Granulocyte sequestration and early failure in the autoperfused heart-lung preparation

Organ Preservation: Current Concepts and New Strategies for the Next Decade

SUMMARY: Organ transplantation has developed over the past 50 years to reach the sophisticated and integrated clinical service of today through several advances in science. One of the most important of these has been the ability to apply organ preservation protocols to deliver donor organs of high quality, via a network of organ exchange to match the most suitable recipient patient to the best available organ, capable of rapid resumption of life-sustaining function in the recipient patient. This has only been possible by amassing a good understanding of the potential effects of hypoxic injury on donated organs, and how to prevent these by applying organ preservation. This review sets out the history of organ preservation, how applications of hypothermia have become central to the process, and what the current status is for the range of solid organs commonly transplanted. The science of organ preservation is constantly being updated with new knowledge and ideas, and the review also discusses what innovations are coming close to clinical reality to meet the growing demands for high quality organs in transplantation over the next few years.

Role of platelets in myocardial ischemia-reperfusion injury in dogs

We investigated the involvement of circulating platelets in myocardial ischemia-reperfusion injury in canine autoperfused heart-lung preparations using filters to deplete platelets and/or leukocytes. The left anterior descending (LAD) coronary artery was occluded for 40 min, followed by 40 min reperfusion, in 3 groups: a leukocyte-platelet-depleted (LPD) group, in which both leukocytes and platelets were depleted; a leukocyte-depleted (LD) group, in which leukocytes alone were depleted; and a control group. There were no differences in hemodynamics or arrhythmias among groups before or during coronary occlusion. After reperfusion, the maximum rate of change in left ventricular pressure during systole and diastole was significantly higher in the LPD group than in the control and LD groups. The LPD group also showed gradual recovery of regional myocardial function and a decrease in the frequency of premature ventricular contractions. The LD group showed a slight improvement in cardiac function and arrhythmias compared with the control group. Although there was no significant difference in the pulmonary arterial plasma level of thromboxane B2 at any stage among groups, the control group showed an increase after reperfusion. These results suggest that platelets are important in reperfusion injury and that the depletion of both leukocytes and platelets effectively protects against reperfusion injury.

Depletion of activated neutrophils by a filter during cardiac valve surgery

PURPOSE

To determine whether inclusion of a neutrophil-specific filter into the extracorporeal circuit during open heart valve surgery alters postoperative outcomes.

METHODS

Convenience sampling of 24 patients undergoing elective open heart valve surgery between July 1993 and June 1994. Patients were randomized to a neutrophil-specific filter (n = 11) or to a standard blood filter (n = 13) during cardiopulmonary bypass.

RESULTS

Neutrophil-specific filter diminished (P < 0.02) the expression of CD18, a neutrophil surface adhesion molecule, at I (84.5 +/- 4.2 vs 94.8 +/- 3.8%), 4 (80.0 +/- 4.2 vs 95.1 +/- 3.9%) and 24 hr (75.2 +/- 4.2 vs 98.2 +/- 3.9%) post-operatively compared with standard filter. Total white blood cell count, neutrophil count, and pro-inflammatory cytokines (IL-6, IL-8) were similar between groups at all times. Measured outcomes including: PaO2 cardiac index, ejection fraction, haemodynamic variables, use of inotropes, spirometry (FEV1, FVC), and hospitalization duration were similar between groups.

CONCLUSIONS

Inclusion of the neutrophil filter during open heart valve surgery selectively depletes activated neutrophils. There were no other detectable differences between the two groups and the use of a neutrophil-specific filter in routine clinical practice for patients undergoing open heart valve surgery is not supported.