Tetralogy of Fallot

1. Dr. Aurangzeb

2. Etienne-Louis Arthur Fallot
Cover of Arthur Fallot’s 1888
publication inscribed to Messieur le
Docteur S. Michel, “Homage from
the author,” and signed “A Fallot.”

3. Neils Stensen , 1671
“ when I opened right ventricle… the probe that
was passed forward and upward along the
interventricular septum entered directly into aorta
just as readily as the probe passed from left
ventricle into aorta. The same aortic canal … was
common to both ventricle. Thus, the aorta receives
blood from both ventricles at same time… as it
partly straddles the right ventricle”

4. Sir Thomas Watson, 1872
“ the septum between the ventricles was
imperfect in its upper part; and the aorta
belonged as much to one ventricle as to the
other. The pulmonary artery would not admit
a goose-quill; the walls of the right ventricle
were as thick as of those of the left”

5. Fallot made an anatomic diagnosis at the
bedside, proved right at postmortem, and
then coined the term “Tetralogy”
“ this malformation consists of a true anatomo-
pathologic type
1. Stenosis of pulmonary artery
2. Interventricular communication
3. Deviation of origin of the aorta to the right,
4. Hypertrophy, almost always concentric of the
right ventricle”

6. • In 1894, Pierre Marie, first used
“Tetalogie de Fallot”
• 1924 Maude Abbott, first used the term
“Tetralogy of Fallot” and “ Fallot’s Tetralogy”

7. • The four salient anatomic components of
Fallot’s tetralogy result from a specific
morphogenetic abnormality that is:
“malalignment of the infundibular septum”

8. Malalignment Of The Infundibular Septum
• the infundibular septum deviates anteriorly and cephalad
• creates a nonrestrictive ventricular septal defect at the site
of malalignment
• encroaches on the right ventricular outflow tract and
causes infundibular stenosis and a biventricular (overriding)
aorta
• The malaligned ventricular septal defect accounts for
systemic systolic pressure in the right ventricle and
concentric right ventricular hypertrophy

9. • Anterior deviation of the conal septum (CS) into the right ventricular
outflow tract (RVOT) results in a large malalignment ventricular septal
defect (asterisk) with aortic override (Ao) as well as significant RVOT
obstruction and RV hypertrophy. RA, right atrium; RV, right ventricle

10. Pentalogy of Fallot
• A variant of TOF
1. ventricular septal defect (VSD)
2. right ventricular outlfow tract narrowing or complete
obstruction
3. right ventricular hypertrophy
4. overriding aorta
5. atrial septal defect (ASD) or patent ductus arteriosus (PDA)
Other variants
• TOF with Pulmonary Atresia
• TOF with Absent pulmonary valve

11. Tetralogy of Fallot
• Gender distribution is approximately equal.
• First cyanotic lesion to described
• First palliative and definitive operation performed
• Model for natural history studies of treated congenital
heart disease
• Lethal if untreated, now has good surgical results
remains a challenge

12. • Incidence would be 577 cases of TOF per
million live births

13. Genetics

14. Environmental factors
• Maternal diabetes
• Maternal phenylketonuria
• Exposure to retinoic acid
• Exposure to trimethadione ( anticonvulsant )

15. Recurrence risk
• If one sibling is affected – 2.5% - 3%
• If more than one sibling affected then 8 %
• If father is affected then- 1.4 %
• If mother is affected then – 0.9% - 2.6 %

16. • The physiologic consequences of Fallot’s
tetralogy depend essentially on two variables
1. The degree of obstruction to right ventricular
outflow
&
2. Systemic vascular resistance.

17. RVOTO: SVR
Pulmonary
resistance
Lesser
resistance
Shunt is left to
right
Resistances
are equal
Shunt is
balanced
Resistance
exceeds systemic
resistance
Shunt is right to
left
SVR
Lesser resistance
Shunt is right to
left
Increase
resistance
Shunt is left to
right

18. • When right ventricular blood preferentially flows
into the aorta, pulmonary blood flow falls
reciprocally, so the left side of the heart is
underfilled.
• Right ventricular systolic pressure cannot exceed
systemic because the ventricular septal defect is
nonrestrictive
• The underfilled left ventricle tends to be reduced
in size with reduced stroke volume.

