Histological Analysis of Endovascular Coil Distribution

H. MORALES; I. LARRABIDE; A. J. GEERS; D. KALLMES; D. DAI; Y. H. DING; A. F. FRANGI

Shangai

Simposio; 8th International Interdisciplinary Cerebrovascular Symposium; 2011

Department of Neurosurgery, Shanghai Hospital

Purpose: The success of endovascular coiling is related to the amount of coils and their distribution inside the aneurysm. However with current imaging techniques, it is not possible to know how coils are distributed after insertion. The purpose of his work is to analyze the coils distribution by using histological images.Method: Eight histological images of five elastase-induced aneurysms in rabbits treated with coils were analyzed. For each image, five regions inside the aneurysm were created. Three of them divide the aneurysm from neck to fundus following its longitudinal axis, called N, D and F. The other two regions split the aneurysm in its core and endolayer, labeled as C and E, respectively. Region E was considered as one coil diameter from the aneurysm wall and neck. The 2D coil density at these regions was calculated and normalized by the total coil density. These densities were calculated as the ratio between the coils and non-coil area at each region. All image measurements were clustered per region for further analysis.Results: The total 2D coil density was 20.932% ±1.260%. The normalized 2D density at F, D and N regions was 1.095% ±0.209%, 0.910% ±0.255% and 1.061% ±0.315%, respectively. The E and C regions has a density of 1.476% ±0.339% and 0.881% ±0.095% respectively.Conclusion: There are non-significant differences among N, D and F regions (p=0.343, ANOVA test), suggesting that coils are homogenously distributed along the aneurysm longitudinal axis. However, there are more coils located at E than at C (p=0.006, paired Student’s t-test), meaning that coils are more prone to be located near wall and neck.