Retrograde pulmonary perfusion as an adjunct to standard pulmonary embolectomy for acute pulmonary embolism

Mortality rates for pulmonary embolectomy in patients with acute massive pulmonary embolism have decreased in recent years. However, it still ranges from 30 to 45% when surgery is performed on critically ill patients, and the mortality rates reach 60% in patients who have experienced a cardiac arrest before the procedure. The causes of death in these patients are generally attributed to right heart failure due to persistent pulmonary hypertension, intractable pulmonary oedema, and massive parenchymal and intrabronchial haemorrhage. Clinical and experimental findings indicate that venous air embolism causes severe or even lethal damage to the pulmonary microvasculature and the lung parenchyma consequent to the release of endothelium-derived cytokines. These findings are similar to those observed when severely compromised patients undergo pulmonary embolectomy for air entrapped in the pulmonary artery during embolectomy, which may lead to fatal outcomes. Retrograde pulmonary perfusion (RPP), besides enabling the removal of residual thrombotic material from the peripheral branches of the pulmonary artery, fills the pulmonary artery with blood and prevents pulmonary air embolism. We believe that the use of RPP as an adjunct to conventional pulmonary embolectomy decreases the morbidity and mortality rates associated with pulmonary embolectomy in critically ill patients.