This document discusses coarctation of the aorta, including: 1. The definition and history of coarctation as a congenital narrowing of the upper descending thoracic aorta. 2. Theories on the pathogenesis of coarctation related to reduced blood flow through the left side of the heart or abnormal ductal tissue. 3. Types of coarctation including preductal and postductal, and surgical techniques for repair such as patch aortoplasty or bypass grafting. 4. Presentation varies from heart failure in neonates to hypertension in older children and adults, with complications including aneurysm and rupture.

2.  The word coarctation has been derived
from latin word ‘COACTERE’, meaning to
contract.

4. Definition of hypoplasia
* Proximal arch : 60% of ascending aorta
* Distal arch : 50% of ascending aorta
* Isthmus : 40% of ascending aorta

5. 1. Definition
A congenital narrowing of upper descending
thoracic aorta adjacent to the site of attachment of
ductus arteriosus.
2. History
Morgagni : 1st description in 1760
Bonnett : postductal & preductal type in 1903
Crafoord : 1st coarctation repair in 1944
Vorsschulte : prosthetic onlay graft or vertical
incision and transverse closure in 1957
Waldhausen : subclavian patch aortoplasty in 1966

6.  Robert gross: 1938 reported possible complication
of severe haemorrhage and paraplegia after
repair of CoA.

8.  Occurrence rate: 0.2-0.6/1000 live births
 Represents 5-8% of all congenital heart disease.
 8th most common congenital heart defect.

9.  Two theories
1. The flow theory
2. The ductal sling theory

10.  Any congenital anomaly that reduces the flow through left
side heart and inturn through aortic isthmus in intrauterine life
leads to poor development and ultimately coactation of
aorta.
 Holds true for infantile or preductal type of coactation.
 Can explain occurrence of coactation with obstructive
lesions of left side like aortic stenosis, bicuspid aortic valve,
congenital mitral stenosis, VSD, shones complex.
 Also explain why the coarctation is not seen with right side
obstructive lesions like TOF, PS, TA.

11.  In patients with no associated intracardiac defects the flow
theory does not explain the occurrence of CoA.
 For these patients the ductal sling theory holds good.
 SKODA more than 100 years ago postulated that it is the
abnormal extension of contractile ductal tissue into the
aorta which is responsible for pathogenesis of CoA.
 Resected specimen shows the extension of ductal tissue in
circumferencial sling extending from ductus arteriosus and
into the surrounding aorta. Contraction and fibrosis of this
ductal tissue sling at the time of ductal closure would lead to
formation of obstructing shelf with in the aorta .

13.  Bonnet in 1903 divided the patients into 2 groups : infantile
type and adult type.
 Later infantile type were known by name of preductal type
and adult type was known by name of postductal type.
 The entity juxtaductal CoA is now a days used to denote
adult type.

16. PREDUCTAL TYPE
1. PDA is patent and large
and provide blood flow
to lower extremity.
2. Tubular narrowing of
isthmus
3. No shelf like narrowing
in aorta.
4. Minimal post stenotic
dilatation of aorta.
5. Minor enlargement of
intercostal arteries.
POSTDUCTAL TYPE
1. The ductus is closed
and no longer acts as a
shunt.
2. No narrowing of
isthmus.
3. Shelf like narrowing with
in the aorta in
juxtaductal position.
4. Post stenotic and
prestenotic aorta is
dilated.
5. Intercostal arteries are
grossly dilated.

20.  3 groups
1. Group I: patients with isolated CoA
2. Group II : patients of CoA with VSD
3. Group III: patients of CoA with complex
intracardiac anomalies other than
simple VSD.

21.  It is a rare condition presumably resulting from the congenital
elongation of the aortic arch .
 The elongation leads to redundancy and kinking of the aorta
which may appear similar to the coarctation but has no
actual obstruction to the blood flow.
 There is no actual pressure gradient in pseudocoarctation.
 There is tendency of dilatation and aneurysm formation due
to the turbulant flow in aorta.

22.  Occurs in 0.5 – 2% cases of coarctation.
 Etiology: congenital or related to other diseases like rubella,
takayashu arteritis, von recklinghausen’s disease.
 Narrowing is diffuse in 1/3rd cases and circumsccribed in 2/3rd
of cases.
 Diagnosis is angiography.
 Treatment is by patch aortoplasty or by bypass graft.

