Clinical benefits of leukocyte filtration during valve surgery

The accumulation of activated leukocytes in the pulmonary circulation plays an important role in the pathogenesis of lung dysfunction associated with cardiopulmonary bypass (CPB). Patients undergoing valve surgery have prolonged CPB owing to the complexity of the surgery. The goal of this study is to determine if arterial leukocyte filters during CPB improve clinical outcomes after valve surgery.

A prospective analysis of all patients receiving only valve surgery with leukocyte arterial filters from June 1999 to June 2002 was compared with a case matched cohort during the same time period. Two hundred fifty patients were identified and compared with a cohort who did not have leukocyte filters used during CPB. The following study points were evaluated preoperatively and postoperatively: white blood cell count, platelet count, arterial blood gas, time to extubation, intensive care unit stay, and total length of hospital stay.

There were 500 patients in the study. The following valve operations were performed: 92 mitral valve replacements, 168 aortic valve replacements, 152 mitral valve repairs, 80 combined valve repair/replacements, and 8 tricuspid valve repairs, all evenly divided between the two treatment limbs. Patients with leukocyte filters had the following findings compared with nonfilter patients: The time to extubation 10.3 versus 16.2 hours (P = 0.009), postoperative respiratory quotient 407 versus 320 (P = 0.02), total length of stay 5.4 versus 7.2 days (P = 0.04).

The use of arterial leukocyte filters in patients undergoing valve surgery leads to earlier extubation, improved oxygenation, and a decreased length of stay. Leukocyte filters should be used during CPB for patients having valve surgery.