EXTERNAL CAROTID ARTERY,
BRANCHES AND LIGATION
1st Yr PG
• External carotid artery is the chief artery which
supplies to structures in the front of the neck
and in the face
EMBRYOLOGY OF ECA
• During the fourth and
fifth weeks of embryological
development, when the
pharyngeal arches form, the
aortic sac gives rise to arteries
– the aortic arches.
• The aortic sac is the
endothelial lined dilation, it is
the primordial vascular
channel from which the aortic
• In the initial stage there are
pairs of aortic arches, which
are numbered I, II, III, IV,
and V. This system becomes
altered in further
• 3rd Arch : forms common
artery, first (cervical) part
of internal carotid
artery (rest of internal
carotid arises from dorsal
aorta), and external carotid
COMMON CAROTID ARTERIES
• Right common carotid artery
is a branch of the
begins in the neck behind the
right sternoclavicular joint.
• Left common carotid artery is
a branch of the arch of aorta.It
ascends to the back of the left
sternoclavicular joint and
enters the neck.
• In the neck,each artery runs
upwards within the carotid
sheath,under cover of the
anterior border of the
• Carotid sheath is
condensation of the
around the main
vessels of the neck.
contains the common
and internal carotid
vein and the vagus
• In the sheath,common
carotid artery is
nerve lies in between.
• The ansa
wall of the
• The cervical
BIFURCATION OF COMMON
• Common carotid artery
bifurcates into external and
internal carotid arteries at the
level of upper border of the
• Two structures of importance
at the bifurcation are
• Carotid sinus is slight dilatation at the
termination of the common carotid artery
or the beginning of the internal carotid
• It receives a rich innervation from the
glossopharyngeal and sympathetic nerves.
Carotid sinus acts as a baroreceptor or
pressure receptor and regulates pressure.
• Carotid body is a small,oval reddish-brown
structure situated behind the bifurcation.
• It receives nerve supply mainly from the
glossopharyngeal nerve, but also from the
vagus and sympathetic nerves.
Carotid body acts as a chemoreceptor and
responds to changes in the oxygen and
carbon dioxide and Ph content of the blood.
External carotid artery
• Generally,it lies anterior to the internal
• It is the chief artery of supply to
structures in the front of the neck and in
• ECA is marked by joining
the following two points.
-A) point on the anterior
border of the
muscle at the level of the
upper border of the
-B) second point on the
posterior border of the
neck of the mandible.
The artery is slightly convex
forwards in its lower half
and slightly concave
forwards in its upper half.
• ECA begins in the carotid
triangle at the level of
upper border of thyriod
cartilage opposite the disc
between the third and
fourth cervical vertibrae.
• In the carotid triangle,it lies
under cover of the anterior
border of the
• As the artery ascends ,it
passes deep to the post.
Belly of digastric and
stylohyoid muscle and
terminates behind the neck
of the mandible by dividing
into the maxillary and
relationsIN THE CAROTID TRIANGLE
Superficially—Cervical branch of facial nerve
Deep to the artery— Wall of pharynx
Superior laryngeal nerve
Ascending pharyngeal artery
ABOVE THE CAROTID
Lies deep in the substance of the
Within the gland, it is related
Deep to the artery—ICA
Structures passing between ECA
Pharyngeal branch of
Total of 8 branches
• ANTERIOR— Superior thyroid
• POSTERIOR-- Occipital
• MEDIAL— Ascending
• TERMINAL— Maxillary
Superior thyriod artery
ORIGIN:Arises from the front of
ECA below the tip of greater
cornua of hyoid bone.
COURSE: Runs downwards and
forwards parallel and just
superficial to the extenal
- It passes deep to omohyoid
,sternohyoid, sternothyroid and
reaches the upper pole of lateral
lobe of thyroid and divides into
its terminal branches.
• It is accompanied by same-
ORIGIN:Arises from ECA opposite
the tip of the greater cornua of
-It may arise in common with the
facial artery, then becoming the
COURSE:Divided into three parts
by hypoglossus muscle.
FIRST PART – In carotid triangle,
extends from origin to the
posterior border of hyoglossus.
