Definition & Overview
Heart and lung transplant is a major surgical procedure that replaces a patient’s diseased heart and lungs with those of a recently deceased donor. It is a rarely performed procedure party due to lack of enough suitable donors and because it places a major strain on the recipient’s body. It is also a high-risk surgery that is associated with a number of serious complications.
The procedure is considered when all other treatment options have failed. It can be recommended for patients with end-stage heart and lung disease. These include pulmonary hypertension and congenital heart disease. It is important that the patient is in relatively good condition and does not have other serious medical problems to be considered for this procedure.
Patients who qualify for the operation are included on the transplant list and have to wait until suitable donor organs become available. The waiting time can be months to several years.
A heart-lung transplant is very expensive and requires the expertise of a multidisciplinary surgical team. To increase the chances of success and to ensure patient safety, it must be carried out in a well-established hospital with a good reputation in the field of heart-lung transplant.
Who Should Undergo and Expected Results?
A heart and lung transplant, or cardiopulmonary transplantation, is indicated for patients with end-stage lung and heart disease. These conditions include acute pulmonary vascular disease, cystic fibrosis, and chronic obstructive lung diseases.
Other indications for this procedure are:
- Primary pulmonary hypertension
- Alpha1 antitrypsin deficiency
- Eisenmenger syndrome
- Idiopathic pulmonary fibrosis
Due to the serious risks associated with the surgery, a heart-lung transplant is not the first treatment prescribed to patients with the conditions mentioned above. Initially, they are provided with medications and advised to make lifestyle changes that may help improve their conditions. If there is no improvement, surgical procedures are then considered. A heart-lung transplant is recommended if all other treatment methods have failed.
The survival rate for heart-lung transplant patients is higher now compared before. The 1-year survival rate is 65% while 5-year survival rate is 40%. Early mortality is typically attributed to acute allograft failure, surgical losses, organ rejection, and obliterative bronchiolitis.
How is the Procedure Performed?
The procedure starts with harvesting the heart and lungs from a recently deceased patient. This part involves cardiectomy (removal of the heart) and pneumonectomy (the surgical removal of a lung). The same procedures are performed on the recipient before the organ donors are transplanted.
The procedure is performed under general anaesthesia. A long vertical incision (median sternotomy) is made in the breastbone to open the chest and access the heart and lungs. A bone saw is used to cut the breastbone open.
To keep the chest open, breast spreaders are used. Surgeons conduct cardiopulmonary bypass using a machine that temporarily replaces the function of the heart and lungs during the procedure.
The surgeons remove the lungs and heart and make sure they cut the blood vessels close enough to the organs so that they will not have a hard time connecting the new organs to the recipient’s blood vessels. Once the original heart and lungs are removed, the new ones are transplanted into the patient’s body.
As soon as the organs are attached to the recipient, the implanted organs start to warm up and acquire the body temperature of the recipient. Soon, the lungs start to inflate and the heart starts beating. When the organs are working well, the surgeons will close the chest and sew it back together.
The 1960s and 1970s marked the start of three heart-lung transplant attempts in humans. While it looked promising, all the patients died with the longest survival period recorded at only 23 days.
In the 1980s, a group of surgeons at Stanford University carried out the same procedure in three patients. All the recipients developed pulmonary vascular disease and one of them died immediately. However, the other two had surprising recovery and survived for five years after the operation.
Surgeons believed that the introduction of the immunosuppressant drug cyclosporine was the key to the success of the procedure as it prevented the recipients’ immune system from attacking the tissues of the newly transplanted organs.
Patients will need to stay in intensive care unit for a week for observation following the procedure. If no complications manifest within the waiting period, the patient is allowed to return home.
Patients are required to visit the hospital and check with their doctor regularly. Immunosuppressant drugs (anti-rejection) are given to prevent the immune system from attacking the transplanted organs. Antibiotics are also given to prevent bacterial infection.
Possible Risks and Complications
Organ rejection is one of the most serious risks associated with the procedure. This could be dealt with immunosuppressant but there are cases when the body reacts so radically that it totally rejects the new organs even with the use of anti-rejection drugs.
Other patients in the past also suffered from bronchiolitis obliterans syndrome (a form of common lung rejection) while some experienced narrowing of the heart arteries. This condition can be treated with minimally invasive cardiac allograft vasculopathy or coronary artery vasculopathy (CAV).
Other risks and possible complications include the following:
Bleeding – Bleeding can happen abruptly as the areas where cardiectomy and pneumonectomy are performed have many blood vessels.
Graft failure. Though numerous tests are done to check the compatibility of the living tissue of the donor with that of the recipient, some things just don’t work out right when the actual transplant happens. The recipient may totally reject the new organ or the whole process may fail due to other unknown reasons.
Damage to nearby nerves. Two of the nerves that are present in the heart and lung area are recurrent laryngeal nerve (RLN) and phrenic nerve. The recurrent laryngeal nerve branches out from cranial nerve X (vagus nerve) and supplies nerves to the larynx muscles (voice box). This nerve is very important because it connects the brain to that part of the neck that allows us to speak.
Phrenic nerve, on the other hand, originates in the neck. It goes down to traverse the lungs and heart before reaching the diaphragm. The procedure could potentially irritate, injure, or damage these nerves. The damage could start a slew of new health problems for the patient.
Trulock EP. Lung and heart-lung transplantation: overview of results. Semin Respir Crit Care Med. 2001 Oct. 22(5):479-88.
Belperio JA, Lake K, Tazelaar H, et al. Bronchiolitis obliterans syndrome complicating lung or heart-lung transplantation. Semin Respir Crit Care Med. 2003 Oct. 24(5):499-530.
Arora S, Gude E, Sigurdardottir V, Mortensen SA, Eiskjær H, Riise G, et al. Improvement in renal function after everolimus introduction and calcineurin inhibitor reduction in maintenance thoracic transplant recipients: the significance of baseline glomerular filtration rate. J Heart Lung Transplant. 2012 Mar. 31(3):259-65.