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Neck dissection
- 1. Neck Dissection Dr Yasha Gupta LADY HARDINGE MEDICAL COLLEGE
- 2. Neck Boundaries 1 = Mandible 2 = Zygomatic Process Of The Temporal Bone 3 = External Auditory Canal 4 = Mastoid 5 = Superior Nuchal Line 6 = External Occipital Protuberance 7 = Manubrium Sterni 8 = Clavicle 9 = Acromioclavicular Joint 10 = Spinous Process Of Seventh Cervical Vertebra
- 3. The Surgical Anatomy īPlatysma muscle: īWide muscular sheet embedded in superficial fascia īOrigin īInsertion īAction īSkin flap
- 4. The Surgical Anatomy īSternocleidomastoid Muscle: īDifferentiated from the platysma by the direction of its fibres īCrossed by the IJV and the great auricular nerve īOrigin īInsertion īNerve supply īAction īboundary of posterior triangle & nodes level II - IV
- 5. Change to picture with labels sterno mastpoid
- 6. The Surgical Anatomy īTrapezius muscle: īOrigin īInsertion īNerve supply īAction
- 7. The Surgical Anatomy īDigastric Muscle īPosterior belly, intermediate tendon, anterior belly īOrigin īNerve supply īThe external and internal carotid artery, 12th & 11th cranial nerves and the IJV lie medial
- 9. The Surgical Anatomy īOmohyoid Muscle: īSuperior & inferior bellies, intermediate tendon īOrigin īNerve supply īAction īSurgical landmark for nodal levels III and IV īThe inferior belly is superficial to the brachial plexus, phrenic nerve and transverse cervical vessels īThe superior belly is superficial to the IJV
- 10. Blood Supply of Head & Neck
- 11. Arteries of Head & Neck âĸ Common Carotid Artery âĸ External Carotid Artery âĸ Internal Carotid Artery âĸ Subclavian Artery
- 12. Common Carotid Arteries Right Common Carotid Artery: ī§ Arises from brachiocephalic artery (Behind right sternoclavicular joint) Left Common Carotid Artery: ī§ Arises from Arch of Aorta ī§ Runs upwards in the neck from sternoclavicular joint to upper border of thyroid cartilage
- 14. Relations of Common Carotid Artery Anterolaterally: ī§ Sternocleidomastoid ī§ Sternohyoid ī§ Sternothyroid ī§ Superior belly of omohyoid Posteriorly: ī§ Prevertebral muscles Medially: ī§ Larynx ī§ Pharynx Laterally: ī§ Internal jugular vein
- 15. Branches of Common Carotid Artery ī§ External Carotid Artery ī§ Internal Carotid Artery
- 17. Branches of External Carotid Artery ī§ Superior thyroid artery ī§ Ascending pharyngeal artery ī§ Lingual artery ī§ Facial artery ī§ Occipital artery ī§ Posterior auricular artery ī§ Superficial temporal artery ī§ Maxillary artery
- 18. Internal Carotid Artery ī§ Begins at the level of upper border of thyroid cartilage ī§ No branches in the neck ī§ Through carotid canal enters into cranial cavity ī§ Supplies brain, eyes, forehead and part of the nose
- 19. Subclavian Artery Right Subclavian Artery: ī§ Arises from brachiocephalic artery (Behind right sternoclavicular joint) ī§ At outer border of 1st rib it becomes Axillary Artery Left Subclavian Artery: ī§ Arsis from Arch of Aorta in the thorax ī§ Runs upwards to the root of the neck & arches
- 20. Jugular Vein INTERNAL JUGULAR VEIN ANTERIOR JUGULAR VEIN EXTERNAL JUGULAR VEIN
- 21. External jugular Vein ī§ Formed behind the angle of jaw by the union of Posterior branch of retromandibular vein with posterior auricular vein. ī§ It drains into subclavian vein ī§ Tributaries: ī§ Posterior external jugular ī§ Transverse cervical ī§
- 22. Internal jugular Vein ī§ Receives blood from brain, face and neck. ī§ Continuation of sigmoid sinus and leave the skull from jugular foramen. ī§ Ends by joining subclavian vein to form brachiocephalic vein. âĸ Tributaries: ī§ Facial vein ī§ Pharyngeal vein ī§ Lingual vein ī§ Superior thyroid vein ī§ Middle thyroid vein
