What is a Heart Transplant?

Heart transplantation is a surgical transplantation for advanced congestive heart failure and severe coronary artery disease. It is an allograft operation in which the human heart that has been determined to be brain dead and successfully matched is completely removed and implanted in the chest cavity of the desired recipient. The recipient's autologous heart is removed (called an orthotopic heart transplant) or reserved to support the donor heart (called an ectopic heart transplant). The average survival after surgery was 13 years. At present, there are more than 100 cases of heart transplantation in China every year, with a three-year survival rate greater than 90% and a five-year survival rate greater than 85%. Heart transplantation is not a conventional treatment for heart disease, but rather a treatment that saves the lives of patients with end-stage heart disease and improves their quality of life.

Basic Information

English name

heart transplantation

Visiting department

Cardiothoracic surgery

Heart transplant indication

1. End-stage heart failure cannot be cured by systematic medical treatment or conventional surgery. Without a heart transplant, there is less than a 50% chance that life expectancy will reach one year.

2. No irreversible damage to other organs (liver, kidney, lung, etc.).

3. Patients and their families can understand and actively cooperate with transplant surgery.

4. Common conditions suitable for heart transplantation: advanced primary cardiomyopathy, including dilated, hypertrophic and restricted cardiomyopathy; coronary heart disease that cannot be treated with surgery and other measures; end stage that cannot be treated with valve replacement surgery Multivalvular disease; complex congenital heart disease that cannot be cured with corrective surgery, such as left ventricular dysplasia; other heart trauma and cardiac tumors that are difficult to treat surgically; extensive coronary artery sclerosis after heart transplantation, Myocardial fibrosis and so on.

In recent years, people have more generally recognized indications for heart transplantation: heart failure survival index (HFSS) <8.1; peak oxygen consumption (maximum oxygen consumption in exercise test to determine VO2) is less than 10ml / kg / .min; intractability of internal medical treatment 3 Grade 4 heart failure; myocardial ischemia that cannot be treated by internal medicine or surgery; symptomatic ventricular arrhythmias that cannot be treated by medicine, pacing, or surgery.

Heart transplant contraindications

Not all patients with heart failure are suitable for heart transplantation. When combined with a serious disease in a system other than the heart, it is considered a contraindication to heart transplantation. The following conditions will increase the incidence of surgical complications:

1. Suffering from severe irreversible liver, kidney or lung diseases and uncontrollable hypertension.

2. Severe diabetes with terminal organ damage (diabetic nephropathy, diabetic neuropathy / retinopathy).

3. Severe peripheral vascular / central vascular disease, peripheral vascular disease that cannot be intervened / surgically treated.

4. Pulmonary hypertension or increased pulmonary circulation resistance.

Active or recently discovered solid organs and hematological malignancies within 5.5 years.

6. Pathological obesity (body mass index> 35Kg / m ² ) or cachexia (body mass index <18Kg / m ² ).

5. Age> 72 years

History of drug, tobacco or alcohol abuse over 6.6 months.

Heart transplant surgery classification

Orthotopic heart transplantation

Orthotopic heart transplantation is to open the chest from the middle of the sternum, expose the mediastinum, open the pericardium, and cut off the large blood vessels to perform auxiliary circulation through an extracorporeal circulation machine. Prior to removal of the donor heart, potassium chloride was injected to stop the heart. After removal, the donor heart was stored in ice. Donor hearts can usually be stored in ice for 4-6 hours. The failed heart was isolated from the recipient s chest after cutting off the surrounding large blood vessels and part of the left atrium. The remaining left atrial tissue retained the pulmonary veins. Tissue anastomosis. After the donor heart beats again, it is detached from the extracorporeal circulation machine and sutured to close the chest.

2. Heterotopic heart transplant

Heterotopic heart transplantation refers to retaining the recipient heart, implanting the donor heart into the chest cavity, and connecting the two hearts and blood vessels to form a "double heart" system. This procedure can give the recipient a chance to recover. If the transplant fails (such as rejection), the donor heart that has the rejection can be excised. Heterotopic transplantation is generally used when the donor's heart function is not strong enough (the recipient's weight is much heavier than the donor's body, the donor's heart is weak, or has pulmonary hypertension).

Care after heart transplant

Early in the period after heart transplantation, ICU monitoring and treatment is needed. When the patient wakes up, he needs to be transferred to a special ward for rehabilitation care. The length of hospital stay and postoperative care depends on the general condition of the patient, the function of the transplanted heart, and the patient's self-care ability. As the length of hospital stay will increase the risk of nosocomial infections, doctors usually hope that patients will be discharged about 2 weeks after surgery, and they should be regularly returned to the hospital for review after discharge. Patients also need some emotional and psychological support. When the patient gradually adapts, the period of returning to the hospital for review can be extended. Because the vagus nerve is severed during surgery, the donor heart generally beats about 100 beats per minute after denervation. After heart transplantation, it is necessary to regularly check and evaluate the function of the transplanted heart, monitor the concentration of immunosuppressive drugs and immune rejection, and actively prevent infection. Immunosuppressants should be taken for a long time to avoid rejection, and myocardial biopsy should be performed regularly to determine whether there is rejection.

Complications after heart transplant

Heart transplant is a high-risk operation, with a mortality rate in the hospital of about 7%. Postoperative cardiac complications include infections, sepsis, donor heart failure, bleeding, coronary atherosclerosis, chronic renal failure, immune rejection, and side effects of taking immunosuppressants. Because heart transplantation is an allogeneic organ transplant, the recipient has the possibility of immune rejection. For heart transplant patients, the risk of immune rejection always exists, so it is necessary to apply immunosuppressants for a long time. However, immunosuppressants have certain side effects, such as increasing the possibility of infection, appearing paresthesia, and prone to tumors. In some patients, renal insufficiency may occur after surgery.

Heart transplant progress

On October 24, 2014, Australian doctors successfully performed a heart transplant using a heart that has stopped beating. This is the world s first dead heart transplant, opening up future organ donation and transplantation methods.

Until now, doctors could only rely on a heart donated by a brain dead patient for transplantation, and they had to keep the beating organs in ice and send them quickly to the recipient for surgery. ^[1]