19. Coronary arteries abnormalities
• Anomalous origin and distribution of coronary arteries are common
• No functional importance but are of considerable surgical importance
• The most common anomalies are origin of a conus artery or the left anterior
descending artery from the right coronary artery or from the right sinus of
Valsalva
• Occasionally single coronary artery
• Major arteries cross RVOT – surgery with transannular incision more difficult
• Rarely, the left anterior descending coronary artery originates from the
pulmonary artery, or the left coronary artery is intramural.

21. Physical examination
• Physically underdeveloped ( failure to thrive )
• Cyanosis
( absent to severe, symmetrically distributed )
• John hunter “ considerable exertion produced a
seeming tendency to suffocation and change from
scarlet tinge to purple”
• Cyanosis manifests after crying feeding or exercise
( increases venous return to the obstructed right
ventricle and augments R-L shunt )

22. Physical examination
• Tachypenia
• Clubbing of fingers and toes
• Squatting (Tiring easily during play or exercise)
• Hypoxic spells

23. Auscultation
• First heart sound is normal, single second heart
sound, and ejection systolic murmur audible at
left lower sternal border that radiates to the back
• Murmur originates at the site of stenosis rather
than across the ventricular septal defect.
• The duration of the systolic murmur is
determined by the balance between resistance at
the site of stenosis and resistance in the systemic
vascular bed

24. Pulmonary resistance
Lesser
resistance
Shunt is left to right
Holosytolic murmur
across VSD
Resistances
are equal
Shunt is balanced
VSD is silent, murmur
audible of PS
Resistance exceeds
systemic resistance
Shunt is right to left
Murmur become
decrescendo,
dimishing and ending
before aortic
component of S2
The pulmonary component of the second heart sound is soft or absent because right ventricular blood
preferentially enters the aorta, so pulmonary blood flow and artery pressure are abnormally low

25. Consequences and Complications
• Polycythemia
• CNS complications
• Bleeding disorders
• Hypoxic spells
• Scoliosis
• Hyperureemia and Gout
• Subacute bacterial endocarditis

26. Polycythemia
Low arterial
oxygen content
Increase
erythropoietin
from kidney
Stimulates bone
marrow and
produces RBCs
Increase oxygen
carrying capacity
• Hematocrit >65% - Inc
viscosity ( disadvantage )
• Relative iron deficiency
• Iron deficient are more
symptomatic and improves
after iron therapy

27. CNS complications
• Brain abscess and vascular stroke
• R-L shunting may bypass the normal effective
phagocytic filtering actions of pulmonary capillary bed
• Could also be due to high viscosity which leads to
tissue hypoxia and micro infarction of brain
complicated by bacterial colonization
• Symptoms- fever, headache and focal neurologic
deficits
• Cerebral venous thrombosis may occur in younger than
2 years

28. Bleeding disorder
• Most frequent are thrombocytopenia and defective
platelet aggregation
• Prolong PT and APTT ,and lower levels of fibrinogen,
factor V and factor VIII
• Symptoms- bruising, petechaie, epistaxis, gingival
bleeding
• RBC withdrawal from polycythemia patients and
replacement with plasma tend to correct the
hemorrhagic tendency and lower blood viscosity

29. Hypoxic spells

30. Hypoxic spells
• Also called paroxysmal hyperpnea, syncopal
attacks, hypoxic or hypercyanotic spells
• Begins with a progressive increase in the rate
and depth of breathing and results in
paroxysmal hyperpnoea, deepening cyanosis,
limpness, syncope, and occasionally
convulsions, cerebrovascular accidents, and
death

31. Hypoxic spells
• Initiated by the stress (feeding, crying, or a
bowel movement, after awakening from a
long deep sleep)
• Sometimes occur without an apparent
precipitating cause

32. Increase
HR
Increase
Cardiac Output
Increase
Venous Return
RVOT is already
obstructed
Increase
R-L shunting
Decrease
systemic PO2 &
PH
Increase PCO2
sleep-sensitive
respiratory
center and
carotid body
overreact
provoking
hyperpnoea
* Infundibular contraction reinforces this pattern but does not initiate it.
Proposed by Gunther et. al

33. Other theories
• Woods et al - Postulated that hypoxemic spells are
caused by spasm of the infundibulum of the right
ventricle which precipitates a cycle of progressively
increasing right to left shunting and metabolic acidosis.
• Surge in Catecholamine release leads to increased
myocardial contractility and infundibular stenosis.
• Both these theories don’t explain the cause of cyanotic spells
in patients with TOF with Pulmonary atresia

34. Other theories
• Kothari et al – argued against the commonly
held views mentioned above and suggested
the role of stimulation of mechanoreceptors in
the right ventricle to be the cause of spells.