- 23. The Surgical Anatomy īSpinal Accessory nerve: SAN īEmerge from the jugular foramen medial to the digastric and stylohyoid muscles and lateral and posterior to IJV īIt passes obliquely downward and backward to reach the medial surface of the SCM near the junction of its superior and middle thirds, Erbâs point
- 24. The Surgical Anatomy īThoracic duct: âĸ Conveys lymph from the entire body back to the blood âĸ Begins at the cisterna chyli âĸ Enters posterior mediastinum between azygous vein & thoracic aorta âĸ Courses to left into neck anterior to the vertebral artery and vein âĸ Enters the junction of the left subclavian vein and the IJV
- 26. Triangles Of The Neck 29 Stylohyoid Mandible Digastric Digastric triangle Submental triangle Carotid triangle Muscular triangle Omohyoid ANTERIOR TRIANGLE Sternocleidomastoid Trapezius Occipital triangle Supraclavic ular triangle POSTERI OR TRIANGLE
- 27. Anterior Triangle īBoundaries īSub-mental triangle īDigastric triangle īCarotid triangle īMuscular triangle
- 29. Lymph Node Levels/Nodal Regions īDeveloped by Memorial Sloan-Kettering Cancer Center īEase and uniformity in describing regional nodal involvement
- 30. AAOHNS Classification Of Cervical Lymph Nodes LEVEL I â Submental / Submandibular Lymph Nodes LEVEL II â Upper Jugular Lymph Nodes LEVEL III â Middle Jugular Lymph Nodes LEVEL IVâ Lower Jugular Lymph Nodes LEVEL V â Posterior Triangle Lymph Nodes LEVEL VI âAnterior Compartment Lymph Nodes LEVEL VII- Superior Mediastinal Lymph Nodes VIVI
- 31. Metastatic Nodal Disease īLevel I â lip, anterior tongue, anterior floor of mouth, buccal mucosa īLevel II, III â tonsil, base of tongue (scalp, external auditory canal) īLevel IV â hypopharynx & larynx īLevel V â nasopharyngeal malignacy īLevel VI â thyroid, subglottic
- 32. Clinical Staging ī Joint UICC/AJCC classification (2009) ī Not only for presence of lymph node but also size, number & laterality ī Applies for all head & neck tumour except nasopharynx, thyroid ī Only clinical classification
- 33. Staging Of The Neck īNX: Regional lymph nodes cannot be Assessed īN0: No regional lymph node metastasis īN1: Metastasis in a single ipsilateral lymph node, < 3cm īN2a: Metastasis in a single ipsilateral lymph node 3 to 6 cm
- 34. Staging of the Neck īN2b: Metastasis in multiple ipsilateral lymph nodes, none more than 6 cm īN2c: Metastasis in bilateral or contralateral nodes < 6cm īN3: Metastasis in a lymph node more than 6 cm in greatest dimension
- 36. īNasopharyngeal Carcinoma īN1 â Unilateral < 6cm īN2 â Bilateral < 6 cm īN3a > 6 cm īN3b â Extension to supraclavicular fossa īThyroid īN1 â Regional node īN1a - Ipsilateral īN1b - Bilateral, midline, contralateral cervical or mediastinal LN
- 37. Types Of Neck Dissection īRadical neck dissection īModified radical dissection īSelective neck dissection īExtended radical neck dissection
- 38. Classification of Neck Dissections īļAcademyâs classification â Based on 4 concepts 1. RND is the standard basic procedure for cervical lymphadenectomy against which all other modifications 2. Modifications of the RND which include preservation of any non- lymphatic structures are referred to as modified radical neck dissection (MRND)
- 39. Classification of Neck Dissections 3) Any neck dissection that preserves one or more groups or levels of lymph nodes is referred to as a selective neck dissection (SND) 4) An extended neck dissection refers to the removal of additional lymph node groups or non-lymphatic structures relative to the RND
- 40. Skin Incision īVascularisation of flaps īExposure īProtection of major vessels īLocalization of primary tumour īConsider previous radiotherapy & reconstruction īCosmesis īPrevious surgical field
- 41. Blood Supply Of Cervical Neck Skin Blood enters from above, below and either side with a resultant watershed in the middle of the neck. Incisions can be planned to utilize this so as to maximize blood supply to each of the neck flaps.
