O slideshow foi denunciado.
Seu SlideShare está sendo baixado. ×
Próximos SlideShares
Neck dissection
Neck dissection
Carregando em…3

Confira estes a seguir

1 de 125 Anúncio

Mais Conteúdo rRelacionado

Diapositivos para si (20)

Quem viu também gostou (19)


Semelhante a Neck Dissections (20)

Mais recentes (20)


Neck Dissections

  1. 1. NECK DISSECTION Dr. Harmandeep Singh Under the Guidance of Dr. D.D. Wagh Sir
  2. 2. Contents • Introduction • History • Surgical anatomy • Levels of lymph nodes • TNM staging • Classifications • Definitions of types of dissections • Surgical procedure • Complications • Algorithm • Conclusion • References
  3. 3. Some simple questions….. • What is neck dissection?? • Why it is done?? • When it has to be done?? • Who developed it?? • Where it is done?? • How it is done?? • What are the structures involved?? • Any complications??
  4. 4. Introduction • Cervical node metastasis is the single most important prognostic factor in head and neck squamous carcinomas. • Cure rates drop in half when there is regional lymph node involvement
  5. 5. Definition • The term neck dissection refers to a surgical procedure in which the fibrofatty contents of the triangles of the neck are removed as a treatment for cervical lymphatic metastases
  6. 6. Emil Theodor Kocher Earned Nobel Prize in 1909 for his work in thyroid and neck surgery — the first ever awarded to a surgeon. 1880 – Kocher proposed removing nodal metastases
  7. 7. 1906 – George Crile described the classic radical neck dissection (RND)
  8. 8. 1967 - Bocca and Pignataro described the “Functional neck dissection” (FND)
  9. 9. EVOLUTION • 1880 – Kocher proposed removing nodal metastases • 1906 – George Crile described the classic radical neck dissection (RND) • 1933 and 1941 – Blair and Martin popularized the RND • 1953 – Pietrantoni recommended sparing the spinal accessory nerves • 1967 - Bocca and Pignataro described the “functional neck dissection” (FND) • 1975 – Bocca established oncologic safety of the FND compared to the RND • 1989, 1991, and 1994 – Medina, Robbins, and Byers respectively proposed classifications of neck dissections
  10. 10. ANATOMY • Skin: – Blood supply: • Descending branches: – The facial – The submental – Occipital • Ascending branches – Transverse cervical – Suprascapular – The branches perforate the platysma muscle, anastomose to form superficial vertically-directed network of vessels
  11. 11. • Platysma muscle: – Wide, quadrangular sheet-like muscle – Run obliquely from the upper part of the chest to lower face – Skin flap is raised immediately deep to the muscle – The posterior border is over or just anterior to IJV and great auricular nerve
  12. 12. • Sternocleidomastoid muscle: – Differentiated from the platysma by the direction of its fibres – Crossed by the EJV and the great auricular nerve from inferior to posterior deep to platysma – The posterior border represent the posterior boundary of nodes level II - IV
  13. 13. Omohyoid Muscle • Inferior belly passes behind the sternocleidomastoid • Superior belly lies close to the lateral border of the sternohyoid and inserted into the lower border of the body of the hyoid bone • The central tendon of this muscle is held in position by a fascial sling derived from investing layer of deep cervical fascia and is prolonged down to be attached to the clavicle and first rib
  14. 14. • MARGINAL MANDIBULAR NERVE: – Located 1 cm in front of and below the angle of the mandible – Deep to the superficial layer of the deep cervical fascia – Superficial to adventitia of the anterior facial vein
  15. 15. • Spinal Accessory nerve: – Emerge from the jugular foramen medial to the digastric and stylohyoid muscles and lateral and posterior to IJV (30% medial to the vein and in 3 -5% split the vein) – It passes obliquely downward and backward to reach the medial surface of the SCM near the junction of its superior and middle thirds, Erb’s point
  16. 16. • Trapezius muscle: – Its anterior border is the posterior boundary of level V – Difficult to identify because of its superficial position – Dissect superficial to the fascia in order to preserve the cervical nerves
  17. 17. • Digastric Muscle: Posterior belly: – Originate from a groove in the mastoid process, digastric ridge – The marginal mandibular nerve lie superficial – The external and internal carotid artery, hypoglossal and 11th cranial nerves and the IJV lie medial
  18. 18. • Brachial Plexus & Phrenic nerve: – The plexus exit between the anterior and middle scalene muscles, pass inferiorly deep to the clavicle under the posterior belly of the omohyoid – The phrenic nerve lie on top of the anterior scalene muscle and receive its cervical supply from C3 – C5
  19. 19. • Thoracic duct: • Located in the lower left neck posterior to the jugular vein and anterior to phrenic nerve and transverse cervical artery. • Has a very thin wall and should be handled gently to avoid avulsion or tear leading to chyle leak
  20. 20. • Hypoglossal nerve: • Exit via the hypoglossal canal near the jugular foramen • Passes deep to the IJV and over the ICA and ECA and then deep and inferior to the digastric muscle and enveloped by a venous plexus, the ranine veins • Pass deep to the fascia of the floor of the submandibular triangle before entering the tongue
  21. 21. Anatomy of the vascularization of neck skin • Kambic and Sirca 1967 stated that arterial supply is in a vertical direction. • descending branches: facial and occipital artery • ascending branches: transverse cervical and supraclavicular arterial branches .
