The intercostals muscles were divided along the lower border of the first rib. The subclavian artery and vein were carefully separated from the superior surface of the rib. Inflammatory reaction can make these vessels adherent and thin. Post stenotic dilatation can also affect the wall of the artery. The medial rim of the rib is carefully separated from endothoracic/Sibsonís fascia to complete the circumferential dissection.