- 46. Radical Neck Dissection īLymph nodes level I â V īNon-lymphatic structures īAccessory nerve īInternal jugular vein īSternocleidomastoid muscle
- 47. Indications īSignificant operable neck disease (N2a,N2b,N3) with spinal accessory or IJV involvement īExtensive recurrent disease after previous selective surgery
- 48. Contraindication īUntreatable primary tumour or unresectable neck disease īPatient unfit īDistant metastasis īSimultaneous bilateral dissection
- 49. Surgical Boundaries īSuperior- angle of mandible īAnterior- contralateral anterior belly of digastric īInferior- clavicle īPosterior- anterior border of trapezius
- 50. īWith traction and countertraction, the skin is incised in one movement with a No. 10 blade through the platysma muscle īIn the posterior part of the neck, the fibers of the sternomastoid muscle are inserted directly into the skin which makes the dissection and identification of the appropriate plane more difficult.
- 51. īMarginal mandibular nerve īCervical branch of facial nerve īBoth nerves curve downwards below and in front of the angle of the mandible across the facial vessels about one fingerâs breadth below the mandible . īThe marginal mandibular nerve then runs Immediately superior to the submandibular gland while the cervical branch runs lateral and inferior to this gland . Both of the nerves then curve upwards again
- 52. ī2 approaches can be used īHayes martin (upward approach) īDownward approach
- 53. Hayes Martin Approach īSternocliedomastoid is divided just above sterno clavicular attachment īInternal jugular vein identified īCarotid sheath is opened to expose internal jugular vein & ligated īThe dissection extends laterally to approach chaissaignac's triangle. īDivide and retract the omohyoid muscle upwards. īMobilize the fat pad overlying the prevertebral fascia. īIdentify and preserve the brachial plexus and phrenic nerve.
- 57. Dissection Of The Posterior Triangle īDissection continues up the anterior border of trapezius to the mastoid tip īFirst accessory nerve is identified īBranches from cervical plexus C3,4 are saved īAccessory nerve dissected away from muscle īUpper end of sternocleidomastoid is cut under tension & digastric is retracted to show IJV
- 59. Division of upper end of IJV īIdentify and preserve the hypoglossal nerve. īSpecimen is mobilized both top and bottom īTop section is completed by finding and ligating the posterior branch of the posterior facial vein. īThe dissection of the posterior triangle is completed by lifting the specimen & dissect between the contents of the posterior triangle and prevertebral fascia.