- Rests on the middle
constrictor,forms a upward loop
which is crossed by hypoglossal
nerve. This loop permits the free
movements of the hyiod bone.
SECOND PART – Deep to
hyoglossus, runs horizontally
forward along the upper border of
hyoid bone between hyoglossus
laterally and middle constrictor,
stylohyoid ligament medially.
THIRD PART [ ‘arteria profunda
linguae’ ]—Also called as deep
-It runs upwards along the anterior
Border of hyoglossus, then
horizontally forwards on the
undersurface of tongue on each
side of frenum linguae.
-In vertical course,it lies b/t the
genioglossus medially & inferior
longitudinal muscle of tongue
laterally. Horizontal part is
accompanied by lingual nerve.
• In surgical removal of tongue , first part of
artery is ligated before it gives any
branches to the tongue or tonsil.
LIGATION OF LINGUALARTERY :
Incision – circling the lower pole of
- Skin, platysma, deep fascia incised,
submandibular gland exposed , lifted,
tendon of diagastric visible.
-Free border of mylohyoid muscle seen,
hypoglossal nerve identified. Digastric tendon
pulled downwards –enlarges the lingual
triangle, hyoglossus muscle visible.
- Muscle divided bluntly, in the gap of its vertical
fibers lingual artery found & ligated.
ORIGIN: Arises from the ECA just above
the tip of greater cornua of hyoid bone.
COURSE: Runs upwards in -- neck as
cervical part ; face -- facial part.
Tortuous course—In neck allows free
movements of pharynx during deglutition,
on face -- free movements of mandible ,
lips, & cheek during mastication & facial
expressions, escapes traction & pressure
Cervical part : Cervical
part Runs upwards on
superior constrictor of
pharynx deep to the
posterior belly of
-It grooves the posterior
makes S-bend [2 loops]
1st winding down over
submandibular gland &
then up over the base
Facial part:The vessel enters the face by
winding around the base of the mandible,
and by piercing the deep cervical fascia,at
the anteroinferior angle of the masseter
• It runs upwards and forwards deep to the
risorus, to a point 1.25cm lateral to the
angle of the mouth.
• Then it ascends by the side of the nose upto
the medial angle of the eye where it
terminates by anastomosing with the dorsal
nasal branch of the ophthalmic artery.
• Facial Artery
to the facial artery as
it passes over the
inferior border of the
anterior to the angle
will diminish blood
flow to that side.
LIGATION OF FACIAL ARTERY.
• Exposed --at the point crossing the lower
border of mandible .
• Using contracted masseter as a landmark,
pulse of facial artery felt at point situated
anterior to the attachment of masseter.
• Incision - at least half inch below the
border of mandible & parallel to it.
ORIGIN:Arises in carotid
triangle from posterior
aspect of ECA ,opposite
the origin of facial artery.
-It is crossed at its origin by
COURSE: Passes backwards
and upwards along & under
cover of lower border of
post. Belly of diagastric ,
crossing carotid sheath,
hypoglossal & accessory
Then it runs deep to the
mastiod process and
muscles attached to it
Then crosses the rectus
muscle at the apex of
the posterior triangle.
Finally it pierces the
trapezius muscle and
ascends in a tortuous
course in the superficial
fascia of the scalp.
Its terminal portion
comes to lie along the
greater occipital nerve.
ARTERYORIGIN: Arises from the
posterior aspect of the
external carotid artery
just above the posterior
belly of the digastric.
COURSE:It runs upwards
and backwards deep to
parotid gland, but
superficial to the styloid
process.It crosses the
base of the mastiod
process and ascends
behind the auricle.
branch arising from the
medial side of the
external carotid artery,
near its commencement.
vertically between the
internal carotid and the
side of the pharynx, to
the under surface of the
base of the skull, lying
on the Longus capitis.
