VIVA – Anatomy – Neck Flashcards
What are the branches of the ECA?
Superior thyroid (ant)
Ascending pharyngeal (medial)
Lingual (ant)
Facial (ant)
Occipital (post)
Post-auricular (posterior)
Superficial temporal and maxillary are terminal
What is your technique for ligation?
Horizontal skin incision at level of hyoid/SMG in skin crease – post 1/3 over SCM
Subplatysmal flaps
Identify ant border of SCM and retract posteriorly
Carotid sheath identified
Vascular loop around common carotid
Identify hypoglossal crossing
ECA usually anterior and superficial to ICA
ICA does not branch in the neck à identify 2 branches of ECA
Ligate ECA between superior thyroid and lingual branches – if ligate lower may cause clot that can migrate proximally
?Need to ligate facial vein
What structures pass between ECA and ICA?
Glossopharyngeal nerve
Pharyngeal branch of vagus
Stylopharyngeus muscle
?Styloglossus
Styloid + stylohyoid ligament
Deep lobe of parotid
Branchial fistula tract
What are the course and branches of Superior Thyroid Artery (Ant)
- Arises at commencement ECA from anterior surface
- Can arise from CCA
- Usually the first branch
- Runs nearly vertically downwards and forward with associated vein
- Enters upper pole thyroid
- External laryngeal nerve closely associated
- Branches
- Infrahyoid
- Superior laryngeal artery
- Pierces thyrohyoid membrane with internal laryngeal nerve
- Branch to SCM
- Supplies
- Adjacent muscles
- Larynx
- Thyroid gland
What are the course and branches of Ascending Pharyngeal (Post)
- Arises just above commencement ECA
- Smallest branch of ECA
- Arises from posterior surface
- In 14% arises from the occipital artery
- Ascends vertically anteromedial to the ICA along side wall pharynx
- Anterior to prevertebral fascia
- Supplies pharyngeal wall, soft palate, tonsil, inferior tympanic branch
- Meningeal branches to foramen lacerum, jugular foramen, hypoglossal
- Branches
- Posterior Meningeal
- Pharyngeal
- Inferior tympanic
What are the course and branches of Lingual Artery (Ant)
- Arises above superior thyroid
- Usually at or above the level of the hyoid
- Runs up then along the upper border greater horn hyoid (or above)
- Deep to digastric and stylohyoid
- Lies against lateral wall of pharynx to pass medial to the posterior border hyoglossus
- Runs with deep lingual vein to tip of tongue
- Crossed by hypoglossal nerve and facial vein
- Branches
- Suprahyoid
- Sublingual
- Dorsal Lingual
- Deep Lingual
What are the course and branches of Facial Artery (Ant)
- Arises above lingual
- Sometimes via a common linguofacial trunk
- At approximate level of digastric / angle of mandible
- Runs upwards and forwards on superior constrictor
- Deep to digastric and stylohyoid muscles but then hooks around posterior belly of digastric to reach upper surface submandibular gland
- Makes an “S” bend curling down over submandibular gland and up over mandible at anterior border of masseter
- Anterior to the facial vein
- Runs upwards and medially to the side of the nose as the angular artery towards the medial canthus
- Deep to platysma / Risorius / Zygomaticus major and minor
- Superficial to buccinators
- Landmarks for FAMM flap
- Based anterior to stensons duct
- Use a doppler
- Branches
- Cervical Branches
- Ascending Palatine
- Tonsillar – given off as lies on superior constrictor à tonsil and soft palate
- Branches to SMG
- Submental artery à given off just before crosses inf border of mandible à runs along inf surface of mylohyoid, between it and digastric à ant belly digastric, mylohyoid and sublingual/FOM
- Muscular branches to muscles of mastication
- Facial Branches
- Superior and Inferior Labial Arteries
- Each divides into two branches
- Both run beneath vermillion margin of lip
- Anastomose end to end at the midline of the lip
- In or behind the deep fibres of orbicularis oris
- Hence fairly superficial on labial side
- Tortuous
- Angular Artery
- Terminal portion of facial artery
- Gives off a lateral nasal artery which can anastomose with the dorsal nasal branch (ophthalmic –ICA)
- Multiple anastomoses with STA / IMA / Ophthalmic / Contralateral Facial
- Superior and Inferior Labial Arteries
- Cervical Branches
What are the course and branches of Occipital Artery (Post)
- Arises from posterior ECA at same level as facial artery
- Crossed at origin by hypoglossal nerve
- SCM branch passes anterior to nerve and “holds it down”
- Passes along lower border posterior belly digastric
- Grooves base of skull at occipitomastoid suture
- Passes back through apex of posterior triangle
- Runs with greater occipital nerve
- Supplies back of scalp
- Branches
- 2 to SCM
- Upper is a guide to accessory nerve
- Mastoid
- Auricular
- Meningeal
- Occipital
- Descending
- 2 to SCM
What are the course and branches of Posterior Auricular Artery (Post)
- Arises above level of digastric
- Can arise within parotid
- Superficial to styloid process
- Passes along upper border posterior belly digastric
- Crosses surface of mastoid
- Runs with lesser occipital nerve
- Branches
- Auricular to pinna and ear
- Stylomastoid branch
- Supplies facial nerve
- Gives off stapedial artery
- Posterior tympanic – Mastoid and stapedial
- Occipital
What are the course and branches of Superficial Temporal Artery
- Terminal branch of ECA
- Runs upwards deep to TMJ
- Crosses posterior root of zygomatic arch
- Branches
- Parotid
- Transverse facial artery near commencement
- Runs just above parotid duct
- Anterior auricular
- Zygomatico-orbital
- Middle temporal artery
- Runs vertically deep to temporalis
- Causes groove in squamous temporal bone
- Anastomoses with deep temporal branches of Internal maxillary artery
- Frontal
- Parietal
What are the landmarks for finding the facial artery for a FAMM flap?
?
What is the blood supply to the SCM?