- 60. Dissection of the Submandibular Triangle ī The fat is divided in the submental area and anterior belly of digastric is identified. ī The anterior part of the submandibular gland is then identified and is dissected to the posterior border of the mylohyoid muscle. ī The upper border of the submandibular gland is freed by dividing and tying the Vessels ī The lingual nerve is identified, branch to the submandibular ganglion is divided ī The submandibular duct is tied and divided ī Facial artery is divided and specimen is removed
- 62. Above Downward Approach ī Incision given and flaps are raised ī Clearance of posterior triangle ī Incision along anterior border of trapezius and SCM s divided ī Posterior belly of digastric is identified ī Clearance proceed downwards ī Accessory nerve, inferior belly of omohyoid, transverse cervical vessels, brachial plexus covered with fascia identified
- 63. ī Supraclavicular dissection ī Fat is divided to locate inferior belly of omohyoid ī Omohyoid is divided and dissection is continued upto the level of prevertebral fascia ī External jugular vein is divided ī SCM is divided at itâs lower end ī IJV is dissected and divided ī Clearance is continued from posterior triangle to midline ī Clearance is done close to artery and nerve ī Tributaries of IJV are carefully divided ī Submandibular triangle clearance
- 64. Modified Neck Dissection īMedina classification (1989) Modified radical neck dissection â Type I (XI preserved) â Type II (XI, IJV preserved) â Type III (XI, IJV, and SCM preserved)
- 65. MRND Type I
- 66. Indications īOperable palpable neck disease ( N1, N2a, N2b) not involving the accessory nerve īN0 neck (occasionally)
- 67. MRND Type II
- 68. MRND Type III
- 69. Indications īTreatment of No neck disease īTreatment of undifferentiated thyroid cancer īSkin tumours eg. Melanoma, SCC
- 70. Approaches for MRND īAnterior approach (Ballantyne) īPosterior approach (Bocca)
- 77. Selective Neck Dissection īAny type of cervical lymphadenectomy with preservation of one or more lymph node groups īFour subtype: īSupraomohyoid neck dissection īPosterolateral neck dissection īLateral neck dissection īAnterior neck dissection
- 78. īRemoval of lymph nodes in regions I âIII īThe posterior limit īThe inferior limit īSCC oral cavity (T1-T4) with N0 īSingle palpable LN in level I or II (controversial) with Ca oral cavity, lip
- 79. Posterolateral Neck Dissection īRemoval of levels II-V īSkin cancer posterior to tragus
- 80. Lateral neck dissection Remove lymph nodes in levels II â IV īCa larynx, orophaynx, hypopharynx T2-4 N0
- 81. Anterior Neck Dissection īRemoval of LN surrounding the visceral structure in the anterior aspect of the neck, level VI īSuperior limit īInferior limit īLaterally īDifferentiated and medullar Ca of thyroid with thyroidectomy
- 82. Extended Radical Neck Dissection īRemoval of additional lymphatic structure other than RND īRetrophayngeal LN īLevel VII LN īHypoglossal nerve īCarotid artery īSkin of neck
- 84. General Complications īAnaesthetic complications īPost operative atelectasis with basal collapse īPneumonia īIschaemic heart diaease īUrinary retention īDeep vein thrombosis
- 85. Local Complications īHemorrhage īWound infection īCarotid artery rupture īNerve injuries īChylous fistula īPneumothorax īCerebral edema
- 86. ThankYou
Editor's Notes
- Neck lies between the lower margin of angle of mandible above and upper border of clavicle below
- Skin flap is raised immediately deep to the muscle Also embedded in it are cutaneous nerves, veins and lymph nodes Origin from deep fascia covering the pectoralis major & deltoid muscle Insertion into lower margin of body of mandible & some fibres blend into muscles of angle of mandible Action depresses the mandible & draws the angle of mouth and lower lip Does not cover the inferior part of the anterior triangle and the posterolateral neck There is some difficulty in raising flap posteriorly and posterior flap tends to become thin
- Crossed by the IJV and the great auricular nerve from inferior to posterior deep to platysma nerve: spinal acessory motor Origin from rounded tendon from upper part of manubrium sterni & muscular part from upper surface of mideal third of clavicle Action- both muscles- flex the extend at atlantoaxial & flex the cervical vertebrae One muscle- tilt the head so that ear touches the shoulder also assist in inspiration (accessory muscle) Blood supply â 1) occipital a. or direct from ECA 2) superior thyroid a. 3) transverse cervical a.