  22. 22. The vasculature can be summarized into • Upper neck region - anterior to the angle of mandible - branches of facial and submental arteries. • Upper lateral neck - the area between ramus of mandible and the sternocleidomastoid muscle-Occipital and external auricular branches of external carotid . • Lower half of neck - The transverse cervical artery and suprascapular artery • Large platysma - cutaneous branches and branches of superior thyroid supplying the front middle portion of the neck.
  23. 23. LYMPH NODES OF HEAD & NECK Conventionally divided into three systems • Waldeyers internal ring • Superficial lymph node system (Waldeyers external ring) • Deep lymph node system (cervical lymph nodes proper)
  24. 24. Waldeyer’s ring • Circular collection of lymphoid tissue within the pharynx at the skull base. • Ring includes the adenoids, tubal and lingual tonsils, palatine tonsils, aggregates on the posterior pharyngeal wall.
  25. 25. Superficial nodal system • Drains the superficial tissues of the head and neck. • Two circles of nodes, one in the head and the other in the neck. • In the head – nodes are situated around the skull base • In the neck – submental, submandibular and anterior cervical nodes.
  26. 26. Deep lymph nodal system Deeper fascial structures of the head and neck drain either directly into the deep cervical nodes or through the superficial system. • A. Junctional nodes • B. Internal jugular nodes • C. Spinal accessory nodes • D. Supraclavicular nodes • E. Nuchal nodes • F. Deep medial visceral
  27. 27. Classification of lymph node levels by Memorial Sloan-Kettering Cancer Center The boundaries of each being defined by surgically visible bones, muscles, blood vessels or nerves. Robbins KT, Medina JE, Wolfe GT, Levine PA, Sessions RB, Pruet CW. Standardizing neck dissection terminology. Official report of the academy’s committee for head and neck surgery and oncology. Arch Otolaryngol Head Neck
  28. 28. Levels of lymph nodes
  29. 29. Draining areas
  30. 30. Spread of cancer in lymphatics • Embolisation • Permeation
  31. 31. Neck Dissection in Oral Malignancy
  32. 32. T Classification • T – Primary tumour : • T x primary tumour that cannot be assessed. • T 0 No evidence of primary tumour. • T is Carcinoma in situ. • T 1 Tumour 2 cms or less in the greatest diameter. • T 2 Tumour 2cms but not more than 4cms in the greatest diamension. • T 3 Tumour more than 4 cms in the greatest dimension.
  33. 33. T 4 a – Lip : Tumour invades through the cortical bone, inferior alvoelar nerve, floor of the mouth or skin. T 4 a – oral cavity : Tumour invades through the cortical bone into the deep extrensic muscles of the tongue ( genioglossus, hypoglossus, palatoglossus, styloglossus ) , maxillary sinus or skin of the face. T 4 b – lip and oral cavity : Tumour invades the massetric space, pterygoid plates, skull base or encases the internal carotid artery.
  34. 34. T staging
  35. 35. N staging No regional lymph node metastases Single ipsilateral lymph node, < 3 cm Single ipsilateral lymph node 3 to 6 cm Multiple ipsilateral lymph nodes < 6 cm Bilateral or contralateral nodes < 6cm Metastases > 6 cm
  36. 36. • Distant metastases – M • M x – distant metastases that cannot be assessed. • M 0 – No distant metastases. • M 1 – distant metastases.
