Creation of Carotid Fusiform Aneurysm in a Canine Model

Abstract

Introduction: Intracranial fusiform aneurysm constitutes a relatively uncommon subgroup of aneurysms. Few reports concentrate on the creation of fusiform aneurysm in the carotid artery in large animals. In this study, we compare the technical feasibility and angiographic features of a canine model of carotid fusiform aneurysm created by a surgical venous-graft with the model induced by porcine elastase with or without balloon assistance. Materials and Methods: Fifteen beagle canines (weighted 15 to 25 kg) were included in the study and randomly divided into 3 groups, each with 5 canines: group 1, porcine pancreatic elastase-induced model; group 2, porcine pancreatic elastase-induced model with balloon assistance; and group 3, surgically venous-grafted model. The surgical success rate and the success rate of aneurysm formation were compared between the 3 groups. An initial digital subtract angiography was performed immediately after the creation of the model, and follow up angiography was performed at 2 weeks and 4 weeks. Results: One dog was excluded from group 2. The technical success rates for groups 1, 2, and 3 were 100%, 80%, and 100%, respectively. At immediate angiography, the diameter of dilated carotid arteries increased significantly compared with control arteries in groups 1 (4.84±0.25 vs. 3.20±0.10 mm), 2 (4.71±0.21vs. 3.39±0.12 mm), and 3 (8.18±0.65 vs. 3.99±0.05mm). Arterial dissection was observed in 2 of 5 animals in group 1. At follow up angiography, 3 models retained medium arterial enlargement and 2 models showed a slight enlargement in group 1; signs of thrombosis appeared in 2 models at 2 weeks and carotid arterial occlusion in all models at 4 weeks in group 2; no apparent change in the size and the morphology was found in group 3. Conclusions: The canine model of fusiform aneurysm of the carotid artery created by surgical venous-graft yields success rates similar to other models, but the aneurysm is more predictable and stable by angiography. The model induced by porcine elastase with balloon assistance also yields a high rate of aneurysm formation. However, the balloon might increase the risk of thrombosis; this did not occur in our model.