Objective: To elucidate the influence of the leukocyte depletion filter (LD-1) on leukocytes, IL-6, myeloperoxidase enzyme (MPO) and the pathological changes of myocardic tissues during cardiopulmonary bypass(CPB).
Methods: Twelve dogs were used in this study. The LD-1, designed and made by ourselves, was fixed on the venous line in the trial group (n=6). It was used during the first 5 min after 2 min of CPB. LD-1 was not installed in the control group (n=6). Circulating leukocytes were counted before CPB, at 10 min, 40 min, 75 min during CPB, at the end of CPB, and 2 h after CPB. Plasma levels of IL-6 and MPO were also determined at the same time. The pathologic changes of left ventricular biopsies were observed before CPB, 5 min after protamine was given, and 2 h after CPB.
Results: The CPB 10 min WBC Count fell to 36% of that Before CPB in LD-1 group, which was lower than the WBC count in the control group synchronously (P < 0.01). But after CPB 2 h, both of them were close to the levels Before CPB in the two groups. In LD-1 group, IL-6 increased at CPB 40 min and reached to the top. But after wards it dropped continuously. The changes were of no significance in MPO and in the pathological examination of myocardic tissues (P > 0.05).
Conclusion: The LD-1 on venous line was capable of decreasing WBC count effectively. As a result, the inflammation factors that leukocytes released were lower, so the program chain of inflammation by CPB was shorter. But LD-1 was not superior in myocardial preservation.