Leukocyte filtration and aprotinin: synergistic anti-inflammatory protection

Abstract

Cardiopulmonary bypass activates an array of cellular and humoral inflammatory mechanisms that culminate in diverse or organ-specific injury. A manifestation of inflammatory injury to the heart, atrial fibrillation ranks among the most frequent and potentially life-threatening postsurgical complications. Pulmonary manifestations of the inflammatory response are also of major concern. Neutrophils activated by passage through the extracorporeal circuit inflict local injury and provoke the inflammatory cascade by producing oxyradicals and proinflammatory factors. This study tested if a combination of leukocyte depletion and aprotinin suppression of neutrophils could minimize postbypass atrial fibrillation and pulmonary dysfunction. In part one, two randomized groups of 90 patients undergoing primary coronary artery bypass grafting received full Hammersmith aprotinin alone (control group) or combined with leukofiltration (study group) and were prospectively examined. The dual treatment decreased the incidence of postoperative atrial fibrillation (7 of 90, 7.8%) by 67% versus aprotinin alone (21 of 90, 23.3%). Respiratory gas exchange in these patients was assessed from pulmonary shunt fraction. In the first two hours postbypass, pulmonary shunt fraction in the dual treatment group increased 40% less than in the group receiving aprotinin alone (p = 0.002), and subsided more quickly and completely over the next six hours. In part two, the cardiopulmonary bypass group receiving aprotinin + leukofiltration was retrospectively compared with 45 patients undergoing off-pump coronary revascularization. A strong, albeit not statistically significant trend (p = 0.08) toward a lower incidence of atrial fibrillation was found in the dual treatment group versus the off-pump group (8 of 45, 17.8%). These findings suggest that combining mechanical and pharmacologic suppression of the systemic inflammatory response could mitigate its deleterious arrhythmic and pulmonary complications.

The effects of various leukocyte filtration strategies in cardiac surgery

“…The 2004 study by the same group assessed the combined outcomes of the first two studies, namely atrial fibrillation and pulmonary dysfunction. It appears that the patient groups were also the same, but in the second part of the report a retrospective comparison of the leukodepleted study group to 45 off-pump bypass cases was made, with no statistically significant differences found [88].…”

Strategic Leukofiltration in Cardiac Surgery

“…At this time, the clamps are removed from the inlet and outlet of the arterial leukofilter and bypass line is clamped. The remainder of the case is performed as usual [12].…”

Long-Term Leukocyte Filtration Should Be Avoided during Extracorporeal Circulation

“…In the present study, neutrophil elastase and free hemoglobin increased in Group L significantly, suggesting that long-term usage of leukocyte filtration exerts deleterious side effects. This statement can be verified by the fact that aprotinin, a serine proteases inhibitor, significantly improves lung function and reduces the incidence of atrial fibrillation in patients treated with a leukocyte filter [26]. …”