2019B Question 15
Describe the anatomy and relations of the right internal jugular vein relevant to performing central venous cannulation.
Examiner Report
The major domains assessed in this question were the anatomy of the right internal jugular vein – its origin, insertion, a description of the pathway the vein travels, the relations of the vein as it travels through the neck, the surface and sono-anatomy anatomy of the vein and their relevance to achieving safe, successful cannulation.
Credit was given for other relevant correct material.
The commonest error was to spend significant time describing central venous cannulation hence not answering the question asked. Other common problems were insufficient detail of the anatomical path and structures around the vein and inaccurate correlation of anatomy and technique. Diagrams unfortunately were commonly poorly drawn and attracted few additional marks, due to errors, no level specified for cross-sections and a lack of labels.
No marks were awarded for discussing clinical utility of CVC insertion. Complications of CVC insertion were also not assessed directly, but credit was given for describing these in light of anatomical relations or aspects of cannulation technique.
The references used for this question were Anatomy for Anaesthetists Ellis and Lawson 9th Ed pp 79-105 and Millers Anesthesia 8th Ed Chapter 45 pp1345-1395
Model Answer
Structure:
- Anatomy description: Location, passage, borders
- Approach: Landmark and ultrasound
- Complications: Especially those relevant to anatomy
Anatomy
| Anatomical: | Details |
|---|---|
| Location | In the anterior triangle - Anterior midline - Anterior border of sternocleidomastoid - Inferior angle of the mandible |
| Origin | - Confluence of R sigmoid sinus + R inferior petrosal sinus, at the jugular foramen |
| Passage | - Passes vertically down the neck - Within the carotid sheath |
| Termination | - R internal jugular vein + R subclavian vein → R brachiocephalic vein - Note direct continuation to SVC and right atrium, hence right internal jugular preferred to left |
| Relation to internal carotid artery | - At C2: Posterior - At C3: Posterolateral - From C4: Lateral - (note may appear posterior in the lower neck if ultrasound applied radially rather than antero-posterior) |
| Relation to other major neck structures | - Anterior: Sternocleidomastoid - Posterior: Lateral mass of C1, anterior and middle scalenes, pleura of lung apices - Medial: Thyroid, trachea, oesophagus - Lateral: Sternocleidomastoid, fascia, skin |
Approach
| Approach | Details |
|---|---|
| Landmark | - Trendelenburg (prevent air embolus) - Head rotated contralaterally - Palpate carotid artery medially - Enter skin in the middle of the triangle formed by the two heads of SCM and clavicle (~C6 level) - Angle needle 30 degrees to the skin - Aim at ipsilateral nipple |
| Ultrasound | - Gold standard - Same prep + position - Probe best positioned for AP view rather than radial view to avoid carotid puncture - Identify vessels by shape, pulsatility, compressibility, direction of blood flow |
Complications
| Complication | Details |
|---|---|
| Damage to surrounds | - Common carotid artery or internal carotid artery → Bleeding, stroke - Vagus nerve - SNS nerve → Horner’s syndrome - Pleura → Pneumothorax - Trachea, oesophagus, thyroid - Thoracic duct → Chylothorax |
| Other | - Arrhythmia (wire in RV) → Myocardial ischaemia if susceptible - Venous air embolism - Bleeding - Infection |