coarctation

1. Coarctation of Aorta

2. Introduction
• Latin term coartatio - means a drawing together
• Aortic coarctation - narrowing at some point
along the course of the aorta
• context of the congenitally malformed heart
– an area of narrowing of the thoracic aorta
– the region of the insertion of the arterial duct
– with or without additional abnormalities of the aortic
arch.

3. History in Brief
Johann Freidrich Meckel ( 1781-1833) - Prussian anatomist
18 yrs / F - Royal Academy of Sciences of Berlin -1750
‘so narrow that its diameter was smaller by half than that
of the pulmonary artery, which it should have exceeded or
at least have equalled in calibre’
Craigie (Paris) – 1789 ‘a very emaciated woman about 50 years old’.
‘ The part of the aorta which is beyond the arch, between the
ligamentum arteriosum and the first inferior intercostal, was so greatly
narrowed that it had at most the thickness of a goosequill. Hence in
taking apart its walls, which had not decreased in this place, there
remained only a small lumen. The part of the vessel which was above
the constriction was slightly dilated; the distal part was of normal
calibre. The most careful dissection did not reveal either in the aorta or
in its vicinity any cause to which this extraordinary condition could be
attributed’

4. Prevalence
• The overall incidence is in the region of 1 in 12,000
• Severn percents of liveborn CHD , higher in stillborn infants
• NERICP ( The New England Regional Infant Cardiac Program )
– 4th
common lesion – surgery / intervention in < 1 yr
– 7.5 % prevalence with Male : Female = 1.27 to 1.74
• Genetics
– XO Turner – 35% incidence
– NOTCH1 – Left sided obstructive lesions – BiAV, AV Stenosis, Coarctation,
HLHS
– DGS - 22q11 deletion-associated with interruption the left common carotid
and subclavian arteries. May be related with CoA
• Environmental
– Seasonal incidence, with paucity of males born between April and August

5. Morphology
• Aortic coarctation - not a uniform entity
• variable degrees of hypoplasia + stenotic areas, within arch
• Tubular hypoplasia - uniform narrowing of part of the arch
• discrete coarctation - localized shelf-like lesion within the
lumen of the arch
• The extreme - interruption of the aortic arch
– Less severe- atresia of the arch - fibrous cord between the
interrupted segments - haemodynamic interruption but
anatomic continuity

6. Edward’s Classification
1. Describe precisely the site of coarctation
2. Irrespective of whether the arterial duct is
patent, closed or ligamentous,
1. Irrespective of the presence of additional
anomalies

7. EDWARD’s Clissification
obstructive lesion within the aortic arch- occupying preductal, paraductal, or postductal
positions

8. Tapered Isthamus
• Most Common
• PDA ( duct/ ligament) + Aortic
Isthmus + Desc Aort
• If Duct Patent –
• Some degree of isthmal hypplasia
• Tapered isthmus
• OBSTRUCTION – Pre-ductal

9. Obstructive Lessions
Infolding of aortic wall | Ductal Tissue Shelf

10. Pinhole Meatus
• Closed arterial duct is
closed
• Ductal shelf -fibrous
diaphragm

11. • Infants with LVOTO or VSD
–Diffuse hypoplasia of TA
–Diffuse hypoplasia of isthmus
Proximal to discrete coarctation

12. Para Ductal Obstruction
• Directly opposite
the mouth of the
duct at insertion
to the aorta,
• Found in one-
tenth of cases

13. Postductal Obstruction
• Distal to the aortic origin of the arterial duct
• Accounts for one-tenth of cases in infancy
• Lack of improvement despite maintenance of
ductal patency with prostaglandin
• norm in adults – Post Ligamental

14. Histology
• thick intimal & medial ridges - protrude post.& lat.
Mostly at the insertion of duct
• distal to the coarc. (the jet lesion) - high-velocity flow
impacts the arterial wall - Intimal proliferation &
disruption of elastic tissue
– infective endarteritis, intimal dissections, aneurysms
• Cystic medial necrosis (depletion and disarray of
medial elastic) aorta adjacent to the coarctation site
– late aneurysm formation or aortic dissection.

