Clinical History
The patient was admitted to the hospital because of coldness, numbness, cyanosis and pain in his right arm.
Imaging Findings
The patient was admitted to the hospital because of coldness, numbness, cyanosis and pain in his right arm. Chest X-ray revealed rudimentary right first rib associated with second rib synostosis. Subsequent spiral CT examination demonstrated the congenital rib anomaly (Fig.1) and the stenosis of right subclavian artery at costo-clavicular level (Fig.2-3), suggesting that clinical findings were due to distal embolism.
The patient underwent thrombolytic treatment followed by transaxillary resection of the right first and second ribs with complete recovery of the symptoms.
Discussion
The thoracic outlet syndromes (TOSs) are a group of common conditions caused by compression at some point between the interscalene triangle and the inferior border of the axilla of the vessels and/or nerves that supply the upper limb. Compression can occur at various anatomic levels: interscalene triangle, costo-clavicular passage, pectoralis minor tendon.
Arterial TOS is usually secondary to the presence of a cervical rib or to a costo-clavicular compression (as in our case) and is often associated with pain, heaviness, fatigue, weakness, pallor, and pulse deficit due to brachial ischemia. The vascular complications of TOS are uncommon and occur in less than 5% of cases (usually associated with an anomalous first rib). Degenerative changes can occur in the subclavian artery and the vessel may become a source of embolism with the risk of acute or chronic upper limb ischemia.
Acute arterial occlusion in patients with TOS is rare and thrombolysis associated with first rib resection is the procedure of choice. If removal of the first rib fails to restore arterial caliber to normal, surgical resection of the artery is required.
Plain radiographs are very important because they may reveal bony anomalies. In addition, spiral CT or DSA are essential to correctly evaluate TOS and choose appropriate treatment.
Differential Diagnosis List
Thoracic outlet syndrome with acute arterial obstruction caused by abnormal first rib.
Final Diagnosis
Thoracic outlet syndrome with acute arterial obstruction caused by abnormal first rib.
