Proposed pathogenesis of Paget-Schroetter disease: Impingement of the subclavian vein by a congenitally malformed bony tubercle on the first rib

Aim: To study and compare the anatomical and clinical pathology of first ribs in patients with Paget-Schroetter Disease (PSD) with first ribs in patients without the disease. Methods: In a case-control study, normal human cadaver first ribs were compared with first ribs from patients with PSD. Ribs, intraoperative videos of transthoracic en bloc surgical resection of the first rib, and preoperative and postoperative dynamic upper extremity venograms were reviewed. Results: Fifteen first ribs were from patients with PSD and seven normal first ribs were from human cadavers. In all patients (100%) with PSD there was a bony tubercle that corresponded to the area of the subclavian vein groove in the normal ribs. In all controls (100%), there was a normal subclavian groove without the presence of a tubercle. On preoperative venograms in patients with PSD, the tubercle accounted for an extrinsic protuberance that compressed the subclavian vein (100%). Intraoperatively, the abnormal bony tubercle accounted for the extrinsic compression of the subclavian vein in all (100%) patients with PSD. Venograms of the upper extremity obtained after first rib resection showed the disappearance of the extrinsic compression on the subclavian vein (100%) and a patent subclavian vein with elevation of the arm in all patients. Conclusions: A bony tubercle at the site of the subclavian vein groove in patients with PSD causes extrinsic compression of the subclavian vein at rest.