Upper 1/3 – branches from occipital artery
Middle 1/3 – branches from superior thyroid or EJV itself or both
Lower 1/3 – suprascapular
Describe the course and segments (7) and branches of the ICA
- Course
- Lateral to ECA initially
- Slopes up and posterior to move to a medial position
- No branches
- Enters carotid canal at base of skull
- Curves upwards from foramen lacerum to enter posterior aspect cavernous sinus
- Between Sphenoid endosteum and inner layer of dura
- Arches up then forwards in medial wall cavernous sinus
- Pierces roof of sinus medial to anterior clinoid process
- Accompanied by SNS fibres (Internal Carotid Nerve)
- Curves backwards along roof of cavernous sinus
- Then curves upwards lateral to the optic chiasma
- Divides into terminal branches at anterior perforated substance
- ACA
- Passes forwards above the optic nerve
- Anterior Communicating Artery
- Lies in chiasmatic cistern
- ACA
Other branch = ophthalmic – commences as ICA emerges from roof of cavernous sinus
Segments
- cervical
- petrous
- lacerum
- cavernous
- clinoid
- ophthalmic
- communicating
What is the relationship of the petrous segment to the cochlea?
The cochlea lies posterior and superior to the petrous carotid in the ant part of the otic capsule
How do you manage tumour involving the cervical ICA?
- Carotid Artery involvement
- Pre-op imaging
- encased carotid defined is on radiology tumour encircles >270 degrees - unresectable
- concern for involvement if wrapping around more than 180, loss of fascial plane between tumour and carotid on MRI, less than 1.8mm of separation
- 50% of those between 180-270 degrees resectable
- balloon occlusion test – if performed without neuro deficit, can go on to resect carotid segment
- resection still has significant morbidity and mortality associated – 60% neurological and up to 40% mortality
If unexpected involvement
- Abandon
- Shave tumour from vessel
- Sacrifice
- See if vascular surgeon available
- Clamp carotid
- Measure stump pressure via transducer (with art line)
- Pressure > 70 resect without reconstruction
- 55-70 resect + reconstruct
- <50 reconstruct + temporary shunt
- Sacrifice as close to skull base as possible (reduce clot propagation)
- Post op heparin SC
- Reconstruction options
- Saphenous vein
- Gortex or Dacron graft
If the ICA is injured during surgery what is your management? Cervical (neck surgery)
ABC - Alert anaesthetist etc
Control proximally with vessel-loop – is there pulsatile back flow from cranial end suggesting intact circle of Willis (90%)?
Options – ligate, repair, temporary shunt
Do not ligate without preop testing (30% stroke)
Call for help (senior surgeon, vascular)
Gain proximal + distal control + vessel loops +/- reconstruction +/- covering with muscle flap, esp. if irradiated
Strict BP maintenance above 110 mmHg (Note: 90% mortality if not maintained)
10% stroke
Often need to sacrifice vagus (+/- permanent trachy + PEG)
Repair if possible
?Javert shunt + ring clamps
Need heparin
Vascular surgeon
Great saphenous vein is good size match
Resection
Incisions above and below vessel
Clamp vessel above and below
Resect medial clavicle if need to get further proximal
Ligate with 0 silk
Post op S/C heparin
Stroke 50%, death 25%
If the ICA is injured during surgery what is your management? Cavernous (FESS)
- Obliterates visualization
- ABC’s
- Inform anaesthetist
- 2 large bore IVC and Immediate fluid resus
- G&H / Crossmatch and order blood
- Lower BP if possible for 1-2min
- Call for help / 2 surgeon technique
- Use the posterior septum to shield the endoscope from the jet of blood
- Use lens cleaning system
- Large calibre suction (12Fr or greater) x2 in contralateral nostril
- Minimise / Control Bleeding
- Head Up
- Ipsilateral CCA compression to slow
- Vascular clamps (wormald) for atraumatic clamp of injury
- Maximise exposure if bleeding controlled with clamps
- “U clip” anastomotic device
- Pack and Pressure
- ? Material
- PJ recommends muscle from SCM in his work (10x10mm)
- Crushed and placed over injury site
- Floseal / surgiflo useful only for venous bleeding
- Intervential radiology / Vascular surgery / Tie off ICA?
- Follow-up
- Needs an angiogram in the flowing months to assess for aneurysm formation
When can the ICA be safely ligated?
Never completely safely – Rutherford vascular surgery says ligation results in 45% mortality and should be reserved only for injuries at BOS that are not amenable to recon
Safer in younger pts and passing balloon occlusion test à Inflated for 20 min, monitor for any change in neuro function, if no changes deflate +/- additional imaging (SPECT, single photon emission CT)
Describe the constrictions of the esophagus?
15cm – cricopharyngeus
23cm – arch of aorta
27cm – L main bronchus
38cm – diaphragmatic hiatus
Blood supply esophagus?
- Inferior thyroid arteries = Upper oesophagus
- Bronchial arteries from Aorta
- Oesophageal branches (L) Gastric artery
- Venous Drainage
- Upper part to brachiocephalic veins
- Middle part to azygos system
- Lower part to (L) Gastric vein à portal vein
- Anastomosis between portal and systemic circulation
Nerve supply esophagus? Extrinsic
- Upper Oesophagus
- RLN
- Middle ganglia cervical SNS ganglia within inferior thyroid arteries
- Middle and Lower Oesophagus
- Thoracic sympathetic trunks
- Greater Sphlancnic nerves
- Vagus (PNS)
- Plexus forms over oesophagus
- Develops into anterior and posterior vagal trunks in lower oesophagus
- Anterior is mainly (L) vagus, posterior (R)
- Motor supply
- Vagus
- Nucleus ambiguous (Upper striated part)
- Dorsal motor nucleus (Lower part)
- Provides secretomotor innervation
- Vagus
Nerve supply esophagus? Intrinsic
Lower 2/3 smooth muscle
- preganglionic = vagus
- postganglionic = myenteric plexus (Auerbach’s) – between inner circular and outer longitudinal
- VIP neurons relax (NO), cholinergic contract
What is Achalasia?
Distal oesophageal flaccidity associated with failure of LOS relaxation
Primary – idiopathic degeneration of ganglion cells in Auerbach’s plexus à loss of post-ganglionic inhibitory neurons à unopposed cholinergic activity
Secondary – carcinoma, CVA, Chaga’s disease, post vagotomy, diabetic autonomic neuropathy, infiltrative disorders
Achalasia - What does it look like on Ba Swallow?
Classic bird beak’s deformity, failure of peristalsis, air-fluid level in upright position
What are the components of the lower esophageal sphincter? (5 components)
Mucosa
Muscularis mucosa
Circular muscular layer
Longitudinal muscular layer
Crural component from diaphragm
What are the surface markings of? IJV
Angle of mandible to between heads SCM
What are the surface markings of? EJV
In a line drawn from the angle of the mandible to the middle of the clavicle at the posterior border of the SCM
What are the tributaries of the IJV?
- Inferior petrosal sinus
- Pharyngeal plexus
- Common Facial vein
- Lingual vein
- Superior thyroid veins
- Many potential variations
Where does the retromandibular vein drain?
It divides into two branches:
- an anterior, which passes forward and unites with the anterior facial vein to form the common facial vein
- a posterior, which is joined by the posterior auricular vein and becomes the external jugular vein.
What forms the EJV?
Formed by the junction of the posterior division of the retromandibular vein with the posterior auricular vein.
What are the tributaries of the EJV?
Posterior external jugular
Transverse cervical
Suprascapular
Anterior jugular vein
In what fascial layer does the EJV run?
Deep to platysma
Superficial to deep investing fascia, but pierces inferiorly to join subclavian
Where does the run and AJV drain?
Commence under chin and run to suprasternal region
Begins near the hyoid bone by the confluence of several superficial veins from the submaxillary region
Its tributaries are some laryngeal veins, and occasionally a small thyroid vein
Pierce deep fascia at suprasternal region entering suprasternal space and anastomose – may drain some of inferior thyroid vein here
Run lateral under SCM to join EJV near termination
Where do the trunks of the brachial plexus run?
Deep to prevertebral musculature
Emerge between middle and anterior scalenes
What is thoracic outlet syndrome?
Compression at the superior thoracic outlet wherein excess pressure placed on a neurovascular bundle passing between the anterior scalene and middle scalene muscles. It can affect one or more of the nerves that innervate the upper limb and/or blood vessels as they pass between the chest and upper extremity; specifically in the brachial plexus, the subclavian artery, and - rarely - the subclavian vein, which does not normally pass through the scalene hiatus.
Causes = congenital (e.g. cervical 1st rib), trauma, tumour
What is the course of the thoracic duct?
Originates anterior to the body of second lumbar vertebra, the cisterna chyli, and ascends, along the right side of vertebral column, through the aortic hiatus of the diagram into the posterior mediastinum, traveling between the aorta (to its L) and azygous vein (to its right) towards the fifth thoracic vertebra, where it crosses to the left and continues to ascend up into the neck.
In the neck located to R of and behind L common carotid/vagus (ant to subclavian)à from here arches upwards, forwards and laterally 3-4cm above root of neck, passing between IJV and in front of ant scalene muscle and phrenic nerve
Opens into IJV, subclavian or junction
Ant to thyrocervical trunk and transverse cervical artery, superior to deep cervical fascia and phrenic
Cross anterior to the vertebral, thyrocervical and subclavian arteries
Where does it pierce the diaphragm?
Through aortic hiatus (T12)
What cervical level does it pass behind IJV?
C7
Where does it end?
Junction of IJV and subclavian (medial border anterior scalene)
What is chyle?
Chemical composition of chyle is similar to that of tissue lymph, with higher concentration of cholesterol, phospholipids, and fat particles, particularly triglyceride rich chylomicrons and long-chain (>10 carbon atoms) esterified fats.
How do you manage a chyle leak? Intraop?
- recognize injury to duct and search for it
- head down/Valsalva if necessary (30mmHg pressure), cream down NGT, abdominal pressure
- loupes
- oversew surrounding tissues with silk (inflammatory reaction), ligar clip
- local flap – pec/SCM
- surgicel
How do you manage a chyle leak? Post op?
- recognize it and confirm Dx with lab testing for chylomicrons
- triglyceride in drain fluid – cholesterol:triglyceride ratio <1 compated to plasma levels
- CXR to rule out chylothorax
- accurate measurement
- nil by mouth or elemental diet with MTC (absorbed directly into portal system – less accessible and practical than fat free)
- pressure dressing on neck
- monitor fluid and nutritional state
- consider TPN – increased risk of infection and venous thrombosis with TPN but likely more effective than low fat diet
- octreotide – somatostatin analogue à nil prospective RCTs b/c low incidence – based on isolated cases and cohorts
- if >600ml/day for 5 days, >1000ml/day from outset or Cx of ongoing leak – return to theatre
- neck exploration and measures as above
- thoracoscopic R side approach thoracic duct ligation – occlusion by mass ligation of tissue above supra-diaphragmatic hiatus between azygous vein and aorta
What are the attachements of the pharyngobasilar fascia?
Pharyngeal tubercle anterior to foramen magnum in midline – pharyngeal raphe – receives fibres from the constrictors
Passes laterally convex forward over longus capitis and back part of foramen lacerum to petrous temporal bone anterior to carotid canal
Attachment to cartilaginous part of auditory tube
Below eustacian tube orifice à sharp posterior border medial pterygoid plate
Continues down to the hamulus of the plate
Point Pharyngobasilar fascia out on the BOS
Point Pharyngobasilar fascia out on the mandible
?Diminishes in thickness as it passes below superior constrictor to be absent by the level of the hard palate
What is Passavant’s ridge?
Upper fibres of palatopharyngeus run horizontally from one side to the anterolateral edge of the aponeurosis on the other side via the posterior wall
Forms a sphincter which when contracted causes posterior wall in pharynx to bulge (Passavant’s ridge)
Some lower fibres from sup constrictor contribute
Soft palate elevation closes nasopharynx
Point on the BOS the origin of LVP and TVP
TVP Origin
- Scaphoid fossa upper medial pterygoid plate
- Lateral cartilaginous Eustacian tube
- Spine of sphenoid
LVP Origin
- Quadrate area inferior surface apex petrous temporal bone, anterior to carotid canal
Adjacent medial cartilaginous eustactian tube
What passes between? BOS + Sup constrictor
- ? Levator Veli Palati (Medial to fascia)
- ?TVP (Lateral to fascia)
- ?Eustachian tube
- ?ascending palatine artery
What passes between? Sup + Middle constrictors
- Plugged by back of tongue
- Stylopharyngeus passes into pharynx
- Styloglossus,Glossopharyngeal and Lingual nerve pass to tongue
What passes between? Middle + inf constrictors
- Gap between middle and inferior constrictor anteriorly
- Closed by thyrohyoid membrane – walls in piriform recess
- Internal laryngeal nerve and superior laryngeal vessels pierce membrane
What passes between? Below inf constrictor
- RLN and inferior laryngeal vessels
What attaches to the styloid process? Muscles (from medial to lateral)
- Stylopharyngeus
- Deepest and highest
- Passes nearly vertically down to larynx
- Passes between ECA and ICA
- Styloglossus
- Arises from anterior inferior process
- Stylohyoid
- Arises high on posterior aspect
- Passes superficial to both ECA and ICA
What attaches to the styloid process? Ligaments
- Stylohyoid ligament emanates from it’s tip
- Passes to lesser horn of hyoid
- Stylomandibular Ligament
- Thickening of deep lamina of parotid fascia
- From vaginal process of tympanic temporal bone to angle of mandible
What are the attachments of the pterygomandibular raphe?
