Modified technique to create morphologically reproducible elastase-induced aneurysms in rabbits

Introduction: The purpose of this study was to create morphologically reproducible elastase-induced model aneurysms in rabbits. Methods: We created 120 elastase-induced aneurysms in rabbits using two different methods: the standard technique (group 1, n=62) and a modified technique (group 2, n=58). In the standard technique a small cutdown with a focal area of exposure of the mid-right common carotid artery (RCCA) was employed, while in the modified technique the RCCA was completely exposed to its origin. We measured aneurysm sizes (neck diameter, width and height) in the two groups. The aneurysm sizes were compared between the two groups using Student's t test, and the standard deviations of the aneurysm sizes were compared between the groups using the F test. Results: The mean aneurysm neck size, width and height in group 1 were 3.4 +/- 1.2 mm, 3.8 +/- 1.0 mm and 8.0 +/- 1.7 mm, respectively, and in group 2, were 3.2 +/- 0.9 mm, 3.7 +/- 0.6 mm and 9.1 +/- 1.8 mm, respectively. The differences in mean aneurysm neck and width between the two groups were not significant (P > 0.05). However, there were significant differences in the standard deviation of these two parameters between the two groups (P < 0.05 and P < 0.01, respectively). The mean aneurysm height in group 2 was larger than in group 1 (P < 0.001), but no significant difference in the standard deviation of this parameter between the two groups was found (P > 0.05). Conclusion: The results indicate that more consistent aneurysm diameters can be created using the modified technique.