Covered Endoprosthesis for the Treatment of an Anterior Tibial Artery Pseudoaneurysm with Arterial-Venous Fistula

Purpose: Lower extremity arterial pseudoaneurysm (PSA) with or without concurrent arteriovenous fistula (AVF) is a rare iatrogenic or posttraumatic condition. We present a case of an anterior tibial artery (ATA) PSA with high-flow AVF.

Materials and Methods: A 62-year-old woman presented with 1 week of lower extremity pain and swelling 2 months after orthopedic surgery for removal of tibial hardware placed for a traumatic fracture 3 years previously. Vascular ultrasound of the right lower extremity was negative for deep vein thrombosis but revealed an 8.3- ´ 2.4- ´ 2.3-cm multilobulated, wide-necked pseudoaneurysm. An alternative service was initially consulted and attempted treatment from a contralateral, up-and-over approach with placement of two overlapping balloon-expandable bare metal coronary stents (BMSs) (2.5 ´ 30 mm and 3 ´ 30 mm) as an attempt at flow diversion. Completion angiography showed no change of the PSA with high-flow AVF. My service was subsequently consulted.

Results: Repeat intervention was performed from an antegrade ipsilateral approach. Angiography confirmed patency of the previously placed BMSs, with the proximal edge angled into the PSA, making it difficult to cross into the ATA distally, necessitating retrograde access. Working antegrade, a 5- ´ 37-mm balloon-expandable Lifestream (BD Bard, Tempe, AZ) stent was placed into the existing balloon-expandable coronary BMSs. A 6- ´ 50-mm self-expandable Viabahn (WL Gore, Flagstaff, AZ) was subsequently placed from the Lifestream stent into the proximal ATA. The balloon-expandable stent was postdilated and sculpted with 4-, 5-, and 6-mm balloons to taper into the normal ATA distal to the PSA. Given the high-flow AVF, the native proximal ATA had dilated to just over 6 mm in diameter. After covered stent placement, the patient clinically improved, and her pain resolved. One-month follow-up ultrasound showed minimal residual filling of the PSA, which was treated with thrombin injection. The stents have remained patent at 10 months.

Conclusions: Use of covered vascular stents in the tibial arteries for traumatic PSA and AVF has been previously described in case reports, but they have primarily used smaller sized coronary-covered stents, many of which require humanitarian use exemption and institutional review board oversight and may not be widely available. Use of larger diameter self-expanding covered vascular stents in the tibial vessels has not been previously described.