Retrograde pulmonary perfusion improves results in pulmonary embolectomy for massive pulmonary embolism

Mortality rates for pulmonary embolectomy in patients with acute massive pulmonary embolism have decreased in recent years. However, they still range from 30% to 45% when the surgery is performed on critically ill patients, and the rates reach 60% in patients who have experienced 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 edema, and massive parenchymal and intrabronchial hemorrhage. 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-air entrapped in the pulmonary artery during embolectomy can lead to fatal outcomes. Besides enabling the removal of residual thrombotic material from the peripheral branches of the pulmonary artery, retrograde pulmonary perfusion fills the pulmonary artery with blood and prevents pulmonary air embolism. In this retrospective study, we analyzed a series of 21 consecutive critically ill patients in whom we applied retrograde pulmonary perfusion while performing standard pulmonary embolectomy. No patient died or experienced major postoperative complications. We believe that the use of retrograde pulmonary perfusion decreases morbidity and mortality rates associated with pulmonary embolectomy in critically ill patients.