Pulmonary vascular complications following lung transplantation: characteristics, incidence and survival

Lung transplantation remains the only curative treatment for patients with chronic end-stage respiratory failure. The main post-transplantation challenges include issues related to immunosuppressive drug use, graft dysfunction and bronchial stenosis. Little is known about less common complications that may follow lung transplantation. The objective of the present study was to assess the incidence, clinical characteristics and impact on survival of symptomatic pulmonary vascular complications following lung transplantation. We conducted a retrospective bicentric study involving 550 patients who underwent lung transplantation between 2012 and 2022. Among this cohort, 65 patients (11.8%) experienced pulmonary vascular complications including pulmonary embolism in 33 (6%) patients, pulmonary hypertension in 8 (1.5%), pulmonary venous stenosis in 20 (3.6%) and pulmonary arterial stenosis in 4 (0.7%). Vascular stenosis were diagnosed after a median time of 4 days [1-9 days] post-surgery. The one-year survival rate after transplantation was 83.2% for patients without pulmonary vascular complications, 86.9% for those with pulmonary embolism, 58.3% in case of pulmonary venous stenosis and 25.0% in case of pulmonary arterial stenosis (Log-rank, p=0.001). Clinical variables were assessed for their association with survival using multivariable analysis. A statistically significant difference in survival was observed in case of surgical vascular complications with a hazard ratio of 3.44 (95% CI: 1.8-6.35, p<0.001). In conclusion, post-surgical vascular stenosis are a rare but severe complication, which may cause early mortality following lung transplantation.