A constriction between the first rib and the collarbone and the anterior scalene muscle with or without a cervical rib can lead to constriction and compression of the structures passing between the two bones – the subclavian vein, subclavian artery and brachial nerve cord. The venous symptoms can range from swelling of the arm when working overhead to arm vein thrombosis. Constriction of the subclavian artery can lead to cold and numb hands when working overhead, as well as vascular occlusion and embolisms in the event of vasodilatation. Compression of the nerves can lead to atrophy of the thenar muscles and the lumbrical muscles.
The first step in the diagnosis is an ultrasound examination in the proving position. In the case of neurological deficits, a nerve conduction velocity measurement is also indicated to confirm the diagnosis and rule out other neurological causes. Furthermore, a CTA in the provocation position is appropriate to assess the vascular, muscular and bony structures in relation to each other.
If indicated and physical therapy is unsuccessful, resection of the first rib via a transaxillary approach is the treatment of choice.
Diagnosis and indication for tansaxillary resection of the first rib should not be treated conservatively.
