[Paresthesia, pain, coldness of the arm and possible responsibility of the thoraco-brachial outlet syndrome].

Paresthesia, pain and coldness of the upper limb strongly suggest ischemia. The questions raised concern the etiology and treatment. 1) Treatment is based on confirmation of the unilateral nature of the disorder requiring search for the a locoregional cause (examination of the subclavian outlet) and on elimination of a cardiac or general origin. Two noninvasive examinations are indicated. An X-ray examination of the upper chest bones is performed to search for an abnormal formation, usually a cervical rib. Presence of a cervical rib indicates a possible damage to the sub-clavian artery in the thoraco-brachial outlet and, inversely, absence of a cervical rib suggests either arterial damage or a fibromuscular cause. Ischemia of the upper limb results from repeated microtrauma to the sub-clavian artery due to a bone-ligament anomaly resulting in thickening and parietal ulceration, and sometimes post-stenosis embolism or in situ thrombosis. Duplex Doppler may be able to identify the nature of the cause without dynamic manoeuvres. An arteriography is essential to confirm the level of the obstacle, its nature, the status of the downstream bed and possible relationship between a bone anomaly and the sub-clavian artery. Several incidences may be required. 2) Therapeutic modalities must take into account the ischemia and its cause. Surgery is required to remove the obstacle and repair the arterial damage, and possibly to remove an embolus. It is relatively easy to remove a cervical rib or repair a bone muscle anomaly, allowing arterial repair with or without venous bypass. Embolectomy of an earlier embolus may require major reconstruction vascular surgery.