Thyroid, facial and lingual artery -- Anatomy and anastomosis

Presenter :- Sarbesh Tiwari.

It is the first branch of external carotid artery.

It usually arises from the anterior wall of the ECA and

passes towards the hyoid bone , then descends to the superior

pole of thyroid gland.

It supplies the thyroid gland, infrahyoid strap muscles, the

upper part of the larynx, middle region of

sternocleidomastoid and cricothyroid.

Origin of Superior thyroid artery.

origin from ECA70- 73 %

origin from CCA Bifurcation 18-21 %

origin from ICA

Variations

The smaller branches of the superior thyroid artery include

:-

1. Infra hyoid

2. The sternocleidomastoid branch.

3. The superior and inferior laryngeal

4. The cricothyroid arteries.

Selective opacification of the Sup. Thyroid A. or ECA

frequently results in dense area of contrast accumulation

in normal thyroid gland.

BRANCHES OF SUPERIOR THYROID ARTERY

The Sup. Thyroid A. terminates in - an anterior, a posterior

and a lateral branch.

The anterior branch is usually the largest ; it supplies the

anterior surface of the upper pole of thyroid and anastomoses

with the artery of opposite side.

Other smaller terminal branches have extensive arterial

communications with branches of inferior thyroid artery, a

branch of thyrocervical trunk.

The sternocleidomastoid and the superior laryngeal branches

may arise directly from the ECA.

ANASTOMOSIS

The superior thyroid artery has extensive anastomoses

with its counterpart from opposite ECA.

And with subclavian artery via the inferior thyroid

artery.

CLINICAL IMPORTANCE

Injection of the inferior thyroid artery (black arrow)

briskly opacifies, in retrograde fashion, the superior

thyroid artery (yellow).

Later images, in thyroid parenchymal phase, show superior

thyroid (yellow) participation in ipsilateral ICA (red)

reconstitution at the level of its proximal external takeoff.

Inferior Thyroid to Superior Thyroid Collateral Reconstitution of the ICA

LINGUAL ARTERY

The lingual artery is the second anterior branch of external

carotid artery.

It usually arises as a separate trunk between the origins of

the superior thyroid artery and facial artery, usually at the

level of C3 vertebra.

In 20 % , it originates with the facial artery from a common

linguofacial trunk.

VARIATIONS OF THE ORIGIN OF LINGUAL ARTERY

Ozur et. al. classified the origin of these arteries which were

arises from the external carotid artery in four types and

reported their incidences.

Type I – Separate origin from ECA – 90 % cases.

Type II – The lingual facial trunk ( 7.5 %)

Type III – The thyrolingual trunk (2.5%) and

Type IV – The thyrolingualfacial trunk.

This artery takes origin from the external carotid artery.

It first runs obliquely upward and medialward to the greater

cornu of the hyoid bone.

It then passes deep to the hypoglossal muscle, extending

downwards and forwards to form a characteristic loop, and

finally, ascending almost perpendicularly to the tongue, turns

forward on its lower surface as far as the tip, under the name

of the deep lingual artery.

Course of lingual artery.

MIP image shows lingual artery, relationship with greater cornu of the hyoid bone and then upward directed into the tongue muscles.

Branches of the Lingual artery ARTERY COURSE TERRITORY

1. Suprahyoid Artery Courses along the superior

border of the hyoid bone,

superficial to hyoglossal

muscle.

serving the muscles in its

vicinity, and anastomosing

with its counterpart on the

other side.

2. Dorsal Lingual Artery Arises deep to the

hyoglossal muscle and

ascends to the dorsum of

tongue

the palatoglossal arch,

mucous membrane of the

tongue, palatine tonsil,

and some of the soft

palate, freely anastomosing

with other arteries in its

vicinity.

3. Sublingual Artery Runs along the

genioglossus muscle and

the sublingual gland.

Sublingual glands and

adjacent muscles of tongue.

Floor of the mouth.

4. Deep Lingual Artery Runs superiorly into the

tongue and gives numerous

ranine branches.

Musculature of the tongue

On the angiogram, , the lingual artery is easy to recognise ,

especially in the lateral view,because of its course, first

upwards , then downwards, and finally upwards again ,

forming a gentle curve that is superiorly concave.

Among the lingual artery branches, the dorsal lingual artery

and the sublingual artery, which runs inferiorly to the deep

lingual artery, are frequently identifiable.

Angiographic appearance of the Lingual artery.

