A porcine model of carotid artery thrombosis for thrombolytic therapy and angioplasty: application of PTFE graft-induced stenosis.

Abstract

To develop a porcine carotid artery thrombosis model for the evaluation of thrombolytic therapy and adjunctive angioplasty procedures. Bilateral carotid thrombosis was induced in 16 pigs using endothelial crush injury followed by external polytetrafluoroethylene (PTFE, 5 x 2 cm2) wrap placement to create segmental carotid stenosis. Light microscopy was used to examine thrombus composition. Selective carotid catheterization was performed via a femoral approach. Two hours following carotid artery occlusion, a urokinase (250,000 IU) and heparin (1000 U) solution was pulse-sprayed in 1 carotid artery while the contralateral vessel received the control saline vehicle. The efficacy of thrombolytic therapy was assessed using carotid arteriography and intravascular ultrasound. The feasibility and technical efficacy of balloon angioplasty within the carotid stenosis model were also evaluated. Carotid artery occlusion occurred in 30 +/- 6 minutes following endothelial injury plus PTFE wrap placement. Histological examination of carotid arteries showed endothelial irregularity with fibrin-rich and platelet-rich thrombus. Urokinase was effective in recanalizing all occluded arteries (100%), while the control saline vehicle showed no effective thrombolysis (p < 0.001). Angioplasty was successful in restoring normal diameter in all arteries (100%). This carotid artery thrombosis model, which incorporates intimal injury with segmental stenosis, is simple to create and reproducible. It provides not only a model for the evaluation of thrombolytic therapy but also a practical training tool for adjunctive endovascular interventions.