Simplified version used for easy representation at bed side
Exception – retrop or isolated innominate a
When all elements of the ring are patent, visualization, especially by tomographic imaging, is straightforward. In cases where the ring is completed by an atretic segment of aorta or ligamentum arteriosum, those segments cannot be visualized with current imaging technologies. However, these rings are recognizable by the presence of one of three â€œdâ€s opposite the side of the aortic arch
Account for 15% to 20% of all congenital
Result from errors in the embryologic
development of the branchial arches,
including errors of involution or migration, or
abnormal persistence of vascular structures.
Strong associations of arch anomalies with
chromosomal and genetic abnormalities are
supported by studies demonstrating a
deletion within chromosome
22q11associated with arch anomalies .
Can be discovered when there are symptoms
of airway or esophageal compression
produced by vascular rings, or anomalies can
be found incidentally on imaging studies
obtained for other reasons
Double aortic arch-Hommel 1737
Right aortic arch –Fioratti,Aglieti-1763
Interrupted aortic arch-Steidele-1788
Bayford,1787-dysphagia by vascular ring-
coined term dysphagia lusoria.
Gross,1945-first division of a vascular ring.
Heart is first seen in the form of two
endothelial heart tubes-18th day of foetal life.
Fusion results in a single tube with a series
of dilatations - beat by 22nd day.
Bulbus cordis represents arterial end of the
tube-prox part conus,distal truncus
Portion ventral to foregut -
Portion dorsal to foregut-
• First arteries to appear are right and left
primitive aorta connected to the
endothelial heart tubes
After fusion of heart tubes,ventral aorta fuse
- aortic sac
During 4th and 5th week, successive arterial
arches appear in 2nd to 6th pharyngeal
Each connects ventrally to aortic sac& dorsally
to dorsal aorta.
Greater part of 1st &2nd arch arteries
5th arch artery regress completely
3rd-common carotid and prox.int.carotid
4th –Lt.-aortic arch b/w LCCA and LSCA.
◦ Rt-prox RSCA
6TH –prox part –prox pulmonary artery
◦ distal part-ductus on left and right side involutes
Lt dorsal aorta-aortic arch distal to LSCA
Rt dorsal aorta-cranial portion-RSCA distal to
4th arch.distal portion-involutes
Portion of dorsal aorta b/w 3rd and 4th
Each 6th arch artery connects to the
pulmonary vascular Tree.
Portion b/w this connection and dorsal aorta-
ductus arteriosus-regresses on right side
Spiral septum formed in truncus in the 5th week
extends to aortic sac. Blood from pulmonary artery
goes to 6th arch artery,from aorta to 3rd &4th arch
Dorsal aorta gives lateral intersegmental branches
to body wall - 7th cervical intersegmental supplies
upper limb bud
Innominate artery - right branch of
Right common carotid artery - right third
Right subclavian - right fourth arch and right
dorsal aorta proximally and right seventh
intersegmental artery distally
Left carotid - left third aortic arch.
Left subclavian - left seventh intersegmental
Anomalies of aortic arch to be conceptualized
as variations in regression of different
segments from a “hypothetical double arch”.
The concept of “hypothetical double aortic
arch” emphasises the potential contribution
of nearly all embryonic arches to components
of definitive arch system.
Demonstrate possible embryologic
explanations for each arch anomaly.
Normal left aortic arch is derived from
Aortic portion of the embryonic truncus
Left branch of the
Left fourth arterial arch
Left dorsal aorta
Left and right arch refers to which bronchus is
crossed by the arch
Echo or angio-branching pattern of
First arch vessel that contains carotid artery
opposite side of arch or Retroesophageal or
isolated vessels-opp to side of arch
MRI and CT-conclusive
Aortic arch anomaly in which trachea and
esophagus surrounded by vascular
The vascular structure need not to be patent
e.g. ligamentum arteriosum.
Double aortic arch most common(40%)
Rt.Aortic arch with left.ligamentum(30%)
◦ Reflex apnoea or choking on eating.
◦ Posture of Hyperextension of neck in infant.
◦ Increased respiratory distress a/w intercurrent
◦ Swallowing difficulty .
