Study design.
Twenty-eight consecutive patients (32 limbs) with TOS who underwent surgery in our department between April 2016 and February 2020 were evaluated. We excluded one patient (2 limbs) with ‘true neurogenic TOS’ on the basis of Gilliatt-Sumner hand22,46,47 associated with bilateral cervical ribs, which were excised by the supraclavicular approach. Among the remaining 27 patients, 30 limbs were included in the present study. There were 14 males and 13 females, and the mean age at surgery was 28.1 years (range, 15–50 years).
Diagnosis.
The diagnosis of TOS is controversial44,45, and no specific set of diagnostic criteria has yet been established48. We diagnosed patients as having TOS on the basis of symptomatic presentation, physical examination maneuvers including the Roos test49, Wright test50 and Moley test2, and lack of any evidence of a more likely cause. Patients with traumatic TOS were excluded. Color Doppler and Duplex ultrasonography are useful diagnostic modalities in this context21,22. The measures assessed included blood flow disruption, low blood flow, and accelerated blood flow in the subclavian artery demonstrated by Doppler sonography, the scalene interval width between the anterior and middle interscalene muscles (interscalene base)28, and the costoclavicular space demonstrated by Duplex ultrasonography26,27 in a resting position with the shoulder in abduction and in the external rotation (ABER) position sitting on a chair (Fig. 5) by a medical technologist (T.K.). Furthermore, enhanced computed tomography (CT) was performed with the shoulder in full abduction to confirm the presence of stenosis of the subclavian artery23–25 and the costoclavicular space29. If peripheral neuropathy such as ulnar and median neuropathy could not be ruled out, nerve conduction studies were also performed.
Surgical technique.
The patient was placed in a lateral position with the arm elevated to expose the axilla using a limb positioner (SPIDER2, Smith & Nephew, Memphis, TN) for the upper extremity and operated on under general anesthesia. The upper limb position was set at 150 degrees of abduction in the early phase (n = 3, Fig. 3a), 90 degrees of abduction with the arm pulled upwards according to Roos33 in the middle phase (n = 15, Fig. 3b), and in the subordinate pivotal position20/zero-position30 in the late phase (n = 12, Fig. 3c). At the beginning, it was difficult to obtain appropriate visualization. Therefore, we changed the position in three stages to improve visualization (Videos 2, 3).
A transverse 4-cm skin incision was made over the third rib between the pectoralis major and the latissimus dorsi muscles at the axillary hairline level (Fig. 3d). Careful dissection was performed to allow confirmation of subclavian artery pulsation with a finger. An arthroscopic incision was made more superior and posterior at the third rib level (Fig. 3d). We used a 4-0-mm 30-degree arthroscope, detached both the anterior and middle inter-scalene muscles from the first rib, excised the first rib piecemeal using bone cutting rongeurs, and neurolysis of the brachial plexus was performed with arthroscopic assistance (Fig. 6, Video 4).
Informed consent was obtained from all included patients and/or a parent (age blow 18).
Postoperative care.
Range of motion exercise for shoulder abduction up to 90 degrees was allowed immediately after surgery, and unlimited shoulder motion was allowed after four weeks. The patients returned to full activities, such as sports, between two and three months after surgery.
Evaluation of clinical data and definitions of outcome variables.
A comprehensive review of medical records was conducted by one observer (H.S.). Demographic and surgical data collected included the following: securing visualization in each upper limb position; intraoperative measurement of the interscalene base; intraoperative blood loss; operation time; preoperative and postoperative QuickDASH; patient satisfaction; and complications at a mean of 25.6 months (range, 12–56 months) after surgery. Patient satisfaction was divided into four categories according to Derkash et al.51: excellent, complete relief; good, almost complete relief; fair, partial relief; poor, no improvement. We compared the clinical results among these patients according to whether they were athletes or not.
Statistical analysis.
The QuickDASH was compared using Wilcoxon test and Fisher’s exact test, while intraoperative blood loss and operation time were compared using Kruskal-Wallis test. Differences at P < 0.05 were regarded as statistically significant. All statistical analyses were performed with the EZR software program (Saitama Medical Center, Jichi Medical University, Saitama, Japan), which is a graphical user interface for R (The R Foundation for Statistical Computing, Vienna, Austria, version 3.6.3)52.