Aneurysm embolization with biologically active coils: An animal study

Objectives: Cellular adhesion on the surface of Guglielmi detachable coils (GDC) promotes accelerated occlusion of aneurysms. We hypothesized that coils coated with transforming growth factor beta (TGFbeta) and vascular endothelial growth factor (VEGF) will promote clot organization and endothelial or cellular proliferation to facilitate closure of large experimental aneurysms relative to uncoated GDC coils. Methods: GDC were inserted either uncoated, coated with albumin, coated with TGF-beta (500 μg/ml) or with VEGF (500 μg/ml) into the ligated common carotid artery of adult male wistar rats for 14 days. Twentyfour adult male Wistar rats (280-300 g) were divided into four groups (n=6 per group). Subjects were killed 2 weeks after implantation and common carotid artery (CCA) segments were harvested and coils were removed. Arterial tissue was evaluated histopathologically. Results: Significant differences in the proportion of aneurysm luminal area (mm ²) was shown among Group I (0.22±0.14 SD) and Group II (0.16±0.8 SD) compared to Group III (0.04±0.03 SD; P<0.05), and Group IV (0.02±0.02 SD; P<0.05) analyzed 2 weeks postoperatively. Light microscopy showed well organized fibrous tissue formation of epithelial cells and intimal hyperplasia around the coils when using the coated GDC's (Group III and Group IV). Conclusion: The result of this study suggests that the coated GDC with TGF-beta or VEGF appears beneficial in promoting endothelization, clot organization, and cellular tissue integration of the coils.