Complex subclavian artery pseudoaneurysm causing failure of endovascular stent repair with salvage by percutaneous thrombin injection.

We report a case of traumatic right subclavian artery pseudoaneurysm, which failed initial treatment by endovascular covered stent. Subsequent catheter angiogram demonstrated filling of the pseudoaneurysm from retrograde flow of the right vertebral artery with outflow through the internal mammary artery. With access to the pseudoaneruysm obstructed, percutaneous thrombin injection was performed. The complex connections of the pseudoaneurysm to the right subclavian, vertebral, and internal mammary arteries resulted in the initial failure of the covered stent to induce thrombosis because of inflow from the right vertebral artery, a so-called "back door vessel".