- Origin- superior nuchal line, ext. occipital protrubence, ligamentum nuchae, c7 spine, supraspinous ligament of all thoracic vertebrae Insertion â lateral 3rd of clavicle, acromian & spine of scapula, Function â elevate and rotate the scapula and stabilize the shoulder Nerve spinal acessory c2 c3 post fibre Denervation results in shoulder drop and winged scapula
- Originate from a groove in the mastoid process, digastric ridge Nerve supply- post. By facial nerve Ant by neevr to mylohyoid division of mandibular nerve of trigeminal nerve âĸ Origin â digastric fossa of the mandible (at the symphyseal border âĸ Insertion â 1) hyoid bone via the intermediate tendon 2) mastoid process Function â 1) elevate the hyoid bone 2) depress the mandible (assists lateral pterygoid) âĸ Surgical considerations â âResidents friendâ â Posterior belly is superficial to: âĸ ECA âĸ Hypoglossal nerve âĸ ICA âĸ IJV â Anterior belly âĸ Landmark for identification of mylohyoid for dissection of the submandibular triangle
- Intermediate tendon is held to hyoid bone by fascial sling
- Origin- inf belly from scapula & suprascapular ligament Intermediate tendon is held to clavicle and 1st rib by a fascial sling Sup belly from lower border of body of hyoid Nerve supply â ansa cervicalis: C1 C2 C3 Action- depresses the hyoid Inferior belly lies superficial to âĸ The brachial plexus âĸ Phrenic nerve âĸ Transverse cervical vessels â Superior belly lies superficial to âĸ IJV
- Exceptions: Right side of head and neck, right upper extremeties, right lung right heart and portion of the liver
- Scm divide neck in ant and posterior triangle
- Bounded above by body of mandible Post by scm ant border Ant by midline
- Ant- submandibular salivary gland, Post- carotid sheath, contents of the submandibular triangle are structures passing through: facial artery (fa) lingual nerve and submandibular ganglion (ln) submandibular duct (smd) lingual artery (la)
- Arteries: Contains cca with external & internal ca, ext carodid with its sup thyroid ascending pharyngial lingual fascial and occipetal branches Veins: IJV,common facial vein,pharyngeal vein , lingual vein. Nerves: 1vagus,2 superior laryngeal branch of vagus with dividing into internal and external laryngeal nerve,3 spinal acessory nerve running over ijv 4 hypoglossal nerve 5 sympathetic chain runs vertically down post to carotid sheath Carotid sheath with its content Lymph nodes: chain of deep cervical lymph nodes, jugulodyagastric lymph nodes beloow post belly of diagastric, juguyloomohyoid above inf belly of omohyoid Floor by 1thyrohyoid mus 2 hyoglossus 3 middle and inferior constrictor,
- The muscular triangle has the following boundaries: Ant:mid line of neck (1) Post superior:superior belly of omohyoid (2) Posteroinferior: sternomastoid (3) The muscles forming and within the triangle are seen in image labeled (these muscles are often called the strap muscles,infrahyoid muscles for obvious reasons: superficial layer sternohyoid (sh) superior belly of omohyoid (oh) deep layer thyrohyoid(th) sternothyroid (st) Contains thyroid larynx trachea esophagus Fllor by strap muscles
- Floor by semispinalis capitis, Splenius capitis levator scapulae, scalenius medius Arteries â subclavian, suprascapular superficial cervical, occipital Veins- subclavian Nerves- spinal accessory, brachial plexus and branches of cervical plexus
- Level II: Upper third jugular chain, jugulodigastric, and upper posterior cervical nodes â Boundaries - hyoid bone (clinical landmark) or carotid bifurcation (surgical landmark) Level III: Middle jugular nodes â Boundaries - Inferior border of level II to cricothyroid notch (clinical landmark) or omohyoid muscle (surgical landmark) âĸ Level IV: Lower jugular nodes â Boundaries inferior border of level III to Clavicle.
- Submental: tip of tongue, floor of anterior part of mouth, incisor teeth, central part of lower lip,skin over chin Submandibular: front of scalp nose,cheek,upper lip lower lip(except central lower lip), frontal maxillary ethmoid sinus, upper and lower teeth(except lower incisor), ant two third tongue (except tip of tongue), floor of mouth and vestibule and gums
- Does not include other prognostic factors â cncurrent co morbidities, HPV status in oropharyngeal malignancy, vascular invasion, Extra capsular invasion of LN. doesnât take into account the level of LN Applies for all head & neck tumour except nasopharynx, thyroid, mucosal melanoma The UICC TNM Classification is an anatomically based system that records the primary and regional nodal extent of the tumor and the absence or presence of metastases. Union for International Cancer Control (UICC), American Joint Committee on Cancer (AJCC) In 1987, the UICC and AJCC staging systems were unified into a single staging system.