◦ Occasionally, in patients with associated
intracardiac anomalies ,the respiratory symptoms
may be mistakenly be attributed to cardiac disease.
The Vascular ring may be suspected from
combination of the History and plain chest
When all elements of the ring are patent,
visualization, especially by tomographic
imaging, is straightforward.
In cases where the ring is completed by an
atretic segment of aorta or ligamentum
arteriosum, those segments cannot be
visualized with current imaging technologies.
However, these rings are recognizable by the
presence of one of three “D” opposite the side
of the aortic arch.
3 d΄s opposite to side of arch-
Diverticulum –large vessel from desc.aorta
giving rise to a smaller calibre vessel with a
Dimple –tapered blindly ending outpouching
Descending aorta in upper thorax opp.to side
of arch-connected by ligamentum arteriosum
Common brachiocephalic trunk (Bovine Arch)
◦ Right innominate and left carotid
from single origin
◦ 10% of normal
◦ Compression of trachea possible
Separate origin of left vertebral artery
◦ Prox to LSCA
◦ 3rd arch vessel smaller than 4th
◦ No Functional significance
a) Lt arch with retroesophageal RSCA
b) Lt aortic arch and retroesophageal
diverticulum of Kommerell
c) Lt aortic arch,rt.descending
aorta,rt.ductus(circumflex aortic arch)
d) Lt aortic arch & isolated RSCA
e) Lt aortic arch with cervical origin of Rt
Also known as anomalous or aberrant right
subclavian artery .
Bayford linked such case with history
of difficulty in swallowing and coined term
0.5% incidence in general population.
m.c. aortic arch anomaly
Incidence in down’s syndrome with CHD Is
very high (38%).
Disappearance of Rt 4th arch-distal Rt
dorsal aorta becomes prox RSCA
forming its retroesophageal portion.
Rt 6th arch (ductus) disappear.
Barium –smaller fixed filling defect on post
aspect of esophagus slanting upward to right
Angio-earlier filling of Rt carotid on aortic
First vascular ring to be diagnosed during life
with barium study.
Similar to previous except for persistent right
6th arch-ligamentum which completes a vasc .
Prox.RSCA dilated to form diverticulum.
Branching pattern similar to earlier
RSCA the last arch vessel .
Descending aorta connected to RPA by
ligamentum-forms vasular ring
Embryology: disappearance of rt 4th arch
but with left distal dorsal aorta forming
definitive distal arch and passing
retroesophageally to a descending aorta
beginning to right of vertebral column.
Plain chest film : left sided aortic arch with
right sided upper descending aorta.
Barium esophagography : Large posterior
indentation from retroesophageal aorta .
Angiography will confirm the course of aorta.
In symptomatic patients the Ring is divided
via right thoracotomy approach.
RSCA arises only from rt ductus.
Right 6th arch persists with dossolution of
right 4 th arch and right dorsal aorta.
RSCA and vertebral fills from PA in foetal life
When ductus closes-retrogradely from circle
◦ Vertebrobasilar insufficiency
◦ Congenital subclavian steal
◦ Absent rt arm pulse
Angiography : Delayed filling of RSCA after
aortic root shoot .
With phase encoded velocity mapping
,retrograde flow in the vertebral artery can be
detected on MRI.
Symptomatic patients are treated with
implantation of subclavian artery into aorta.
Marker of 22q11 deletion.
(Marker of CATCH 22)
Innominate trifurcates in the neck-RSCA
travels back to thorax
Subclavian artery arises from 3rd arch in stead
of 4 th .
3 rd arch being more cephalad gives origin to
RSCA in the neck.
A single aortic arch that crosses rt mainstem
13-34% in TOF
30-40% in truncus arteriosus
20% in pul.atresia with VSD
8-10% in transposition.
a) Right aortic arch-mirror image type
b) Rt aortic arch with retroesophageal
diverticulum of Kommerell
c) Rt arch with retroesophageal LSCA
d) Rt arch with Lt desc aorta and Lt ligamentum
Sequence of arch vessels-lt.innominate,rt
Ligamentum lt sided.
