular assist device (L-VAD). These LVADs increase the difficulties and operating time during the preparation of the recipients. Recipients with congenital heart disease pose specific technical problems related to initial malformations and/or various palliative interventions. Heart transplantation in CHD patients is usually complicated by multiple previous operations, cardiac defects, abnormal situs, and collateral circulation, which should be precisely recorded before the heart transplantation. Case No. 1 had a VSD, i.e. a congenital heart disease. Case 2 had dilated cardiomyopathy of unidentified etiology. Case No. 3 had dilated cardiomyopathy, whose etiology was Duchenne Muscle Dystrophy. Though VAD has been widely used for end-stage heart failure and bridge-to-transplantation or destination therapy, VAD application in CHD patients is not extensively used [16] . VADs in pediatric and adult CHD populations are increasing due to the shortage of donor’s hearts and an increasing number of patients with heart failure [17] [18] . Previous studies found that VAD therapy can prolong survival in high-risk CHD patients who would either die or be delisted due to clinical deterioration [19] .

Total heart transplantation requires careful preparation and perfect cooperation between the collection and transplantation teams. Particular attention should be paid to the condition of the pulmonary arterial bed. Accurate assessment of pulmonary vascular resistance. Several factors determine the outcome of HTx, such as ABO and HLA compatibility, graft size, ischemic time, and age. Active infection, peripheral vascular disease, malignancies, and increased BMI are frequent contraindications. The major complications of HTx include graft rejection, graft angiopathy, primary graft failure, infection, neoplasms, and retransplantation. Advances in the field of HTx encompass novel monitoring for acute cellular rejection and antibody-mediated rejection (Nikolaos) [20] .

The 3 patients were operated on under general anesthesia and extracorporeal circulation, with moderate hypothermia. The heart transplant technique was the bicaval technique for the 3 patients. There are currently two surgical techniques used in cardiac transplantation: the right atrial (RA) technique and the bi-caval technique. The latter is a more recent technique and has become more popular than the former. In RA cardiac transplantation, when the native heart is explanted, the posterior walls of both atria of the recipient heart are left in place ( Figure 9 ) and are anastomosed to the donor heart [21] .

Figure 9. Right atrial technique (Backer, transplantation 2015) [22] .

In the bi-caval technique ( Figure 10 ), the RA is also explanted from the recipient, leaving only the posterior wall of the left atrium (LA) with four pulmonary veins attached [21] . Anastomoses are made between the LA, aorta, IVC, SVC, PA.

Studies have shown that bicaval anastomosis is less likely to require a pacemaker, and patients need less time in the hospital [23] . The bicaval technique preserves normal atrial morphology, sinus node function, and valvular function [24] . As a result, it has consistently been associated with a decreased incidence of atrial arrhythmias and the need for pacemaker implantation. However, potential disadvantages include an increased ischemic time and the possibility of narrowing of the caval anastomosis.

The immediate postoperative follow-up was simple for the 3 patients.

Heart transplantation is considered one of the most effective treatments for end-stage heart failure, giving patients another chance for survival and an improved quality of life. However, this practice faces impediments in Africa due to various barriers, including inadequate infrastructure, a lack of personnel for such procedures, a shortage of organ donors, negative beliefs regarding organ donation, and economic constraints. In 2021, it was reported in Uganda that one of the major barriers to performing a heart transplant was the financial challenge it poses on the part of the patient and the medical facility due to it being an expensive procedure [25] . The infrastructure required to support heart transplantation is often unavailable in many African countries. This includes specialized cardiac centers with dedicated intensive care units, sophisticated diagnostic materials, surgical equipment, tissue typing, cross-matching, and some viral studies [26] . Although there are difficulties, heart transplantation will give patients a second chance. They will then be able to contribute to the development of Africa.

Heart transplantation according to the bi-caval procedure has made it possible to treat children with end-stage heart failure in Seoul National University Hospital. End-stage heart failure in Africa is clearly increasing among the young working population. Although Africa faces a range of challenges, heart transplantation is reproducible in sub-Saharan Africa. Also, given the scarcity of donors and the morbidity and mortality of transplants, emphasis could be placed on other means of acquiring grafts, in particular xenotransplantation and cardiac tissue bioengineering.