Costochondral calcification, osteophytic degeneration, and occult first rib fractures in patients with venous thoracic outlet syndrome.
OBJECTIVE
Subclavian vein (SCV) compression in venous thoracic outlet syndrome (TOS) has been attributed to various anatomic factors, but a potential role for costochondral degeneration in the underlying first rib has not been previously examined. The purpose of this study was to examine the frequency of costochondral calcification (CC), osteophytic degeneration (OD), and occult first rib fractures (FRFx) in patients with venous TOS.


METHODS
Thirty-seven patients (21 male, 16 female) were referred for surgical treatment of venous TOS during a 12-month period, with a mean age of 30.7 ± 1.8 year (range, 12-55). Thirteen (35%) had acute SCV effort thrombosis and 24 (65%) had chronic symptoms (>14 days). Twenty (54%) had undergone SCV thrombolysis, 11 (30%) had persistent SCV occlusion, and 10 (27%) had concomitant symptoms of neurogenic TOS. All patients underwent paraclavicular thoracic outlet decompression with complete resection of the first rib to the sternum, with 20 (54%) having concomitant SCV reconstruction. The presence or absence of CC, OD, and FRFx was determined by direct visual examination of the rib at operation and following debridement of the excised specimen.


RESULTS
One patient had a cervical rib but there were none with radiographic first rib abnormalities. In contrast, FRFx were observed at surgical resection in 16 of 37 patients (43%). All FRFx were small, nondisplaced, linear lesions located within an area of CC in the anterior rib, typically in association with OD and perivenous soft tissue thickening. The mean age of patients with FRFx was higher than those with a normal first rib (38.1 ± 1.5 years vs 25.0 ± 2.3 years; P < .0001), and FRFx were present in 16 of 21 (76%) patients ≥ 30 years of age but in no patients younger than 30 (P < .0001).


CONCLUSIONS
A high proportion (43%) of patients with venous TOS exhibited CC, OD, and a previously undetected FRFx, including 76% of those over the age of 30. These lesions occur in the cartilaginous anterior rib where they are clinically occult and undetected by standard radiographic imaging. We postulate that age-related CC may predispose to OD and stress-induced FRFx, and that inflammation, fibrosis, and anatomic distortion in the surrounding soft tissues may contribute to SCV compression.
Center for Thoracic Outlet Syndrome and Department of Surgery (Section of Vascular Surgery), Washington University School of Medicine, St. Louis, MO 63110, USA.
George G
GG
Sheng
Yazan M
YM
Duwayri
Valerie B
VB
Emery
Anna M
AM
Wittenberg
Clementine T
CT
Moriarty
Robert W
RW
Thompson
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002114:Calcinosis / Q000209:etiology* / Q000473:pathology; D002648:Child; D003251:Constriction, Pathologic; D003646:Debridement; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D054850:Osteophyte / Q000209:etiology* / Q000473:pathology; D010027:Osteotomy; D011446:Prospective Studies; D012253:Rib Fractures / Q000209:etiology* / Q000473:pathology; D012272:Ribs / Q000293:injuries* / Q000473:pathology / Q000601:surgery; D018570:Risk Assessment; D012307:Risk Factors; D013350:Subclavian Vein / Q000473:pathology*; D013901:Thoracic Outlet Syndrome / Q000150:complications* / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult