Prevention of pulmonary edema developing in autoperfusing heart-lung preparation by leukocyte depletion

We investigated the preventive effect of leukocyte depletion on the development of pulmonary edema in a 12 h autoperfusing heart-lung preparation (AHLP). Sixteen mongrel dogs were divided into two groups: control group (group C, n = 9) and leukocyte depleted group (group L, n = 7). In group L, leukocytes were depleted with a leukocyte removal filter prior to the preservation. Extravascular thermal volume (EVTV) was measured by thermal-dye dilution technique as a parameter of pulmonary edema during preservation. The white blood cell (WBC) count was measured before and during preservation. After the procedure, extravascular lung water (EVLW) was measured by a gravimetric technique. In group C, the WBC count significantly decreased soon after the start of preservation, and subsequently remained without significant changes. In group L, the WBC count was maintained at a low level during the entire course of preservation. In group C, EVTV increased significantly with the preservation time. In group L, a significant increase in EVTV was only found at 12 h to a smaller extent than in group C. EVLW was significantly smaller in group L than in group C. In conclusion, the development of pulmonary edema was apparently prevented in the 12 h canine AHLP model by leukocyte depletion, and pulmonary leukocyte sequestration was considered as a cause of pulmonary edema in AHLP.