Lung transplantation

Abstract

Lung transplantation is an accepted treatment option for end-stage lung disease in selected patients. Over the past 40 years, more than 40,000 transplants have been performed worldwide. Emphysema, pulmonary fibrosis, cystic fibrosis, and primary pulmonary hypertension are the most common indications. This surgical treatment is becoming increasingly successful with better early and long-term survival rates. However, challenges such as organ shortage, primary graft dysfunction, late graft dysfunction, and long-term immunosuppression-related morbidity still persist. This review will discuss current clinical lung transplantation and future directions.The first successful lung, heart, and heartlung transplantations were performed in dogs by Russian physiologist and surgeon Vlademir Demikhov, demonstrating the technical feasibility of these procedures. In 1949, Henry Metras described important technical concepts such as preserving the left atrial cuff for pulmonary venous anastomosis and preserving the bronchial arterial system to prevent airway anastomotic problems. However, this technique did not gain widespread popularity.In 1963, James Hardy performed the first human lung transplantation. The recipient did not survive beyond 18 days and died from renal failure. This initial lung transplantation attempt sparked an intense wave of activity in the field of experimental and clinical lung transplantation. However, the results were highly disappointing. Approximately 20 years after the first attempt, a total of 38 transplants were performed, and only 2 patients survived for 6 and 10 months. Most patients who survived for more than 10 days died from bronchial anastomotic complications.In 1981, Bruce Reitz and Norman Shumway performed the first successful heart and lung transplantation at Stanford University, paving the way for contemporary clinical lung transplantation outcomes.In 1983, Dr. Cooper and his team performed the first successful single lung transplantation for idiopathic pulmonary fibrosis (IPF) at Toronto General Hospital. This was the first long-term survival after lung transplantation. The recipient survived for 7 years.In 1992, Prof. Weder performed the first successful lung transplantation in Zurich. This was a unilateral right lung transplantation in a patient with emphysema.Indications for lung transplantation have expanded over time and encompass various spectrum of parenchymal and vascular diseases. Chronic obstructive pulmonary disease (COPD) remains the most common indication for transplantation (31%). The second most common indication comprises the broad category of interstitial lung disease or pulmonary fibrosis (30%). Cystic fibrosis (16%) is the third most common indication. Idiopathic pulmonary arterial hyper- tension (PAH) (2.9%) represents a low proportion. The referral and listing criteria for transplantation for the main indications are shown in Table 1. The list of absolute contraindications is provided in Box 1. Due to increasing experience, single relative contraindications are generally not considered prohibitive, especially if they can be treated before or after transplantation. The accumulation of relative contraindications is usually prohibitive for transplantation. Patients with single organ failure with respiratory failure requiring extracorporeal membrane oxygenation (ECMO) or mechanical ventilation or tracheostomy are no longer considered prohibitive relative contraindications (Box 2).Box 1. Absolute contraindications for transplantation- Cancer within the past 2 years. Generally, a disease-free period of 5 years may be appropriate.- Untreatable advanced dysfunction of another major organ system (e.g., heart, liver, or kidney).- Untreatable chronic extrapulmonary infection, including chronic active viral hepatitis B, hepatitis C, and human immunodeficiency virus.- Significant chest wall/ spinal deformity.- Documented noncompliance or inability to adhere to medical treatment.- Untreatable psychiatric or psychological condition, inability to adhere to or cooperate with medical treatment.