23. 1. Collateral circulation
2. Aneurysm formation of intercostal arteries
* 3rd, & 4th rib notching * after 4 years of age
3. Coronary artery dilatation and tortuosity
* due to LVH
4. Aortic valve
* bicuspid (27-45%) * stenosis ( 6 - 7%)
5. Intracranial aneurysm
* berry type intracranial aneurysm in some patients
6. Associated cardiac anomaly
* 85% of neonates presenting COA

24.  More developed in adult or postductal type as ductus is
closed and collaterals are the only source of blood supply to
the lower half of body.
 There is progressive enlargement of collateral blood vessels
around the coarctation segment.
 Collateral flow predominantly arisese from:
1. Subclavian artery and its branches: Internal thoracic artery ,
intercostal artery, scapular artery, cervical artery, vertebral
artery, spinal artery.
2. Epigastric artery.

26. 1. Incidence
* 5-8% of CHD (5 per 10000 live births)
* Isolated CoA (82% of total CoA)
male:female = 2:1
CoA + VSD 11%,
COA + other cardiac anomalies 7%
* Complex CoA ; no sex difference
2. Survival of pure CoA
* 15% : CHF in neonate or infancy
* 85% : survive late childhood without operation
* 65% : survive 3rd decade of life (2% at 60 years)
3. Bacterial endocarditis : common in 1st 5 decades
4. Aortic rupture : 2~3rd decade
5. Intracranial lesion : subarachnoid hemorrhage(cong.
Berry aneurysm)

27.  Congestive heart failure(26%)
 Bacterial endocarditis (25%)
 Spontaneous rupture of aorta (21%)
 Intracranial haemorrhage(13%)

29.  Narrowed aorta produces increased left
ventricular afterload and wall stress, left
ventricular hypertrophy, and congestive
heart failure.
 Systemic perfusion is dependent on the
ductal flow and collateralization in
severe coarctation

30.  Bimodal distribution
 Group 1 : presents in first week of life
 Group 2 : presents in childhood and adolescent

31.  They have ductal dependent circulation.
 Comes to light after closure of ductus with cardiovascular
shock , renal failure and acidosis. They are a medical
emergency.
 Due to less collateral flow in infancy ischemia of organs distal
to coarctation occurs.
 At same time sudden increase in LV afterload leads to acute
CHF.
 Management includes ventillation , sedation, correction of
acid base balance, prevent hypothermia, prevent
hypoglycemia, maintain optimum perfusion by inotropes and
PGE1 infusion to keep ductus patent followed by surgical
intervention when organ functions were optimised.

32.  Majority of patients are asymptomatic and presents with
hypertension on routine examination.
 Symptomatic patients may presents with :
1. Headache and epistaxis due to systemic hypertension
2. Claudication due to reduced blood flow to lower extremity
3. Increased incidence of aneurysm of circle of willis leading to
stroke
4. Aortic aneurysm proximal or distal to coarctation
5. Aortic dissection
6. Atherosclerotic heart disease with MI
7. Congestive heart failure.
8. Bacterial endocarditis (fever).

33.  Diagnosis in new born
 Diagnosis in children and adult

34.  Newborn with severe CoA and ductus closure will present in
shock , renal failure, acidosis.
 Physical examination: tachycardia, tachypnoea, pale
appearance, lower extremity pulses absent, upper extremity
pulses are thready.
 Child is hypotensive, liver enlarged
 CXR shows cardiomegaly and evidence of CHF.
 ECG shows left ventricular strain pattern
 2 D echo shows lack of pulsatile flow in descending aorta,
coarctation site and associated cardiac anomaly ,
anatomical details of arch.

35.  Cardiac catheterization: not routinely done but can be done
in patients with suspected complex congenital cardiac
anomalies.
 CT angiography: in cases where cardiac cath is not
necessary but imaging of arch is not adequate CT
angiography is indicated to see anatomy of arch.

36.  Mostly asymptomatic
 Upper extremity hypertension with diminished femoral pulses.
 ECG: reveals LVH and LV strain pattern.
 CXR Shows:
1. Rib notching(inferior border of 3-9 ribs) if patient is above 4
years of age due to erosion byenlarged collaterals.
2. Classic 3 sign due to dilatation of LSCA , narrowing of
coarctation site and dilatation of post stenotic segment.
3. Cardiomegaly
4. E sign on barium filled oesophagus

37.  2 D echo: mostly diagnostic and shows all the necessary
details, a shelf is seen posteriorly in coarctation segment.
 Cardiac catheterization study is required only if there are
associated intracardiac anomalies, a question with regards
to collaterals and when visualization by 2 D echo is poor.
 MRI is more beneficial in older children for anatomy of arch.

43.  Indications for operation
1. Reduction of luminal diameter greater
than 50% at any age
2. Upper body hypertension over 150mmHg
in young infant ( not in heart failure )
3. CoA with congestive heart failure
at any age

44.  General considerations
 Specific techniques
 Advantages and drawbacks of different
techniques
 Complications and management.

