Digital Ischemia Associated with a Thrombosed Aneurysm of the Dorsal Interosseous Artery. A Case Report*

Abstract

True aneurysms in the upper extremity are unusual, particularly in the absence of trauma3,9. We report the treatment of digital ischemia caused by thrombosis of an aneurysmal dorsal interosseous artery. Our report is noteworthy in that the patient also had bilateral congenital absence of the radial artery, a rare and embryologically primitive variation of human anatomy8. A fifty-five-year-old healthy woman who worked at a restaurant was referred to us because of a twenty-four-hour history of pain, numbness, and bluish discoloration of the left index finger. Clinical examination revealed an absent radial pulse and a positive Allen test7, denoting inadequate inflow through the radial artery. For the Allen test, the patient performed repeated, forceful flexion and extension of the digit while the examiner applied pressure to the volar radial and ulnar arteries at the wrist with his thumbs and pressed on the dorsal aspect of the wrist with his forefingers. When the pressure over the radial artery was released, the hand remained white and ischemic, indicating no perfusion through that artery. Sensation in the index finger was diminished, with two-point discrimination of greater than twenty millimeters. Notably, the radial pulse was not palpable at the wrist on the contralateral, asymptomatic side. Arteriography of the left upper extremity revealed a four-centimeter filling defect in what initially appeared to be an anomalous radial artery. In addition, no flow through the radial artery was seen (Fig. 1). Local intra-arterial infusion of urokinase (100,000 units per hour) was begun, and repeat angiography, twenty-four hours later, demonstrated restoration of blood flow to the affected digit. A long fusiform aneurysm was now evident at the site of the previous filling defect (Fig. 2). Clinically, the digital pain and discoloration decreased. The …