BACKGROUND: We investigated the previously undescribed phenomenon of ulnar artery occlusion on clenching to make a fist, following the presentation of a patient to our unit with idiopathic ulnar-sided hand pain. This led us to study this unusual finding in a cohort of asymptomatic patients. METHODS: Ninety-one radial and ulnar arteries were studied in 23 volunteers by color duplex ultrasonography. The subjects were all asymptomatic, their ages ranged from 18 to 78 years, and included 10 males and 13 females. RESULTS: Twenty-two percent of ulnar arteries occluded on clenching a fist, resulting in the hand relying on in-flow solely from the radial artery. All arteries opened up following fist release allowing anterograde flow. Furthermore, 11% of superficial palmar branches of radial arteries occluded on fist-making. The pattern of flow on making a fist showed an initial burst of reverse flow followed by reduced or occluded flow and subsequently an increase in antegrade flow after release of the fist. No subject could occlude both radial and ulnar arteries simultaneously. CONCLUSIONS: We discuss these findings in view of the potential clinical implications in terms of Raynaud's phenomenon, scleroderma, and importantly, the potential for false-positive findings of pathological ulnar artery occlusion on ultrasonography.
BACKGROUND: We investigated the previously undescribed phenomenon of ulnar artery occlusion on clenching to make a fist, following the presentation of a patient to our unit with idiopathic ulnar-sided hand pain. This led us to study this unusual finding in a cohort of asymptomatic patients. METHODS: Ninety-one radial and ulnar arteries were studied in 23 volunteers by color duplex ultrasonography. The subjects were all asymptomatic, their ages ranged from 18 to 78 years, and included 10 males and 13 females. RESULTS: Twenty-two percent of ulnar arteries occluded on clenching a fist, resulting in the hand relying on in-flow solely from the radial artery. All arteries opened up following fist release allowing anterograde flow. Furthermore, 11% of superficial palmar branches of radial arteries occluded on fist-making. The pattern of flow on making a fist showed an initial burst of reverse flow followed by reduced or occluded flow and subsequently an increase in antegrade flow after release of the fist. No subject could occlude both radial and ulnar arteries simultaneously. CONCLUSIONS: We discuss these findings in view of the potential clinical implications in terms of Raynaud's phenomenon, scleroderma, and importantly, the potential for false-positive findings of pathological ulnar artery occlusion on ultrasonography.