35. Management of hypoxic spells
• Calm the child
(give the child to family member's, but not always possible.)
• Knee-Chest Position
(compresses abdominal aorta/femoral artery to increase SVR )
• Oxygen
(helps to decrease PVR)
• Morphine
(calms, decreased Resp rate, and also decreases PVR)
(dose: 0.1-0.2 mg/kg, I/M , S/C. I/V)
• Crstalloids or colloid fluid boluses
(10-20 ml/ kg by rapid push)
add sodium bicarbonate 1-2mEq/kg

36. Management of hypoxic spells
• Intravenous Phenylephrine
(increase SVR)
• Intravenous beta-blockers
(relaxes infundibular muscle spasm causing RVOTO)
(Slows HR (↓ R→ L Shunting)
(Slight ↑ in SVR)
• Ketamine
(Increase SVR and sedate )
• Correct anemia
(transfuse whole blood – keep Hb upto 16 gm/dl)
• Early sugery

37. • Squatting for relief of dyspnea is a time-
honored hallmark of TOF
• Taussig described the preference for certain
postures other than squatting, namely, the
knee-chest position, lying down, or sitting
with legs

39. Prevention of hypoxic spells
• Propranolol (1-4 mg/kg/day) in divided doses
(helps defer surgery till a time when child is older)
Complications of hypoxic spells
• May lead to brain damage
• May lead to cerebral venous sinus thrombsis/
small occult thrombosis
• Repeated spells may also lead to growth
retardation

40. Hyperuricemia and Gout
• Occurs in older patients in uncorrected TOF or
inadequately repaired TOF
Scoliosis
• Children with chronic cyanosis often have
scoliosis

41. Differential diagnosis
• TGA with VSD and PS
• DORV with VSD and PS
• Univentricle with PS
• TA with VSD and PS

42. Electrocardiogram
• P wave amplitude is normal
(right atrial contraction is not increased)
• P wave duration is short tends to short
(underfilled and relatively small left atrium )
• PR interval is normal ( normal conduction )

43. Electrocardiogram
• QRS axis same as that of newborn ( axis and
direction of ventricular depoarization does not
change because functional demand of right
ventricle does not change )
• Right ventricular hypertrophy is characterized
by a tall monophasic R wave confined to V1, rS
pattern in V2

44. R-L shunt

45. Balanced shunt

46. L-R shunt

47. R-L shunt
Balanced shunt
L-R shunt

48. X-ray
• Normal size heart
• Reduced pulmonary vascularity
• Boot shaped or coeur en sabot appearance
( combination of small underfilled left
ventricle that lied above ventricular septum,
inferiorly concentrically hypertrophied RV
• Look for thymic shadow( absent in DiGeorge
syndrome )

50. Echocardiogram
I. VENOUS CONNECTIONS
II. ATRIAL SEPTUM
III. ATRIOVENTRICULAR
CONNECTIONS
IV. VENTRICULAR SEPTAL
DEFECT
V. VENTRICULOARTERIAL
CONNECTIONS
*Segmental approach should be used
VI. THE RIGHT VENTRICULAR
OUTFLOW TRACT
VII. PULMONARY VALVE
VIII.GREAT ARTERIES
IX. CORONARY ARTERIES

51. VENOUS CONNECTIONS
• Mostly situs solitus
• 10% of patients have L-SVC draining in to RA
• Parasternal long-axis view typically
demonstrates a dilated coronary sinus, a
finding that should prompt the suspect a L-
SVC

52. ATRIAL SEPTUM
• 1/3rd of patients with unrepaired TOF have an ASD.
• Defects in the atrial septum are best imaged from
the subcostal scan planes because the atrial septum
is perpendicular to this imaging plane
RVOTO
Not
significant
L-R shunting
Significant
obstruction
Bidirectional/
R-L shunting

53. ATRIOVENTRICULAR CONNECTIONS
• Concordant atrioventricular connections
• The tricuspid and mitral valves are usually
structurally normal
• 2% of patients have a complete
atrioventricular septal defect may be present

54. VENTRICULAR SEPTAL DEFECT
• Typical VSD is an anterior malalignment type of outlet VSD
(74%)
• Perimembranous VSD without aortic-tricuspid fibrous
continuity due to a muscular rim (18%)
• Doubly committed subarterial defect (5%)
• Atrioventricular septal defect in continuity with the
subaortic defect (2%)
• Inlet VSD with straddling tricuspid valve (1%)
All of these types of VSD in TOF are unrestrictive

