Management of coactation of aorta

1. MANAGEMENT OF COARCTATION
OF AORTA

2. Indications for intervention
• Patients of CoA presenting with left ventricular dysfunction, even
though the gradient across is <20 mmHg, where left ventricular
dysfunction is considered to be due to tight CoA (Class I).
• Patients with CoA gradient ≥20 mmHg (Class I)
• Patients with gradient <20 mmHg, but having upper limb
hypertension, left ventricular hypertrophy, or significant collateral
formation (Class IIa).
• Patients with hypertension who have >50% narrowing at the site of
CoA, relative to aortic diameter at diaphragm on
CTA/cMRI/angiography, irrespective of pressure gradient (Class IIa).

3. • Intervention is not indicated if Doppler gradient across coarctation
segment is <20 mmHg with normal left ventricular function and no
upper-limb hypertension (Class III).

4. Critical neonatal coarctation
Coarctation presenting with heart failure in infancy requires immediate and
aggressive treatment
Initial stabilisation - inotropic and diuretic support
Correction of metabolic factors- acidosis, hypoglycaemia, hypothermia and
anaemia
May be intubated and mechanically ventilated
Keep high PVR and pCO2 of above 45 mm Hg (this reduces L –R shunt and
increases ductal flow to lower body
PGE1- at 0.05 – 0.1 mcg/kg/min, maintains ductal patency
Neonate should be closely observed for apnea and hypotension
After stabilisation repair should be performed on emergency

5. Timing of intervention
• With left ventricular dysfunction/congestive heart failure or severe
upper-limb hypertension (for age): Immediate intervention (Class I)
• Normal left ventricular function, no congestive heart failure, and mild
upper-limb hypertension: Intervention beyond 3–6 months of age
(Class I)
• No hypertension, no heart failure, normal ventricular function:
Intervention at 1–2 years of age (Class I)
• In patients with significant CoA associated with a sizable VSD, both
defects should be repaired in a single stage (Class I).

6. SURGICAL MANAGEMENT –
GENERAL PRINCIPLES

7. • Two arterial lines- right radial and femoral and a central venous line.
• If right SCA arises anamolously beyond the coarctation, Temporal
artery can be used.
• Nasopharangeal temperature probe
In neonates and young infants temp- 35 *c to be maintained,
in older patients 33-34 * c
• Right lateral decubitus position

8. • Left posterolateral thoracotomy through 4th ICS
• Upper lobe of left lung is retracted anteriorly, medially and inferiorly
• Mediastanial pleura over the isthmus is opened and pleural flap is
retracted using multiple stays
• DTA, ductus, LCCA and LSCA are dissected and looped.
• Plane of dissection is in the areolar tissue just superficial to
adventitia.

10. Identify the vagus nerve and the left recurrent laryngeal nerve
Identify the large lymphatic vessel which frequently passes over the
proximal left subclavian artery, either preserve it or ligate and divide it.
Avoid injury to Abbott’s artery which frequently arises from adjacent
distal aortic arch (2 cm in the vicinity of origin of LSCA posteriorly)

11. Abott’s Artery • This artery does not occur in
normal individuals although
occurs infrequently in
coarctation of aorta.
• Origin: posterior wall of aortic
arch or back of subclavian artery,
around 2cm radius near the
origin of SCA.
• Course: It runs cranially and
turns medially to cross behind
the carotid artery and aortic
arch.

13. Physiology of aortic clamping
Sudden increase in LV afterload – acute increase in LV wall tension and
ischaemia may occur – decreased contractility and VF
With a VSD there may be greatly increase in L to RT shunting – avoid
hyperventilation and high inspired O2
Maintain proximal aortic BP(100-120 mmhg in infants), so that
adequate MAP is maintained distal to the clamp, to help prevent the
complications of paraplegia.

