Review of arterial thoracic outlet syndrome with a report of five new instances.

Arterial damage, causing ischemia of the limb, occurs in less than 5 per cent of all instances of thoracic outlet syndrome. Arterial complications are usually associated with cervical ribs or rudimentary first ribs, but 12 per cent have occurred in patients with no osseous abnormality. The physiopathologic factors begin with compression of the subclavian artery which, in most patients, produces stenosis, poststenotic dilatation, formation of aneurysms and mural thrombosis. In other patients, aneurysms do not form, but the compression still causes stenosis, intimal injury and mural thrombosis. With either scenario, distal embolization can occur and produce signs and symptoms of ischemia that can limb-threatening. In this study, more than 200 patients reported previously and five additional sides in four patients were reviewed. Treatment depends upon the condition of the patient at presentation. Those with osseous abnormalities and no aneurysm or symptoms are not treated, while those with poststenotic dilatation or small aneurysms undergo rib resection only. Aneurysms more than twice the arterial diameter, intimal injury or mural thrombus are indications to resect, replace or bypass the subclavian artery. Patients who have had distal embolization and severe ischemic symptoms require, in addition to the aforementioned, distal thromboembolectomy, dorsal sympathectomy or both. Good results from treatment have been reported in 84 per cent of the 137 patients reported since 1970; 3 per cent required amputation and 3 per cent had cerebral emboli. Because the severe arterial complications were primarily the result of delayed therapy, they can best be avoided by early recognition, diagnosis and treatment.