Lung transplantation is the surgical removal of a healthy lung or part of a lung from a living person and then its transfer into someone whose lungs no longer function. Heart-lung transplantation is the surgical removal of both the heart and lungs from a recently deceased person and then their transfer into someone whose heart and lungs no longer function.
(See also Overview of Transplantation and Heart Transplantation.)
Lung transplantation is done for people whose lungs no longer function. Most recipients are people who have one of the following disorders:
Severe chronic obstructive pulmonary disease (COPD)
Primary pulmonary hypertension
One or both lungs can be transplanted. When a lung disorder has also damaged the heart, one or both lungs and a heart may be transplanted at the same time. Single and double lung procedures are about equally common and are at least 8 times more common than heart-lung transplantation.
Because preserving a lung for transplantation is difficult, lung transplantation must be done as soon as possible after a lung has been obtained.
The percentage of people who survive after receiving a lung transplant is
At 1 year: Over 80%
At 5 years: Over 50%
A heart-lung transplant is done for
Certain heart abnormalities that are present at birth (for example, Eisenmenger syndrome)
A severe lung disorder that has also caused heart damage
Both donors and recipients undergo pretransplantation screening. This screening is done to be sure that the organ is healthy enough for transplantation and the recipient does not have any medical conditions that would prohibit transplantation.
Donors
Lung transplants can come from a living donor or from someone who has recently died. Donors must be under 65 years old, have never smoked, and not have a lung disorder. The size of the donor's and recipient's lungs must match.
Donation from a living donor is possible because the donor can live with one healthy lung.. People cannot donate more than one entire lung and usually donate only one part of a lung (a lobe). A person who has died can provide both lungs or the heart and lungs.
Procedure
Before the procedure, the recipient is often given antibiotics to prevent infections from developing.
Through an incision in the chest, the recipient’s lung or lungs are removed and replaced with those of the donor. The blood vessels to and from the lung (pulmonary artery and pulmonary vein) and the main airway (bronchus) are connected to the transplanted lung or lungs. In a heart-lung transplant, the recipient's damaged heart is also removed and replaced with the donor heart.
The operation takes 4 to 8 hours for one lung and 6 to 12 hours for two lungs. A heart and lung may be transplanted at the same time. The hospital stay after these operations is usually 7 to 14 days.
Drugs to inhibit the immune system (immunosuppressants), including corticosteroids, are started the day of transplantation. These drugs can help reduce the risk that the recipient will reject the transplanted lung.
Complications
Transplantation can cause various complications.
Infections
The risk of infection is high after lung transplantation because of the following:
The lungs are continually exposed to air, which contains bacteria and other microorganisms that can cause infections.
Immunosuppressants, which are needed to help prevent rejection of the transplanted lung, make the body less able to defend against infections.
Poor healing
The site at which the airway is attached sometimes heals poorly. Scar tissue may form, narrowing the airway, reducing air flow, and causing shortness of breath. Treatment of this complication consists of widening (dilating) the airway—for example, by placing a stent (a wire-mesh tube) in the airway to hold it open.
Rejection
Even if tissue types are closely matched, transplanted organs, unlike transfused blood, are usually rejected unless measures are taken to prevent rejection. Rejection results from an attack by the recipient's immune system on the transplanted organ, which the immune system recognizes as foreign material. Rejection can be mild and easily controlled or severe, resulting in destruction of the transplanted organ.
Rejection of a lung transplant can be difficult to detect, evaluate, and treat. Doctors use a flexible viewing tube (bronchoscope) to periodically examine the airways and remove a sample of lung tissue. This procedure helps them identify rejection and check for infections.
Most people who receive a lung transplant develop some symptoms of rejection within a month of transplantation. Symptoms include fever, shortness of breath, cough, and fatigue. Fatigue develops because the transplanted lung cannot provide enough oxygen to supply the body.
In up to one half of people, symptoms of chronic rejection gradually develop more than a year after transplantation. In such cases, doctors usually detect scar tissue that has formed in the small airways and gradually blocked them.