14. • Distal mean aortic pressures of 50mmhg should be maintained.
Various maneuvers are used to maintain this pressure
• Administration of volume expanders
• Start inotropes- Dobutamine and/or dopamine.
• Reduced anaesthetic during the period of aortic cross clamp.
• Readjust the proximal clamp to exclude the subclavian artery if feasible.
• Allow intercostal arteries to remain open.
• If distal pressures fall inspite of all these measures, left heart bypass/Fem-
fem bypass/intraaortic shunt.

15. Prevention of spinal cord and renal ischaemia
Limit cross clamp time to not more than 30 min
Do not sacrifice intercostal arteries
Systemic hypothermia (34-35 deg C)
Topical cooling – wash left pleural cavity with ice cold saline
Methylprednisolone (25 mg/kg) and Mannitol (1 gm/kg)
Intrathecal papavarine

16. Physiology and management of declamping
Distal clamp released first to deair the Aorta
Then proximal clamp released slowly
Marked fall in arterial pressure- due to acute fall in SVR and wash out
of lactic acid and other metabolites from lower body.
Maintain adequate ventilation and baseline systemic pressures for next
5min to prevent development of intractable ventricular fibrillation 3 to
4 min after removal of clamp.
- Declamping syndrome

17. Preventing Decalmping Syndrome
Adequate volume loading before declamping
Sodium Bicarbonate administration
Vasopressin infusion(peripheral vasoconstrictor)
Gradual release of clamp.
Care should be taken particularly in unstable infants and prolonged
clamp time.

18. • Gradient below 10 mm Hg is desirable
• Gradient 10-20 mm Hg –
- ensure if gradient is due to arch morphology - acceptable
- if there is chance of tight anastamosis – redo the anastomosis
• Gradient above 20 mm Hg – redo anastomosis

19. RESECTION AND END TO END
ANASTOMOSIS

20. The first coarctation repair in a patient was performed by Crafoord
and Nylin in October 1944
Crafoord C, Nylin G. Congenital coarctation of the aorta and its surgical treatment. J Thorac
Cardiovasc Surg. 1945;14:347–61.
(Karolinska Institute Sweeden)
Gross’s first patient was operated on in June 1945
Gross R, Hufnagel C. Coarctation of the aorta. Experimental studies regarding its surgical
correction. N Engl J Med. 1945;233(10):287–93.
(Children’s Hospital Boston)

21. Proximal control – (loop) in case of injury occurred at the time of
dissection of the descending aorta and its attendant collateral vessels,
first area for dissection - lateral side of the descending aorta and its
collateral vessels (enlarged intercostals).
The ligamentum arteriosum is dissected free with careful visualization
and preservation of the left recurrent laryngeal nerve.
The final area for dissection is the medial proximal descending thoracic
aorta. This area is left until last since injury to a collateral vessel here
can result in difficult bleeding

22. Clamping
Heparin (1mg/kg)
The coarctation segment is excised
End to end anastomosis - using either PDS or a continuous prolene
suture
Declamping

24. Advantages-
Completely removes ductal tissue
No prosthetic material used
Blood supply to left arm maintained
Disadvantages
Tension on suture line
Extensive dissection
Presence of a circumferential anastomosis- stenosis
Lack of growth of hypoplastic arch
Presence of ductal tissue in adjacent normal appearing aorta.

25. Solutions to the problem of circumferential anastomosis
Use of absorbable sutures
Use of interrupted sutures anteriorly
Zig zag suture line

27. RESECTION AND EXTENDED END
TO END ANASTOMOSIS

28. Coarctation resection with extended end-to-end anastomosis was first
described by
Amato in 1977
A method of enlarging the distal transverse arch in infants with hypoplasia and coarctation of the
aorta. Amato JJ, Rheinlander HF, Cleveland RJ Ann Thorac Surg. 1977 Mar; 23(3):261-3.

