Femoral pseudo-aneurysm causing DVT

Clinical History

The patient presented 5 days after cardiac catheterization (right-sided femoral access) with swelling and pain of the right leg. Clinical examination revealed tenderness along the course of the femoral vessels. Furthermore a non-pulsatile mass was palpable in the right groin. Infection parameters were normal and there was no fever. D-dimer was elevated.

Imaging Findings

Contrast-enhanced CT angiography with arterial and venous phase acquisitions was performed from the abdominal aorta to the trifurcation vessels. A pseudo-aneurysm (PA) originating from the right common femoral artery (CFA) was detected (Fig. 1a). The PA measured approximately 3 cm. It was situated medially to the artery, and compressed the femoral vein. There was a well defined connection/neck between the PA and the CFA (Fig. 1b). In the venous phase scan no contrast filling was present in the right femoral vein (Fig. 2). However, the right iliac veins and popliteal vein were contrast filled. This finding was suggestive of femoral vein DVT, and the diagnosis was confirmed with Doppler and compression ultrasound. The CT scan showed no haematoma or signs of abscess formation in the groin. CT showed swelling of the right leg compared with the left (Fig. 3).

Discussion

PA formation (false aneurysm) is a common complication of vascular interventional procedures. It may occur in up to 8% of procedures [1]. As the CFA is the most commonly used access artery during interventional procedures, femoral PA is common. It is however uncommon that PA cause DVT, only few cases have been described in the litterature [2, 3]. Imaging options in patients with suspected PA, include Doppler ultrasound and CT angiography. Both modalites are effective to diagnose PA. If concurrent DVT is suspected, ultrasound might be advantageous as venous compression testing can be performed. In the present case both modalities were applied; CT was performed first and ultrasound was performed to confirm the DVT diagnosis.
Treatment options for femoral PA include simple compression, ultrasound-guided percutaneous thrombin injection, and surgical removal. Thrombin injection have proven to be an effective treatment of femoral PA [1, 4]. However, when concurrent DVT is present in the femoal vein, thrombin injection should not be performed. The reason is that even though the PA thromboses after injection, it is still necessary to remove it surgically to release the compression on the femoral vein. Thrombin induce inflammatory reaction around the vessels making surgery difficult [5].
In the present case, the patient underwent successful surgical removal of the PA. The DVT resolved after anti-coagulant therapy.
The important teaching point of the present case is that femoral PA may cause DVT.

Differential Diagnosis List

Final Diagnosis

Femoral pseudo-aneurysm causing DVT

URL:	https://eurorad.org/case/10208
DOI:	10.1594/EURORAD/CASE.10208
ISSN:	1563-4086