Persistent bilateral sciatic arteries--an unusual presentation.

A 20-year-old m a n suddenly developed a cold white painful left lower leg after playing football although there was no history of trauma. On examination no pulses were palpable or detectable with Doppler ultrasound below the left c o m m o n femoral artery. A right trans-femoral lumbar aortogram (TFLA) demonstrated bilateral persistent sciatic arteries with intimal irregularity at the level of the acetabulum on the left (Fig. 1) and occlusion of all 3 calf vessels (Fig. 2). The superficial femoral artery was complete on the right, rejoining the sciatic artery at the knee but was incomplete on the left (Fig. 3). A diagnosis of thrombosis and subsequent em-bolism at the site of an intimal tear was made and a low dose infusion of streptokinase 6 0 0 0 units/h commenced via a catheter advanced down to the popliteal artery. After 24 h the left foot was w a r m and pink but still pulseless and the streptokinase infusion was replaced by an intravenous heparin infusion 40 000 units/24 h for 5 days. However, the foot again became critically isch-aemic with rest pain and a Doppler pressure index of only 0.39. A repeat TFLA 1 week later showed that the irregularity in the left sciatic artery had been replaced by slight dilatation raising the possibility of an aneurysm although a mass in the buttock was not detectable clinically or by ultrasound scanning. All 3 calf vessels were still occluded and so a lumbar sympathectomy and popliteal embolec-tomy was performed. Organised thrombus was retrieved Ad~tress for correspondence: I. Fig. 1. TFLA demonstrating a persistent left sciatic artery arising from the common lilac artery with intimal irregularity at the level of the acet-abulum (arrowed).