45.  Approach:
1. Posterolateral thoracotomy through 3rd or 4th ICS.
2. Median sternotomy approach is better in patients with
associated cardiac anomalies that are to be repaired
simultaneously.
 Arterial pressure monitoring lines are placed in right radial
artery and femoral artery.
 In cases where rt subclavian artery arises below the
coarctation segment then instead of radial line use temporal
artery for proximal aortic pressure monitoring.
 Multiple chest collaterals are ligated and divided individually

47.  The lung is retracted anteriorly and mediastinal pleura
overlying the coarctation segment is incised.
 The descending aorta , left subclavian artery , isthmus of
aorta, ductus arteriosus and transverse aortic arch distal to
left carotid artery is mobilised.
 ABOTT ARTERY: this artery is not found in normal subjects but is
seen in CoA patients arising from posterior wall of aortic arch
or lt subclavian artery. When encountered it should be
ligated.

49.  Maintain proximal aortic pressure high during cross clamp to
provide adequate arterial pressure distal to the clamp to
prevent paraplegia.
 In adults 160-200 mm hg , in children 100-120mmhg
 The distal aortic pressure should not < 45mm hg

50.  If the distal aortic pressure falls below 45 mmhg, following
steps are to be taken
 1] use plasma expanders
 2] use iontrops
 3]relocate the clamp if possible
 4]use of partial left heart CPB with left atrial & descending
aortic cannulation
 5] prevent acidosis
 6] never use SNP

51. 1] resection & end to end anastomosis
2] prosthetic patch aortoplasty
3] prosthetic interpositio graft
4] resection with extended end to end
anastomosis
5]subclavian flap aortoplasty
6] balloon dilatation angioplasty
7] bypass grafts

52.  Described by crafoord & nylin 1944 in adults
 Described by kerklin in 1955 in infant
 Narrowed coarctation segment is excised with direct end to
end circumferential anastomosis of aorta
 Ductus is ligated & divided at the same time

57.  High rate of recoarctation at surgical
site[ 20-86%] particularly in the age of < 1
yr
 This technique does not address issue of
hypoplastic transverse arch
 Not possible in older children as arch &
descending aorta are more fixed &
difficult to mobilise

59.  Use of silk suture instead of monofilament
suture
 Inadequate resection of ductal tissue
 Lack of growth at circumferential suture
line
 Lack of growth of hypoplastic transverse
arch

60.  Introduced by vosschulte in 1957 mainly for
patients of 1-16 yrs.
 access is through left 4th ICS
 Aorta is incised longitudinally in region of
coarctation with prolongation of incision well
above & below
 Patch extent upto left subclavian artery
 Is isthmus is also hypoplastic, the patch may be
extended upto left carotid artery with clamp
position proximal to left carotid artery

65.  The collateral vessels are preserved & do not
require ligation & division
 Allows enlargement of isthmic hypoplasis
 Anastomosis is tension free
 The posterior aortic wall & even hypoplastic aortic
arch grows after repair

66.  Recoarctation [9%]
 Aneurysm formation of aortic wall
opposite to patch

68.  Described by robert gross in 1951using
aortic homograft
 I960 , cooley & debakey used decron
graft
 Indicated in patients > 10 yrs of age
,patients with associated aneurysm ,
patients with complex long segment
coarctation & patients with recurrent
coarctation.

69.  Inability of prosthetic graft to grow with
child
 Longer cross clamp time
 Increase incidence of bleeding

70.  Introduced by waldhausen & nahrwold in 1966
 Indicated in infants
 Operation is perform through left 4th ICS
 The aota is clamped proximal to left subclavian and dital to
coactation
 Left subclavian is ligated distally near the origin of vertebral
artery & divided
 The aorta is opened longitudinally & incision extended upto
left subclavian
 The subclavian flap is folded onto the aorta

72.  Techniques is simple
 Short cross clamp time
 Avoidence of prosthetic matarial
 Easy hemostatic controll
 Increase anastomotic growth due to use
of autologous flap

73.  Left arch ischemia due to ligation of left
subclavian
 Poor growth & function of left upper limb
 Aneurysm formation
 Recoarctation[ 13%]

75.  Given by Amato in1966
 Perform by left thoracotomy or median sternotomy
 Indicated in coarctation with hypoplastic distal transverse
arch
 Adequate mobilzation of descending aorta, first two ot three
intercostal vessels are ligated & divided, arched vessels are
looped, clamp is placed between innominate & left carotid ,
ductal tissue excised, the coarctation segment is also excised
& incision is made in transverse arch upto proximal clamp &
the two segment of aorta anastomosed
 Mortality is 2% & recoarctation is 4%