ORIGIN:Large terminal branch
given off behind the neck of the
COURSE: Divided into three
parts by lateral pterygiod
• The first or mandibular
portion passes horizontally
forward, between the ramus of
the mandible and the
where it lies parallel to and a
little below the auriculotemporal
nerve; it crosses the inferior
alveolar nerve, and runs along
the lower border of the lateral
• The second or pterygoid portion runs
obliquely forward and upward
superficial to the lower head of the
• The third or pterygopalatine portion
passes between the two heads of the
lateral pterygiod and pterygomaxillary
fissure,to enter into the pterygopalatine
fossa where it lies in front of the
First or Mandibular
• Deep Auricular.
• Anterior Tympanic.
• Middle Meningeal
• Accessory Meningeal
• Inferior Alveolar.
Second or Pterygoid
• Deep Temporal.
Third or Pterygopalatine
•Greater palatine artery
•Aretry of pterygiod canal
ORIGIN: The smaller of the two terminal
branches of the external carotid, appears,
to be the continuation of ECA. It begins in
the substance of the parotid gland, behind
the neck of the mandible.
COURSE: It runs vertically upwards
crossing over the root of the zygomatic
-about 5 cm. above this process it divides
into two branches, a frontal and a parietal.
• Relations.—As it
crosses the zygomatic
process, it is covered by
the Auricularis anterior
muscle, and by a dense
fascia; it is crossed by
the temporal and
zygomatic branches of
the facial nerve and one
or two veins, and is
accompanied by the
which lies immediately
Besides some twigs to the parotid gland, to the
temporomandibular joint, and to the Masseter muscle,
its branches are:
• Transverse Facial.
• Anterior Auricular.
• Middle Temporal.
INDICATIONS OF LIGATION
• Acute massive epistaxis
• Hereditary teliangectiasis
• Aneurysms( traumatic
aneurysms, of head and
neck, parotid gland)
• THERE ARE TWO SURGICAL EXPOSURES TO
LIGATE THE ECA
» CAROTID TRIANGLE
» RETROMANDIBULAR FOSSA
Supine position with shoulder on roll, neck
extended and turned to opposite side.
1)Upper border of
-lower border of
-Anterior border of
Ligation in carotid triangle:
-ICA doesn’t branch in the neck,except for
-ECA is usually anterior and superficial to
ICA but not always.
-Follow the ECA to its 2nd branch,atleast.
Incision of skin at
level of angle ,
border of SCM,
to the anterior
border of the
muscle to the level
• Dissection is carried through
skin,platysma,then anterior border of SCM
is identified and retracted posteriorly.
• A clamp is used to dissect anterior to the
muscle parallel to great vessels ,to identify
• The CCA is carefully separated from other
contents of sheath.
• The IJV, vagus nerve and ansa hypoglossi
are retracted posteriorly.
• Usually at this
loop is placed
loosely around CCA
to obtain control.
• Then dissection is
carried up along the
CCA to the
• At this point
hypoglossal nerve is
should be preserved.
-ICA doesn’t branch in the
neck,except for rare
-ECA is usually anterior and
superficial to ICA but not
-Follow the ECA to its 2nd
-A 2-0 silk tie is placed
between the superior
thyriod and lingual
-The wound is closed in
layers after the removal of
vesicular loop from CCA
-Damage to vital structures.
-Retrograde thrombus formation.
-Persistence of bleeding due to collateral
LIGATION IN RETROMANDIBULAR
Done when there are maxillary artery injuries.
• Skin incision--- at line starting at the tip of
mastoid process , circling the mandibular
angle, continuing forward below the
mandible one inch.
• Skin & posterior fibers of platysma are cut,
the retromandibular vein or EJV is located,
tied & cut.
• Branches of great auricular nerve cut --
permit mobilization of cervical lobe of
• Attachment of parotid capsule to the anterior border of
sternomastoid severed with scalpel. Parotid gland
• post. Belly of digastric ,stylohyoid muscle is visible.
Above this stylomandibular ligament can be palpated
if lower jaw of the patient is pulled forward.
• This movement--- widens the entrance into
retromandibular fossa , tenses the stylomandibular
• Pulsations of ECA are felt , isolated & tied.
• After ligation of the external carotid artery the
circulation is later re-established by the free
communication between most of the large
branches of the arteries and its corresponding
artery in the opposite side and also
anastomosing with the internal carotid