ANTITHROMBOTIC POTENCIES OF ENOXAPARIN IN MICROVASCULAR SURGERY - INFLUENCE OF DOSE AND ADMINISTRATION METHODS ON PATENCY RATE OF CRUSHED ARTERIAL ANASTOMOSES

This study evaluated the influence of the dose and administration meth ods of enoxaparin, a low-molecular-weight heparin, on the patency rate of crushed rat femoral arteries following anastomosis. An impact crus h with a 25-kg magnitude was applied to a 2-mm segment of 100 rat femo ral arteries, followed by anastomosis. The arteries were divided into five groups: group 1 received systemic enoxaparin alone with a relativ ely high dose (45 IU) twice a day for 3 days; groups 2 and 3 received topical irrigation with a lower (15 IU/mL) concentration and a higher (45 IU/mL) concentration, respectively; group 4 received systemic and topical application al a lower (15 IU) dose and concentration (15 IU/m L); and group 5 received systemic and topical application at a higher (45 IU) dose and concentration (45 IU/mL). The results of this study d emonstrate the following: (1) topical irrigation with enoxaparin at a concentration of 45-IU/mL-three times higher than that recommended for clinical use adjusted by body weight (15 IU/mL)-is effective for anti thrombotic action; (2) a combination of systemic and local application does not offer additional benefit in the patency rate when compared t o local irrigation alone; (3) systemic administration alone does not p revent. thrombus formation; and (4) enoxaparin is potentially useful t o enhance the patency rate in compromised microvessels.