55. Parasternal long-axis view showing the large ventricular
septal defect (asterisk) with approximately 50% aortic
override (Ao) of the VSD

56. Ventriculoarterial Connections
• Ventriculoarterial connections concordant.
• The aorta does characteristically override the
ventricular septum.
• >50% aortic override (predominant RV origin
of the aorta) in patients with double outlet
right ventricle

57. The Right Ventricular Outflow Tract
• Assessment of the RVOT is critically important
in patients with TOF
• Muscular obstruction often begins at the
crista supraventricularis and extends to the
pulmonary valve annulus

58. Pulmonary Valve
• The pulmonary annulus is often hypoplastic
• Pulmonary valve may be acommissural,
unicommissural, bicommissural, or tricommissural with
thickening/dysplasia
• The z-score of the pulmonary valve annulus should be
recorded.
• Pulmonary annular z-score of less than – 2 is likely to
indicate the need for a transannular surgical approach

59. Pulmonary Valve
• The presence and severity of pulmonary valve
regurgitation should also be noted

60. Great Arteries
• Supravalvar stenosis may be in the main
pulmonary artery
• This narrowing is important because patch
angioplasty of the main pulmonary artery may be
needed to relieve this obstruction during surgical
repair
• Anatomy of the branch pulmonary arteries is
important to define.

61. Great Arteries
• Branch pulmonary artery z-scores should be
calculated and focal stenoses should be
identified
• Severe branch pulmonary artery hypoplasia
may make complete repair difficult.
• Important to document additional sources of
pulmonary arterial blood supply

63. CORONARY ARTERIES
• Up to 10% of patients with TOF
• The unifying feature of important coronary artery
anomalies is the presence of a coronary artery
crossing the RVOT
• A prominent conal branch can be differentiated
from an anterior descending artery in that a conal
branch terminates in the infundibulum, while an
anterior descending coronary artery will occupy
the interventricular groove.

65. CT angiogram
• Non invasive modality
• Excellent for PA anatomy, MAPCA’s
• May obviate the need for cath in many cases

66. Cardiac MRI
• Important in the serial follow-up of TOF patients to monitor
the potentially deleterious effects of chronic PR on RV
volume and function and to identify patients whose RV
compensatory mechanisms are failing even before
symptoms develop
• MRI measurements are routinely applied in clinical decision
making regarding interventions such as pulmonary valve
replacement
• Contraindicated in patients with pacemakers or
defibrillators and may be limited by arrhythmia, patient
claustrophobia, and the need to breath-hold effectively.

67. Indication for Cath
• Poor echo windows
• Branch PA not visualized
• Hypoplastic PA’s
• Multiple VSD’s
• Suspicion of collaterals
• Hemodynamic measurements
• Uncertainty regarding anatomy or surgical
approach
• Cardiologists/surgeon unhappy with echo study

68. Cardiac catheterization
• Determine the presence or absence of a
central pulmonary arterial confluence
• Detailed analysis of the systemic arterial
collateral blood supply to the pulmonary
arterial tree, which includes identification of
the degree of intercommunication among the
various vascular pathways, must be done.

69. Cardiac catheterization
• If a PA confluence is present, the systemic-to-pulmonary
collateral vessels may communicate directly with it or
connect to it indirectly by a connection to a peripheral PA
• Angiographic evaluation should be tailored to the type of
systemic-to-pulmonary collateral artery anatomy
• Selective injections in the systemic-to-pulmonary collateral
arteries usually is to delineate the extent of the pulmonary
arterial tree supplied by each collateral vessel and to
determine which type of PA connection is present

70. Natural history
• Survival rate, if untreated.
• 66% 1st year
• 50% 3rd year
• 25% 1st decade

71. Management
• Counselling
• Caloric supplementation
• Medical management
• Surgical managemet

72. Propranolol
• Decreases right-to-left shunt
• Presumably due to a change in right ventricular
contractility
• Cyanosis at rest, reduced O2 during activity,
hypoxic spells or angiographic evidence of
functional stenosis of RVOT
• Dose: 1-4 mg/kg divided in 8-6 hourly

73. Iron therapy
• Consumption of iron is more in polycythemia
• Relative iron deficiency
• Microcytic hypochromic RBC

74. Surgical Management of TOF

75. Evolution of surgery
• 1940’s – era of palliation
• 1955-1980’s – era of staged repair
(transventricular)
• 1980- present – era of primary repair
( transatrial )
• 1990’s neonatal repair

76. SURGICAL
MANAGEMENT
Palliative
Classic BT shunt Modified BT
shunt
Pott’s shunt
Waterston
shunt
Total correction
Percutaneous
Palliation

77. Indication of palliative surgery
• Age <3 months
• Small branch pulmonary arteries ( Z-score less
than 2)
• Pulmonary atresia <2 years
• Anomalous origin of coronary artery
• Significant non-cardiac issues i.e. renal
dysfunction, neurological issues etc.

