CANDIDATE SELECTION AND LISTING
Timing for referral and listing is always challenging for lung transplant candidates, particularly with any form of pulmonary hypertension (PH). PH as an indication for lung transplanation highlights the importance of interdisciplinary collaboration between the referring pulmonary hypertension and transplant center teams. As a general rule, patients should be considered for transplantation when they are at high risk of death within 1 to 2 years or have unacceptable quality of life, can survive the wait for organs and the surgery itself and have a high chance of living a near normal life after lung transplantation 7. Patients with severe forms of PH like alveolar capillary dysplasia, pulmonary veno-occlusive disease (PVOD), pulmonary capillary hemangiomatosis and pulmonary vein stenosis, can progress rapidly to respiratory failure, making early referral vital8. Patients with IPAH or other forms of pulmonary vascular disease that meet the following criteria should be referred for evaluation: NYHA functional class III or IV, rapidly progressive disease, and optimized use of targeted pulmonary hypertension treatment (Table 1 ). Early referral gives the lung transplant e and families the opportunity to address barriers identified during evaluation. Contraindications to pediatric lung transplant include conditions that predispose the patient to a poor post-transplant outcome, such as poor adherence to therapy and concomitant organ failure not suitable to transplant 8. Timing of listing should take into consideration waiting time (patient’s blood type and size, local policy regarding priority 9), center’s expertise related to extracorporeal support 10 and the patient’s disease trajectory. Listing should be considered when patients meet the following criteria 7: NYHA functional class III or IV without improvement after 3 months of combination therapy including prostanoids, cardiac index < 2 liters/min/m^2, mean right atrial pressure of > 15 mmHg. However, it has been noted that pediatric patients often have preserved cardiac index and no elevation of right atrial pressure even with advanced disease11. Furthermore, children often have preserved exercise tolerance at a later stage of disease than adults making exercise intolerance potentially too late a marker of severe disease12. Other risk factors that predict poor survival include: significant hemoptysis, pericardial effusion, progressive right heart failure, von Willebrand factor levels of > 240%, elevated uric acid levels, and persistently elevated plasma levels of brain natriuretic peptide > 180 pg/mL 8.