15. Associated Malformations
• coarctation complex in neonates
– aortic coarctation
– Hypoplasia of the isthmus
– patency of the arterial duct
– presence of an interatrial communication
– PFO
• VSD – PM , Muscular, Malalinged
– potentiate flow to the pulmonary pathway
– reduced flow through the aortic isthmus in fetal life

16. Valvular Pathologies

17. SHONE COMPLEX
1. supravalvar mitral
membrane (SVMM), or
mitral ring
2. valvular and subvalvular
aortic stenosis
3. “parachute” mitral valve
4. coarctation of the aorta

18. Other Intracardiac Anomalies
• atrioventricular canal defect
• d-transposition
– with or without tricuspid atresia
• the Taussing Bing type of DORV
• congenitally corrected transposition of the great vessel
• Coarctation of the aorta is also an important component
of the hypoplastic left heart syndrome.

19. DIAGNOSES IN 216 INFANTS (<1 year OLD) WITH COARCTATION
TREATED AT THE UNIVERSITY OF MICHIGAN FROM 1960 TO
1992

20. Extracardiac Vascular Anomalies
• Brachiocephalic artery anatomy
– The left subclavian artery arise at the site of coarc. - stenotic at origin
– The right subclavian artery arises anomalously below the coarctation -
4% to 5% of cases
• Subclavian steal syndrome
– Reverse vertebral artery flow to subclavian artery
• Both subclavian arteries arise beyond the coarctation
• Collateral arterial circulation
• Berry aneurysms of the circle of Willis - 3% to 5%
– responsible for cerebral vascular accidents in patients with arterial
hypertension

21. Collateral System
• Rarely present in infants , gradually develops throughout childhood
• Bypass the obstruction and augment perfusion to the lower body
• The most common pattern
– Large aberrant artery arising RSA, and supplying the aorta below
–
– Various branches of LSA, including the thyrocervical trunk
– Left intercostal arteries via the left internal thoracic artery
• leading to notching of the ribs
– Anterior spinal artery through the left vertebral artery
– Artery of Abbott
• Arises from the posterior aspect of the isthmus, and passes medially behind
the carotid artery and transverse arch

22. Extracardiac Nonvascular Anomalies
• Turner syndrome
• abnormalities of the musculoskeletal system, genitourinary system,
gastrointestinal system, or respiratory system - 25%
• Kabuki syndrome
– Genetic abnormality associated with developmental delay, joint laxity,
cleft palate
– characteristic facial appearance with arched eyebrows
– It is associated with a hypoplastic isthmus and juxtaductal CoA in 25%
of patients
– anomalous origin of one or both coronary arteries from the
pulmonary artery

23. Embryology ( 6th
– 8th
Week Gest.)
• third aortic arches persist as the common carotid arteries
• The left fourth aortic arch forms the thoracic aortic arch and isthmus
• the right fourth arch normally involutes
• Sixth Arch - proximal pulmonary arteries | Distal ductus arteriosus
A thoracic coarctation - abnormal development of left fourth and sixth aortic arches

24. Two concepts
• The Ductus tissue theory
– Migration of ductal smooth muscle cells into the periductal aorta
– Subsequent constriction and narrowing of the aortic lumen
• The Hemodynamic theory
– Hemodynamic disturbances- reduce the blood flow through the fetal aortic
arch
– Fetus aortic isthmus receives 10% of the combined ventricular output,
diameter about 70% to 80% of ascending aorta
• Coarctation in females with Turner syndrome
– fetal lymphatic obstruction - distended thoracic ducts that compress the
fetal ascending aorta

25. Hemodynamics
• Disturbances may occur postnatal
• Increases impedance to left ventricular outflow
• Elevating systolic pressure - LVOT + Aorta
– The systolic pressure gradient generated across
the coarctation may be as high as 50 to 60 mm
Hg at rest
– Pressure gradients may exist throughout systole
and diastole

27. Different Hemodynamics in New Born
• Rapid CoA manifestation
• Myocardium lacks normal structure
• Decrease density of beta-receptor
• Poor adaptability to increase volume

28. Newborn or Infancy with CoA

29. Changes over a Time
• Left Ventricular Myocardial Hypertrophy
– EDV- N , ESV – R  LVEF – R/N
• Left ventricular diastolic dys
– Decreased rate of early left ventricular diastolic relaxation
– Poor diastolic filling
– Shift of left ventricular filling into late diastole
• Associated conditions – AS Inc ESP / MR VSD Inc EDP
• Later – Inc LVEDP  LAP PVC

30. Clinical Manifestations
• Asymptomatic - grow normally unless cardiac or noncardiac anomaly +
• Femoral pulses- absent /weak + delayed compared with brachial pulses
• Differences of 20 mm Hg or more - significant obstruction
• Discovery of a femoral pressure even a few mm Hg lower than that in the
arms is suspicious
• When the pressures are measured directly- damping of the lower body
pressure curves compared with those for the upper body
• Diastolic hypertension in the lower extremities, despite a systolic pressure
gradient, suggests hypertension of some other cause
– abdominal coarctation with involvement of the renal arteries