78. McGoon ratio
• The McGoon ratio includes the combined
diameters of both PAs ( right and left prior to
branching ) and the diameter of the aorta just
above diaphragm

79. McGoon ratio
• Normal value is more than 2
• If <1 , means pulmonary artery is diminutive, poor
prognosis
• If 1- 1.5 , palliative surgery ( if complete correction is
done, Qp:Qs is increased, pulmonary artery can not
accommodate the blood, leads to pulmonary edema,
RV dilation and then RV dysfunction )
• If 1.6-1.7, grey zone for complete correction
• If >1.8 , complete correction

80. Nakata index
• Calculated from the diameter of PAs measured
immediately proximal to the origin of upper
lobe branches of the respective branch PAs .
The sum of the cross sectional area (CSA) of
right and left PAs is divided by the body
surface area of the patient
• Nakata index = CSA of RPA (mm2) + CSA of LPA
(mm2)/ BSA (m2)]

81. Nakata index
• Normal value 330 +/- 30 mm2/BSA
• If < 100 mm2/BSA, can not survive
• If >200 mm2/BSA, complete correction be
done
• If 100-200 mm2/ BSA, palliative surgery

82. Total Neo-pulmonary artery index
(TNPAI)
• Nakata index is of limited use for evaluation of
the adequacy of PAs in single stage repair strategy
where unifocalization of several APCs is followed
by total repair at the same operation
• A composite index of native PAs and the APCs
that will be unifocalized was needed, in order to
determine whether the VSD could be closed at
surgery.

83. Total Neo-pulmonary artery index
(TNPAI)
• Nakata PA index is measured
• APCs index is calculated by addition of CSA of all
significant APCs divided by the BSA. CSA of each APC is
calculated from diameter of the respective vessels
measured on preoperative angiogram
• The sum of total APC index and PA index is called TNPAI
• >250 mm2/m2 – suitable for single stage repair
including VSD closure ( low RV/LV pressure ratio
postoperatively)

84. Classic BT shunt
(Blalock-Taussig shunt)
• The first surgical systemic artery to pulmonary
artery shunt
• Named after Alfred Blalock (surgeon to first
perform this procedure) and Helen
Taussig (pediatric cardiologist, who designed
the shunt)
• In this procedure native subclavian artery is
connected pulmonary artery
• Prefer in neonates and infants
• Not preferred for older children or adults

85. Advantages of BT shunt
• Subclavian artery is flow regulator ( low
incidence of excess pulmonary blood flow)
• Easy to close at time of complete correction
• Less distortion of pulmonary arteries
• Potential for adaptive growth of anatomosis

86. Disadvantages of BT shunt
• Extensive mediastinal dissection
Phrenic nerve damage
Recurrent laryngeal nerve damage
Horner syndrome
Chylothorax/hemothorax
• Subclavian artery sacrificed
Steal phenomenon: Possible abnormal growth and
strength of ipsilateral arm to the shunt
Acute ischemia

87. Modified BT shunt
• A 3.5- or 4-mm Gore-Tex shunt is
anastomosed end to side to the
innominate artery and to the ipsilateral
branch pulmonary artery
• A flow regulated through shunt
• Done on opposite to aortic arch
• Can be done by lateral thoracotomy or
median sternotomy

88. Advantages of MBT shunt
• Mediastinal dissection limitied
• Subclavian artery is preserved
• Less tendency to deform hypoplastic PAs
• Adequate shunt length
• Size of the shunt depends on
age/weight of patient
duration of palliation required
size of inflow systemic artery
presence of additional pulomanary blood flow
Pulmonary vascular resistance

89. Disadvantages/Complication
• Prosthetic material; lack growth potential,
obstruction
• Pulmonary overflow; not flow regulator
• Distortion of PA