Hamulus à Mandible above post end mylohyoid line
Ends at level of post border of last molar tooth
Draw the thyroid cartilage from the side and mark the areas of attachments of muscles
What is Killian’s triangle?
Triangular area in the wall of the pharynx between the thyropharyngeus part of the inferior constrictor of the pharynx and the cricopharyngeus muscle, also of the inferior constrictor muscle of the pharnyx
What is Laimer’s triangle?
Upper oesphagus below cricopharyngeus
Post wall composed of circular fibres only as longitudinal fibres swinging laterally
What is the origin + insertion of Salpingopharyngeus
Arises from lower part of cartilaginous eustacian tube
Runs down to blend with palatopharyngeus and inserts of post border thyroid lamina
What is the origin + insertion of Stylopharyngeus
Arises from deep aspect styloid process high up
Inserts on posterior border thyroid lamina
What is a Thornwaldt’s cyst?
Common incidental benign midline nasopharyngeal mucosal cyst
Forms as a result of retraction of the notochord where it contacts with the endoderm of the primitive pharynx. Initially is forms a small diverticula. Eventually inflammation results in obliteration of the mouth, resulting in a cyst.
The cyst is lined by respiratory epithelium and accumulates with fluid with variable proteinaceous content.
Describe the surgical approaches to the oropharynx
- Transoral
- Mandibulotomy (median, paramedian or lateral)
- Mandibulectomy
- Median translingual pharyngotomy
- small midline BOT lesions
- Suprahyoid pharyngotomy
- small midline BOT lesions
- Lateral pharyngotomy
- tongue drop “Columbian neck tie
What is a composite resection?
?
What is a Commando resection?
Combined mandibular and oral cavity resection + neck dissection
Draw a lymph node
Draw a section through the tonsil
Tonsil Blood supply?
- Mainly via lower pole
- Tonsillar Br of dorsal lingual a anteriorly (from lingual a)
- Tonsillar Br of ascending palatine a posteriorly (from facial a)
- Tonsillar br of facial a (Largest) – arches over upper border of styloglossus and pierces sup constrictor
- Upper pole arterial supply
- Ascending pharyngeal artery posteriorly
- Lesser palatine artery anteriorly (via descending palatine from maxillary a)
Lymphoid compartments?
- Reticular crypt epithelium
- Perifollicular zone (rich in T-cells)
- Mantle zone of follicle
- Germinal centre of follicle
- Efferent lymphatics only
What structure provides the blood for most tonsil bleeds?
Paratonsillar vein
What are the subregions of the hypopharynx?
Posterior pharyngeal wall
Piriform fossae
Post-cricoid region
Lateral pharyngeal wall
What are the borders of the piriform fossa?
- Inverted pyramid
- From pharyngoepiglottic fold to inferior border of cricoid cartilage (commencement of cervical esophagus)
- Aryepiglottic fold medially + arytenoid and cricoid cartilages
- Thyroid cartilage anterolaterally
- Medial pyriform mucosa forms post wall of paraglottic space à separated from endolarynx by AE folds and lat cricoarytenoid muscles
- Thyrohyoid membrane superolaterally
What are the muscles of the soft palate?
Tensor veil palatini
Levator palate
Palatoglossus
Palatopharyngeus
Muscularis uvulae
What are the Attachments of?
- Tensor Palati
- Origin
- Scaphoid fossa upper medial pterygoid plate
- Lateral cartilaginous Eustacian tube
- Spine of sphenoid
- Trianglular muscle passes down between pterygoid plates
- Tendon turns medially around pterygoid hamulus above the origin of buccinators
- Either attached to or flattens as the palatine aponeurosis
What are the Attachments of? Levator Palati
- Origin
- Quadrate area inferior surface apex petrous temporal bone, anterior to carotid canal
- Adjacent medial cartilaginous eustactian tube
- Quadrate area inferior surface apex petrous temporal bone, anterior to carotid canal
- Rounded belly inserts on nasal surface aponeurosis between 2 heads palatopharyngeus
- Forms a “V” shaped sling
What are the Attachments of? Palatoglossus
- Arises from undersurface palatine aponeurosis
- Passes down to interdigitate with styloglossus
What are the Attachments of? Palatopharyngeus
- Arises from 2 heads
- Anterior from posterior border hard palate and anterior aponeurosis
- Posterior head from posterior aspect palatine aponeurosis
- Heads arch down and join running in palatopharyngeal fold with the lower part blending with the stylopharyngeus and salpingopharyngeus
- Inserts mainly on posterior border thyroid lamina and horns
What are the Attachments of? Muscularis Uvulae
- 2 strips of muscle on upper surface aponeurosis
- From posterior nasal spine of palatine bone to mucosa of uvula
Innervation of soft palate?
- All supplied by pharyngeal plexus
- Nucleus Ambiguus via cranial accessory nerve and pharyngeal branch of vagus
- Exceptions
- Tensor Palati = Br from nerve to medial pterygoid (V3)
- Secretomotor via pterygopalatine ganglion running in lesser palatine nerves (Superior salivary nucleus / nervus intermedius / Greater petrosal)
- Also carry taste
- Sensation via lesser palatine (V2)
- Slight overlap with CNIX
- Gag reflex
- CNIX afferent
- CN X efferent
Which is the most internal of the pharyngeal muscles?
Palatopharyngeus
Point to the attachments of the sphenomandibular ligament
What are the boundaries of the fossa of Rosenmuler?
Anterior: Eustachean tube and levator veli palati muscle.
Antero-laterally - TVP
Posterior: Pharyngeal wall mucosa overlying the pharyngobasilar fascia and retro pharyngeal space, containing the retropharyngeal lymph nodes of Rouviere.
Superior: Foramen lacerum, petrous apex, carotid canal posteriorly, and the foramina ovale and spinosum anterolaterally.