32. CoA in Grownups
• male (59%) , asymptomatic, older
• Searching for the cause of hypertension
• Rib notching observed on a chest radiograph
• Evaluation for a heart murmur
• Other cardiac lesions

33. Cardiac Examination
• Systolic ejection murmur of low intensity - the base & left
interscapular region
• Murmur appears to extend into diastole
• Systolic click, due to a bicuspid aortic valve
• Collateral - continuous murmurs-intercostal arteries, scapulae
and anterior abdominal wall
• cardiac apex
– Systolic murmur – MR / diastolic murmur - MS

34. Evaluations - ECG
• Infants – Normal
• LV hyper + ST strain + T wave depression 
AS / Myocardial disease
• Children – LVH, deep S in Rt chest leads
• RVH  Sev PAH ( VSD , MS )

35. Chest CXR
• Infants
– Cardiomegaly
– Inc pulmonary vascular markings
– Rib notching is not present in infants
• In older children and adolescents - normal or only mildly enlarged heart
size
– The pulmonary vascular markings are normal
– Abnormal contour of the aortic arch in frontal film
– Localized indentation of the aorta at the site of coarctation (3 sign).
– Immediately below the 3 sign, a prominent descending aorta may be noted
owing to poststenotic dilation
– Rib notching-uncommon in those younger than 5 years of age
– Barium swallow-localize discrete coarctation - barium-filled esophagus, an E
sign may be seen on the frontal or left anterior oblique film

36. CXR

37. Echocardiography
•Suprasternal long-axis view
– localized narrowing of the thoracic aorta just beyond the origin of the left
subclavian artery
– The posterior shelf
– Associated findings -isthmus hypoplasia, poststenotic dilation, , diminished
systolic pulsations in the descending aorta
•Color flow Doppler
– localizing the site of obstruction
– Hemodynamic severity of a coarctation
• A peak instantaneous pressure gradient may be determined
• Diastolic runoff
•Intracardiac lesions

39. CT / MRI Imaging
• Define - location + severity of coarctation + anatomy
of the arch
• PDA + Collateral
• MRI
– Three-dimensional surface rendering
– Assessment of aortic flow - estimate pressure gradients
• CT
– CT angiographic - very rapidly (typically in 4 to 5 seconds)
– Ionizing radiation.

40. Cardiac Catheterization and Angiography
• Diagnostic
– Nature and severity of the coarctation associated
intracardiac lesions
1. Anatomy (discrete or long segment), location, and severity
2. Status of PDA / direction/magnitude shunting
3. Presence and extent of the arterial collateral circulation.
4. Associated intra-cardiac lesions.
5. Assess left ventricular function.
6. Assess pulmonary artery pressure and resistance; this is of
particular importance in patients with intracardiac lesions.

43. Indications for Intervention
• “An uncomplicated coarctation with a consistent
systolic blood pressure gradient between the
arms and legs of more than 20 mm Hg”
• This procedure, even in the asymptomatic
patient, should be undertaken soon after
diagnosis (preferably by age 2 years.
– Residual hypertension despite successful relief is very
common (24% to 38%) in older patients

44. Presentation in Infancy
• Initially stabilizing the patient with inotropic support and diuretic therapy
• Prostaglandin E1 to promote ductal patency and improve perfusion of the
descending aorta and renal and mesenteric beds
• Metabolic disturbances, such as acidosis, hypothermia, hypoglycemia, or anemia
• Early repair - morbidity and mortality from left ventricular failure in infants with
severe coarctation treated with medical management alone
• The surgical risks are higher for infants who present with congestive heart failure
resulting from complex coarctation associated with major intracardiac anomalies
• Post repair associated cardiac lesion may improve
– VSD
– Hypoplasia of aortic valve

45. Presentation in Childhood
•The risk for late recurrence of coarctation appears to be increased when
repair is performed <1 yrs of age
– Normal descending aorta has attained 55% of its final adult diameter by 3 years of age
– Significant hemodynamic obstruction at rest occurs only if the aortic diameter is
reduced by >50%
– Restenosis following coarctation repair after 3 years of age should be uncommon
•Increased risk for residual hypertension and early atherosclerotic
cardiovascular disease if delayed into late childhood and adolescence.
•Long term follow up study concluded that these outcomes are optimized if
elective coarctation repair is performed at approximately 1.5 years of age.
•Coarctation repair - recommended at 2 to 3 years of age in asymptomatic
children without severe upper-extremity hypertension.

