[Anatomical study and clinical observation of thoracic outlet syndrome].

OBJECTIVE

To investigate the etiology of thoracic outlet syndrome (TOS) from the point of anatomical and clinical view.

METHOD: Anatomical study was made on both sides of 30 cadavers. The minimus scalene muscle and the insertions of anterior and middle scalene muscle were dissected and observed. Clinically, 45 cases of thoracic outlet syndrome (TOS) were treated and followed up.

RESULT: The minimus scalene muscle was found in 88.3% of the cadavers. T(1) nerve root or the lower trunk of brachial plexus crossed the first rib just over the proximal tendinous part of minimus scalene muscle. Of 45 cases of TOS 34 presented neck-shoulder-pain 17 had. Unchanged symptoms postoperatively, and 7 had aggravated symptoms. Of the recent 8 cases of TOS, 7 presented neck-shoulder-pain. However, the symptom remained in only case after the resection of the tendinous tissue around 5, 6 nerve root from anterior and middle scalene muscle.

CONCLUSION

The tendinous tissue of minimus muscle is the cause of the compression of T(1) nerve root or the lower trunk of the brachial plexus. The crossed tendinous origins from the anterior and posterior tubercle of C(4,5) transverse process is the cause of the compression of C(5,6) nerve root or the upper trunk of brachial plexus.