Postero lateral (apex): Carotid canal opening and petrous apex posteriorly, foramen ovale and spinosum laterally. Lateral: Tensor palati muscle, mandibular nerve and parapharyngeal space.
What are the 4 parts of SCM?
Sternomastoid
Sterno-occipitalis
Cleido-occipitalis
Cleidomastoid
Through which parts of SCM does CN XI run?
Between cleidomastoid (deep) and remaining parts
Embryology of SCM?
Epipericardial ridge - contains the mesodermal rudiments of the sternocleidomastoid, trapezius, and the infrahyoid and lingual musculature. The nerves of the epipericardial ridge are the hypoglossal and spinal accessory. The proliferation of mesoderm in this area eventually causes overgrowth and narrowing of the third, fourth, and sixth arches into an ectodermal pit, known as the cervical sinus of His
Draw the hyoid and mark where the muscular attachments are
What is the insertion of the omohyoid?
- Origin attachment lateral to sternohyoid at lateral inferior hyoid bone
- Passes deep to SCM lying over carotid sheath and IJV where it forms a tendon held down by investing fascia
- Runs back horizontally to attach to upper border scapula and transverse scapula lig à investing fascia secures
What are the boundaries of the post triangle?
- Posterior Border SCM
- Anterior border Trapezius
- Clavicle
- Roof = Investing layer deep cervical fascia
- Floor = Prevertebral fascia
What are the muscles of the floor of the post triangle?
Splenius
Levator scapulae
Scalene post
Scalene medius
+/- Scalene ant / Serratus Ant / Semispinalis capitis
What are the attachments of scalenus anterior?
- Origin
- Anterior tubercles C3-6
- Muscle passes forward and laterally under prevertebral fascia
- Insertion is scalene tubercle and adjacent ridge of the inner upper surface 1st rib.
Trachea - Cervical levels?
C6-T5
Trachea - How many rings?
- 15-20 horse-shoe shaped rings of hyaline cartilage, deficient posteriorly
Trachea - Length?
- Total length 11cm
- 5cm within neck
- Stretches to ~15cm with inspiration
Trachea - Compressions?
How many rings can you resect for primary anastomosis?
- Maximum length of segment to be rescted is 5-6cm (less in the elderly b/c less elasticity, short people)
What are the tracheal releasing manoeuvres?
- Older pts lose elasticity of annular ligaments à need releasing procedures when more than 1-2cm resected
- Can release annular ligaments in young people à extra 2.5cm à place incision on one side of lat trachea above anastomosis and on opposite side below to preserve blood supply to both tracheal segments
- Mobilisation procedures to allow tension free closure
- Suprahyoid release – 5cm
- Release of mylohoid, geniohyoid, genioglossus and stylohyoid ligament
- Body of hyoid transected in the midline- to insertion of digastric tendon
- Allows up to 5cm of release of larynx/trachea
- Mediastinal mobilization of trachea – 6cm
- Suprahyoid release – 5cm
Why are foreign bodies more likely to go down the right main bronchus?
- Shorter, wider and more vertical than (L)
What are the CXR signs of FB inhalation?
Air trapping - early
Atelectasis or consolidation - late
Pneumothorax
Pneumonia (several days after event)
Comparison of inspiratory and expiratory CXRs may show inspiratory hypoinflation (atelectasis) and expiratory hyperinflation due to ball-valve effect à initially then proceeds to consolidation on lung
Expiratory hyperinflation w/. mediastinal shift toward the normal side on expiration (ball-valve effect)
What are the branches of the cervical plexus?
- Anterior Rami C1-4
- Lies in series with brachial plexus on scalene medius and behind the prevertebral fascia
- NOT IN POSTERIOR TRIANGLE but lies under upper SCM
- Receives
- Grey rami communicans from superior cervical ganglion
- Sensory Branches
- Supply posterior fossa meninges, front and sides of neck, while also contributing to scalp, face and chest
- C1-3 Meningeal branches
- C1 ascend with hypoglossal
- C1/2 ascend with vagus
- C2/3 pass thru foramen magnum
- Lesser Occipital Nerve (C2)
- Hooks around accessory
- Runs up on posterior border SCM
- Supplies posterior upper neck and post-auricular region +/- Auricle
- Greater Auricular Nerve (C2/3)
- Passes vertically up lateral surface SCM
- Supplies angle of mandible, preauricular region, parotid fascia, Cranial surface auricle and Lateral lower ½ auricle below EAC, mastoid skin
- Transverse Cervical nerve (C2/3)
- Curves around posterior border SCM
- Pierces investing fascia
- Supplies front of neck from chin to sternum via ascending and descending branches
- Ascending branch may communicate with cervical branch facial nerve
- Supraclavicular nerve (C3/4)
- Exits posterior border SCM and branches (Medial, intermediate and lateral)
- Supplies skin down to sternal angle, across R2 to ½ way down deletion and back along spine of scapula
- Motor Branches
- Segmental to prevertebral muscles
- Longus capitis / Longus Coli / Scalenes
- Thyrohyoid and Geniohyoid
- Via C1 branch running with hypoglossal
- C2/3 to SCM and C3/4 to trapezius
- Mainly proprioceptive but some motor
- Inferior root Ansa Cervicalis
- Formed by C2/3
- Runs lateral to IJV
- Descends to join superior root at Ansa
- Superior root from C1
- Phrenic Nerve
- C4 with C3/5 contributions
- Runs vertically over scalene anterior under prevertebral fascia
- Passes lateral to ascending cervical branch of Inferior thyroid atery
- Behind Subclavian vein to enter mediastinum
- Sometimes joined by accessory phrenic arising from nerve to subclavius below subclavian vein
- Sole motor supply to Diaphragm
- Sensory distribution to Diaphragm, pericardium, pleura and peritoneum
- Segmental to prevertebral muscles
Describe the ansa cervicalis
Loop of nerves that are part of the cervical plexus. It lies superficial to the internal jugular vein in the carotid triangle.
Branches from the ansa cervicalis innervate three of the four infrahyoid muscles: the sternohyoid muscle, the sternothyroid muscle, and the omohyoid muscle. It does not innervate the thyrohyoid muscle, which receives its innervation from the ventral root of C1.
Has 2 roots – superior root from C1 via hypoglossal, inferior root from C2-3
Parapharyngeal space Boundaries?
