Introduction Aneurysm is defined as a permanent dilation of an artery with a 50% increase in its normal diameter Epidemiology Incidence rare < 1 per 100,000 Etiology Pathophysiology traumatic true aneurysm blunt trauma weakens the arterial wall causing it to dilate appear more uniform in shape false aneurysm (e.g. pseudoaneurysm) pentrating trauma to arterial wall replaced by organized hematoma and fibrous wall appear more 'sac-like' in shape non-traumatic inflammatory atherosclerotic Presentation History recent blunt or penetrating hand trauma Symptoms slow-growing painful mass many be sensory disturbance due to compression of adjacent digital nerve Physican exam palpable mass may be pulsatile in ~ 50% of cases may occur in any of the 5 digits most common in thumb > index > ring finger Imaging Radiographs indication usually not helpful concern of destructive lesion findings usually normal Doppler ultrasound or angio–computed tomography (CT) scan indication pre-operative confirmation findings size and location of lesion thrombus formation collateral circulation Differential Arteriovenous fistulas Neurilemmomas Foreign body granulomas Ganglions Epidermoid cysts Treatment Nonoperative observation and analgesics indications small, asymptomatic lesions ultrasound-guided thrombin injection indications some reports use this techique in lesions arising more proximal in the hand or wrist. Operative surgical exploration and ligation indications symptomatic lesions with adequate collateral circulation technique ligation performed proximal and distal repair with interpositional grafting indications symptomatic lesions with inadeaquate collateral circulation Techniques Digital artery aneurysm repair end-to-end anastomosis and an autogenous interpositional vein or arterial graft Complications Digital ischemia Chronic pain