Anterior Scalene

Each subclavian vein is a continuation of the axillary vein and runs from the outer rim of the first rib to the medial rim of the anterior scalene muscle. Here the subclavian and internal jugular veins join inside the anterior edge of the superior thoracic opening and create right and left innominate veins behind the sternal manubrium. The vein usually has a pair of valves about 2 cm from its end. The heads of clavicles extend posteriorly into the superior thoracic opening, displacing the veins posteriorly from the sternum. Because of the anteroposterior slope of the superior aperture, the arteries are... 

One solution is to use a telescopic technique with progressively larger sizes to enlarge the costoclavicular route. Therefore, because the subclavian vein is compressed between the clavicle and anterior scalene muscle when the shoulder is displaced posteriorly and downward, it is advantageous to have the shoulder in neutral position with no roll during sheath advancement to keep the vein wide open. When sheath advancement is not possible or unsuccessful despite using the telescopic technique, and if the lead is free from adhesions, the Pisa approach [32] may be helpful. 

The thoracic outlet region includes the brachial plexus nerves and the subclavian artery and vein. These neurovascular structures traverse restricted spaces in which they can be compressed, the most important of which are the interscalene triangle, the costoclavicular space and the retropectoralis minor space (Fig. 6.16a) (Demondion et al. 2000). Both subclavian artery and brachial plexus nerves pass through the interscalene triangle, a space bordered by the anterior scalene musde anteriorly, the middle scalene muscle posteriorly and the first rib inferiorly. 

The physician palpates superficially at first and then more deeply into the tissues. The texture of the tissues is evaluated including bogginess, ropiness, or a change in tone of the muscles. Although the tissues posteriorly are being evaluated for an indication of the presence of somatic dysfunction, the anterior neck tissues should be evaluated as well. The scalene muscles and the sternocleidomastoid muscles can give important clues regarding cervical pain or motion restriction. 

The first, second, tenth, eleventh, and twelfth ribs are considered atypical ribs. The first rib is flat, has the greatest curvature and the shortest length of all the ribs, and has no angle or costal groove. Its superior surface has grooves for passage of the subclavian vessels and elevations for the attachment of the anterior and middle scalene muscles. The single facet of the head articulates with the body of the T1 vertebra. 

Rib one often has a component of elevation, possibly caused by the pull of the anterior and medial scalene muscles, as well as the medial upward pull of the sternocleidomastoid on the rib via the medial clavicle. 

The lirst rib is probably the rib most commonly involved in somatic dysfunction of all the ribs. It is affected by trauma, stress, and posture as well as by dysfunction ofthe C7-T1 complex. The patient may report "shoulder" pain, stiff neck, upper back or neck pain, and an inability to turn the head while driving. The first rib can impinge the neurovascular bundle as it passes between it and the clavicle through the costoclavicular space. The anterior and middle scalene muscles, which raise the first rib, may likewise compress the brachial plexus when they are in spasm and result in thoracic outlet syndrome symptoms. The patient s symptoms are then described as pain, numbness, or paresthesias ofthe arm or hand on the involved side. The physician needs to be aware that this may cause confusion should the patient demonstrate a herniated cervical disc on magnetic resonance imaging [MRO. The symptoms may be caused by the rib dysfunction rather than the herniated disc, so evaluation ofthe rib for normal motion and treatment of any dysfunction should be performed in these cases. Osteopathic manipulation may save the patient unnecessary surgery. 

The transverse processes of the cervical vertebrae project from the junctions of the pedicles and laminae and act primarily as attachments for muscles, such as the scalene muscles. Each process has a U shape formed by two prominent bony tubercles, anterior and posterior, which form its walls, and a thin lamina, which forms its floor (Guha etal. 1996). This lamina is pierced by the vertebral artery, which... 

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