Superior:
Temporal bone medial to foramen ovale (lateral to this is considered the infratemporal fossa)
Sphenoid bone including the carotid canal, jugular foramen and hypoglossal foramen
3 bony landmarks
- scaphoid fossa
- spine of sphenoid
- styloid process
3 fascia
- pharyngobasilar fascia
- tensor veli palatine fascia
- medial pteryoid fascia
Inferior:
Posterior belly digastric and greater horn hyoid
Posterior:
Prevertebral fascia
Anterior:
Pterygomandibular raphe
Medial pterygoid fascia
Medial:
Superior constrictor – fascia over
Tensor and levator veli palatini muscles
Lateral:
Fascia over medial pteryoid
Mandibular ramus
Deep lobe of parotid
Posterior digastric
Parapharyngeal space Contents?
Divisions: Separated by styloid process or fascia that extends from styloid process to tensor veli palatine
1. Pre-styloid compartment: Anterolateral
Contents:
- Fat
- Muscle: styloglossus and stylopharyngeus
- Lymph nodes?
- Deep lobe of parotid gland
- Minor and ectopic salivary glands
- Arteries: Internal maxillary, ascending pharyngeal
- Veines: Pharyngeal venous plexus?
- Nerves: Branches of the mandibular division of the trigeminal nerve namely inferior alveolar, lingual and auriculotemporal
2. Post-styloid compartment: Posteromedial
Contents:
- ICA
- IJV
- CNs IX-XII
- SNS chain
- Lymph nodes
- Glomus tissue
Parapharyngeal space Most common tumours?
Salivary neoplasms – 90% pleomorphic
Paragangliomas
Neurogenic – mainly schwannoma
Parapharyngeal space Surgical approaches?
Transcervical-transparotid
Transcervical
Transoral
Transcervical-transmandibular
Infratemporal fossa
Parapharyngeal space Manoeuvres to improve access?
Mandibulotomy
Division of stylomandibular ligament
Removal/mobilization of SMG
Excision of superficial parotid
Ia, IIb dissection
Removal of styloid
Division of post belly of digastric
What are the structures running vertically in the root of the neck from medial to lateral?
Trachea/oesphagus
RLN
Vagus
Thoracic duct
Sympathetic chain
Vertebral artery
Thyrocervical trunk
Phrenic nerve
Anterior scalene
Brachial plexus
Middle scalene
What are the branches of the subclavian artery? And the branches off them?
1st part subclavian artery before is passes behind scalene anterior. Gives off 3 branches
- Vertebral artery
- Arises from upper convexity subclavian
- Passes up to foramen of C6
- Thyrocervical trunk
- Arises lateral to vertebral artery
- Divides into
- Transverse cervical
- Suprascapular
- Inferior thyroid artery
- Internal thoracic artery
- Arises from lower surface
- Passes down over apex of lung
- Crosses phrenic
2nd part lies behind scalene anterior
- Costocervical trunk arises here
- Divides into superior intercostal artery and deep cervical artery
- Deep cervical artery passes up behind transverse process C7 and ascends to anastomose with occipital artery
3rd part - Dorsal scapular artery arises here
- Runs infront of scalene medius
- Thru bnrachial plexus
- Then passes deep to levator scap
What is the course of the vertebral artery?
Course divided into 4 parts
1st part
- arise from 1st part of subclavian artery
- runs upward and backward between the Longus colli and the Scalenus anterior.
- in front of it are the internal jugular and vertebral veins, and it is crossed by the inferior thyroid artery; the left vertebral is crossed by the thoracic duct also.
- Middle cervical ganglion is medial and anterior to artery
- Stellate ganglion lies medial but posterior à connected by ansa subclavia
2nd part
- second part runs upward through the foramina in the transverse processes of the C6 to C2 vertebræ
- surrounded by branches from the inferior cervical sympathetic ganglion and by a plexus of veins which unite to form the vertebral vein at the lower part of the neck.
3rd part
- at the C1 level, the vertebral arteries travel across the posterior arch of the atlas through the suboccipital triangle before entering the foramen magnum
- The third part issues from the C2 foramen transversarium on the medial side of the Rectus capitis lateralis.
- further subdvided into the vertical part V3v passing vertically upwards, crossing the C2 root and entering the foramen transversarium of C1, and the horizontal part V3h, curving medially and posteriorly behind the superior articular process of the atlas, the anterior ramus of the first cervical nerve being on its medial side; it then lies in the groove on the upper surface of the posterior arch of the atlas, and enters the vertebral canal by passing beneath the posterior atlantoöccipital membrane.
- This part of the artery is covered by the Semispinalis capitis and is contained in the suboccipital triangle
4th part
- pierces the dura mater and inclines medialward to the front of the medulla oblongata
- placed between the hypoglossal nerve and the anterior root of the first cervical nerve and beneath the first digitation of the ligamentum denticulatum.
- at the lower border of the pons it unites with the vessel of the opposite side to form the basilar artery.
- piercing the lateral angle of the posterior atlanto-occipital membrane. It deeply grooves the posterior arch of the atlas before entering the skull through the foramen magnum.
What are the branches of the sympathetic trunk?
- Somatic (Grey)
- Pass to all 8 cervical nerves
- Superior ganglion to 1st 4
- Middle to 5/6
- Inferior to 7/8
- Pass to all 8 cervical nerves
- Visceral Branches
- One branch from each plexus to cardiac plexus
- All branches pass behind common carotid and usually behind subclavian
- Vascular branches
- Superior ganglion to ICA and ECA
- ICA branches via internal carotid nerve
- Distributed to pterygopalatine ganglion and eyeball
- Motor supply dilator pupillae
- Distributed to pterygopalatine ganglion and eyeball
- ECA branches accompany all vessels
- Also supplies pharyngeal plexus, submandibular and otic ganglia
- ICA branches via internal carotid nerve
- Middle ganglion gives branches to;
- Subclavian artery
- Inferior thyroid artery (Visceral only)
- Inferior ganglion
- Branch to vertebral artery (Somatic)
- Superior ganglion to ICA and ECA
Boundaries of the suboccipital triangle?
- bounded by rectus capitis posterior major and the superior and inferior oblique muscles
- floor contains the posterior arch of the atlas and the posterior atlanto-occipital membrane.
- across the floor runs the vertebral artery, and through the floor emerges the suboccipital (CI) nerve.
- across the roof run the greater occipital (C2) nerve and the occipital artery.
