A lung transplant replaces a patient’s severely diseased lungs with healthy lungs from a deceased donor. This complex surgical procedure restores respiratory function and improves the quality of life for individuals with end-stage pulmonary disease. The process is highly regulated, beginning with rigorous selection and continuing with lifelong medical management to ensure the organ’s success.
Candidate Evaluation and Listing
Before consideration for a transplant, a comprehensive evaluation determines the patient’s medical and psychosocial suitability. This involves extensive testing to assess all major organ systems and check for co-existing conditions that might compromise the surgery’s outcome. Patients must demonstrate the resilience necessary to adhere to the demanding pre- and post-transplant care plan, including strict medication schedules and rehabilitation protocols.
Once approved, the patient is placed on the national waiting list and assigned a Lung Allocation Score (LAS). This score, ranging from 0 to 100, prioritizes patients based on the urgency of their need and the predicted benefit from a transplant. The calculation incorporates factors such as age, body mass index, oxygen dependence, and measures of heart and kidney function.
A higher LAS indicates greater medical urgency or a better chance of post-transplant survival, moving the patient higher in the allocation queue. This system directs the limited supply of donor organs toward patients most likely to benefit. The patient remains on the list, with their score periodically updated, until a suitable donor organ becomes available.
The Transplant Procedure
The surgical procedure begins once a viable donor organ is secured and the recipient is prepared. The operation’s complexity depends on whether a single or double-lung transplant is performed. A single-lung transplant typically takes six to eight hours, while a double-lung transplant can take eight to 12 hours. Incisions vary: a lateral incision is used for a single-lung procedure, and a horizontal “clamshell” incision is used for a double-lung transplant.
During the operation, the patient is often connected to a cardiopulmonary bypass machine, which temporarily takes over the function of the heart and lungs by circulating and oxygenating the blood. This allows the surgical team to work on a still field. The diseased lung is removed, and the new donor lung is positioned within the chest cavity.
The surgeon connects three main structures to establish function in the new organ: the main airway (bronchial tube), the pulmonary artery (carrying deoxygenated blood to the lung), and the pulmonary veins (carrying oxygenated blood back to the heart’s left atrium). Once these connections are complete, the new lung is slowly re-inflated and reperfused with the patient’s blood before the chest is closed.
Immediate Post-Surgical Recovery
The patient is transferred directly to the Intensive Care Unit (ICU) for monitoring immediately after the transplant. The primary focus is managing Primary Graft Dysfunction (PGD), a reperfusion injury that causes the new lung to swell and function improperly. PGD typically manifests within the first 72 hours and requires supportive care, including lung-protective ventilation or extracorporeal membrane oxygenation (ECMO) in severe cases.
The medical team works to stabilize the patient, aiming for extubation—the removal of the breathing tube—within the first two to three days for uncomplicated cases. Early mobilization is a critical goal, with physical therapy starting in the ICU to prevent muscle wasting and improve strength. This phase ensures the new organ is functioning and surgical incisions are healing.
As the patient stabilizes, they move out of the ICU into a step-down unit. The initial hospital stay generally lasts a few weeks. During this time, the patient and caregivers are educated on wound care, nutrition, and the complex medication regimen. Patients are discharged once they meet physical milestones, such as walking a certain distance and managing their medications.
Lifetime Immunosuppression and Monitoring
The immune system recognizes the transplanted lung as foreign and will attack it, leading to rejection. To prevent this, the recipient must adhere to a lifelong regimen of immunosuppressive drugs that dampen the immune response. The maintenance protocol typically involves a combination of medications, such as a calcineurin inhibitor, an antiproliferative agent, and a corticosteroid, which suppress different components of the immune cascade.
This medication protocol introduces the risk of infection and other side effects, requiring a careful balance to prevent rejection without over-suppressing the immune system. A long-term concern is chronic rejection, often presenting as Bronchiolitis Obliterans Syndrome (BOS). BOS involves progressive inflammation and scarring of the small airways, leading to airflow obstruction and a decline in lung function.
Long-term survival depends on monitoring, including frequent clinic visits, regular blood tests, and pulmonary function tests. Surveillance bronchoscopies, often involving a lung biopsy, are performed periodically to inspect the airways and detect early signs of rejection or infection. This ensures timely adjustment of immunosuppression therapy. BOS affects approximately half of all recipients within five years, making continuous surveillance mandatory.