Any kind of heart transplantation is done as a last resort measure. This means no other medical or surgical procedures will improve the patient’s heart condition. There are two different types of heart transplant procedures. The most common one is an orthotopic procedure in which the patient’s heart is replaced with a donor heart. The second and rarer procedure is the heterotopic transplant. It is also known as a “piggyback” transplant since the donor heart is essentially piggy backed to the patient’s own heart. It is only used in special situations and is only performed at a handful of transplantation centers.
The first heterotopic human heart transplant was performed in 1974 by Dr. Christiaan Barnard. He was a South African doctor who also performed the first orthotopic transplant. During a heterotopic heart transplant, the heart of the patient is not removed before implanting the donor heart. The donor heart is positioned in the body so the chambers and blood vessels of both hearts can be connected to form a ‘double heart’. The most important part of the operation is to line up the two left atria so they can be merged.
To begin the procedure, the patient is giving anesthesia. They are then hooked up to a bypass machine that will keep oxygenated blood flowing through their body. Next, the chest cavity of the patient is opened up and the patient’s heart and the donor heart are joined. Once the blood flow to the heart is restored, the donor heart should start beating. The chest cavity is then sewn up and the patient is moved to ICU where they are monitored by the transplant team.
Eligibility for a Heterotopic Transplant
There are three reasons why a patient would undergo a heterotopic transplant instead of an orthotopic one. One reason is that the donor heart is too small for the recipient’s body and would not be able to function by itself. The second reason is that the donor has a weak heart and needs the recipient’s heart to help it function. The third reason is that the recipient suffers from pulmonary hypertension (high blood pressure in the pulmonary artery).
The advantages to having a heterotopic transplant versus an orthotopic transplant are:
- The heterotopic procedure allows for the possibility of the patient’s heart to recover with the help of the donor heart.
- The recipient still has a heart if the donor heart is rejected.
- The patient’s original heart assists the donor heart in healing from any injury sustained during the transplant procedure.
The disadvantages of a heterotopic transplant are:
- There is a risk of infection in the original heart.
- There can be continuing angina from the original heart muscle.
- The operation is risky and more difficult because the heart is opened four times to make all the necessary connections.
The heterotopic heart transplant makes it possible for some people to receive a heart transplant when they otherwise wouldn’t be able to. This procedure gives them a donor heart to help their own heart pump and work more efficiently.