- Rectus capitis posterior major arises from the outer surface of the bifid spinous process of C2 vertebra and extends obliquely upwards and outwards to be attached to the lateral part of the area below the inferior nuchal line. Its action is to extend the head and rotate it (with the atlas) back towards its own side.
- The inferior oblique (obliquus capitis inferior) is attached between the outer surface of the bifid spine of the axis (below rectus capitis posterior major) and the back of the lateral mass of the atlas. Its action is to rotate the atlas (and the skull with it) back towards its own side.
- The superior oblique (obliquus capitis superior) extends from the back of the lateral mass of the atlas to the lateral part of the occipital bone between superior and inferior nuchal lines. Attached to atlas and skull it can only move one on the other—the movement is of lateral flexion of the skull combined with slight extension.
What are the boundaries of the masticator space?
Investing layer in deep cervical fascia splits to surround mandible and mastication muscles thus forming this space.
- Limited by
- Anteriorly – attachment of fascia in front of muscles to mandible/maxilla
- Superiorly – by origin of temporalis from skull
- Superficially – by temporalis origin from temporalis fascia
Freely communicates superomedially with temporal space medial to zygomatic arch
Describe the sensory innervation of the face (branches included)
Via trigeminal nerve
- Zones of innervation meet at the margins of he eyelids and lips and curve upwards
- Greater Auricular contributes to the area over the angle of mandible
- Also provide proprioception to the muscles of the face
Describe the parasympathetic nervous supply of the H+N
From superior and inferior salivary nuclei
Otic ganglion
- Small body lying between tensor palati and mandibular nerve
- Just below foramen ovale
- 2-3mm diameter
- Flat and closely applied to medial aspect of mandibular nerve
- Function
- Relay for parasympathetic secretomotor for the parotid ganglion
- Input
- Preganglionic fibres arise from
- Lesser Petrosal branch of CNIX – from inferior salivar
- May contain a few fibres from X via Arnolds nerve
- Lesser Petrosal branch of CNIX – from inferior salivar
- Preganglionic fibres arise from
- Output
- 3 motor branches of V3 closely associated with and sometimes pass thru the ganglion
- Nerve to Medial Pterygoid
- Nerve to tensor tympani
- Nerve to tensor veli palatine
- Consist of motor and proprioceptive fibres
- Postgangionic fibres via Auriculotemporal nerve
- Communicating twig from the sympathetic plexus of the middle meningeal artery
- 3 motor branches of V3 closely associated with and sometimes pass thru the ganglion
Describe the sympathetic nervous supply of the H+N
Draw the layers of the upper eyelid
- Orbital septum forms the framework
- Thickened at lid margins as tarsal plate
- Dense fibrous tissue
- Crescent shaped that curve with the eyeball
- Eyelashes attach to tarsal plates
- Contain Meibomian Glands
- Modified sebaceous glands
- Secrete oily substance minimising tear evaporation
- Palpebral conjunctiva densely adherent to tarsal plates
- Orbicularis oculi is anterior to the tarsal plate
- Attaches to anterior lacrimal crest and margins of orbit
- Septum thickens here as the medial palpebral ligament
- Anchors tarsal plates to anterior lacrimal crest
- Lateral palpebral ligament is thinner and fuses with raphe of orbicularis oculi
- Attaches to marginal tubercle of Zygomatic bone
- Palpebral fissure sits between the lids
- Thickened at lid margins as tarsal plate
- Orbicularis Oculi
- Palpebral part lies anterior to tarsal plates
- Thin skin and loose fibrous tissue sit between the muscle and skin surface
What are the branches of the maxillary nerve?
- Meningeal
- Anterior MCF sensation
- Zygomatic
- Arises in Pterygopalatine fossa
- Runs above maxillary nerve to enter inferior orbital fissure
- Runs along lower lateral aspect orbital wall and enters zygomatico-orbital foramen where it divides into 2 branches
- Prior to division gives off a communicating branch to lacrimal nerve providing ecretomotor fibres to the lacrimal gland
- Zygomaticofacial Nerve
- Emerges from foramen on outer surface zygomatic bone
- Supplies overlying skin
- Zygomaticotemporal nerve
- Emerges in temporal fossa via fossa on surface zygoma
- Supplies skin over anterior temple at level of upper lid
- Posterior Superior Alveolar Nerve
- Runs thru pterygomaxillary fissure on posterior wall maxilla
- Infraorbital
- Enters orbit via Inferior Orbital fissure
- Runs with infraorbital artery
- Enters Infraorbital canal
- Emerges thru infraorbital foramen beteen levator labii superioris and levator anguli oris
- Immediately breaks into a tuft of branches
- Palpebral branches to lower lid and cheek
- Nasal branches to side of nose and ala
- Labial branches to upper lip and gum
- Many anastomoses with facial nerve branches
- Enters orbit via Inferior Orbital fissure
- Nasopalatine nerve
- Thru Sphenopalatine foramen
- Crosses roof of nose
- Distributed to septum and incisive gum of hard palate
- Lateral posterior superior nasal nerve
- Pass thru Sphenopalatine foramen
- Supply posterosuperior quadrant of lateral nasal wall
- Greater Palatine Nerve
- Passes down thru greater palatine canal
- Runs forward from greater palatine foramen to supply hard palate mucosa
- Nasal branches supply post/inf lateral nasal wall and medial wall maxillary sinus
- Lesser Palatine Nerves (2)
- Pass down behind greater palatine nerve
- Exit via lesser palatine foramen
- Innervate soft palate and mucosa of palatine tonsil
- Pharyngeal Nerve
- Passes back thru palatovaginal canal
- Emerges at roof of nose
- Supplies mucosa of upper nasopharynx, sphenoid and ethmoid sinuses
Orbital branches supply orbit periosteum
Draw the layers of the upper eyelid
Draw and label the superior orbital fissure
What are the attachments of the orbital septum?
- Laterally, the septum is attached to the orbital margin, 1.5 mm in front of the lateral orbital tubercle attachment of the lateral palpebral ligament à Eisler fat pocket separates the lateral palpebral ligament from the orbital septum
- from there, the septum continues along the superior orbital rim at the arcus marginalis
- superomedially, the septum bridges the supraorbital groove, passes inferomedially anterior to the trochlea, and then follows the posterior lacrimal crest. As it runs down the posterior lacrimal crest, it lies anterior to the medial check ligament and posterior to the Horner muscle (and hence, behind the lacrimal sac).