90. Pott’s Shunt
• Shunt formed between the descending
aorta and the left pulmonary artery
• First performed in 1946
• No longer performed

91. Waterston shunt
• Shunt formed between the ascending
aorta and the right pulmonary artery.
• First performed in 1962
• No longer performed

92. Complication of waterston/Pott’s
shunt
• Increased Pulmonary blood flow leading to
Pulmonary hypertension and Heart failure
• Difficulty in correcting the shunt during
corrective surgery
• Distorsion of Rt/Lt PA; Rt/Lt PA aneurysm

93. Patency of shunt
• To maintain patency of the shunt, use heparin
in initial post-op days followed by aspirin until
corrective surgery is done
• Mortality rate is <1%

94. Management of suspected
thrombosed Shunt
• Sustained desaturation/ desaturation and
disappearance of shunt murmur
• Resuscitate the patient/manage spell
• Urgent Echo to see the patency of the shunt
• Increase SVR: give boluses
• Decrease PVR: sedate the child
• Start heparin with bolus followed by maintenance
• Intervention: percutaneous ( thrombolysis/stent)
surgical shunt revision

95. Management of pulmonary overflow
• Hyperemic lung fields on chest x-ray
signs of right heart failure
• Increase SaO2
• In milder for form: restrict fluids and give diuretics
• In severe form: (Inc PVR/Dec SVR)
inotropes may be needed
shunt may need clipped/banded/re-done

96. Bridge to complete correction
Percutaneous
palliation
PDA stenting
Balloon
valvuloplasty
RVOT
stenting

97. Percutaneous Palliation
• In cyanotic infants percutaneous placement of a stent or
balloon valvuloplasty across the stenosed RVOT which
improves pulmonary flow and allows growth of the native
pulmonary arteries
• Stenting of RVOT can destroy the native pulmonary valve
• Reserved for the limited number of, usually very young,
premature or small, infants in whom a transannular patch
will almost certainly be necessary in any case, or in whom
the pulmonary arteries are diminutive and would increase
surgical mortality or morbidity

98. • Balloon valvuloplasty is preferable over the
shunt as
it is less traumatic
avoids thoracotomy
reduces the likelyhood of the distorsion of PA

99. Complete Repair
• The first intracardiac repair of TOF was by C.
Walton Lillehei and his team at the University
of Minnesota during their remarkable series of
45 cross-circulation cases that started on
March 26, 1954

100. Complete Repair
• Surgical timing remains a debated topic
First controversy, should symptomatic neonates
and infants below a certain age or size be
palliated before complete repair or should all TOF
patients have a primary repair regardless of size
or age?
Second controversy relates to acyanotic neonates
and young infants and whether they should be
repaired at diagnosis

101. Goal of Complete surgical repair
• Complete and secure closure of VSD
• Complete relief of RVOT obstruction
while preserving
ventricular function
AV conduction
tricuspid valve
pulmonary competence, if possible

102. Assessment prior to surgery
• LSVCS/ ASD/ Tricuspid regurgitation
• RV function/ Nature of RVOT obstruction
• Size of pulmonary annulus/ RPA-LPA at hilum
• Location and number of VSD’s
• LV functions, degree of aortic overide
• Coronary anatomy
• PDA, MAPCA’s, shunt, collaterals

103. Contraindications
• Presence of anomalous coronary arteries
• Very low birth weight
• Small pulmonary arteries
• Multiple VSD’s
• Multiple co-existing intracardiac malformation

104. Types of complete repair
• Transventricular repair
• Transatrial-Transpulmonary repair
Surgery during early infancy, when the pulmonary annulus is markedly stenotic, frequently
requires the insertion of a long and wide transannular patch

105. Complete Repair
• Many anesthetic agents cause systemic
vasodilation, which can greatly exacerbate any
right-to-left shunting, possibly leading to
profound hypoxia and potential hemodynamic
collapse
• Maintaining adequate volume status with a
hemoglobin level of at least 10mg/dL

106. Complete Repair
• Use of a high inspired oxygen level
• Avoidance of inhalational agents as they have
a significant vasodilatory affect
• Induction of anesthesia with intravenous
agents including narcotics and ketamine can
minimize unwanted vasodilation

107. Complete Repair
• Transesophageal echocardiography should be
performed in every patient and should be
interpreted preoperatively and
postoperatively by a paediatric cardiologist.