No vascular ring.
Almost always associated
with CHD (48% TOF)
Dissolution of left dorsal aorta distal to the
origin of left 7 th intersegmental artery
So, left 4th arch becomes proximal left
Left Sixth arch persists- left ductus arises
from underside of left innominate artery and
passes to LPA .
Alternatively right ductus persists giving true
mirror image of normal.
Second most common vascular ring .
Sequence –lt carotid,rt carotid ,RSCA,a large
retroesophageal vessel( diverticulum) from
which LSCA arises
Lt ligamentum completes the ring
Disappearance of Lt 4th arch and persistence
of 6th arch
Should be differentiated from rt
aortic arch with retroesophageal
Symptoms of vascular ring with right sided
aortic arch on plain chest film should raise
the suspicion of this anomaly .
Barium study reveals a large posterior
indentation on the esophagus.
Branching pattern of arch vessels on echo.
Angiography reveals characteristic branching
pattern and abrupt change in calibre from
diverticulum to subclavian artery.
MRI ideal for diagnosis .
Surgical division of ductus in symptomatic
patients via left thoracotomy.
Similar to previous one except for the
absence of retroesophageal diverticulum.
Sequence –lt carotid,rt carotid ,RSCA,
Ductus is rt sided.
No vascular ring.
Involution of left 4th and 6th aortic arches.
Associated with conotruncal anomalies .
Higher incidence of 22q11 deletion.
Also known as circumflex right aortic arch.
Aortic arch itself crosses midline to the left at
the level of T4 vertebral body -connects to lt
ductus to form vascular ring
Sequence –lt innominate,rt carotid ,RSCA or lt
carotid,f/b right carotid,right
subclavian,finally left subclavian.
Aortic arch is retroesophageal and not the
Embryology : Dissolution of either left dorsal
aorta distal to takeoff of the left subclavian artery
or the left fourth arch. Persistent left sixth arch
connects to the left sided dorsal aorta
completing vascular ring .
Barium study :downward slanting left
oesophageal indentation .
Mobilisation of retroesophageal aortic segment
and reanastomosis of asc and dec aorta using
tube graft may be needed in symptomatic adults
in addition to simple division of ligamentum.
Sequence : right carotid, right SCA,f/b
retroesophageal left innominate artery .
Ductus or ligamentum connects LPA with base of
innominate a. completing vascular ring.
Embryology : dissolution of left branch of
truncoaortic sac and left 4 th arch .The left dorsal
aorta supplies left 7th IS artery and left 3 rd arch.
Clue for diagnosis is single carotid artery arising
from proximal aorta.
In symptomatic patients surgical division of
ligamentum with implantation of innominate
artery to ascending aorta is required.
Vessel arises exclusively from pulmonary artery via ductus
arteriosus but without connection to aorta.
3 forms : Isolation of LSCA (m.c.),Isolation of left carotid
and isolation of Left innominate .
CHD in more than 50% (m.c. TOF).
Presentation: diminished pulse amplitude or blood
pressure in left arm , subclavian steal
syndrome,pulmonary artery steal (if duct patent)
The dignosis should be suspected in pt with right sided
aortic arch with diminished pulse amplitude or blood
pressure in left arm .
Delayed filling of LSCA via vertebral artery during aortic
arch shoot confirms diagnosis.
Arch found above level of clavicle
1.normal branching pattern
2.anomalous subclavian artery and vascular
ring with descending aorta contralateral to
arch or retroesophageal diverticulum.
2nd group-divided according to carotid origin
(bicarotid trunk or separate origin of ext & int
First group usually has left sided arch while
second group has right sided.
Separate origin of vertebral artery can be
seen in both groups.
-Failure of normal descent of aortic arch system
-Persistence of ductus caroticus & involution of 4th
arch-3rd arch becomes definitive aortic arch with
separate origin of ext &int carotid from it.
- Pulsatile mass in supraclavicular fossa or the
- Symptoms of vascular ring
- Subclavian steal in patients with stenosis or
atresia of LSCA .
oPresumptive diagnosis can be made by notation
of loss of femoral pulse during brief compression
of the mass.
