[Ultrasound image of the hypothenar hammer syndrome]

A traumatic lesion of the ulnar artery (Hypothenar Hammer Syndrome, HHS) is a very rare cause of acral ischemia of the upper extremity.

Evaluation of the efficacy of ultrasound techniques in the diagnosis of the HSS.

Based on the knowledge of the patient's history and clinical examination we investigated forearm, hand and digital arteries by continuous wave Doppler. By means of colour-coded duplex sonography (CCDS) we demonstrated the course of the radial and ulnar arteries to the palmar arch. For comparison we used the results of preintervention angiography.

The diameter of the distal ulnary artery measured in healthy women was 1.8 +/- 0.32 and in men 2.2 +/- 0.46 mm. Among 268 patients with ischemia of the hands we diagnosed HHS in four cases. We identified an aneurysm of the ulnary artery in one case and a thrombotic occlusion in three cases. The thrombotic occlusion of the ulnar artery led to a dilatation of the vascular lumen. The occlusion length could be determined. Vessels diameter and echogenecity gave information about the age of the thrombosis.

The continuous wave Doppler is a major diagnostic contribution because of its ability to register hemodynamic changes. Additionally, CCDS with its combination of sonomorphology and hemodynamics enables a distinction between HHS and other causes of digital ischemia. The CCDS more precisely refines the indications for preinterventional angiography in acute ischemia syndromes of the hand.