77.  Low rate of recoarctation
 Avoidance of left arm ischemia & growth
disorder
 It addresses & corrects hypoplasia of
transverse arch
 Avoid prosthetic material
 Limits the potential for aneurysm
formation
 Preseves normal vascular anatomy

79.  It is the currently procedure of choice for
infants < 1 yr of age & in many children
also.

80.  Described by elliott
 Indicated in transverse arch hypoplasis
 Clamps are placed proximal to left
carotid also involving some part of rihght
innominate artery
 Allows extension of arch incision more
proximal than extende E to E
anastomosis

81.  Described by sos in 1979 In patients with
neonatal coarctation
 Indications
 1] patients with major systemic illness that
increase the risk of surgery
 2] older patients with mild discrete
coarctation with poor collateral
formation
 3] for dilataion of recurrent coarctation

84.  Formation of aneurysm near dilatation
site
 Residual gradient > 20 mm hg
 Aortic rupture with stents
 In stent stenosis particularly in younger &
low birth weight children [31%]

86.  Two stage response
 First response is due to release of strech
on baroreceptor on carotid bodies after
removal of obstruction , it subsides within
24 hrs and it is due to increased
sympathetic activities
 Second response is due to elevated level
of renin angiotensin, it appears within 48-
72 hrs of first response

87. 1] mesenteric arterities & ischemia – child
develop abdominal pain tenderness
distension , GI bleeding requiring
laprotomy
 Keep the patient NPO for 32-48 hrs

88.  In immediate postoperative period
esmolol & nicardipine can be used to
titrate B.P.
 ACE inhibitors can be used for second
phase response
 Preoperative administration of
propranolol is quite useful in blunting
sympathetic response & managing
postoperative hypertension

89.  There is a tendency of persistence of
hypertension even after repair of
coarctation which is proportionate to
age of patient

91.  Described by hufnagel & gross in animals
 Bing described paraplegia in humans after coarctation repair
in 1948
 Incidence is 0.4%- 1.5%
 The incidence is correlated with length of cross clamp time [>
49 min] & presence of abberent origin of right subclavian
below coarctation
 Management of aortic pressure is crucial
 SSEP are a possible method to assess reversible spinal cord
ischemia

92.  Both true & false aneurysms can form as
a complication of coarctation repair
 Risk factor for aneurysm formation
 1] patch aortoplasty at advance age
 2] operation on recoarctation
 3]use of decron as compare of PTFE
patch

93. Risk factor for recoarctation:
1] age < 2months
2] weight < 2 kg
3] residual ductal tissue
4] use of silk sutures for anastomosis

94.  Postoperative arm to leg peak systolic
pressure gradient of > 20 mmhg
acrossed repaired area
 Simultaneous arm & leg pressure
measurement are best way to exclude
posssibilty of residual obstruction
 Physical examination coupled with MRI
angiography is most accurate.

95.  Resection & E TO E anastomosis have
high recoarctation rate { 19%} followed
by flap aortoplasty {13%}
 Resection with extended E TO E
anastomosis have lowest recoarctation
rate{6%}
 Treatment is balloon dilatation , if not
successful reoperation is considered,
reoperation is difficult owing to dense
scarring & adhesions.

96.  For patients with long segment
coarctation, very dense adhesions or
those requiring cardiac operations,
jacobs & coworker suggested bypass
graft from ascending to descending
aorta through combined thoracotomy &
median sternotomy approach
 Kenter also reports extra anatomic
bypass grafts.

99. 1. CoA proximal to left subclavian artery
* 1% of all COA
* reverse subclavian flap
* abdominal CoA : 0.5 ~ 2%
2. Mild or moderate coarctation
* degenerative change prone to occur
3. Prevention of paraplegia
* Collateral circulation, hypothermia(< 45min at 33 deg C)
* Descending aortic pressure under 50mmHg after clamp
4. Recurrent coarctation
Increased mortality and morbidity
5. CoA with VSD or other anomalies
Increased mortality and morbidity

100.  Echocardiography is primary diagnostic
tool
 CT & MR angiography is very useful
specially to delineate the anatomy of
transeverse arch
 Coarctation should be repaired at the
time of diagnosis to prevent late
hypertension

101.  Resection & extended E TO E
anastomosis is treatment of choice for
infants , neonates & young children
 Interposition graft placement is indicated
in older children & adults
 Balloon dilatation is initial procedure of
choice for recoarctation if unsuccessful
reoperation with patch aortoplasty or
graft interposition is recommended.