Procedural anatomy Flashcards
(153 cards)
Internal jugular vein originates?
Jugular bulb (confluence of the inferior petrosal sinus and sigmoid sinus)
* exits the skull via the jugular foramen
How does the IJ descned in the neck? Relationship to the carotid?
- Descending laterally to the internal carotid and later common carotid in the carotid sheath
- To ICA
◦ At C2 - IJV posterior to ICA
◦ At C3 posterolateral
◦ From C4 anterolateral (common carotid) at the apex of sedilots triangle between he two heads ot the SCM
Where does the IJ terminate
- Terminates behind the sternal end of the clavicle where it joins the subclavian vein to form the brachiocephalic vein - the inferior end dilates to from the inferior bulb of the IJV which has a bicuspid valve permitting blood flow toward the heart
How is the path of the left and right IJ slightly different?
- Right IJ follows a direct course inferiorly to the SVC
- The left IJ courses to the right after it joins the subclavian vein to become the brachiocephalic vein which courses inferiorly as it joins the SVC
Tributaries to the IJ vein (4 primary)
- inferior petrosal sinus - enters superior bulb of the IJV after leaving the jugular foramen
- Facial vein - empties at the level of the hyoid, may receive the superior thyroid, lingual or sublingual veins
- Lingual veins - at the origin of the lingual artery
- Pharyngeal veins - from venous plexus of the pharyngeal wall emptying at the angle of the mandible
- Superior and middle thyroid veins
- The occipital vein may drain into the IJV
Anterior borders of the IJ vein
- Anteriorly - SCM, fascia, platysma, fascia, skin
Posterior borders of the IJ vein
- Posterior - lateral mass of C1 (transverse process), scalene muscles, cervical plexus, sympathetic chain, phrenic nerve, vertebral vein, 1st part o subclavian artery, and lung pleura (thoracic duct on left)
Medial borders of IJ vein
- Medially by internal carotid, thyroid, trachea, oesophageal
Lateral borders of the IJ vein
- Lateral - fascia, skin, SCM
Name 4 major relationships of the IJ vein and describe their relative passage
- To ICA
◦ At C2 - IJV posterior to ICA
◦ At C3 posterolateral
◦ From C4 anterolateral (common carotid) at the apex of sedilots triangle between he two heads ot the SCM - Vagus nerve - posteriorly in the carotid sheath between the carotid and the IJV; 9th to 12th cranial nerves above common carotid artery and vagus
- Cervical sympathetic plexus and phrenic nerve posterior to carotid sheath behind the ICA in the prevertebral layer of the deep cervical fascia
- Deep cervical lymph nodes close to vein
- External jugular crosses the sternomastoid belly of the SCM running posteriorly and more superficial to the IJV - later perforating the deep fascia to drain into the subclavian vein
- PLeura rises above the clavicle and is close to the vein at its termination
- Thoracic duct passes inferior and lateral to the confluence of the L IJV and SCV (as it joins on the superior margin of the subclavian vein near the jugular-subclavian junction) and may be injured during LEFT IJV cannulation - the right lymphatic duct can also be injuries during R cannulation but due to its smaller size this is less common
What is the triangle used to ascertain surface anatomy of the IJ vein
- Sedillots Triangle formed from 2 heads of SCM (sternal heat medially, clavicular heat laterally) and clavicle superior border of medial third - enter at the middle of the triangle
What is Sedillots triangle? Describe its makeup
- Sedillots Triangle formed from 2 heads of SCM (sternal heat medially, clavicular heat laterally) and clavicle superior border of medial third - enter at the middle of the triangle
If you use Sedillots triangle for insertion of an IJ describe the surface anatomy for insertion
- Sedillots Triangle formed from 2 heads of SCM (sternal heat medially, clavicular heat laterally) and clavicle superior border of medial third - enter at the middle of the triangle
- Palpate the artery and entry site is lateral to this at approximately C6
- Aim caudally, 30 degree angle to frontal plane parallel to sagital plane and towards ipsilateral nipple
Descibe the USS characteristics of the IJ
Ultrasound - deep to SCM thin walled, non pulsatility and compressible. Either halfway between clavicle and mastoid, or 1/3 of the way up from the clavicle (i.e. slightly lower). Too low and risk of pneumothorax increased but increased separation from carotid, too high and in beard, difficult to dress neatly, carotid closer.
Central approach to the blind IJ insertion technique?
- Central - apex of triangle formed by each muscle belly of the SCM and the clavicle, insert 1cm above apex of head of SCM and clavicle advancing 60cm to skin aiming towards ipsilateral nipple (45 degrees off a coronal plane, needel advaned in a sagital plane) with aspiration of blood at 3cm
Anatomical variations of the IJ vein
Anatomical variations
* Variation in its relationship to the carotid artery - further lateral, or medially overlying the carotid artery anteriorly
* Partial or complete duplication
* Stenosis or occlusion
* Intraluminal membranes, webs or inverted valves
* Congenital aneurysm
* Absent IJV
Describe the path of the external jugular vein
- Crosses SCM sternomastoid belly running posteriorly and more superficial to the IJV later eprforating the deep fascia to drain into the subclavian vein
Origin of the subclavian vein
a direct continuation of the axiliary vein beginning at the lateral border of the first rib as the vein passes deep to the clavicle
Course of the subclavian vein
- The subclavian vein travels medially superficially and superior to the first rib forming a slight groove, posterior to clavicle
- Arches up, medially then down to its termination
- Turns infero-medially entering thoracic inlet into the mediastinum passing anteiro the scalenus anterior
Landmarks on surface anatomy of the subclavian vein
◦ Clavicle
◦ Two muscle bellies of SCM
◦ Suprasternal notch
◦ Deltopectoral groove
◦ Manubrosternal junction
Describe the infraclavicular approach to a subclavian line?
◦ Insert the needle a 1-2cm inferior and lateral to (Deltoid tuberosity of clavicle) junction of medial third of clavicle, 2-3cm inferior to deltopectoral groove aiming towards suprasternal notch (non dominant index finger stays in the supraclavicular notch) and keep neelde parallel to floor
‣ Needle should pass under the junction o the medial 1/3 and lateral 2/3 of the clavicle and directed at index finger/supra sternal notch or just superior
What critical safety aspects to blind insertion of a subclavian line do you need to be aware of? 2 things to never do
- Never angle posteriorly - artery or lung
* Never angle inferior - lung
* Puncture reasonable distance from the clavicle else you’ll never get under it - the more medial you come the more it opposes the pleura
Layers of insertion for a subclavian line
‣ Skin
‣ Subcutaneous fat
‣ Clavicular head of pectoralis major
‣ Clavipectoral fascia enclosing subclavius
‣ Subclavian vein
‣ Further insertion would penetrate scalenus anterior –> subclavian artery/brchial trunk plexus –> pleura
How does the subclavian vein relate to the artery?
◦ Runs together with artery deep to vein throughout course - superior and posterior
◦ Subclavian artery is separated from subclavian vein by scalenus anterior - artery posterior to same