Frequency of the Pectoralis Minor Compression Syndrome in Patients Treated for Thoracic Outlet Syndrome

Background: Pectoralis minor compression syndrome (PMCS) is a compression of the neurovascular structures in the subpectoral tunnel and remains underestimated in the management of patients with thoracic outlet syndrome (TOS). Its underdiagnosis may be responsible for incomplete or failed treatment. The aim of the study was to evaluate the frequency of PMCS in our experience. Methods: We retrospectively reviewed all patients treated for TOS in our department. We selected those in whom PMCS was diagnosed with a systematic dynamic arteriography. Surgery was performed using the Roos axillary approach when a first rib resection was associated or an elective approach when a first rib resection was not associated. Results: From January 2004 to December 2014, 374 surgeries for TOS were performed in 279 patients, which included 90 men (sex ratio = 0.48) with a mean age of 40.1 +/- 10 years old. Among these patients, 63 (22.5%) underwent 82 interventions (21.9%) for PMCS, including 26 men (sex ratio = 0.70, P < 0.05) with a mean age of 37.9 +/- 9.4 years old. Tenotomy of the pectoralis minor muscle was performed using axillary approach if it was associated with a first rib resection in 74 cases (90.2%) or through an elective approach in 8 cases (9.8%) if it was isolated. Four (4.9%) postoperative complications were found (1 hematoma [1.2%], 1 hemothorax [1.2%], 1 scapula alata [1.2%], and 1 subclavian vein thrombosis [1.2%]), all after an axillary approach. In 63 cases (79.7%), preoperative symptoms were resolved. In 14 cases (17.7%), symptom resolution was incomplete, and 2 patients (2.6%) had recurrent symptoms. Conclusions: Evaluation of PMCS in TOS is justified by its frequency and the simplicity and low morbidity of the surgical procedure.