Endoscopic Assisted First Rib Resection for Thoracic Outlet Syndromes in Overhead Throwing Athletes

OBJECTIVES: Thoracic outlet syndrome (TOS) is a complex of signs and symptoms resulting from compression of the nerves and vessels supplying the upper limb. Repetitive and cumulative stress of the upper extremity in athletes are associated with TOS. Despite of several previous reports, TOS is incompletely understood, difficult to diagnose, and often poorly managed. Especially, etiology and pathology on throwing athletes with TOS have not been still unknown. Recent articles showed that with the help of the endoscope, more safety and less invasive surgery has been achieved. We consider that intraoperative observations will lead to analyses the pathology of TOS in athletes. The purpose of this retrospective study was to investigate characteristic clinical features, objective imaging, intraoperative findings, and surgical outcomes of patients with TOS in overhead throwing athletes. METHODS: This study analyzed 158 cases of TOS (47 women and 111 men) who underwent endoscopic assisted first rib partial resection. Patients were divided into 2 group: athletes (89 patients) and non-athletes (69 patients). The diagnosis of TOS was based on clinical features, plane radiographs, ultrasonography, three-dimensional computed tomography angiography, and MRI. Indications for this surgery included failure of more than 6 months of conservative treatment or evidence on artery interruption on 3D angiography or obvious narrowing of interscalene region on ultrasound. Conventional transaxially approach described by Roos with endoscopic assist was underwent for partial resection of the first rib and decompression of neurovascular bundle. Intraoperative findings involved as follows; Interscalene distance (ISD): the distance between the posterior edge of the anterior scalene and the anterior edge of the middle scalene, Neurovascular bundle (NVB) patterns: based on alignment of the nerve, artery, and vein, following three types; parallel type, oblique type, and vertical type. Evaluation was performed through use of the clinical rating system of Roos’s classification, DASH, intraoperative endoscopic findings, plain radiographs, and ultrasonography. The mean follow-up period was 17.4 (from 6.4 to 42.4) months. RESULTS: We found characteristic clinical features in athletes with TOS compared with non-athletes as follows; younger (16.7 years vs 36.3 years), shorter duration of symptoms (7.8 vs 26.0), and better outcomes (excellent or good percentage in Roos score; 91.0 % vs 73.9 %). Intraoperative findings showed no significant differences of ISD and NVB patterns between athletes and non-athletes. On the other hand, anatomical variation including abnormal bundle was found more frequently in athletes compared with non-athletes (Figure 1, Table1). There were no major complications. CONCLUSIONS: In conclusion, endoscopic assisted transaxially approach for first rib resection in TOS provided a superior magnified clear visualization and safely sufficient decompression of neurovascular bundle. The current study showed better clinical outcomes in athletes compared with non-athletes. Several factors including younger, shorter duration of symptoms, and anatomical variation would reflect to the result. The orthopaedic surgeon should be aware of the possibility of TOS in an adolescent who plays an overhead throwing sport. Appropriate surgical indication would provide them superior clinical outcomes.