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

Most frequent post lung transplantation challenges include issues related to immunosuppressive drug use, graft dysfunction and bronchial stenosis. However, data on less frequent complications-particularly those affecting the pulmonary vasculature-remain limited. This study aimed to evaluate the incidence, clinical features, and impact on survival of symptomatic pulmonary vascular complications following lung transplantation.

We conducted a retrospective study involving 550 patients who underwent lung transplantation between 2012 and 2022.

Within this cohort, 63 (11.5%) patients experienced pulmonary vascular complications, comprising pulmonary vein obstruction in 20 (3.8%) patients, pulmonary arterial obstruction in 4 (0.8%) patients, pulmonary embolism in 33 (6.0%) patients, and pulmonary hypertension in 6 (1.1%) of them. Vascular obstructions 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, compared with 58.3% in those with pulmonary vein obstruction, 25.0% in those with pulmonary arterial obstruction, 86.9% in patients with pulmonary embolism (Log-rank, p = 0.001). Clinical variables associated with survival were evaluated using multivariate analysis, revealing a significantly poorer prognosis in the context of surgical complications, with a hazard ratio of 3.44 (95% CI: 1.80-6.35; p < 0.001).

Post-surgical vascular obstruction is a rare yet severe complication that can lead to early mortality after lung transplantation. By contrast, the incidences of pulmonary embolism and pulmonary hypertension are similar to those observed in the general population.