- Pt preferance Prev radiotherapy Number of level required fr asses purpose Any prev sx incision Site of primary
- Blood enters from above, below and either side with a resultant watershed in the middle of the neck. Incisions can be planned to utilize this (Figure 199.2) so as to maximize blood supply to each of the neck flaps.
- Lazy s to reduce scar tissue contracture There are number of incision to perfor neck dissection Mc: Y type (or crile) or schobinger incision
- Previously irridiated patient mc fee
- In N0 disease where flaps are required pec major or latissimus dorsi
- Encasement of ICA, brachial plexus, prevertebral fascia âĻ.. Preserve one IJV
- . It is important to keep the platysma on the skin flaps since it provides an important blood supply and increases the strength of the wound in the postoperative period. Blood supply to the cervica l neck ski n . may have to be removed because disease extends onto, into or even through it. In this situation, the overlying skin may have to be removed as well. In the past it has been said that the platysma should be removed as part of the routine operation because there are lymphatics within it, but if these lymphatics are invaded by cancer then the patient is probably incurable The assistant places double skin hooks or a rake retractor under the platysma and applies traction in an upward direction and similar countertraction to the specimen identifies the subplatysmal plane and the dissection continues using a knife so that the flaps are quickly raised. Dissection here causes very little bleeding, provided the branches of the external and anterior jugular veins are tied so that any significant bleeding usually means that the operator is in the wrong plane.
- During the dissectio n in the upper neck when the upper flap is being raised, there are two branch es of the facial nerve which should be preserved whenever possible The most important of these is the marginal mandibular nerve and, of somewhat less i mportance, its cervical Branch . The first supplies the muscles around the mouth and the seco nd supplies the part of the pla tysma that crosses the mandib le a nd is inserted into the corner of the mouth so that divisio n of ei ther nerve can lead to a weakness of the lower lip. There are a number o f ways t o p rotect these two nerves. The easiest method is to cut t h rough the deep investing layer of fascia at the level of the hyoid bone and expose the capsule of the lower part of the submandibular gland . The fascia ca n then be eleva ted as a flap over the mandible taking the nerve with it and the flap is then sutured superiody. A less reliable method of protecting them is to ligate and divide the facial vessels on the submandibular gland and lift them over the mandible, but this technique fails when the nerve&apos;s course is lower than usual and it can also com promise the removal of pre- and post-facial nodes which m ay be involved in tumours of the oral cavity.
