There have been reports of anomalous muscular slips between scalenus anterior and scalenus medius muscles.
There also have been few case reports of absence of scalenus anterior muscle.
Structures in this region commonly assessed by clinicians include the cervical lymph nodes, external jugular vein, brachial plexus, SCM and scalenus
In one subject, a vein was identified between the scalenus
anterior and scalenus
medius muscles amongst the trunks (see Figure 5).
The muscles most commonly involved in the thoracic outlet region are the two scalene muscles (scalenus
anterior and scalenus
medius) attaching to the first rib, the subclavius muscle attaching between the clavicle and first rib, and the pectoralis minor attaching at the coracoid process.
Surgical treatment for symptoms produced by cervical ribs and the scalenus
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.
The key points in both the approaches are (1) complete resection of bony, cartilaginous, and fibrous parts of (2) complete resection of the scalenus
anterior muscle at the scalene tubercle on the first rib and (3) arterial exploration and reconstruction.
Passive treatment included manipulative therapy of the cervical and thoracic spine, ischemic compression of trigger points and cross frictional massage of the pectoralis major and minor, the scalenus
group and the sub-occipital group of muscles.
Complete dissection of the neck was done and the roots were followed up to the intervertebral foramina by removing scalenus
In the root of neck each artery arches across the dome of pleura behind the scalenus
anterior muscle which divides it into three parts viz.
A variant of omohyoid presenting as an additional muscle belly extending between clavicle and hyoid bone (1), The superior belly of omohyoid attached to the transverse process of the C6 anterior to the scalenus
medius (2), double omohyoids (3, 4), absence of superior belly (5), short omohyoid4 and cleidohyoid (4, 6) were reported.