Lung transplantation is a complex medical intervention reserved for individuals with end-stage lung disease when all other therapies have failed to provide adequate quality or length of life. The decision to pursue this surgery requires a structured, multi-phase evaluation designed to ensure the patient can survive the procedure and thrive afterward. The journey, from initial referral to being placed on the waiting list, is a rigorous assessment of medical urgency and the projected benefit of the transplant.
Initial Referral and Basic Eligibility Criteria
The first step is a referral, typically initiated by a primary pulmonologist, to a specialized lung transplant center. Centers only consider patients whose life expectancy is projected to be less than two years without a transplant, but who have a high probability of surviving the procedure and the subsequent 90 days.
A patient must demonstrate the absence of active malignancies, generally requiring being cancer-free for at least five years (excluding some localized skin cancers). Severe dysfunction of other major organ systems, such as end-stage liver or kidney disease, typically results in immediate disqualification unless a multi-organ transplant is planned. Furthermore, patients cannot have an active infection or be recent users of illicit substances or tobacco, often requiring documented abstinence for at least six months.
Chronological age alone is no longer an absolute exclusion for candidacy. Modern assessment focuses more on physiological age, meaning a healthy, active older patient may be a better candidate than a frail younger patient with multiple serious co-existing conditions. The transplant team must assess the patient’s physical reserve to endure the surgery and the intensive recovery period.
The Comprehensive Pre-Transplant Evaluation
Once initial criteria are met, the candidate moves to a comprehensive, multi-day evaluation designed to provide the transplant committee with an in-depth risk profile. This intensive assessment involves surgeons, pulmonologists, social workers, dietitians, and financial coordinators. The evaluation is broadly organized into medical testing, psychosocial assessment, and logistical review.
Medical testing focuses particularly on cardiac health, as the heart must tolerate the stress of major surgery and post-transplant blood flow changes. This includes procedures like right heart catheterization to measure pulmonary pressures and coronary angiography to rule out significant coronary artery disease. Pulmonary function tests, including a six-minute walk test, quantify the patient’s current functional limitation and oxygen requirements.
Infectious disease screening involves detailed blood tests for viruses like HIV and hepatitis, and checking for colonization with multi-drug-resistant bacteria. The psychosocial assessment evaluates the patient’s mental health, motivation, and the strength of their personal support network. This support is crucial for adherence to lifelong post-transplant medication regimens and follow-up care.
The logistical and financial review confirms the patient’s ability to manage the responsibilities following surgery. This involves verifying insurance coverage for the procedure and the expensive, lifelong immunosuppressive medications required to prevent organ rejection. The team also assesses the patient’s ability to live near the center or relocate quickly when an organ becomes available, and the reliability of their support system for transportation and daily care.
Understanding the Listing Decision and Allocation System
The final listing decision is made by a multidisciplinary review board that analyzes all data collected during the pre-transplant evaluation. The board determines if the risks of surgery are outweighed by the potential survival benefit and if the patient is prepared for the complex post-transplant lifestyle. If approved, the patient is formally added to the national waiting list maintained by the Organ Procurement and Transplantation Network (OPTN), managed by the United Network for Organ Sharing (UNOS).
Priority is determined by the Composite Allocation Score (CAS), a numerical formula implemented in 2023 to replace the older Lung Allocation Score (LAS). The CAS is a dynamic score, ranging from 0 to 100, which quantifies a candidate’s medical urgency and expected survival benefit. The core principle is to prioritize organs for the sickest patients who are statistically most likely to have a successful long-term outcome.
The score is calculated using objective medical factors. These factors include the patient’s diagnosis, dependence on mechanical ventilation or high levels of oxygen, current kidney and heart function, and physical endurance measures. A higher CAS number indicates a greater priority for receiving a donor lung, ensuring the limited supply goes to those who most urgently need them.
Maintaining Active Status While Waiting
Being listed requires the patient to maintain an “active” status through continuous effort and compliance. Patients must engage in mandatory pre-transplant pulmonary rehabilitation to build and preserve muscle strength, which is linked to better outcomes after surgery. The goal is to keep the body physically fit, often requiring a body mass index (BMI) to be maintained within a specific range, typically between 17 and 30.
Regular follow-up appointments, often every two to three months, are required to update medical records and ensure all tests remain current. Any significant change in health status, such as a new infection or hospitalization, must be reported immediately to the transplant coordinator. Failure to comply with the mandated testing schedule or prescribed regimen can result in the patient being placed on “inactive” status, making them temporarily ineligible for an organ offer.
The patient must be in a state of constant readiness for the transplant call, able to travel to the center quickly once a donor organ becomes available. This requires keeping the transplant team updated on travel plans and ensuring contact information is always current. Maintaining this level of preparedness, compliance, and physical health is the patient’s primary responsibility while awaiting the call.