  37. 37. Staging N0 N1 N2 N3 T1 I T2 II T3 III T4 IV
  38. 38. Impact of pattern of nodal metastasis on neck dissection Level of nodal involvement Site of primary tumour Submental(IA) Floor of mouth, lips and anterior part of tongue Submandibular(IB) Retromolar trigone, glossopalatine pillars,lateral floor of mouth& anterior tongue Jugulodigastric(II) Hypopharynx, base of tongue, tonsil, nasopharynx & larynx Mid jugular(III) Hypopharynx, base of tongue, tonsil, nasopharynx & larynx Lower jugular(IV) Thyroid, nasopharynx & hypopharynx Supraclavicular(V) Lung, thyroid, gastrointestinal & genito urinary system Posterior triangle(VI) Nasopharynx
  39. 39. Factors affecting nodal metastasis • Anterior portions < posterior portions. • Tumor size. (T) • Perineural and perivascular invasion are associated with a high risk of nodal metastasis. • Poorly differentiated tumors > well-differentiated tumors. • Tumor thickness. Ref - Jatin Shah’s Head & Neck Surgery & Oncology 4th Edition
  40. 40. •Excluding the hard palate and lip, approximately 30% of patients with oral cavity cancer will present with cervical metastases • Depth of invasion greater than 8 mm was associated with a 41% rate of occult metastasis. •Tumour depth > 5mm --- Increased risk of neck metastasis
  41. 41. Assessment of cervical lymph nodes • Clinical Examination • Ultrasound • Ultrasound guided fine needle aspiration cytology • Computed tomography • Magnetic resonance imaging • PET • Sentinel node biopsy
  42. 42. • PET scan - highest specificity (82%) • Ultrasound - highest sensitivity (84%) • Due to high number of small lymph node metastases from oral cavity carcinoma, the non-invasive neck staging methods are limited to a maximum accuracy of 76% • Elective neck treatment should be mandatory for all patients with squamous cell carcinoma of the oral cavity
  43. 43. • Sentinel lymph node is defined as a lymph node to which a tumor first metastasizes • SLNB if negative for metastases, lymph node dissection is not necessary. • Use in oral cancer – controversial • One of the main problem of SLNB of oral cancer is skip metastasis in which the disease bypasses level 1 and 2 nodes and goes directly to level 3-4 Sentinel node biopsy Ref - Jatin Shah’s Head & Neck Surgery & Oncology 4th Edition
  44. 44. When neck dissection has to be done? • The incidence of metastatic disease for the upper aerodigestive tract varies widely, from 1-85%, depending on the site, size, and differentiation of the tumor. • The rate of ipsilateral metastatic disease in patients with stage T3-T4 squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or supraglottis is approximately 50%. • The rate of bilateral or contralateral metastatic disease in these patients varies from 2-35%. • 20 – 30 % of the malignancies of tongue metastasize to clinically undetectabe cervical nodes
  45. 45. Patterns of cervical lymph node metastasis from squamous carcinomas of the upper aerodigestive tract. Am J Surg. 1990 Oct;160(4):405-9 • A consecutive series of 1,081 previously untreated patients undergoing 1,119 RNDs for squamous carcinoma of the head and neck was reviewed to study the patterns of nodal metastases. • Predominance of certain levels was seen for each primary site. Levels I, II, and III were at highest risk for metastasis from cancer of the oral cavity. • SOHND (clearing levels I, II, and III) for N0 patients with primary squamous cell carcinomas is recommended
  46. 46. • For patients with clinical cervical lymph node metastases a therapeutic neck dissection is necessary and a modified radical dissection is regarded as the safest option. Management of the neck in patients with T1 and T2 cancer in the mouthBJOMS Vol 40, issue 6 .December 2004, Pages 494-500
  47. 47. Does N0 neck require treatment?? • The metastases rate to the neck from oral cancer is 34%. • Observation if probability is less than 20% • Elective neck dissection - >20 % • The lymph nodes at the highest risk of metastases from oral cavity cancers are those at level I, II, III. • Contralateral neck dissection: The primary oral cancer is midline ,bilateral along the tip of tongue or approaches /crosses midline.
