The vertebral artery (VA) arises from the superior surface of the first part of the subclavian artery medial to the scalenus anterior
Careful dissection of the subclavius muscle was performed following which the scalenus anterior
and scalenus medius muscles were identified and removed in piecemeal.
It is usually attached to the first rib, close to the insertion of scalenus anterior
* Our patient had a first rib resection, partial division of the scalenus anterior
and medius muscles, and lysis of the cervical band.
It passes between longus colli and scalenus anterior
muscle, behind the common carotid artery and the vertebral vein through the foramina in the transverse processes of all of the cervical vertebrae except the seventh, curves medially behind the lateral mass of the atlas and enters the cranium via the foramen magnum.
[1,2] Muscle abnormalities were found in the scalenus anterior
, scalenus medius and sternocleidomastoid muscles.
The posterolateral boundaries of Sibson fascia are the vertebral column, first rib, levator scapulae muscle, and scalenus medius muscle; the medial boundary is formed by the superior mediastinal structures; and the anterior boundary is formed by the scalenus anterior
and sternocleidomastoid muscles.
Intra operatively there was a thick walled, multilobulated cyst in the supraclavicular region within the muscles of scalenus anterior
and posterior and going underneath the deltoid muscle.
The muscles attaching to the first rib are the scalenus anterior
, the scalenus medius, the serratus anterior, and the intercostaes.
In the physiotherapeutic literature scalenus anterior
has been depicted as palpable and measurable by surface electromyography (EMG) within the posterior triangle of the neck, but without explaining in detail how this is achieved.
Abnormalities include: a drooping shoulder girdle, a cervical rib or fibrous band, an abnormal first rib, continual hyperabduction of the arm, or--rarely--compression of the edge of the scalenus anterior
The result, according to her, was that she suffered thoracic outlet syndrome, requiring the removal of the first rib on her right side, and scarring of the brachial plexus nerve, necessitating the severing of the scalenus anterior