29. Hypoplastic aortic arch - radically extended end to end anastomosis –
• Dissection is carried along the proximal aortic arch and up to the
distal ascending aorta. The proximal innominate artery is also
defined.
• Ensure that there is not an aberrant right subclavian artery.
• C-clamp is applied which partially occludes the distal ascending aorta
and proximal innominate artery.

30. • The aortotomy is extended across the entire surface of the aortic arch
into the distal ascending aorta.
• ensure that retraction on the proximal C-clamp does not interfere
with perfusion of the innominate artery.
• Both the left common carotid artery and left subclavian arteries must
be occluded during the clamp period.

34. LEFT SUBCLAVIAN PATCH
AORTOPLASTY

35. Concern regarding growth of a circumferential anastomosis
Waldhausen 1966
Proposed the ingenious left subclavian patch aortoplasty procedure.
This procedure eliminated a circumferential anastomosis but failed to
eliminate the abnormal ductal tissue.
Repair of coarctation of the aorta with a subclavian flap - Waldhausen JA, Nahrwold DL J
Thorac Cardiovasc Surg. 1966 Apr; 51(4):532-3.

36. • The left subclavian artery is mobilized to the level of the first rib
• left vertebral artery should be ligated in order to prevent a
subsequent left subclavian steal phenomenon.
• Do not ligate multiple branches of the distal subclavian artery as this
can increase the risk of left limb ischemia.
• PDA can be kept patent especially in mild LV hypoplasia.
• subclavian artery is ligated distally

38. • LSCA opened longitudinally with the incision being carried along the
isthmus of the aorta and several millimeters beyond the coarctation
Some authors have recommended excision of the coarctation shelf,
although there is concern that this increases the risk of subsequent
aneurysm formation.
• The subclavian artery is turned down as a flap.
• The toe of the flap is sutured into the most distal extent of the
descending aortotomy

40. Advantages-
Technically simple
Avoidance of circumferential suture line(growth potential)
No prosthetic material
Easy hemostatic control
PDA can be kept patent.
Disadvantages-
LSCA is sacrificed
Hypoplastic distal arch can’t be managed simultaneously
Abnormal ductal tissue is left in situ- may cause re-coarctation
(high recoarctation rates)

41. Prevention of limb ischaemia with subclavian flap aortoplasty
Implant LSCA into LCCA –separate cervical incision
Graft between remnant LSCA and aorta
Using technique of subclavian translocation rather than flap
(teles de Mendoca, J thoracCardiovasc Surgery, 1985)

42. REVERSE LEFT SUBCLAVIAN PATCH
AORTOPLASTY

43. This is a very useful technique for dealing with hypoplasia of the distal
aortic arch.
• It is usually performed in conjunction with resection and end to end
anastomosis.
• Proximal control is obtained with a C-clamp which incorporates the
proximal aortic arch as well as the distal left common carotid artery
• The isthmus is controlled with a straight or slightly angled neonatal
Debakey clamp.
• This allows continuing flow through the ductus to perfuse the lower
body in the neonate with a patent ductus

45. • LSCA opened longitudinally along its rightward aspect with the
incision extended across the superior surface of the distal aortic arch
and then distally along the left common carotid artery opposite to the
left subclavian incision.
• The flap is turned back retrograde towards the left common carotid
artery with the toe being sutured into the common carotid incision
• Following release of the clamps and having secured hemostasis,
attention can now be directed to the coarctation area itself - A
resection and end to end anastomosis is performed

47. MODIFICATIONS OF LEFT
SUBCLAVIAN PATCH AORTOPLASTY

48. The technique described by Meier avoids a circumferential aortic
anastomosis but provides ongoing continuity of the left subclavian
artery
• left subclavian artery is widely mobilized but ligation of the vessel
itself and the vertebral artery are not required.
• LSCA is divided at its origin from the aorta. It is filleted open on its
rightward face.
• aortotomy is extended from the point of left subclavian origin across
the coarctation and beyond
• left subclavian artery is now advanced and is sutured into the
aortotomy as a flap

