A novel radiological approach for the experimental study of angiogenesis: angiography of the chick embryo and its chorioallantoic membrane.

We use a modification of the digital substraction angiography (DSA) technique to visualize the vascular system of the chorioallantoic membrane (CAM) of the developing chick embryo. After catheterization of the central vein of the CAM with a metallic needle and injection of contrast medium, angiography was performed at specified follow-up intervals (1-2.5 images per second) using the Philips DVI-S Angiography Unit. By applying the vascular casting technique we were able to visualize the vessels of the CAM and to study the existing complex vascular-anatomical relationships. Our results show that DSA demonstrates the development of the circulatory system of the chick embryo (heart and vessels) and the vessels of its CAM effectively. By applying for the first time interventional radiology techniques on the chick embryo system, it has been possible to study morphological changes of the vessels during angiogenesis in vivo. These results suggest that this technique can be a proven and valuable tool in the quantitative assessment of angiogenesis.