Randomised Controlled Trial Comparing the Incidence of Steal Syndrome in the Two Types of anTEcubitaL Fossa Arteriovenous fistuLa AVF (STEAL Trial)

Arteriovenous fistulas (AVF) are the safest form of vascular access for long-term haemodialysis in patients with end-stage renal failure. The strategy in creating an AVF in the upper limbs is to start at a distal site and if that fails, to attempt an AVF on a more proximal site i.e. from wrist, forearm to elbow. The most common type of AVF is the radiocephalic AVF at the wrist. A more proximal AVF is often created as a primary procedure when there is poor vasculature in the distal forearm or as a secondary procedure when a wrist fistula has failed. Traditionally, brachiocephalic fistulas (BCF), which involves anastomosing the cephalic vein to the brachial artery, have been the most common type of AVF created in the antecubital fossa at the elbow level. Other common types of antecubital fossa arteriovenous fistula (AFF) are the brachiobasilic (BBF) and brachio-median cubital AVF.

Steal syndrome relates to hand ischaemia associated with AVF creation, and is a major risk of AVF formation. The symptoms of steal syndrome ranges from cold extremities, numbness, hand claudication (pain after exercise), to rest pain and tissue loss. Steal syndrome can also be measured by Digital Brachial Pressure Index. Severe steal syndrome is debilitating, and limb-threatening, and requires surgical revision or ligation of the AVF. This leads to additional surgical risks and loss of dialysis vascular access.

Diabetes and the types of AVF have been found to be independent risk factors for developing steal syndrome following AVF creation1. The highest risk is seen in patients with a proximal AVF i.e. BCF/BBF; up to 50% of patients in some studies, compared to 5-8% in all upper limb AVFs.

An alternative technique that may reduce risk of steal in this group of patients is to anastomose the vein to the radial artery or ulnar artery, distal to the brachial artery bifurcation. This technique, theoretically, will only 'steal' blood from one artery e.g. radial artery if the anastomosis is created on the proximal radial artery so blood flow can therefore be maintained by the ulnar arterial system.

Recent studies have suggested that using the proximal radial or ulnar artery reduced the risk of steal to as low as 0% to 3%. The type of arterial inflow to an AFF is therefore a potentially significant factor in causing steal syndrome. There is, however, no current randomised controlled trial to prove this hypothesis.