2007

Increasing Success of Lung Transplantation

Points to Remember

• Lung transplantation remains an effective option for end-stage idiopathic pulmonary fibrosis and emphysema.
• Conditions for which lung transplantation is performed have been expanded in specialized centers such as Mayo Clinic and now include pulmonary hypertension, cystic fibrosis, and obliterative bronchiolitis.
• Distribution of donor lungs now occurs by a lung allocation score that has decreased recipient waiting time.
• Long-term lung transplant patient survival rates at the Mayo Clinic Transplant Center exceed the national average.
  

Traditional Indications for Lung Transplantation

Lung transplantation is considered for patients with end-stage and life-threatening lung diseases. Idiopathic pulmonary fibrosis and emphysema are the 2 leading indications for lung transplantation in the United States. Other conditions that may benefit from lung transplantation are cystic fibrosis and other severe forms of bronchiectasis that require bilateral lung transplantation.

To be approved for lung transplantation, patients should meet most of the following selection criteria:

• Age <65 years
• Healthy body weight (no obesity or cachexia)
• Medically refractory lung disease
• No serious cardiac, hepatic, or renal diseases
• Ability to follow a complex medical program
• HIV negative
• No smoking, no alcohol or other drug abuse
• No osteoporosis
• No long-term corticosteroid use

Additional Indications

Other diagnoses are increasingly and cautiously being added at advanced transplant centers. Patients with end-stage pulmonary hypertension may also be candidates for lung transplantation. Mayo Clinic is one of the few centers that has historically specialized in the care of pulmonary hypertension and is a center of excellence for these patients.

Cystic fibrosis is a genetic disease characterized by recurrent lung infections and severe bronchiectasis. Cystic fibrosis, due to the nature of the disease, requires bilateral lung transplantation. Although cystic fibrosis often involves the pancreas and gastrointestinal tract, leading to diabetes and malnutrition, outcomes can be excellent after lung transplantation.

At select transplant centers, patients with scarring diseases of small airways, such as obliterative bronchiolitis, are also considered for lung transplantation. This disease can occur spontaneously but is encountered increasingly after bone marrow transplantation. Mayo Clinic Transplant Center specialists have developed successful postoperative protocols for patients with special needs such as these.

When to Refer

Referral of a patient for consideration of lung transplantation is appropriate at any time in a patient's illness, and the medical appointments generally take about 1 week. However, referral is most effective when it is evident that a patient is no longer responding to medical therapy. Evaluation and selection for lung transplantation are highly individualized. In 2005, a lung allocation score (LAS) was introduced for the prioritization of potential recipients on the waiting list. The LAS is based on a formula designed to identify those patients most at risk without transplant and most likely to benefit from surgery. Since the LAS was initiated, average times on the waiting list have decreased, and this shortened waiting time clearly benefits the sickest patients. While patients are on the waiting list, Mayo Clinic lung transplant specialists are actively involved in their care, both to enhance their functional status while waiting and to improve the chance of successful transplantation. With this active management of lung transplantation candidates, Mayo Clinic has repeatedly had the lowest waitlist mortality among US lung transplant programs.

Lung Transplant Risks and Benefits at a Glance

Among transplantable organs, lungs have relatively high potential for complications, including infection and rejection. However, overall outcomes, especially early after the transplant procedure, are improving at all US transplant centers. During the past 10 years, the national 1-year survival rate for lung transplant recipients has improved from approximately 75% to 80%-85%. Mayo Clinic's 1-year survival rate is 86%.

• Improved survival is largely the result of advances in surgical techniques, transplanted organ preservation, and postoperative care.
• The adverse effects of immunosuppressive drugs or other complications still limit long-term outcomes. In general, infection or acute and chronic rejection reduces survival rates by 5% to 10% per year after transplantation, a trend that has improved only modestly in recent years. Mayo Clinic's 3-year survival rate is similar to the national rate at approximately 65%.
• A majority of patients develop some degree of obliterative bronchiolitis between 1 and 5 years after receiving a transplant. The cause is most likely an immune-related response in the transplanted organ, manifested by gradual decline in lung function.