46. Surgery
• End to end anatomosis ( ETE )
• Extended ETE
• Sublclavian Flap Angioplasty ( SFA )
• Subclavian tranlocation ( SFA + LSCA reimplant)
• Synthetic patch angioplasty

47. Resection and End to end anastomosis
• First reported in
1945 by Crafoord
and Nylin
• surgical treatment of
choice – discrete coa
• Extended end-to-end
anastomosis
– broader longitudinal
incision across the
proximal aorta

48. Prosthetic patch aortoplasty
• Vossschulte ( 1961 )
• Longitudinal incision
across the coarctation
• Extending onto the
proximal LSCA
• Area is enlarged with a
patch of Dacron or Gore-
Tex

49. Subclavian Flap Aortoplasty
• Waldhausen & Nahrwold - 1966
• LSCA ligated & divided
• longitudinal incision - extended
through the proximal subclavian
artery and beyond the
coarctation.
• The proximal subclavian stump
then is turned down & used as a
patch of autologous tissue
• vertebral artery is ligated

53. Complications of Sx Repair
• Postoperative paradoxical hypertension
• Spinal cord ischemia and paralysis
• Recurrent laryngeal or phrenic nerve injury
• Chylothorax
• Bleeding
• Infection

54. Postcoarctectomy Syndrome
Paradoxical Hypertension
• Occur during the first 3 to 5 days following coarctation repair, with
systolic and diastolic pressures rising above pretreatment levels
• In severe cases, mesenteric arteritis and bowel ischemia may occur
• The mechanism is related to rebound activation of the sympathetic
nervous system and the renin-angiotensin system.
• Prevented with beta-blocker therapy and by aggressive antihypertensive
therapy during the immediate postoperative period.

55. Spinal Cord Injury
• Aortic cross-clamping severely compromises perfusion to
the descending aorta and spinal arteries
• Avoided by ensuring
– Adequate descending aorta perfusion when the aorta is cross-
clamped
– Limiting total cross-clamp time to 30 to 35 minutes
– Minimizing the number of intercostal arteries sacrifice
– Avoiding hyperthermia
– hypothermia if necessary .
– Left heart bypass may be necessary in some patients to
maintain adequate descending aorta perfusion when the aorta
is cross-clamped.

56. Percutaneous Balloon Angioplasty
and Stenting
• Accepted as effective therapy for a recurrent postoperative coarctation
• Controversial as a primary treatment strategy for a native coarctation
• Performed in a retrograde fashion from the femoral artery
•
• Balloon diameter is chosen to equal the diameter of the aortic isthmus; if
necessary for optimal gradient relief, a larger balloon may be used but not
exceeding the diameter of the aorta at the diaphragm
• Angioplasty enlarges the coarctation lumen by expanding the diameter of
the lesion and by producing linear intimal and medial tears at the
coarctation site
• The medial tears are shallow, but rarely some may extend to the
adventitia

57. Angioplasty for Native
Coarctation
• A multicenter report was published in 1990 from the Pediatric
Valvuloplasty and Angioplasty Registry
• Balloon angioplasty was performed in 140 patients whose age ranged
from 3 days to 29 years and acutely decreased the systolic pressure
gradient from 48 mm Hg to 12 mm Hg, with an increase in the coarctation
diameter from 3.9 mm to 8.8 mm.
• A residual gradient >20 mm Hg was reported in 14% of the patients.
• A follow-up study of 59 children, >2 years, documented a residual
gradient of more than 20 mm Hg in 27% of patients. In the remaining
patients, the mean residual systolic gradient was 6 mm Hg (median
gradient 8 mm Hg).
• Aneurysm formation is 5 to 10%

58. Angioplasty for Recurrent Postoperative
Coarctation
• The pediatric angioplasty registry reported acute data on 200
patients undergoing balloon angioplasty for recoarctation of the
aorta
• The systolic pressure gradient decreased acutely from 42 mm hg to
13 mm hg
• Diameter of the recurrent coarctation increased from 5.2 to 8.9
mm.
• Residual pressure gradients >20 mm hg were present in 20% of the
patients.
• One study suggests a poorer response to angioplasty after
coarctation resection and extended end-to-end anastomosis

