9-46: Lung Transplantation

INTRODUCTION

Lung transplantation is a therapeutic option for patients with end-stage lung disease who have not responded to other therapies. The full topic is beyond the scope of this text, therefore only issues related to candidate selection and post-transplant care will be discussed.

CANDIDATE SELECTION

Patients should be considered for lung transplantation if they have advanced, progressive lung disease despite appropriate medical therapy. The most common indications are interstitial lung disease, COPD, cystic fibrosis, and pulmonary arterial hypertension. The International Society of Heart and Lung Transplantation has produced guidelines for candidate selection; broadly speaking, the ideal candidate has a high (greater than 50%) risk of dying within 2 years without lung transplantation, has minimal other comorbidities, is very likely to survive transplantation, and has good social support. Contraindications are numerous and include obesity (generally BMI greater than 30 is a relative, and greater than 35 a nearly absolute, contraindication), active smoking or substance abuse, uncontrolled infection, active malignancy, significant organ dysfunction (eg, cirrhosis, CKD, heart failure, unrevascularizable coronary disease), and medical noncompliance. Each transplant center has a slightly different selection process, however common practice includes a detailed multidisciplinary evaluation. Patients should ideally be referred to transplant centers before the need for transplantation is emergent.

CARE AFTER TRANSPLANTATION

As with other solid organ transplantation, care of the post–lung transplant patient is particularly concerned with immunosuppression and prophylaxis against infection, as well as with management of the side effects of immunosuppression. Most patients are immunosuppressed with a combination of a calcineurin inhibitor (eg, tacrolimus), a cell-cycle inhibitor (eg, mycophenolate mofetil), and glucocorticoids. Most centers screen for rejection with regular PFTs as well as bronchoscopies and biopsies, particularly in the first 1–2 years after transplantation.

Common complications include acute cellular rejection (treated with intensified immunosuppression), infection, chronic rejection (for which few effective treatments exist), and sequelae of immunosuppression. These include hypertension, dyslipidemia, diabetes mellitus, CKD, osteopenia/osteoporosis, and increased risk of malignancy, especially skin cancers. Post-transplant care thus necessitates close cooperation between the patient’s transplant team and his or her other physicians.

OUTCOMES AFTER TRANSPLANTATION

While lung transplantation can be transformative for those suffering from advanced lung disease, long-term survival remains limited to those receiving kidney or liver transplants. As of the 2021 International Society of Heart and Lung Transplantation Report, median survival after lung transplantation was approximately 7 years. Survival is affected by many variables; two consistent findings have been that survival is improved in double (versus single) lung transplant patients, and in those transplanted for cystic fibrosis (versus other indications).