Topical effect of aprotinin on the surgical wound in cardiac surgery

Managing fibrinolysis without aprotinin

Cardiopulmonary bypass increases perioperative bleeding and produces a consumptive coagulopathy, which is defined as the simultaneous production of thrombin and fibrinolysis. Thrombin formation and fibrinolysis primarily occur in the surgical wound and peak at the time heparin is reversed by protamine. Neither aprotinin nor lysine analogs successfully control bleeding in many complex procedures, reoperations, aortic resections, or in implantations of mechanical circulatory devices. This analysis reviews the mechanisms involved and current treatment protocols, with the conclusion that changes in treatment protocols rather than use of a specific anti-fibrinolytic drug may provide better control of bleeding in these patients.

Angiogenesis in the latissimus dorsi muscle using different regimens of electrical stimulation and pharmaceutical support

It is our contention that the prevention of ischemia-reperfusion injuries immediately after latissimus dorsi muscle (LDM) mobilization and enhancement of angiogenesis will be effective in improving cardiomyoplasty results. The investigations were performed on adult sheep. Three hours after LDM mobilization, various stages of leukocyte-endothelium interaction were revealed: leukocytes binding to the endothelium, leukocyte destruction of endothelium, and leukocytes leaving capillaries through gaps in the endothelium. Fifty-six days after mobilization various stages of necrosis were discernible. The area occupied by capillaries was 3.45 +/- 0.26% vs. 3.99 +/- 0.24% in control muscle; most of the endothelial cells exhibited morphologic degeneration. Electrical stimulation with 60 CPM actually decreased the capillary density to 2.15 +/- 0.7%, and most of the endothelial cells were damaged, with disrupted plasma membranes. Muscle subjected to 15 CPM increased the percent of capillaries to 5.01 +/- 0.56%, and endothelial cells appeared normal in ultrastructure. Pharmaceutical support prevented muscle damage and accelerated revascularization. After 56 days of autologous biological glue (ABG) application, the area occupied by capillaries was 5.57 +/- 0.24%. This increased to 8.47 +/- 0.72% when aprotinin (proteinase inhibitor) was added to ABG, and to 9.40 +/- 1.24% with pyrrolostatin (free radical scavenger). Both ABG application with aprotinin and electrical stimulation at 15 CPM prevent the LDM from postmobilization damage, and increase angiogenic potential.

Effects of minimal-dose aprotinin on coronary artery bypass grafting

OBJECTIVE

To evaluate the effects of minimal-dose aprotinin in patients undergoing coronary artery bypass grafting, we conducted a prospective randomized study.

METHODS

A total of 167 patients were randomized to receive no aprotinin treatment (control, n = 57), minimal-dose aprotinin (1.0 x 10(6) KIU; n = 55), or low-dose aprotinin (2.7 +/- 0.5 x 10(6) KIU; n = 55). Blood loss and transfusion requirements, parameters of clotting and fibrinolysis, renal function, and early graft patency rates were assessed.

RESULTS

Postoperative blood loss and transfusion requirements were significantly (p = 0.01) lower in both the minimal-dose and low-dose groups than in the control group. The increase in D-dimer level after cardiopulmonary bypass was significantly (p < 0.05) less marked in the low-dose group than in the control group. The alpha 2-plasmin inhibitor and plasminogen activator inhibitor-1 levels were significantly (p < 0.05) greater in the minimal-dose and low-dose groups than in the control group after bypass, suggesting the prevention of fibrinolysis by both aprotinin doses. No statistically significant differences in postoperative renal function and early vein graft patency rates were noted (control group, 93.8%; minimal-dose group, 95.5%; low-dose group, 92.3%; p = 0.25).

CONCLUSIONS

Aprotinin was not associated with a significant increase in the prevalence of renal dysfunction or early vein graft occlusion. Minimal-dose aprotinin inhibited enhanced fibrinolytic activity and reduced blood loss and transfusion requirements after bypass equivalently to low-dose aprotinin. The dose of 1 x 10(6) KIU added to the pump prime may be acceptably effective in reducing blood loss in patients undergoing primary coronary operations.