Persistent Sciatic Artery Aneurysm as a Rare Cause of Acute Lower Limb Ischemia.

A 61-year-old female was admitted in our emergency department due to continuous progressive pain of her right thigh and calf, with numbness in her toes. Her past medical history included balloon angioplasty without stent implantation of the right superficial femoral and popliteal artery two years ago. The patient was taken directly into the angiosuite, where embolization and occlusion of the right superficial femoral artery were identified. She underwent an aspiration thrombectomy and catheter-directed thrombolysis overnight (Fig. 1), after which there was clinical and angiographical improvement of the extremity’s perfusion. On the second day the patient complained of recurrent pain in her right calf. A color duplex scan and a computer tomography angiography identified a partially thrombosed aneurysm of a persistent sciatic artery (Class Ia) as the cause of the popliteal embolization (Fig. 2, 3) [1]. Subsequently aneurysm exclusion through ipsilateral retrograde popliteal access (Viabahn 11 mm×50 mm, Viabahn 13 mm×50 mm; W. L. Gore & Associates, Flagstaff, AZ, USA) (Fig. 4) was carried out. A postoperative duplex ultrasound showed an improved perfusion of the extremity. The patient was discharged on the third postoperative day, with a single antiplatelet therapy with aspirin prescription, and no events of recurrent embolization were observed during a 2-year follow-up.

Fig. 1

The angiogram showed the hypoplastic superficial femoral artery (A) and the occlusion (B). The arrow indicates the complete persistent sciatic artery (Class Ia). At the time of examination, this was thought to be an arteriovenous malformation.

Fig. 2

Sagittal (A) and coronal (B) maximal intensity projection images of a computed tomography angiography showed the aneurysm of the persistent sciatic artery (circles) in the right gluteal region.

Fig. 3

Longitudinal (A) and transverse (B) pictures of color duplex scan showed the partially thrombosed aneurysm of the persistent sciatic artery.

Fig. 4

Angiogram before (A) and after (B) exclusion of the aneurysm. The circle shows the aneurysm of the persistent sciatic artery. The arrow indicates the sciatic artery after stent-graft implantation.

Persistent sciatic artery is a rare anomaly of the internal iliac artery during embryogenesis. There is a risk of aneurysmal degeneration in up to 60% of the cases, which may further lead to distal embolization and lower limb ischemia [2]. Due to its localization and variable femoral and sciatic connections, both open and endovascular management are challenging. Open surgery is associated with increased risk of sciatic nerve injury. Endovascular management is viable through a femoral, popliteal, or transgluteal approach. However, a retrograde popliteal approach is the technically easiest approach to access the sciatic artery; otherwise, access via the contralateral femoral artery and elongated aberrant internal iliac artery will be required [3].