Affiliations: Istituto di Semeiotica Medica e Geriatria, Università di Siena, Italy
Abstract: This study concerns the effect of intravenous thrombolysis in patients suffering from Peripheral Obliterative Arterial Disease (POAD) at the stage of “Accelerated Limb Ischemia” (ALI). In a previous study on 17 patients, where Streptokinase was employed, there was complete or partial reopening of obstructed vessels in 5 cases and an improvement of clinical conditions in 10 cases. Unfortunately, 6 (35%) patients experienced significant side effects. Subsequently, in 9 POAD patients, we employed rt-PA at the dosage of 100 mg infused i.v. over a period of 4–6 hours. This treatment showed a clinical and instrumental improvement in a high percentage of patients without any important side effects. The effect of the treatment was examined by means of Doppler ultrasound, strain gauge plethysmography and Transcutaneous oxygen tension (TcPO2). Haemorheological and fibrinolytic parameters were also assessed and no important changes were observed either in blood or plasma viscosity in spite of the reduction of fibrinogen concentration (especially in the Streptokinase group) and the improvement of leg perfusion. Explanation of this aspect was sought through an “in vitro” study: here rt-PA was added to blood samples so as to obtain a more definite fibrinolysis. Before and after the addition of rt-PA, blood and plasma viscosity, fibrinogen, FDP and FDP-E were examined. The results illustrated that the reduction of plasma and blood viscosity was not as significant as the disappearance of fibrinogen might have led us to expect and showed a marked increase of fibrinogenolytic products (FDP and FDP-E). These findings reinforce the working hypothesis stating that fibrino(geno)lytic products can affect plasma and blood viscosity as much as the intact fibrinogen molecule does. So it was concluded that the beneficial results obtained with fibrinolytic agents, in patient with POAD at the ALI stage, are due to the reopening of vessels and not to the rheological effect.
