Abstract
BACKGROUND: Thoracic outlet syndrome (TOS) is a rare condition (∼1-3 per 100,000) caused by neurovascular compression at the thoracic outlet. Arterial involvement is uncommon and may result from chronic or dynamic subclavian artery compression leading to endothelial injury, thrombosis, and distal ischemia. Hypothenar hammer syndrome (HHS) is an uncommon cause of hand ischemia due to repetitive trauma to the ulnar artery and palmar circulation and has been reported in athletes engaged in repetitive high-impact hand activities (e.g., baseball, karate, golf, volleyball). CASE PRESENTATION: We report a 16-year-old male volleyball player with a one-month history of cold, pale fingers (Raynaud phenomenon), most pronounced in the right middle finger, accompanied by right upper limb numbness and pain. Initial vascular ultrasound was unremarkable and autoimmune investigations were negative. CTA acquired in an overhead/provocative position demonstrated focal narrowing of the right subclavian artery at the costoclavicular space, compatible with arterial thoracic outlet compression (aTOS-spectrum). Targeted duplex ultrasonography of the hand demonstrated palmar arterial wall irregularity/thickening with intraluminal thrombus and digital ischemia, consistent with distal palmar arterial thrombosis in the HHS spectrum. Provocative maneuvers (Adson's and Roos tests) were positive. The patient underwent ultrasound-guided intra-arterial thrombolysis of the ulnar artery with urokinase, along with anticoagulation and vasodilator therapy (papaverine and prostaglandin E1) and shoulder rehabilitation; symptoms improved mildly on follow-up. CONCLUSION: Unilateral Raynaud-like digital ischemia in young athletes may reflect distal palmar arterial thrombosis in the HHS spectrum; provocative-position thoracic outlet compression should be interpreted cautiously, and management should prioritize reperfusion and surveillance.