Posterior Tibial Neuropathy Secondary to Pseudoaneurysm of the Proximal Segment of the Anterior Tibial Artery with Delayed Onset

Abstract

Anterior tibial artery is a nonvital artery which is one of the three arteries of the leg. This artery has a short proximal l segment in the popliteal region and a long segment in the anterior compartment of the leg designated as distal segment. With consideration of the deep location of the proximal segment in the popliteal fossa, it is less susceptible to trauma and subsequent formation of an aneurysm. On the contrary, the superficial long distal segment is more susceptible to trauma with high chance of pseudoaneurysm formation at the site of unrecognized injury. In this article, a 38-year-old military man being manifested about a decade after a trivial missile fragment injury with progressive posterior tibial neuropathy is presented. A giant pseudoaneurysm arising from the proximal segment of the anterior tibial artery was confirmed with angiography and the exact size of this pathology was documented with contrasted computed tomographic scan. The aneurysmal sac removal was accomplished after ligation of the corresponding artery proximal and distal to the sac followed by tibial nerve neurolysis which result in full recovery. In careful review we found that neither pseudoaneurysm arising from the proximal tibial artery nor posterior tibial neuropathy due to the compressive effect of the aneurysmal sac of this segment has been reported previously. Our primary purpose for reporting this case is not to describe the rarity of pseudoaneurysm formation at proximal segment of this artery but rather to describe delayed-onset posterior tibial vascular compressive neuropathy due to such an aneurysm. Eventually due to the potential sequel of a pseudoaneurysm, it is important for the surgeons to have high index of suspicion to prevent a missed or delayed diagnosis.

Keywords: anterior tibial artery; missile fragment; posterior tibial neuropathy.

Fig. 1

( A , B ) 0, AP and lateral femoral artery angiography show the pseudoaneurysm arising from proximal anterior tibial artery in popliteal region (black arrow head).The tibioperoneal trunk is patent (white arrow head). The posterior tibial artery (black arrow) is demonstrated where peroneal artery (white arrow seems to be narrow probably because of the compressive effect of the pseudoaneurysm. A small missile fragment is demonstrated in both views (short black arrows).

Fig. 2

Contrasted CT scan showing the actual size of the aneurysm with its pseudocapsule being presented as rim enhancement. The patent part of the aneurysm is demonstrated as a hyperdense mass compatible with fresh blood which is surrounded by isodense area compatible with old clot. An artifact may be due to the missile fragment hidden behind the bone.