108. Goals for intra/postoperative TEE
evaluation
• Residual VSD, including size, location, and gradient
• Residual RV outflow tract obstruction, including location
and gradient PV regurgitation
• Main and proximal branch PAs
• Residual patent foramen ovale or ASD, including flow
direction
• TV regurgitation, including gradient (for estimation of RV
systolic pressure)
• Aortic valve regurgitation
• RV size and function
• LV size and function
• Residual PDA, including size, flow direction, and gradient

109. Steps of complete repair
• A median sternotomy is performed
• Size of the thymus should be noted before subtotal
excision
• If a prior shunt was performed it is carefully isolated
following systemic heparinization and aortic and
bicaval cannulation
• Cardiopulmonary bypass is initiated with moderate
hypothermia (28°C)

110. Steps of complete repair
• Shunt is excised from the pulmonary artery and a
patch augmentation using fresh autologous
pericardium is performed
• The aorta is cross-clamped and cold-blood
cardioplegia is delivered in an antegrade fashion
through a cardioplegia cannula inserted into the
aortic root.
• The cavae are snared, and a generous medial
right atriotomy is made

111. Steps of complete repair
• RVOT is examined and resected
• The hypertrophic muscle bundles projecting from the
septomarginal and septoparietal bands can be divided or
partially excised
• A longitudinal pulmonary arteriotomy is made and carried
into the two anterior sinuses in the case of a trileaflet valve
• A pulmonary valvotomy is performed using a number 11
blade, dividing the typically partially fused commissures
back to the level of the arterial wall, allowing for maximal
opening through the preserved annulus

112. Steps of complete repair
• The pulmonary arteriotomy is then closed with a
pantaloon pericardial patch, which maximizes the
size of the pulmonary root completely relieving
supravalvar obstruction
• Inspection of the orifice of the branch pulmonary
arteries, especially the left pulmonary artery,
should be done as this is frequently stenotic in
TOF patients and can be corrected with an
extension of the pericardial patch onto the
branch PA or a separate patch if necessary

113. Steps of complete repair
• The VSD is closed by placing a series of interrupted horizontal
mattress sutures using 5-0 Ethibond with Teflon pledgets around
the circumference of the defect
• The right atrial incision is closed using two layers of running Prolene
suture
• The heart is carefully de-aired and the cross-clamp is removed
• After separation from cardiopulmonary bypass, direct
measurements of the right ventricle and left ventricle pressures are
made using a 21-gauge spinal needle attached to a pressure
transducing line

114. Steps of complete repair
• If the right ventricle/left ventricle (RV/LV)
pressure ratio is greater than 0.7 , the
transesophageal echocardiography is carefully
assessed for level of residual obstruction
• Owing to the relatively high incidence of
junctional ectopic tachycardia (JET) following TOF
repair, regardless of the rhythm after separation
from bypass, temporary atrial and ventricular
pacing wires are placed

117. FATE AND COMPLICATIONS

118. Long-Term Survival in Patients With Repair of
Tetralogy of Fallot: 36-Year Follow-Up of 490
Survivors of the First Year After Surgical Repair
• The mean duration of follow-up was 25.3 years
• 85% have 36-year-survival
• Patients with normal HCT levels showed improved
long-term survival
• Mortality was linear in the first 25 years after the
operation and equaled 0.24% per year. Thereafter, it
increased significantly to 0.94%/year
Journal of the American College of Cardiology Volume 30, Issue 5, 1 November 1997, Pages 1374-1383

119. • While it dramatically alters a patient's life
expectancy, surgical repair of TOF is not a cure
and the hearts of patients with repaired TOF
remain anatomically, physiologically, and
electrically abnormal.

120. Predictors Of Poor Long Term
Outcomes
• Late repair
• Ventricular dysfunction
• Long QRS duration
• RV ESV 45ml/m2

121. Complications
• Early re-operation and interventions
• Arrhythmias and sudden death
• Aortopathy
• Phrenic nerve injury
• Chylothorax/hemothorax
• Delayed sternal closure
• Endocarditis

122. Early Reoperation and Reinterventions
• The most common indication for early re-operation after
repair of TOF is residual RVOT obstruction
• Residual stenosis can be at infundibular, valvular or branch
pulmonary arteries.
• The amount of residual obstruction at the conclusion of initial
repair, as assessed by the RV/LV pressure ratio, is directly
related to the incidence of reoperation
• A study showed that RV/LV pressure ratio greater than 0.85
was associated with a 2.5 times increased risk of death and a
7.3 times increased risk of reoperation

