The decision to perform a single or double lung transplantation depends mainly on the type of lung disease the patient has. If the disease involves infection (e.g., cystic fibrosis), both lungs must be transplanted. This is because the anti-rejection medications (immunosuppressants), which are necessary for all transplant patients, suppress the immune system and, therefore, increase risk of infection.
However, if the lungs are damaged but not infected (e.g., emphysema), one lung can be left in place. Patients with pulmonary hypertension do better if they have a double lung transplant. Age can also be a factor. Older adults tend to have more problems following a double lung transplant because it is a longer and more complex surgery. Therefore, they do better with a single lung transplant, when possible.
In the case of a single lung transplant, the lung that is most damaged is the one that is transplanted. This is determined by a test called ventilation-perfusion scan, which shows the blood flow to different areas of the lungs. Areas that indicate less blood flow are the ones with the greater damage.
While the patient is under general anesthesia, the surgeon makes an incision in the chest. If it is a single lung transplant, the incision is made on the right or left side, depending on which lung is being replaced. A double (bilateral) transplant requires an incision across the chest, beneath the breast area.
The donor organ, which has been chilled to preserve it until transplantation, must be transplanted within six hours after being removed from the donor. As soon as the new lung(s) arrives in the operating room, the recipient's lung is immediately removed and the donor organ is placed in the chest cavity. When it is a double transplant, the organ with the poorest function is removed first and replaced.
Once the new organ is in place, the surgeon connects the pulmonary artery, pulmonary vein and the main airway (bronchus) of the donor organ to the patient's vessels and airway. Drainage tubes are inserted to drain air, fluid, and blood out of the chest for several days to allow the lungs to fully re-expand.
The surgery can take from four to eight hours, depending on whether it is a single or double lung transplantation and if complications occur.