Selective injection of the lingualartery. Branches of the trunkarising from the main trunk anddorsal lingual artery. Sublingualbranches ( arrow the angles).

FACIAL ARTERY

The facial artery usually arises as the third anterior branch of the external carotid artery just above the origin of the lingual artery, at the level of greater cornu of hyoid bone in the carotid triangle.

The level of origin is situated at 1- 3.5 cm from the carotid bifurcation ( minimal in short necked person ) and 0.5 to 1 cm from the origin of the lingual trunk.

Therefore the lingual trunk is a more constant landmark.

An origin from a common linguofacial trunk is present in 20 %.

COURSE OF THE FACIAL ARTERY

The facial artery has a tortuous course extending obliquely upward over the body of the mandible and passing forward and upwards across the cheek to the angle of mouth.

It then ascends in a sinous course along the side of the nose to end as the angular artery at the medial angle of the eye.

The angular artery anastomoses with the dorsal nasal artery, a terminal branch of the ophthalmic artery.

Branches of the Facial Artery

The main branches of the facial artery are :-

1. Ascending palatine artery.

2. Artery to submandibular gland.

3. The submental artery.

4. Inferior and superior labial arteries.

5. Lateral nasal artery.

6. Teminates by dividing into Alar and angular branches.

Other branches are the pterygoid artery and inferior masseteric artery.

Artery Course Territory

1. Ascending Palatine Artery Arises from 1st part of facial artery , ascends medially along pharynx.

Soft Palate , Pharynx and Tonsils.

2. Artery to Submandibular gland

Arises at the lower border of mandible.

Its 4-5 terminal branches ramify in the SMG.

3. The submental artery Largest branch of facialartery.

Angiography : It originates on the ascending limb of the second curve of facial artery.

4. Inferior and superior labial artery

Arises at the lower and upper dental arches respectively

Forms an arterial arcade around the lips.

5. Lateral Nasal Artery Dorsum and ala of nose.

6. Angular artery Terminal portion of the facial artery

Gives off branches to thepalpebral and nasal branches as well as to lacrimal region.

Variation of the Facial artery

1. Pharyngeal Anastomoses : - The ascending palatine artery

anastomoses with the pharyngeal branches of the ascending

pharyngeal artery and descending palatine branch &

accessory meningeal artery ( br. Of IMA). Thus is a

potential site of EC- IC anastomoses since the accessory

meningeal artery has branches that anastomoses with ICA.

2. Sublingual Anastomoses :- An anastomosis around the

sublingual gland and the base of the tongue which is usually

dominated by the submental artery ( br. Of FA) and links it

with the infrahyoid artery ( br. Of superior thyroid artery) and

the sublingual artery ( br. Of lingual artery ).

Anastomoses of the Facial artery

3. Jugal anastomotic branches :- Branches to the masseter

and buccinator muscles which anastomoses with their

counterpart arising from the IMA over a wide area of the

cheek region. This is a potential route of collaterals to

develop in the event of occlusion of IMA, FA & ECA.

4. Periorbital anastomosis :- The angular artery anastomoses

with the supratrochlear and dorsal nasal branches of the

ophthalmic artery at the medial orbital margin , which can

establish a collateral circulation when the ICA is occluded.

5. Nasal Anastomosis :- It is anastomosis between the

sphenopalatine artery and descending palatine artery (

br. Of IMA) with the nasal branches of the alar artery

and superior labial artery ( brs of the FA) inferiorly and

with the anterior and posterior ethmoidal arteries ( br.

Of oph artery) superiorly.

These branches also supply the vasa-vasorum of the

cranial nerves.

Artery Cranial nerve at risk

1. Superior thyroid artery Vagus (X), superior laryngeal

nerve.

2. Lingual XII, extracranial segments(

multiple branching depending on

the regional hemodynamic

balance)

3. Facial artery Rare direct CN association.

Thyroid gland tumors :- Malignant thyroid are highly vascular.

They are however rarely referred for pre-resection embolisation.

Role of superior thyroid artery in superselective intra-arterial

chemotherapy .

Role in hyperthyroidism :- The mechanism is to block most of

the blood supply to the thyroid gland, thus leading to necrosis

and later fibrosis of thyroid tissue which will decrease thyroid

hormone secretion.

Embolisation of both the superior and one

inferior thyroid artery will destroy 70- 80 % of gland achieving

similar results to subtotal thyroidectomy.

Thank you