Effects of exogenous surfactant instillation in clinical lung transplantation: a prospective, randomized trial

Despite the introduction of low potassium-based preservation strategies for clinical lung transplantation, relevant early graft dysfunction occurs in up to 20% of cases after lung transplantation. This was found to be frequently associated with postreperfusion surfactant dysfunction. We performed a randomized, prospective study investigating the effect of exogenous surfactant instillation into human donor lungs on posttransplant surfactant function and on clinical outcome.

Exogenous surfactant was instilled into 15 donor lungs before retrieval via bronchoscopy. Bronchoalveolar lavage fluids were taken before instillation as well as 24 hours after transplantation. Surfactant function, phospholipids, and protein content in bronchoalveolar lavage fluids were assessed and clinical data prospectively recorded. Pulmonary function testing was performed 4 weeks after lung transplantation. Additionally, the best forced expiratory volume in 1 second was determined within the first year after lung transplantation. The control group consisted of 14 patients receiving donor lungs without surfactant instillation in randomized order. Pulmonary function test results were further compared with those of 154 consecutive recipients of bilateral lung transplants, which were not involved in the study (historical control).

No deaths occurred during the first year after lung transplantation. Surfactant function in donor lungs was within normal ranges before harvest. In the control group, surfactant function was markedly impaired after reperfusion. This was significantly improved by surfactant substitution. Protein content of the bronchoalveolar lavage fluid in the surfactant group was significantly lower, indicating less leakage through the alveolocapillary membrane. Forced expiratory volume in 1 second after 4 weeks was significantly higher in the surfactant group than in either control group (P = .034 and .01, respectively). Interestingly, the best forced expiratory volume in 1 second during the first year after lung transplantation was significantly higher in both control groups compared with forced expiratory volume measured in examinations 4 weeks after lung transplantation (P = .01). The best forced expiratory volumes in 1 second of control patients were comparable with those in surfactant lungs 4 weeks after transplant.

This study indicates a protective effect of exogenous surfactant instillation to donor lungs before retrieval on post-lung transplantation surfactant function and on early clinical outcome. This approach may help to improve the outcome after lung transplantation in the future.