[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Head and neck](https://durgical.com/en/anatomy/region/head-and-neck/) › Carotid sheath [Muscular system](https://durgical.com/en/anatomy/system/muscular-system/) · [Head and neck](https://durgical.com/en/anatomy/region/head-and-neck/) # Carotid sheath The carotid sheath is a tube of tissue in the neck holding the carotid artery, the internal jugular vein and the vagus nerve together. [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=head_neck&select=carotid_sheath&side=r) Opens in the Durgical app, no sign-up needed. ## What it is A fascial tube around the carotid artery, internal jugular vein and vagus nerve. ## What it does Keeps the three together; surgeons open it in carotid surgery. ## Key points - Formed by contributions from all three layers of the deep [cervical fascia](https://durgical.com/en/anatomy/superficial-investing-cervical-fascia/) (investing, pretracheal, prevertebral); runs from the skull base ([carotid canal](https://durgical.com/en/anatomy/carotid-canal/), [jugular foramen](https://durgical.com/en/anatomy/jugular-foramen/)) to the root of the neck - A route for infection between the skull base and the mediastinum: pharyngeal and parapharyngeal infections can track down along it - Lemierre syndrome: after a sore throat, septic thrombophlebitis of the internal jugular vein (classically Fusobacterium necrophorum) with septic emboli to the lungs - Anterior cervical [spine](https://durgical.com/en/anatomy/region/spine/) surgery passes medial to the sheath: the sheath is retracted laterally and the trachea and oesophagus medially ## Key facts **Where** Skull base to the [aortic arch](https://durgical.com/en/anatomy/aortic-arch/), either side of the trachea and oesophagus **Function** Contains the common and internal carotid arteries, internal jugular vein and vagus nerve; ansa cervicalis on its front ## Relations **In front** [Sternocleidomastoid](https://durgical.com/en/anatomy/sternocleidomastoid-muscle/) and the infrahyoid muscles, with the [omohyoid](https://durgical.com/en/anatomy/omohyoid-muscle/) crossing it; the [ansa cervicalis](https://durgical.com/en/anatomy/ansa-cervicalis/) on or in its front wall **Medial** Larynx and [trachea](https://durgical.com/en/anatomy/trachea/), [pharynx](https://durgical.com/en/anatomy/pharynx/) and oesophagus, the [thyroid gland](https://durgical.com/en/anatomy/thyroid-gland/) and, in the groove between trachea and oesophagus, the [recurrent laryngeal nerve](https://durgical.com/en/anatomy/recurrent-laryngeal-nerve/) **Behind** Prevertebral fascia with the [sympathetic trunk](https://durgical.com/en/anatomy/sympathetic-trunk/), the [longus colli](https://durgical.com/en/anatomy/longus-colli-muscle/) and [longus capitis](https://durgical.com/en/anatomy/longus-capitis-muscle/), and the cervical transverse processes **Above** At the skull base it continues into the poststyloid part of the parapharyngeal space, where cranial nerves IX to XII run close to it **Contents** [Common carotid artery](https://durgical.com/en/anatomy/common-carotid-artery/) and, higher, [internal carotid artery](https://durgical.com/en/anatomy/internal-carotid-artery/) medially; [internal jugular vein](https://durgical.com/en/anatomy/internal-jugular-vein/) laterally; [vagus nerve](https://durgical.com/en/anatomy/vagus-nerve/) behind and between them; deep cervical lymph nodes along the vein ## How to find it Its line runs from the sternoclavicular joint up to midway between the mastoid process and the angle of the [mandible](https://durgical.com/en/anatomy/mandible/), under the anterior border of the sternocleidomastoid. On ultrasound, the round pulsatile carotid lies medial to the larger, compressible internal jugular vein, the standard view for central line placement. ## On imaging Contrast CT shows abscess or fluid tracking along the sheath, internal jugular vein thrombosis as a non-filling vein with an enhancing wall, and spread of cancer to the [neck lymph nodes](https://durgical.com/en/anatomy/lymph-nodes-of-neck/) of the jugular chain. ## Clinical notes - Carotid endarterectomy and neck exploration open the sheath along the anterior border of the sternocleidomastoid, protecting the vagus nerve behind and the [hypoglossal nerve](https://durgical.com/en/anatomy/hypoglossal-nerve/) above - [Head and neck](https://durgical.com/en/anatomy/region/head-and-neck/) cancers spread to the deep cervical (jugular chain) nodes around it; radical neck dissection removes the internal jugular vein, the [accessory nerve](https://durgical.com/en/anatomy/accessory-nerve/) and the sternocleidomastoid with them, modified forms keep one or more - Deep neck abscesses next to the sheath can erode the carotid artery or thrombose the internal jugular vein ## Anatomical variants - The internal jugular vein usually lies lateral to the carotid, but in some people it overlaps the artery from the front, and turning the head increases the overlap; this is why central lines are placed under ultrasound with the head kept near neutral - The right internal jugular vein is usually larger than the left ## Memory aid Vein outside, artery inside, vagus at the back between them. ## Related conditions - [Deep neck infection and Ludwig angina](https://durgical.com/en/conditions/deep-neck-infection-and-ludwig-angina/) - [Carotid artery stenosis](https://durgical.com/en/conditions/carotid-artery-stenosis/) ## Test yourself Think of the answer, then tap the question to see it. ## What are the contents of the carotid sheath and how are they arranged? Common (then internal) carotid artery medially, internal jugular vein laterally, vagus nerve behind and between them, with deep cervical lymph nodes along the vein. ## Which fascial layers form the carotid sheath? All three layers of the deep cervical fascia: investing, pretracheal and prevertebral. ## What is Lemierre syndrome? After a sore throat, septic thrombophlebitis of the internal jugular vein (classically Fusobacterium necrophorum) with septic emboli to the lungs. ## On ultrasound for central line placement, how are the carotid artery and internal jugular vein told apart in the carotid sheath? The round, pulsatile carotid lies medial; the larger, compressible internal jugular vein lies lateral. ## Which nerve lies on or in the front wall of the carotid sheath? The ansa cervicalis. [Add to my cards (5)](https://durgical.app/estudiar/?add=/en/anatomy/carotid-sheath/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** vagina carotidis TA2 2214 **Official Spanish (DeCS)** Vaina carotídea DeCS D005205 **English (TA2)** Carotid sheath ## Related - [Internal jugular vein](https://durgical.com/en/anatomy/internal-jugular-vein/) - [Vagus nerve](https://durgical.com/en/anatomy/vagus-nerve/) - [Common carotid artery](https://durgical.com/en/anatomy/right-common-carotid-artery/) Sources: Terminologia Anatomica (TA2); [DeCS](https://decs.bvsalud.org/es/ths/resource/?id=5309); [Anatomy, Head and Neck: Carotid Sheath](https://www.ncbi.nlm.nih.gov/books/NBK519577/). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/carotid-sheath/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/carotid-sheath/