59. Coarctation Stenting
• A stent implanted with balloon angioplasty, support to the dilated aortic segment.
• Decrease coarctation restenosis related to vessel recoil and may also diminish the
late incidence of aneurysm formation.
• Beneficial in some patients with transverse arch hypoplasia
• Restenosis is uncommon following coarctation stenting
• Growing children may need to be dilated further when the child has grown
• Late aneurysm formation at the coarctation site may occur after stenting, but
seems to be less frequently encountered than after balloon angioplasty alone
• Stent therapy for coarctation is performed by a retrograde arterial approach

60. Prognosis
• The prognosis for a normal life following successful repair of
coarctation in childhood is excellent.
• Normal growth and development are to be expected
• Only minimal restrictions should be placed on physical activity
– Without a significant residual systolic gradient (<10 mm hg at rest),
– With normal upper-extremity blood pressure at rest and with
exercise,
– Without an aortic aneurysm
– Without significant associated intracardiac lesions,

61. CLINICAL AND HEMODYNAMIC CONDITIONS
THAT MAY AFFECT LONG-TERM PROGNOSIS
AFTER REPAIR OF COARCTATION
1. Residual or recurrent coarctation
2. Hypertension (rest and exercise)
3. Aortic aneurysm
4. Aortic dissection
5. Intracranial hemorrhage
6. Diminished left arm growth/subclavian steal
7. Endocarditis/endarteritis
8. Associated intracardiac lesions

62. Residual Coarctation
• Implies the presence of an aortic arch gradient
immediately after repair
• Inadequate repair of the coarctation
• Hypoplasia of the isthmus
• Hypoplasia of transverse aortic arch.
• There is good evidence to suggest that the
transverse aortic arch may grow in some children
following coarctation repair in infancy

63. Recurrent Coarctation
•Implies the development of restenosis after an initially successful repair
•Recurrent coarctation most commonly occurs - inadequate growth at the coarctation
repair site,
•Rare if repair is performed after the child is 2 years of age
•Recent surgical experience suggests that the use of an extended end-to-end
anastomosis may substantially decrease the risk of recurrent coarctation
•Residual and recurrent coarctation after balloon angioplasty also occur more
commonly when the procedure is performed in infancy

64. Hypertension
•The long-term prognosis following repair of coarctation may be
adversely affected by :
– Systemic arterial hypertension
– Premature atherosclerotic cardiovascular events
•The increase in aortic blood flow across a relatively non- distensible
coarctation repair site with dynamic leg exercise
•Patients with exercise hypertension, but without significant anatomic
stenosis following coarctation repair, may benefit from beta-blocker
therapy with a decrease in exercise hypertension and coarctation
gradient

65. Aortic Aneurysm & Dissection
• The incidence of postoperative aortic aneurysm is highest following prosthetic patch aortoplasty
– Once present, such aneurysms may progress rapidly and may be responsible for aortic rupture and sudden
death (100).
– Aortic aneurysms also occur following balloon angioplasty of coarctation
– The risk of aortic aneurysm following coarctation angioplasty varies widely in published reports, with the
larger follow-up studies estimating its incidence to be approximately 5% to 10%
– Late aneurysms have been identified less commonly after coarctation stenting.
• Factors predisposing to dissection:
– Include cystic medial necrosis of the aortic wall
– Atherosclerosis,
– Persistent arterial hypertension
– Dilation of the ascending aorta, which is particularly common in patients with turner syndrome.

66. Intracranial Events
•Intracranial hemorrhage may occur late following
coarctation repair
– with or without associated hypertension
– related to the presence of berry aneurysms in the
circle of Willis
•Cerebrovascular accidents have been an important
cause of late morbidity in the larger studies of long-
term outcome following coarctation repair

67. Affected Left Arm Growth
• Left subclavian flap aortoplasty - sacrifice the
subclavian artery
– Responsible for detrimental long-term effects
– Diminished arterial blood supply to the left arm
– Arm claudication with exercise
– Diminished growth of the left arm
– The subclavian steal syndrome - occur if the
vertebral artery remains intact distally

68. Endocarditis / Endartiritis
• Important morbidity in patients with coarctation of the
aorta.
• Endocarditis may occur on a bicuspid aortic valve or
other associated intracardiac lesions
• Endarteritis typically occurs at or just distal to the site
of coarctation repair
– In the area of turbulence
– Intimal thickening
– Resulted in mycotic aneurysms

69. Celoria and Patton Classification

70. Celoria and Patton Classification