Entry 8

Severance of External Jugular Vein

The external jugular vein (EJV) begins with the union of the retromandibular vein and the posterior auricular vein at the inferior angle of the mandible. After crossing the sternocleidomastoid muscle just deep to the platysma and then enters the lateral cervical region. The EJV terminates in the sublavian veins and is responsible for draining most of the scalp and side of the face. The EJV has 8 branches with 5 located in the neck; these include the ascending pharyngeal, superior thyroid, lingual, facial and occipital veins.

Severance of the EJV posterior to the border of the sternocleidomastoid muscle where it pierces the roof of the lateral cervical region where the lumen is held open by the tough investing layer of deep cervical fasica. The negative intrathoracic pressure will suck air into the vein causing a churning noise in the thorax and cyanosis. This could cause a venous air embolism filling the right side of the heart with froth, and nearly stopping blood flow. Application of firm pressure to the severed jugular vein will stop the bleeding and entry of air into the vessel until it can be sutured.
http://www.bartleby.com/107/144.html

Carotid Occlusion and Endarterectomy

The internal carotid arteries (ICA) are major arteries of the head and neck that are the continuations of the external carotid arteries. The distinction between the two vessels occurs at the level of the superior boarder of the thyroid cartilage. The ICA ascends to enter the cranium through the carotid canals in the petrous parts of the temporal bones and become the main blood suppliers of the brain and structures in the orbits.

Atherosclerotic, cholesterol deposits, thickening of the intima of the ICA, which may obstruct blood flow. Symptoms depend on a varying degree of obstruction; a partial occlusion may cause a transient ischemic attack (TIA). TIA is a sudden focal loss of neurological function, e.g. dizziness and vertigo,  that disappear within 24hrs. Arterial occlusion may cause a minor stroke, which is a loss of neurological function such as weakness or sensory loss on one side of the body that exceeds 24hrs. and is gone within 3 weeks. A noninvasive procedure to check for an occlusion is called a Doppler. Once located a procedure called carotid endartercetomy, which is stripping off of the plaque blocking the vessel. After the operation pharmaceutical aids are given to inhibit clot formation until the endothelium has regrown.
http://en.wikipedia.org/wiki/Endarterectomy

Injury to the Suprascapular nerve

The suprascapular nerve originates from the union formed by the 5^th and 6^th cervical nerves. It runs lateral beneath the trapezius and the omohyoideus muscles, and enters the supraspinatous fossa through the suprascapular notch, below the superior transverse scapular ligament. It then passes beneath the supraspinatus muscle and curves around the lateral border of the spine of the scapula to the infraspinatous fossa. The nerve innervates the supraspinatus and infraspinatus muscles.

            Trauma to the suprascapular nerve is usually caused by a fracture of the middle third of the clavicle. Injury of this nerve results in loss of lateral rotation of the humerus at the glenohumeral joint. The ability to initiate abduction of the limb is also affected. Nonsurgical treatment is accomplished by avoiding overhead activities, and the rehab of muscles; unfortunately the overall success is limited and inconclusive. Surgical treatment is the released from the tunnel that has trapped the nerve. Usually performed at the suprascapular notch and/or spinoglenoid notch. This treatment is usually associated with a high rate of pain relief and functional improvement.
http://en.wikipedia.org/wiki/Suprascapular_nerve