- The transfixion stitch on the lower end i s known as the &apos; houseman&apos;s suture&apos; since, if it fails in the early hours of the morning following surgery, it is the houseman who knows about it first If bleeding does occur, do not allow an assistant to grab a large bleeding vessel with artery fo rceps or a ttemp t diathermy as this will only convert a small hole in to a large one. The bleeding injured vessel should be identified and occluded temporarily with pressure or arterial clamps and the defect repaired using 6.0 Ethilo n . The danger of tea ring the lower end of t he vein is no t blood loss, but air embolism. If the vein is torn before it is divided, put a finger on the hole and ask the anaesthetist to tilt the patient&apos;s head downwards. Tie the area of the vein above and below the hole and pass ligatures above a n d below the tear. When these are tied, the finger may be lifted off the vein . This is the triangle between longus colli a nd sca len us a nterior, their attachments to the t ubercle o f C6 ( Cha issaignac&apos;s o r carotid tubercle) and the su bclavian ar t ery is the base phrenic nerve is identified as it runs over scalenus anterior from lateral to medial, It lies behind the prevertebral fascia and is safe as long as this layer is not breached This triangle contains branches of the thyrocervical trunk, the vertebral vein and the thoracic duct and it is here that the cervical lymphatics terminate (scalene nodes) and occult disease may occur
- everything that is impOliant in the posterior triangle lies below, that is caudal to, the accessory nerve and that this nerve runs in the roof It exits the lateral border of the sternomastoid muscle at the j unction of its upper third with the lower two-thirds, best ways to identify the nerve is where it exits from sternomastoid. This is known as Erb&apos;s point and can be identified 1 cm above the point where the great auricular nerve winds around the muscle on its way to supply the parotid fascia. Other ways of identifying it are either to dissect up the anterior border of trapezius in the posterior triangle until the nerve is encountered. Another way of finding the nerve is to draw a line laterally from the laryngeal prominence through the posterior triangle and the nerve will usually cross th at line as it runs from Erb&apos;s point to the lower posterior corner of the posterior triangle. At this point, every attempt should be made to preserve shoulder function and even if the accessory nerve has to be divided, it is wise to preserve the branches to trapezius from the third and fourth cervical nerves. These lateral branches arise from the cervical plexus, being ultimately derived from C3 and C4 (Figure 199. 12). They arise deep to th e sternomastoid muscle and pass laterally beneath the fascia covering the floor of the posterior triangle to supply the trapezius muscle and also to give off a communicating branch to the accessory nerve. It is essential that the fascia is preserved on the floor of the posterior triangle if these nerves are to be preserved.
- Its position may be located by palpating the transverse process of C2 over which it lies, but with the neck extended to the Contralateral side, this landmark is usually just in front of the vein. The hypoglossal nerve runs across the external carotid, lingual and occipital arteries and may form, like the digastric, a convenient tunnel which can be followed anteriorly. The hypoglossal tunnel is a particularly useful landmark when tumour is stuck near the carotid bifurcation. The occipital artery crosses the p osterior part of the internal jugular vein and this should also be ligated now to prevent further troublesome bleeding. The specimen is now mobil ized both top and bottom and the top section is com pleted by finding the posterior branch of the posterior facia l vein half an inch anterior to the interior j ugular vei n . This is l i ga ted and divided.
- The fat is d ivided i n the submental area and this displ ays the anterior belly o f the digastric m uscle. The anterior part of the submandibular gland is then identified and is dissected to the posterior border of the mylohyoid m uscle. The upper border of the submandibular gland is freed by dividing and tying the vessels, including the facial artery, that cross the lower bord er of the mandible. The mylohyoid m uscle is retracted in a forward direction to reveal the submandibular duct and, at this point, the lingual nerve is pulled down in a curve. The latter is freed by divid ing the fascia around the submandibular gangl io n with a knife. The lingual nerve gives off a small but co nstant branch to the submandibular ganglio n . This branch is usually accompanied by a vessel that can cause troublesome bleeding i f it is not properly ligated. The lingual nerve is identified, and two artery forceps a re placed below it to d ivide the branch to the subma n d ibular ganglion . This allows the nerve to spring back upwards behind the body of the mandible. The submandibular duct is tied and d iv ided and d u r ing both of these manoeuvres, the hypoglossal nerve is kept u nder co nstant direct v isio n to avo id any damage. The specimen is then removed following tra nsfixion and divisio n o f the facial artery as it winds over the poste rio r border o f the digastric muscle at the posteroi nferior border of the subman dibular gland.
- Accessory nerve is situated 5cm above the insertion of trapezius at clavicle along its ant border
- Supraomohyoid neck dissection: The posterior limit is the cutaneous branches of the cervical plexus and posterior border of SCM The inferior limit is the superior belly of the omohyoid where it cross IJN It may be useful in conjunction with elective superficial parotidectomy in intermediate thickness melanoma, SCC in facial region ant to tragus
- Subtyped I â III depending on the preservation of SAN, IJV and /or SCM
- Superior limit, hyoid bone Inferior limit, suprasternal notch Laterally, the carotid sheath
- Comprehensive ND- rnd & mrnd, which remove all 5 levels