238 Arteriovenous fistula
Salient features
Examination
• Hypertrophy of the affected arm
• Prominent, dilated, tortuous veins
• Continuous thrill over the fistula; listen for continuous bruit
• Collapsing pulse; increased pulse pressure indicating hyperdynamic circulation.
• Look for signs of cardiac failure.
• Elicit Branham’s sign: slowing of the pulse on occluding the feeding vessel of the fistula.
• If the fistula is in the upper limb, then perform Allen’s test: the radial and ulnar arteries are occluded at the wrist and the hand is exercised; the arteries are then released one at a time to establish which is the dominant feeding vessel.
