SURGICAL ANATOMY OF NECK & Neck dissection

surgical anatomy of neck with surgical anatomical & radiological boundaries with levels og lymph node in neck

1. SURGICAL ANATOMY OF NECK Presented by: Dr. Vijay Tiwari Guided by: Dr. Abhimanyu Kadapathri

2. INTRODUCTION The neck is the portion of the trunk which connects the head and thorax and provides a passage for the important structures which pass between them.

3. TRIANGLES OF NECK The sternocleidomastoid muscle divides each side of the neck into two major triangles :- a) Anterior triangle b) Posterior triangle

4. STERNOCLEIDOMASTOID MUSCLE Origin Insertion Nerve Supply Blood Supply Actions

5. ANTERIOR TRIANGLE Sub-divided into following triangles Submental Digastric Carotid Muscular

6. SUBMENTAL TRIANGLE

7. POSTERIOR TRIANGLE

8. CONTENTS

9. Contents Occipital Triangle Subclavian Triangle Nerves Spinal Accessory Nerve 3 trunks of brachial plexus 4 cutaneous branches of cervical plexus: Lesser occipital (C2) Greater Auricular (C2, C3) Anterior / Transverse cutaneous nerve (C2, C3) Supraclavicular nerves (C3, C4) Nerve to serratus anterior (long thoracic C5, C6, C7) Muscular branches: 2 small branches to levator scapulae (C3, C4) 2 small branches to Trapezius (C3, C4) Nerve to rhomboideous (C5) Nerve to subclavius (C5, C6) C5 & C6 roots of brachial plexus Suprascapular Nerve (C5, C6) Vessels Transverse cervical Artery & Vein 3 rd Part of Subclavian Artery & Vein Occipital Artery Suprascapular Artery & Vein Commencement of TCA & termination of TCV Lower part of External jugular vein Lymph nodes Supraclavicular nodes Occipital nodes Few members of supraclavicular nodes

10. FASCIAL LAYERS Divided into 2 layers: Superficial Layer Forms a thin layer that encloses the platysma muscle. Closely associated with adipose tissue Contains superficial veins, cutaneous nerves and superficial lymph nodes. Subplatysmal flap protects the blood supply to the skin

11. 2. Deep Cervical Fascia Divided into following: Investing Layer Pretracheal Layer Prevertebral layer Carotid Sheath

12. LYMPHATICS OF NECK Divided into Regional Nodes & Deep Cervical Nodes: Regional nodes:

13. 2. Deep Cervical Nodes Divided levels as defined by the American Academy of Otolaryngology-Head and Neck Surgery.

14. BLOOD VESSELS

15. Marginal Mandibular Nerve Should be preserved in neck dissections Most commonly injury dissection level Ib Can be found: 1cm anterior and inferior to angle of mandible At the mandibular notch Deep to fascia of the submandibular gland (superficial layer of deep cervical fascia) Superficial to adventitia of the facial vein More than one branch often present Travels with sensory branches that are sacrifice d

16. Spinal Accessory Nerve Originates in the spinal nucleus – may extend to the fifth cervical segment Union of motor neurons Passes through two foramen Foramen Magnum – enters the skull posterior to the vertebral artery Jugular Foramen – exits the skull with CN IX, X and the IJV

17. CN XI – Relationship with the IJV A.G. da silva & D.C. Garco on Anatomic variations in r elationship between the spinal accessory nerve & I nternal J ugular V ein – systematic review

18. Crosses the IJV Crosses lateral to the transverse process of the atlas Occipital artery crosses the nerve Descends obliquely in level II (forms Level IIa and IIb

19. Penetrates the deep surface of the SCM Exits posterior surface of SCM deep to Erb’s point Traverses the posterior triangle ensheathed by the superficial cervical fascia and lies on the levator scapulae Enters the trapezius approx. 5 cm above the clavicle

20. Phrenic Nerve Sole nerve supply to the diaphragm Supplied by nerve roots C3-5 Runs obliquely toward midline on the anterior surface of anterior scalene Covered by prevertebral fascia Lies posterior and lateral to the carotid sheath

21. Hypoglossal nerve Motor nerve to the tongue Cell bodies are in the Hypoglossal nucleus of the Medulla oblongata Exits the skull via the hypoglossal canal Lies deep to the IJV, ICA, CN IX, X, and XI Curves 90 degrees and passes between the IJV and ICA – Surrounded by venous plexus ( ranine veins ) Extends upward along hyoglossus muscle and into the genioglossus to the tip of the tongue Iatrogenic injury Most common site - floor of the submandibular triangle, just deep to the duct Ranine veins

22. THORACIC DUCT Conveys lymph from the entire body back to the blood Exceptions: Right side of head and neck, RUE, right lung right heart and portion of the liver Begins at the cisterna chyli Enters posterior mediastinum between the azygous vein and thoracic aorta Courses to the left into the neck anterior to the vertebral artery and vein Enters the junction of the left subclavian and the IJV