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 (TGF-beta) 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 mu g/ml) or with VEGF (500 mu g/ml) into the ligated common carotid artery of adult male wistar rats for 14 days. Twenty-four 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.