THE DOUBLE-TUCK MODEL - A NEW ANIMAL-MODEL OF ARTERIAL THROMBOSIS

PURPOSE: To develop an animal model of a fibrin- and platelet-rich int raluminal arterial thrombus with abnormal mural substrate to simulate in situ thrombosis of human atherosclerotic arteries. MATERIALS AND ME THODS: Parallel studies of the crush-thrombin model (CT) and double-tu ck model (DT) were performed and evaluated with use of angiography and histologic analysis. Ten Yorkshire swine (1-6 months; 20-30 kg; 10 fe males) underwent right femoral and carotid cutdowns performed after ad ministration of general anesthesia (4 mL intravenous thiopental sodium , isoflurane 2% in 1 L of oxygen), After angiography, the CT model was created in the left carotid artery and the DT model was performed in the right carotid artery, Angiograms were obtained at 20 minutes (n = 1), at 1 hour (n = 3), at 2 hours (n = 4), and at 3 hours (n = 2) befo re sacrifice, After sacrifice, histologic specimens were stained with hematoxylin-eosin (H-E stain) and phosphotungstic acid hematoxylin for fibrin. The specimens were examined for endothelial irregularity and adhesion, platelet aggregation, fibrin layering, vessel wall injury, a nd adventitial hemorrhage, The findings were quantified as 0 = absent, 1+ = slight, 2+ = moderate, and 3+ = severe, RESULTS: Angiographic re sults were similar, However, histologic analysis of the CT model showe d severe damage to the arterial wall with dissection in nine of 10 ani mals. In the DT model, no dissection was found (n = 10), Endothelial i rregularity was found in six of 10 arteries treated with the CT method , as compared with nine of 10 arteries prepared with the DT model; end othelial adhesion was found in five DT arteries and in four CT arterie s, Platelet aggregation was present equally in both methods. A fibrin- and platelet-rich thrombus was created in five of 10 examined arterie s by both methods, CONCLUSIONS: The DT model creates endothelial irreg ularity leading to formation of a platelet- and fibrin-rich thrombus, adherent to the vessel wall without damage to the media. This contrast s with the CT method, which created medial dissection in nine of 10 ar teries, One hour is the minimum time required to produce a good qualit y thrombus; 2 hours is the optimum time, The DT model is proposed as a useful tool in the development of new devices, drugs, and biotechnolo gic advances.