Objective: In spite of the advances in technology and surgical techniques, cardiac surgical operations with the use of cardiopulmonary bypass (CPB) are still associated with pulmonary morbidity and mortality. The purpose of this study is to morphologically analyze the structure of air-blood barriers in patients who underwent coronary artery bypass grafting (CABG) with use of CPB.
Design: The investigation involved 50 patients aged 48-75 who underwent CABG with the use of extracorporeal circulation (ECC). Lung tissue specimens, which were taken before and after CPB, were observed with light and electron microscopy.
Results: Both light and electron microscopic observations of pre-pump specimens did not show any pathological changes within the terminal part of the respiratory system. Morphological observations of tissue samples obtained after CPB revealed features of air-blood barrier injury and presence of surfactant within the alveolar capillaries.
Conclusion: Whatever the mechanism of the aforementioned changes one should be aware that the presented results indicate that air-blood barriers become leaky after CABG is performed with the aid of ECC.