  48. 48. • Most surgeons use an occult metastatic potential of 20% or greater to determine need for elective treatment of the N0 neck. Based on the paper by Mendenhall et aI., the occult metastatic rate for given subsites is as follows: • - 15-20% T1 - glottis, retromolar trigone, gingiva, hard palate, buccal mucosa; • - >20% T1 - oral tongue, soft palate, pharyngeal wall, supraglottis, tonsil; T2 - floor of the mouth, oral tongue, RMT, gingiva, hard palate, buccal mucosa; T1-T4 - nasopharynx, piriform sinus, base of the tongue; T2- T4 - soft palate, pharyngeal wall, supraglottis, tonsil; T3-T4 - floor of the mouth, oral tongue, RMT, gingiva, hard palate, buccal mucosa.
  49. 49. • The following surgical outline was suggested: – SCC oral cavity anterior to circumvalate papilla • Supraomohyoid – SCC Oropharynx, larynx and hypopharynx • level I- IV or level II-V – SCC with N+ nodes • RND – SCC with 2-4 positive nodes or extracapsular spread • RND and adjuvant therapy Shah Cancer July 1;109-113: 1990
  50. 50. Aims of Neck Dissection • Remove gross disease in patients with clinical evidence of nodal involvement (therapeutic neck dissection) • Remove occult metastases in patients whose tumor characteristics make one suspicious of occult cervical metastases (elective neck dissection or END)
  51. 51. The definition of the different types of neck dissections were outlined in the 1991 classification : 1) The radical neck dissection is considered to be a standard basic procedure for cervical lymphadenopathy. 2) When one or more of the non lymphatic structures are preserved which otherwise are routinely removed during radical neck dissection then it is termed as modified radical neck dissection.
  52. 52. 3) When the alteration involves preserving the 1 or more lymph node groups / levels routinely removed in radical neck dissection the it is termed as selective neck dissection. 4) When the alteration involves the removal of additional lymph node groups or non lymphatic structures relative to the radical neck dissection the procedure is called as extended radical neck dissection.
  53. 53. Classification  1991 classification 1. Radical neck dissection 2. Modified radical neck dissection 3. Selective neck dissection a ) supra omohyoid b ) lateral c ) posterolateral d ) anterior 4. Extended neck dissection  2001 classification 1. Radical neck dissection 2. Modified radical neck dissection 3. Selective neck dissection Here each variation is depicted by the term “ SND “ and the use of parentheses to denote the levels or sublevels removed 4. Extended neck dissection
  54. 54. Medina classification (1989) – Comprehensive neck dissection • Radical neck dissection • Modified radical neck dissection – Type I (XI preserved) – Type II (XI, IJV preserved) – Type III (XI, IJV, and SCM preserved) – Selective neck dissection
  55. 55. Spiro’s three- tiered classification-1994 • Radical (4 or 5 levels resected) • Conventional radical neck dissection • Modified radical neck dissection • Extended radical neck dissection • Modified and extended radical neck dissection • Selective (3 node levels resected) • Supra-omohyoid neck dissection • Jugular dissection (levels 11-1V) • Any other 3-node levels resected • Limited (no more than 2 nodes levels resected) • Para tracheal node dissection • mediastinal node dissection
  56. 56. Radical neck dissection • Indications – Extensive cervical involvement or matted lymph nodes with gross extracapsular spread and invasion into the X1, IJV, or SCM – Significant operable neck disease (N2a,2b,2c) – Access prior to pedicled flap reconstruction – Occult primary – Prescence of lymphangioma, haemlymphangioma, residual branchial cyst, fistula along with the malignancy.
