What is Heart Transplant?
A heart transplant, or a cardiac transplant, is a surgical transplant procedure performed on patients with end-stage heart failureor severe coronary artery disease. As of 2008 the most common procedure is to take a working heart from a recently deceasedorgan donor (cadaveric allograft) and implant it into the patient. The patient's own heart is either removed (orthotopic procedure) or, less commonly, left in place to support the donor heart (heterotopic procedure). Post-operation survival periods average 15 years. Heart transplantation is not considered to be a cure for heart disease, but a life-saving treatment intended to improve the quality of life for recipients.
- Kidney Transplant
- Liver Transplant
- Bone Marrow Transplant
- Corneal Transplant
- Guidelines for Liver Transplant
- Guidelines for Kidney Transplant
Heart transplantation is a surgical process which undertakes to replace a diseased or non-functioning heart with a healthy one. The surgeon removes the heart of patients by making a transaction in the aorta, the main pulmonary artery and the superior as well as inferior vena cavae, and then dividing the left atrium. This leaves the back wall of the left atrium that has the pulmonary vein openings in place. After this, the donor's heart is connected by sewing together the recipient and donor vena cavae, aorta, pulmonary artery and left atrium.
The donor for heart transplant is someone who is either brain dead or on ventilation. After removing the healthy heart from such a patient it is dipped in a solution before the transplant takes place.
IndicationsThis procedure can be recommended in the following cases:
- Severe heart disease since birth
- Coronary artery disease
- Heart valve disease with congestive heart failure
- Life-threatening abnormal heart beats (when other therapies fail)
- Aortic disease
- Coronary artery disease
- Heart disease symptoms including angina, shortness of breath and palpitations.
- Vascular disease
- Congestive heart failure
- Atrial fibrillation and flutter
- Hypercholesterolemia and risk factor modification
- Myocardial Infarction
- Mitral valve prolapsed
Patients for whom this surgery is not recommended:
- Kidney / lung/ liver disease
- Insulin-dependent diabetes with poor function of other organs
- Blood vessel disease of the neck and leg
- Other life-threatening diseases
A typical heart transplantation begins when a suitable donor heart is identified. The heart comes from a recently deceased or brain dead donor, also called a beating heart cadaver. The patient is contacted by a nurse coordinator and instructed to come to the hospital for evaluation and pre-surgical medication. At the same time, the heart is removed from the donor and inspected by a team of surgeons to see if it is in suitable condition. Learning that a potential organ is unsuitable can induce distress in an already fragile patient, who usually requires emotional support before returning home.
The patient must also undergo emotional, psychological, and physical tests to verify mental health and ability to make good use of a new heart. The patient is also given immunosuppressant medication so that the patient's immune system does not reject the new heart.
Schematic of a transplanted heart with native lungsand the great vessels.
Once the donor heart passes inspection, the patient is taken into the operating room and given a general anaesthetic. Either an orthotopic or a heterotopic procedure follows, depending on the conditions of the patient and the donor heart.
The orthotopic procedure begins with a median sternotomy, opening the chest and exposing the mediastinum. Thepericardium is opened, the great vessels are dissected and the patient is attached to cardiopulmonary bypass. The donor's heart is injected with potassium chloride (KCl). Potassium chloride stops the heart beating before the heart is removed from the donor's body and packed in ice. Ice can usually keep the heart usable for four to six hours depending on preservation and starting condition. The failing heart is removed by transecting the great vessels and a portion of the left atrium. The patient's pulmonary veins are not transected; rather a circular portion of the left atrium containing the pulmonary veins is left in place. The donor heart is trimmed to fit onto the patient's remaining left atrium and the great vessels are sutured in place. The new heart is restarted, the patient is weaned from cardiopulmonary bypass and the chest cavity is closed.
In the heterotopic procedure, the patient's own heart is not removed. The new heart is positioned so that the chambers and blood vessels of both hearts can be connected to form what is effectively a 'double heart'. The procedure can give the patient's original heart a chance to recover, and if the donor's heart fails (e.g., through rejection), it can later be removed, leaving the patient's original heart. Heterotopic procedures are used only in cases where the donor heart is not strong enough to function by itself (because either the patient's body is considerably larger than the donor's, the donor's heart is itself weak, or the patient suffers from pulmonary hypertension).
'Living organ' transplant
Rather than cooling the heart, the living organ procedure keeps it at body temperature and connects it to a special machine called an Organ Care System that allows it to continue pumping warm, oxygenated blood. This technique can maintain the heart in a suitable condition for much longer than the traditional method.
The patient is taken to the ICU to recover. When they wake up, they move to a special recovery unit for rehabilitation. The duration of in-hospital, post-transplant care depends on the patient's general health, how well the heart is working, and the patient's ability to look after the new heart. Doctors typically prefer that patients leave the hospital 1 – 2 weeks after surgery, because of the risk of infection and presuming no complications. After release, the patient returns for regular check-ups and rehabilitation. They may also require emotional support. The frequency of hospital visits decreases as the patient adjusts to the transplant. The patient remains on immunosuppressant medication to avoid the possibility of rejection. Since the vagus nerve is severed during the operation, the new heart beats at around 100 beats per minute unless nerve regrowth occurs.
Immunosuppressive agents are continued in the intensive care unit.
The patient is regularly monitored to detect rejection. This surveillance can be performed via frequent biopsy or a gene expression blood test known as AlloMap Molecular Expression Testing. Typically, biopsy is performed immediately post-transplant and then AlloMap replaces it once the patient is stable. The transition from biopsy to AlloMap can occur as soon as 55 days after the transplant.