Both rt and lt arches present.
Both arches can be patent or one hypoplastic or
Persistence of both rt and lt 4th arch which join
TA sac to their respective dorsal aortae
Only one 6th remain.
Symmetric origin of 4 arch vessels from
respective arches when both patent
Rarely a/w other CHD, when present-TOF most
Form complete vascular rings.
When both arches are patent, rings typically tight
and present with sridor in first week of life.
Diagnosis can be made on plain chest film
when both arches are patent.
Tracheal air column is indented by more
superior right sided arch and inferior left
Confirmation with further imaging is
important to identify atretic segment.
Surgical division of ring in symptomatic.
First reported by Van praagh in 1969
Double lumen aortic arch in which both
arches appear on same side of trachea.
Frequently associated with CHD; however can
be incidental finding without clinical
2 common sub categories-
◦ Subway vessel beneath normal arch(4th arch)that
extend from innominate to take off of LSCA
◦ Double lumen aortic arch with atresia of superior
arch with patent inferior arch-common origin of all
brachiocephalic vessels from asc.aorta
Defined as complete separation of ascending
and descending aorta
Celoria and Patton classification(1959)
◦ Type A-interruption distal to SCA that is ipsilateral
to 2nd carotid artery
◦ Type B-interruption b/w 2nd carotid and ipsilateral
◦ Type C-interruption b/w carotids.
Each of the types subcategorised to 3 types
◦ 1.without retroesophageal or isolated subclavian
◦ 2.with retroesophageal subclavian artery
◦ 3. with isolated subclavian artery
Type A-aorticopulmonary septal defect,TGA
Type B- most common
a/w conotruncal anomaly with large
malaligned VSD with subaortic obstruction,
Interrupted rt arch seen only in DiGeorge
Type A-Involution of both dorsal aorta distal
to 4th arch and prox to persistent 6th arch
which supplies descending aorta .
Type b-Involution of one 4th arch and one
dorsal aorta b/w 4th and 6th.
Type C-Involution of one limb of truncoaortic
sac,associated proximal 3 rd arch and entire
4 th arch with persistence of dorsal aorta
between 3rd and 4 th arch.
Present with acute cardiovascular collapse or
heart failure after closure of ductus in first
days of life.
Absence of all limb pulse with strong carotid
pulse suggest type B with anomalous
2 D echo is most important diagnostic tool .
3 D reconstructive MRI is useful for
identifying branching pattern and site of
Surgical approch depends on the degree of
subaortic obstruction .
1.If subaortic diameter > 5 mm primary
2.If subaortic diameter < 3mmbypass subaortic
region – associate MPA with ascending aorta using
homograft augmentation to complete aortic
Aortic arch is reconstructed by liberal dissection
around two arch components with direct
anastomosis of two ends.
Anomalous pulmonary artery branch arising
from ascending aorta in presence of a MPA
◦ More common
◦ Embryonic branch pul.artery joins rt side of TA
sac,but fails the leftward migration to join MPA
◦ High incidence of aorticopulmonary septal defect
◦ a/w TOF in 74%
◦ Embryonic branch pul.artery fails to join TA sac
CCF in infancy f/b early development of
pulmonary vascular disease.
LPA arises from RPA and passes b/w trachea
and esophagus-Pulmonary artery sling.
Only Anomaly in which a major vascular
structure passes between trachea and
Tracheal compression-Severe respiratory
distress and stridor,Milder forms may exists
Isolated anomaly, rarely a/w TOF
Anterior indentation on barium swallow.
Bronchoscopy needed prior to surgery to rule
out complete cartilagenous ring .
Systemic to pulmonary shunts are best
carried out using side with innominate artery.
Knowledge of sidedness of aorta may be very
useful in the repair of eosophageal atresia or
Anatomical variations or anomalies in
brachiocephalic arteries my pose difficulty in
Carotid artery stenting as well as may
increase complication rates..
Aortic arch anomalies and vascular rings can
be interpreted on the basis of embryology
With the develpoment Of MRI and CT, 3-D
reconstruction is possible.
Intervention required only when symptomatic
or when a/w other cardiac anomalies.