  57. 57. Contraindications – Untreatable primary tumor – Patients unfit for tumor surgery – Distant metastasis – Unresectable neck disease – Significant bilateral neck disease
  58. 58. Extent  Removes  Nodal groups I-V  SCM, IJV, XI  Submandibular gland, tail of parotid  Preserves  Posterior auricular  Suboccipital  Retropharyngeal  Periparotid  Perifacial  Paratracheal nodes
  59. 59. Preoperative Considerations 1. - Age and Sex of the patient 2. - Consent /any allergies/ lab reports/vital signs 3. - Location of the Primary 4. - Unilateral vs. Bilateral Neck Dissection 5. - Location of Adenopathy/ Type of Neck Dissection 6. - Likelihood of Postoperative Radiation 7. - Patterns of Skin Necrosis in different Skin flap designs 8. - Potential for Wound healing problems 9. - Need for reconstructive flaps 10.- Tracheotomy may affect blood supply of some flap designs
  60. 60. POSITION OF THE PATIENT 1. The patient is laid supine 2. The head turned opposite side and hyperextended, resting on head ring 3. Upper end of the operating table elevated approximately 30 degree. 4. Mastoid tip., Ear lobule, Body of the mandible, midline of the chin, supra-sternal notch, clavicle and region of trapizius muscle insertion should be visible
  61. 61. General Rules General Rule of Placing the Incisions in Lines of Relaxed Skin Tension Lines (RSTL) 1. Horizontal Curving Incisions placed at a level in the neck depending on the site of the tumor 2. Facial incisions for parotid tumors can be combined with various neck incisions depending on preoperative considerations 3. High submandibular incisions should be placed at least 2cm below body of mandible 4. General Rule of placing vertical incisions so that weakest blood supply areas and trifurcations are away from (usually posterior to) carotid artery and at right angles for at least 2cm then with a "lazy" S-shape to minimize potential for scar contracture
  62. 62. • 1.Good exposure of the neck and primary disease. • 2. Ensure viability of the skin flaps. Avoid acute angles • 3. Protect carotid artery even in the cases of wound infection • 4.Considered preoperative factor—previous radio or chemotherapy. • 5. Facilitate reconstruction Example, if pectoral muscle is used a lower limb should be near the clavicle to enable flap accommodation. • 6. It should be cosmetically acceptable
  63. 63. Incisions Y incision Mc fee incision 63 Schobinger Incision Modified schobinger Conley’s Double Y
  64. 64. Apron incision Half apron incision 64 H incision
  65. 65. Steps Of Radical Neck Dissection
  66. 66. Incision
  67. 67. Dissection of the posterior triangle begins at the anterior border of trapezius
  68. 68. Dissection of the posterior triangle medially leads to exposure of brachial plexus, phrenic nerve and cutaneous roots of the cervical plexus
  69. 69. Specimen reflected posteriorly and anterior flap elevated to expose the sternal head of SCMM
  70. 70. Sternocleidomastoid muscle is detached from the sternum and clavicle and retracted cephalad to expose the carotid sheath
  71. 71. Internal jugular vein is ligated and divided after common carotid and vagus nerve is exposed and retracted medially
  72. 72. Dissection proceeds cephalad along the carotid sheath up the skull base
  73. 73. The upper skin flap is now elevated preseving the mandibular branch of the facial nerve
  74. 74. Supraclavicular dissection 95
  75. 75. Dissection of the posterior triangle 96
  76. 76. Retraction of the posterior belly of digastric show the upper end of the IJV in level II 97
  77. 77. Division of the veins related to hypoglossal nerve 98
  78. 78. Levels II-V dissection completed by removing the specimen and dissecting the IJV from carotid artery and vagus nerve 99
  79. 79. Surgical field following RND
  80. 80. Shoulder syndrome “Physical changes occuring in the shoulder joint due to denervation of trapezius leading to destabilization of scapula,pain and weakness and deformity of shoulder girdle,restricting the patient’s ability to abduct shoulder not above 90 ” -Nahum MD
  81. 81. Modified radical neck dissection(MRND) – Excision of same lymph node bearing regions as RND with preservation of one or more non- lymphatic structures (XI, SCM, IJV) – MRND is analogous to the “functional neck dissection” described by Bocca 102
  82. 82. Three types (Medina 1989) . • Type I: Preservation of SAN • Type II: Preservation of SAN and IJV • Type III: Preservation of SAN, IJV, and SCM ( “Functional neck dissection”) 104
  84. 84. MRND TYPE III Advantages : – Reduce postsurgical shoulder pain and shoulder dysfunction – Improve cosmetic outcome – Reduce likelihood of bilateral IJV resection in a pt with bilateral lymph node metastasis.
