The heart and lung transplantation involves a coordinated triple operative procedure consisting of procurement of a donor heart-lung block, excision of the heart and lungs of the recipient, and implantation of the heart and lungs into the recipient. A heart and lung transplantation refers to the transplantation of one or both lungs and heart from a single cadaver donor.
Combined heart and lung transplantation is intended to prolong survival and improve function in patients with end-stage cardiac and pulmonary diseases. The majority of recipients have Eisenmenger syndrome (37%), followed by idiopathic pulmonary artery hypertension (28%) and cystic fibrosis (14%). Eisenmenger syndrome is a form of congenital heart disease in which systemic-to-pulmonary shunting leads to pulmonary vascular resistance. Eventually, pulmonary hypertension may lead to a reversal of the intracardiac shunting and inadequate peripheral oxygenation, or cyanosis. (1)
However, the total number of patients with Eisenmenger syndrome has been declining in recent years, as a result of corrective surgical techniques and improved medical management of pulmonary hypertension. Heart-lung transplants have not increased appreciably for other indications either, as it has become more common to transplant a single or double lung and maximize medical therapy for heart failure, rather than perform a combined transplant. In these, patient survival rates are similar to lung transplant rates. Bronchiolitis obliterans syndrome is a major complication; 1-, 5-, and 10-year patient survival rates are 68%, 50%, and 40%, respectively. (1)
In 2011, 25 adults and 2 children under 18 years of age received heart/lung transplants in the United States. As of the end of September 2012, there were 51 patients on the waiting list for heart-lung transplants. (2)
Potential contraindications for heart-lung transplant, subject to the judgment of the transplant center, include:
- Known current malignancy, including metastatic cancer
- Recent malignancy with high risk of recurrence
- Untreated systemic infection making immunosuppression unsafe, including chronic infection
- Other irreversible end-stage disease not attributed to heart or lung disease
- History of cancer with a moderate risk of recurrence
- Systemic disease that could be exacerbated by immunosuppression
- Psychosocial conditions or chemical dependency affecting ability to adhere to therapy
When the candidate is eligible to receive a heart in accordance with United Network for Organ Sharing (UNOS) guidelines for cardiac transplantation, the lung(s) shall be allocated to the heart-lung candidate from the same donor. When the candidate is eligible to receive a lung in accordance with the UNOS Lung Allocation System (LAS), the heart shall be allocated to the heart-lung candidate from the same donor if no suitable Status 1A isolated heart candidates are eligible to receive the heart. Status 1A is described below. (3)
The United Network for Organ Sharing (UNOS) prioritizes donor thoracic organs according to the severity of illness as follows (2):
A patient is admitted to the listing transplant center hospital and has at least one of the following devices or therapies in place:
- Mechanical circulatory support for acute hemodynamic decompensation that includes at least one of the following:
- Left and/or right ventricular assist device implanted;
- Total artificial heart;
- Intra-aortic balloon pump; or
- Extracorporeal membrane oxygenator (ECMO);
- Mechanical circulatory support;
- Mechanical ventilation;
- Continuous infusion of inotropes and continuous monitoring of left ventricular filling pressures;
- If criteria a, b, c, and d are not met, such status can be obtained by application to the applicable Regional Review Board.
A patient has at least one of the following devices or therapies in place:
- Left and/or right ventricular device implanted, or
- Continuous infusion of intravenous inotropes.
A patient who does not meet Status 1A or 1B is listed as Status 2.
Status 7 patients are considered temporarily unsuitable to receive a thoracic organ transplant.