Collateral ante- and retrograde flow pattern.

<p>DSA directly after implantation of a catheter port shows timely filling of the superior cava vein (SCV) (A), the right atrium, ventricle, pulmonary arteries (PA), (B) as well as the aortic arch (AA) and supraaortic arterial vessels (C). One week later, the SCV was occluded at the site of the catheter tip (arrow head) (D) and retrograde flow (dotted arrows) of contrast agent leads to filling of perivertebral “ladder-like” and cervicothoracic collateral veins (E). Finally, the intercostal veins (ICV) are contrasted and a faint filling of the right ventricle and the lungs is observed. Another week later (G-I) complete occlusion of the parent vessel is evident. This results in retrograde flow of contrast agent along the outside of the catheter (H and I), which continues outside the jugular vein.