Pseudoaneurysm of distal anterior tibial artery

Clinical History

87-year-old female patient with previous history of right tibio talocalcaneal arthrodesis for Rheumatoid Arthritis, complaints of slowly increasing swelling on the distal aspect of the right leg for few weeks.

Imaging Findings

Angiogram demonstrates a large pseudoaneurysm arising from the distal anterior tibial artery. The peroneal artery is patent. The posterior tibial artery is occluded distally although this reforms at the ankle joint via collaterals from the peroneal artery.
Post procedure Angiogram films show a 3.5mm Jomed covered stent on a 0.014 system, successfully deployed across the origin of the pseudo aneurysm. Post procedure the anterior tibial artery is patent throughout and the pseudo aneurysm was excluded with no filling present.

Discussion

Pseudo or false aneurysms are often caused secondary to trauma (with or without fractures of the neighbouring bones) and surgery. Pseudoaneurysms are different from true aneurysms. Psedoaneurysms have a fibrous wall, when compared to true aneurysms which have normal vessel wall covering.
Here we show a typical case of false aneurysm of distal anterior tibial artery caused by locking screws used in tibiotalocalcaneal arthrodesis.
Psedoaneurysm is caused by tangential trauma to the vessel wall. Initially both the patient and the physician are usually unaware of the injury. Subsequently the blood clot formed after the laceration of the vessel wall liquefies and starts to become a pulsatile mass hence it is descriptively termed 'Pulsating Haematoma'. [2]

The pulsating mass usually increases in size progressively, to present clinically as external swelling. Pseudoaneurysms can also present with pressure symptoms and/or with pain which is often due to erosion of the nerves or the bone. These aneurysms if left alone for long time eventually can rupture (depending on the location) and can cause death. Hence it is important to diagnose this condition early and treat it accordingly.

Diagnosis is done with angiogram, preferably with MR angiography.

Several methods of repair have been described in the literature including excision of the aneurysmal sac, repair of the lateral wall, endoaneurysmorrhaphy, limited arterial resection and end-to-end anastomosis, resection and graft placement and ligation of the artery [1], depending on the location and the collateral supply.
In this case we used a 3.5mm Jomed covered stent on a 0.014 system which was successfully deployed across the origin of the pseudoaneurysm.

Differential Diagnosis List

Final Diagnosis

Psedoaneurysm of anterior tibial artery

URL:	https://www.eurorad.org/case/10277
DOI:	10.1594/EURORAD/CASE.10277
ISSN:	1563-4086