Ultrasound-guided thrombin injection of femoral artery pseudoaneurysms

To evaluate whether the positive initial results for ultrasound-guided percutaneous thrombin injection of pseudoaneurysms, reported predominantly in small retrospective series, would be supported in a larger prospective trial.

In April 1999, our institution adopted ultrasound-guided thrombin injection as the initial treatment for post-catheterization arterial pseudoaneurysm. Colour Doppler imaging delineates the pseudoaneurysm, its neck and the adjacent artery. A 22-gauge spinal needle is attached to a 1-mL syringe preloaded with thrombin at a concentration of 1000 U/mL. Under ultrasound guidance, the needle tip is positioned within the pseudoaneurysm, and real-time colour Doppler imaging is used to monitor the pseudoaneurysm as thrombin is slowly injected. Thrombus formation commences almost immediately, and in most cases, occlusion is complete within 5 seconds.

We successfully treated 61 pseudoaneurysms in 61 consecutive patients. The amount of thrombin injected ranged from 20 U to 3000 U (mean 435 U); 55 pseudoaneurysms were successfully treated after a single injection, and 6 patients required a repeat injection for complete occlusion. One patient had 2 pseudoaneurysms treated on consecutive days, and 1 developed a symptomatic vasovagal reaction, which was treated conservatively. No other significant procedural complications were encountered. Fifty-nine patients had a follow-up groin Doppler sonogram between 1 and 5 days after treatment.

Ultrasound-guided percutaneous thrombin injection is an effective, simple, fast and safe treatment for post-catheterization arterial pseudoaneurysm. It has replaced ultrasound-guided compression repair at our institution and is now our treatment of choice.