51. SYNTHETIC PATCH AORTOPLASTY

52. Vossschulte (1961)
Concerns about high recoarctation rates following end-to-end
anastomosis led to attempts to augment the coarcted segment with
prosthetic material – Patch aortoplasty
Vossschulte K. Surgical correction of coarctation of the aorta by an “isthmusplastic”
operation. Thorax. 1961;16:338–45.
approach was popular in the 1970s and was particularly championed
by Ebert and Mavroudis,

53. • an unacceptably high (10-30 %) risk of late aneurysm formation.
• Current indications:
• Patient is too small for an interposition graft and anatomy precludes it
for extended end to end anastomosis
• Recoarctation.

56. Advantages
Limited mobilisation, minimal dissection, collaterals do not require ligation
and division
Simultaneous enlargement of isthmic hypoplasia.
Relatively short clamp time
No tension on suture line
Posterior aortic wall and hypoplastic arch can grow.
Disadvantages
Prosthetic material
Ductal tissue left in situ
Aneurysm formation as high as 30 % (both true and false)

57. CHOICE OF OPERATION

58. In the first few months (upto -3 mo)
Resection and End to end anastomosis or extended end to end
anastomosis with or without enlarging subclavian flap
Subclavian flap aortoplasty is useful in
Reoperation in young children as circumferential mobilisation is not
needed
Also in neonates with borderline LV (20-25 ml/m2) where it is desirable
to preserve PDA

59. Prosthetic Patch aortoplasty is indicated only in special situations
Recurrent coarctation not responding to balloon angioplasty
In critically sick infant and inability to reopen ductus with PGE1
Neonate with borderline LV to preserve PDA
Reoperations.
Children too small to undergo interposition graft and anatomy
precluding extended end to end anastomosis.

60. Coarctation proximal to LSCA
In infants and young children
Choice is reverse SCA flap aortoplasty
In older children
Amato’s technique
Anastomosing basal part of LCCA to the basal part of LSCA may be used
In older patients associated with aneurysm of SCA
Resection and graft interposition may be used – high morbidity and mortality
Ventral aorta repair is better palliative operation

61. For recurrent coarctation
Patch aortoplasty is the procedure of choice in most cases
In young children subclavian flap aortoplasty may also be used
In older patients extra anatomic bypass

62. COMPLICATIONS

63. EARLY
Injury to RLN, Vagus and Phrenic nerve.
Thoracic duct injury.
Hemorrhage.
Paraplegia.
Left arm ischemia.
Cerebral vascular accident.
Paradoxical hypertension.
Post coarctation syndrome.

64. Paradoxical hypertension
BP elevation to greater than preop levels – sympathetic response (catecholamines)
Two phased- elevation of SBP in first 24-36 hrs and later elevation of Diastolic BP –
RAS (48-72 hrs)
Threshold – SBP- 120 mm Hg
In early phase combination of SNP and beta blocker
Later- captopril therapy
Usually transient lasts for few days
Sometimes may last for months
Carries high risk for development of post coarctation syndrome – needs prompt
management

65. Post coarctation syndrome
Abdominal distension, pain and absent bowel sounds
d/t intestinal ischaemia sec to splanchnic vasospasm
Predisposing factor- paradoxical HTN – elevated RAS
Necrotising mesenteric arteritis – small arteries and arterioles
Luminal thrombosis,
inflammatory cell infiltrate of entire arteriolar wall,
Fragmentation of internal elastic lamina
Fibroblastic proliferation
Marked mesenteric lymphadenitis
Bowel becomes edematous and cyanotic
SMA and vein remain patent
Alternatively d/t acute over distension and pulsatile post coarctation vessels
t/t- NG decompression of bowel, Antihypertensives, Rarely laparotomy

66. Paraplegia
Lerberg et.al (1982)- incidence of paraplegia is 1.5%
Brewer and coworkers(1972) reported incidence of 0.41%
Situations that may fail to develop collaterals
• Coarctation in infants
• Coa proximal to left subclavian
• Coa with pda supplying DTA
• Coa with stenosis at origin of left subclavian artery
• Coa with aberrant right subclavian arising distal to coarctation
• Less than severe narrowing at coarcted area
• Re-repair.

