Hemorheology in Surgery—A Review

Abstract

The rheological behavior of blood and its components under physiologic and pathophysiologic conditions is reviewed, with a focus on the type and extent of pathohemorheological changes in surgical patients during hospitalization and thereafter, as well as their clinical consequences with regard to thromboembolic complications. During the operation and the postoperative period various hemorheological and hemostasiological alterations acquire clinical signifcance: 1. hyperreagibility of platelets with increased aggregation and adhesion ten dency 2. changes in fibrinogen, albumin, and globulin concentrations, which af fect viscosity and red cell aggregation 3. impairment of red cell deformability 4. increase in clotting factors 5. disturbance of fibrinolysis characterized by diminution of plasmatic plas min and increase in antiplasmin activity In addition, anesthetic techniques have also been shown to affect he morheological and hemostasiological parameters. The complex pattern of pathohemorheological and hemostasiological changes shows that thromboembolism in the course of surgical interventions is provoked by multifactorial disorders. Thrombosis prevention should, therefore, counteract both hemorheological and hemostasiological disturbances. Since pathohemorheological and pathohemostasiological changes are al ready detectable before, and increase during operation, preventive measures should start before the surgical intervention to obtain maximum benefit. Therapeutic possibilities for the avoidance of these multifactorial distur bances are discussed with particular reference to pentoxifylline, which satisfies the complex requirements of a hemorheologically and hemostasiologically active therapeutic agent.