  85. 85. Selective Neck Dissection – Cervical lymphadenectomy with preservation of one or more lymph node groups – Four common subtypes: • Supraomohyoid neck dissection • Posterolateral neck dissection • Lateral neck dissection • Anterior neck dissection Indication: primary lesion with 20% or greater risk of occult metastasis
  86. 86. Lymphatic Drainage
  87. 87. SND: Supraomohyoid type • Most commonly performed SND • Definition – En bloc removal of cervical lymph node groups I-III – Posterior limit is the cervical plexus and posterior border of the SCM – Inferior limit is the omohyoid muscle overlying the IJV
  88. 88. Surgical procedure
  89. 89. SND: Lateral Type • Definition – En bloc removal of the jugular lymph nodes including Levels II-IV • Indications – N0 neck in carcinomas of the oropharynx, hypopharynx, supraglottis, and larynx
  90. 90. SND: Posterolateral Type • Definition – En bloc excision of lymph bearing tissues in Levels II-IV and additional node groups – suboccipital and postauricular • Indications – Cutaneous malignancies • Melanoma • Squamous cell carcinoma • Merkel cell carcinoma – Soft tissue sarcomas of the scalp and neck
  91. 91. SND: Anterior Compartment • Definition – En bloc removal of lymph structures in Level VI • Perithyroidal nodes • Pretracheal nodes • Precricoid nodes (Delphian) • Paratracheal nodes along recurrent nerves – Limits of the dissection are the hyoid bone, suprasternal notch and carotid sheaths • Indications – Selected cases of thyroid carcinoma – Parathyroid carcinoma – Subglottic carcinoma – Laryngeal carcinoma with subglottic extension – CA of the cervical esophagus
  92. 92. Types of neck dissections
  93. 93. Extended Neck Dissection • Definition – Any previous dissection which includes removal of one or more additional lymph node groups and/or non-lymphatic structures. – Usually performed with N+ necks in MRND or RND when metastases invade structures usually preserved. • Indications – Carotid artery invasion – Other examples: • Resection of the hypoglossal nerve resection or digastric muscle, • dissection of mediastinal nodes and central compartment for subglottic involvement, and • removal of retropharyngeal lymph nodes for tumors originating in the pharyngeal walls.
  94. 94. Complications INTRAOPERATIVE • Hemorrhage • Carotid sinus reflux • Pneumothorax • Air embolus • Embolism • Nerve damage • Chylous fistula POST OPERATIVE • Hematoma • Wound infection • Skin flap loss • Salivary fistula • Chylous fistula • Blindness • Facial edema • Electrolyte disturbances • Carotid artery rupture
  96. 96. Important facts • High incidence of occult mets in T1 & T2 leisons involving floor of mouth ( 21% & 62%) • Crossing the midline increases the incidence of contra/ bilateral nodal mets lesion 1cm away from midline …15% lesion within 1 cms of midline… 15-30% lesion crossing the midline……..>30 % 20 – 30 % of the malignancies of tongue metastasize to clinically undetectabe cervical nodes High incidence of skip metastasis- cancer of tongue
  97. 97. Neck Dissection for Thyroid Malignancy • Regional lymph node metastasis from primary differentiated carcinomas of the thyroid gland occurs in a high proportion of patients with a papillary carcinoma. • First Echeleon Lymph nodes are Level V, VI. • Sequentially progresses to II,III,IV.
  98. 98. Neck Dissection in Thyroid Malignancy • Central compartment node dissection is undertaken for dissection of regional lymph nodes for metastases from primary differentiated carcinomas of the thyroid gland • When the primary tumor is extensive • With invasion of the capsule of the thyroid gland • With extension beyond the capsule of the thyroid gland • If the primary tumor is of significant dimensions or involves both sides of the thyroid gland, then bilateral tracheoesophageal groove lymph node dissection is undertaken. • As long as findings of the lateral part of the neck are grossly negative, a central compartment node dissection of the neck is considered adequate
  99. 99. References • Mastery of Surgery – J.E. Fischer, K.I. Bland • Textbook of Head & Neck Surgery & Oncology 4th Edition.– Jatin P. Shah • Stell & Marans Textbook of Head & Neck Surgery & Oncology 5th Edition. • Robbins KT. Classification of neck dissection: current concepts and future considerations. Otolaryngol Clin North Am. Aug 1998;31(4):639-55 • Shah JP: Patterns of lymph node metastasis from squamous carcinomas of the upper aerodigestive tract. Am J Surg 1990, 160:405-409. • Medina JE, Byers RM: Supraomohyoid neck dissection: Rationale, indication and surgical technique.Head Neck 1989, 11:111-122 • Y. Ducic , L. Young , J. Mclntyre: Neck dissection: past and present. Minerva Chir 2010;65:45-58
  100. 100. Thank You!