67. LATE COMPLICATIONS
Recurrent coarctation
Aneurysm formation
Subclavian steal
Poor development of upper limb
Residual hypertension
Graft infection

68. MANAGEMENT OF COARCTATION IN ADULTS

69. BALLOON ANGIOPLASTY

71. Indications for balloon angioplasty
• Critically ill neonates who are considered high risk for surgery
(shock-like syndrome and severe left ventricular dysfunction): Balloon
angioplasty to tide over the crisis (Class IIa)
• Infants with native coarctation: Surgery (Class I) or balloon
angioplasty (Class IIa)
• Infants with recoarctation : Balloon angioplasty (Class I)

72. • Children <25 kg with native coarctation: Balloon angioplasty (Class I) or
surgery (Class IIa)
• Children <25 kg with recoarctation: Balloon angioplasty ± stenting (Class I)
• Children >25 kg and adults with native coarctation: Catheter-based stenting
(Class IIa)
• Children >25 kg and adults with recoarctation: Catheter-based stenting
(Class I)
• Elective endovascular stenting of aorta is contraindicated in children <10
years of age (Class III).
•

73. Indications for stenting
• Native coarctation where risk of rupture of aorta is high
• a. BAV with ascending aorta dilation
• b. Nearly atretic isthmus (<3 mm diameter)
• c. Turner syndrome
• d. Age >60 years
• e. Marfan syndrome
ii. Recoarctation with aneurysm or pseudoaneurysm at the site of CoA.

74. Complications of balloon angioplasty
• Aortic rupture
• Aortic dissection
• Aneurysm formation
• Femoral artery injury and thrombosis
• Restenosis

75. Complications of stenting
• In a growing child, creates a fixed stenosis.
• Occlusion of branch vessels
• As a large size sheath is required for deployment, femoral artery
injury is a possibility

76. There is ongoing controversy regarding the advisability of balloon
angioplasty for native coarctation
However, balloon angioplasty remains the standard of care for
recurrent coarctation following previous surgical repair

77. Neonatal - Balloon angioplasty for native coarctation
It is generally accepted that the risk of recurrence is extremely high
after balloon angioplasty in the setting of neonatal coarctation
Preferable - palliate the child medically including prostaglandin
infusion rather than subjecting the neonate to the risks of the invasive
procedure of balloon angioplasty.

78. In the infant or older children
risk of coarctation recurrence after balloon angioplasty is acceptable
and perhaps equivalent to the risk of recurrence following surgery.
The technique is not completely free of the risk of paraplegia.
Abnormal ductal tissue is not removed with this technique.
Technique is dependent on tearing of the media and intima.
This may result in a high incidence of late aneurysm formation.
Certainly aneurysm formation has been described in at least 5% of
patients with relatively short long term follow-up

79. RESECTION AND INTERPOSITION GRAFT
Gross (1948)
End to end anastomosis with interposition graft
Treatment of certain aortic coarctations by homologous grafts; a report
of nineteen cases. GROSS RE Ann Surg. 1951 Oct; 134(4):753-68.

80. In older children and adults if the coarctation segment is long
It is excised and a prosthetic conduit or homograft is interposed

81. • Indicated for patients > 10 yrs of age
• Long and complex coarctation segment.
• When tension exists in end to end anastomosis.
• Selected patients of recurrent coarctation.
• When further resection of aorta is required , where aorta is thinned
out due to poststenotic dilatation.

82. EXTRA ANATOMIC BYPASS

83. Indications
• Recurrent Coa
• Coa in adults
• Aortoarteritis with long segment coarctation.
• Coarctation with left pleuropulmonary fibrosis.
• Coarctations with associated cardiac lesions.