- line of attachment crosses the lacrimal sac fascia to reach the anterior lacrimal crest at the level of the lacrimal tubercle
- from there, it passes inferiorly down the anterior lacrimal crest and laterally along the inferior orbital rim
- a few millimeters lateral to the zygomaticomaxillary suture, the attachment leaves the rim and lies several millimeters from it on the facial aspect of the zygomatic bone, thus forming the fat-filled premarginal recess of Eisler. The line of attachment then continues to again reach the lateral orbital rim, just below the level of the Whitnall ligament.
- blends with some fibres of levator palpebrae superioris superiorly
Draw the visual pathway
What visual field defects are associated with lesions at each level?
Draw a coronal section through the ITF at the level of C1
What are the origins, insertions (and point to these on the skull), nerve supply of Medial pterygoid?
- Arises from 2 heads
- Deep head (larger) – medial surface lateral pterygoid plate and fossa between it aand medial pterygoid plate
- Diverges down from lateral pterygoid
- Superficial head from tuberosity of maxilla and pyramidal process of palatine bone
- Passes over lower margin lateral pterygoid
- Fuses with main muscle
- Deep head (larger) – medial surface lateral pterygoid plate and fossa between it aand medial pterygoid plate
- Runs down and back at 45deg to reach angle of mandible where it inserts on the border
- Mylohyoid nerve runs deep to muscle adjacent mandible
- Innervation via mandibular nerve
Name the branches of the Maxillary artery
Terminal branch of ECA
Course
- Passes deep to neck of mandible and superficial to sphenomandibular ligament to enter infratemporal fossa à auriculotemporal nerve above and veins below
- Deep to lower head lateral pterygoid then passes between both heads à highly variable
- Passes through pterygomaxillary fissure to enter pterygopalatine fossa
- Lies below maxillary nerve
- Within pterygopalatine fossa it gives off 5 branches that pass with the branches of the pterygopalatine ganglion
Divided into 3 parts by the lateral pterygoid muscle
- 5 branches from each part
- 1st part (5 Branches)
- Before the lateral pterygoid muscle
- Inferior alveolar Artery (Mandibular foramen)
- Runs down to inferior alveolar nerve
- Supplies pulp of mandibular teeth
- Mental branch from mental foramen
- Middle meningeal artery (Spinosum)
- Arises in Infratemporal fossa
- Embraced by roots auriculotemporal nerve
- Passes thru foramen spinosum to enter MCF
- Passes laterally on MCF floor
- Turns up over greater wing of sphenoid
- Then divides into anterior and posterior branches
- Accompanied by veins
- Frontal branch towards pterion then vertx
- No supply to brain, only bones of the skull vault
- Accessory meningeal artery (Ovale)
- Dura of middle fossa and meckels cave
- Trigeminal ganglion
- Deep auricular artery
- Supplies EAC
- Passes between cartilage and bone
- Anterior tympanic artery (Petrotympanic fissure)
- ME and TM
- 2nd Part (5 Branches)
- Lateral pterygoid
- Medial pterygoid
- Deep temporal branches (2)
- Masseteric
- Lingual branch
- Buccal branch
- 3rd part
- Beyond lateral pterygoid within pterygopalatine fossa
- Leaves fossa as Sphenopalatine artery
- Posterior Superior Alveolar artery
- Divides into dental branches which pierce posterior wall of maxilla separately – distributed to molar teeth and mucous membrane of maxillary sinus
- Gingivival branch runs along alveolar margin up to 1st molar
- Greater palatine artery
- Pharyngeal artery – palatovaginal
- Artery of pterygoid canal
- Infraorbital artery
Passes thru infraorbital fissure with infraorbital nerve
What are the branches of V3?
Describe the path of the lingual nerve
Passes below lateral pterygoid on side wall of pharynx
Passes between medial pterygoid and mandible
Passes between pterygomandibular raphe and mylohyoid insertions
Enters mouth on surface of mylohyoid by passing below the inferior border of superior constrictor at its’ mandibular attachment
Lies against mandibular periosteum at 3rd molar then runs on upper surface mylohyoid à Gives of gingival branch
Runs deep between sublingual gland and mandible
Passes under submandibular gland duct and runs forward on surface hyoglossus
Cavernous sinus - Draw a coronal cross section through it
What are the landmarks (name 5) for finding the accessory intraoperatively?
1cm above Erbs point
Enters trapezius muscle 3-5cm above clavicle (lower 1/3)
Under posterior belly of digastric
Crosses the anterior /lateral surface of the IJV
- 70% anterior
- 26.8% posterior
- 3.2% through
Upper branch of occipital artery is a guide to the accessory nerve in front of the upper border of the SCM
Draw the jugular foramen
Point to Dorello’s canal on the skull
Name the branches of the ophthalmic division and their branches
Name the branches of the mandibular nerve
Draw the superior orbital fissure
Draw the jugular foramen
Name the structures passing through foramen lacerum
- located at the junction of the body and greater wing of sphenoid, petrous apex and occipital bone
- in the fresh state the lower part of this aperture is filled up by a layer of fibrocartilage à no major structure passes from cranial cavity to exterior
- transmits ICA, deep petrosal nerve and greater petrosal nerve ® Vidian nerve, meningeal branch from the ascending pharyngeal artery and an emissary vein from the cavernous sinus to the pterygoid plexus
Name the structures passing through Foramen Magnum
- located in the occipital bone
- dura mater attached to margins
- transmits the apical ligament of the odontoid process of axis, tectorial membrane, medulla and meninges, spinal part of CN XI, meningeal branches of upper cervical nerves, vertebral arteries, anterior spinal artery and posterior spinal arteries
- lower medulla with spinal arteries and veins, vertebral arteries and spinal roots of CN XI transverse foramen in subarachnoid space
- meningeal branches of vertebral artery and communicating veins from occipital sinuses to internal vertebral plexus lie outside dura
- adherent to DM is tectorial membrane, then in front cruciform and then alar ligaments
Point on skull to the mandible the attachments of:
Buccinator
Medial Pterygoid
Lateral pterygoid
Genioglossus + geniohyoid
Masseter
Digastrics
Sup constrictor
Pharnygobasilar fascia
Foramen ovale (+ what travels through?)
Mandibular nerve (V3), lesser petrosal nerve (or petrosal foramen), accessory meningeal artery and an emissary vein from the cavernous sinus to the pterygoid plexus (or foramen of Vesalius)