84. Options for extra-anatomic bypass
• Aortic arch – DTA
• Asc aorta – DTA
• Asc aorta – Infrarenal abdominal aorta
• Asc aorta – supraceliac abdominal aorta.

85. Ventral Aorta Repair
• Through midline incision both ascending aorta and supraceliac abdominal
aorta is exposed and graft is inserted.
• Wukasch and collegues reported first use of this repair in 1977.
Advantages of this repair
• Avoidance of redo thoracotomy
• No dissection in collateral rich area.
• Easily reproducible
• No cardiac manipulation or cardiopulmonary support needed.

86. • Graft placed
• Intra pericardialy right to rt atrium
• Large collaterals and dense
adhesions not encountered

87. RESULTS

88. Survival
Early deaths-
2-10 % in neonates and 1 % in
infants and older children
Time related survival-
risk is highest immediately
following repair,
Falls rapidly and after 1 year,
reaches a constant
1 month, 1, 10 and 25 years
survival- (in a heterogenous
group) 98%, 97 %, 91% and 81 %
respectively
Modes/causes of late death-
Persistent/ recurrent HTN
Rupture of intracranial aneurysm/
aortic aneurysms/acute aortic
dissections
Acute MI
Incremental risk factors for late
death-
Late age at operation
Associated cardiac anomalies
Persistent/ recurrent coarctation
and HTN
Aneurysm formation/ CAD

89. Late post operative upper body hypertension
Upper body pressure is often elevated during early post op period and
gradually decreases
By 5 years after repair 80-90 % have normal upper body pressure at rest, but
with exaggerated response to exercise
After 5 years post repair the prevalence of patients with normal BP declines,
by 20 yrs only 40-50 % have normal BP
Factors-
Endocrine factors
Reduced compliance and increased reactivity of upper body vessels to
vasomotor responses
Poorly compliant aorta proximal to coarctation
Morphologically persistent or recurrent coarctation

90. Persistent (residual) or recurrent coarctation
Resting peak gradient of > 20 mm Hg is considered significant
Persistent coarctation- presence of aortic gradients immediately after repair
Recurrent coarctation- development of restenosis after initial successful repair
Prevalance of persistent or recurrent coarctation is highly variable – 0 to 60%
Procedure of choice for recurrent coarctation is balloon dilation
If not successful then surgery
Indication for reintervention-
Luminal diameter <50 %
Heart failure and upper body hypertension (>140 mm Hg in infants and children)

91. Technical factors are mostly
responsible for persistant
coarctation
Insufficient resection of long
narrow segment
Inadequate mobilisation –
excessive tension on suture line
Suture line thrombosis
Incorrect fashioning of subclavian
flap
Failure to resect an obstructing
intimal ridge
Use of small tube graft/ kinking
Hypoplastic distal arch associated
Recurrent coarctation has been
attributed to
Lack of growth of circumferential
suture line in end to end
anastomosis
Remodeling of remnant ductal
tissue
Trauma from vascular clamps

92. Paraplegia after repair
Brewer (1972) found an incidence of 0.42 % in review of 12,532 patients
Factors
Prolonged ischaemia time
Division of 3-4 intercostal arteries
Reoperations
Poorly developed collaterals – large PDA, coarctation prox to LSCA, RSCA distal
to CoA
Paraplegia is noticed immediately after surgery, but may be upto 2 weeks after
surgery

93. Late aneurysm formation
• A true or false aneurysm occurs commonly (10-30 %) late after patch
aortoplasty
• True aneurysm develops in aortic wall opposite to prosthetic patch
• False aneurysms occur at suture line and incidence increases with every
follow up
Wall shows medial degeneration – excess pressure transmission from stiff
patch
Excessive resection of intimal ridge
Treatment-
For small aneurysms- endovascular stenting
Large aneurysms- excision and interposition graft

94. Thank you