123. Early Reoperation and Reinterventions
• When present in the branch PAs, these are
often amenable to catheter-based balloon
plasty and/ or stent placement
• Residual VSD, residual ASD, RVOT aneurysm,
severe tricuspid regurgitation, heart block,
phrenic nerve injury, and chylothorax

124. Arrhythmias and sudden death
• Arrhythmias and conduction disturbances are significant
both for their prevalence and serious consequences
• Most common cause of mortality late after TOF repair is
sudden death, presumably attributable to ventricular
arrhythmias
• Most common disturbance is right bundle branch block,
which results from RVOT and/or sutures from the VSD
repair.
• Complete heart block is a relatively uncommon
complication

125. Arrhythmias and sudden death
• Junctional ectopic tachycardia can result in
major hemodynamic instability in the
immediate postoperative period.
• Treatment includes correction of electrolytes,
mild hypothermia (33–35°C), reduction or
elimination of catecholaminergic infusions,
sedation, and treatment with amiodarone

126. Arrhythmias and sudden death
• Late arrhythmias after TOF repair include both
atrial and ventricular tachycardia (VT)
• SVT seen in TOF patients is atrial re-entry
tachycardia. Re-entrant circuits also develop in
scar areas around atrial incisions
• The risk of sudden death includes QRS duration
greater than 180msec, older age at repair, severe
pulmonary regurgitation, history of sustained VT,
and left ventricle systolic dysfunction

127. Aortopathy
• Dilation of the aorta is seen in 12% to 24% of adult
patients with TOF
• In patients with aortic dilation, aortic root size seems
to progressively increase over a period of years
• Aortic dissection following TOF appears to be a rare
complication
• The importance of aortopathy in circulatory function
and mortality remains incompletely understood.

128. Late complication
• Incomplete relief of RVOTO, residual VSDs , TR, and
RVOT aneurysm result in RV dysfunction
• Pulmonary insufficiency is most important physiologic
disturbance, and electric problems from RBBB or
patchy ventricular fibrosis
• These can be well-tolerated in the childhood and early
adulthood but adults are at high risk developing
exercise impairment and arrhythmias, biventricular
dysfunction, and premature cardiac death

129. Pulmonary Regurgitation and the Fate of Right
Ventricle
• Common complication in TOF repair, is more
severe in patients with transannular patch
• Volume load on the RV
• RV responds to chronic volume loading with an
adaptive remodelling, which while initially
compensatory, ultimately proves detrimental
• Compensatory RV dilation and hypertrophy
maintain forward flow and wall stress

130. Pulmonary Regurgitation and the Fate of Right
Ventricle
• RV compensatory adaptations become inadequate and
TOF patients with severe PR begin to develop RV
contractile dysfunction
• For a period of time, RV dysfunction remains reversible
with intervention to abolish PR
• If untreated, the damage progresses and permanent
myocardial injury ensues manifested as an inability of
the RV to regain normal dimensions and as overt RV
failure with increased risk of ventricular arrhythmia
and sudden cardiac death

132. Indications for pulmonary valve replacement
EUROPEAN SOCIETY OF
CARIOLOGY
AMERICAN HEART ASSOCIATION CANADIAN
CARDIOVASCULAR
SOCIETY
Class I Symptomatic patients with
severe PR
and/or
PS (RV systolic pressure >60 mm
Hg,
TR velocity >3.5 m/s)
Severe PR
and
Symptoms or decreased exercise
tolerance
Class IIa Severe PR or PS (or both)
and either
Severe PR Free PR
RV size Moderate to severe RV
enlargement
EDVi 170 mL/m 2
Progression of
RV size
Progressive RV dilation Progressive RV
dilation
RV function Progressive RV dysfunction Moderate to severe RV
dysfunction
Moderate to severe
RV
dysfunction
TR Progressive TR, at least
moderate
Moderate to severe TR Important TR

133. EUROPEAN SOCIETY OF
CARIOLOGY
AMERICAN HEART ASSOCIATION CANADIAN
CARDIOVASCULAR
SOCIETY
PS RV systolic pressure greater than
80 mm Hg, TR velocity 4.3 m/s
Peak instantaneous
echocardiography gradient
greater than 50 mm Hg
or
RV/LV pressure ratio greater than
0.7
or
Residual RVOT obstruction
(valvular or subvalvular)
with progressive and/or severe
dilatation of the RV
with dysfunction
RV pressure at least
2/3
systemic pressure
Exercise
capacity
Decrease in objective exercise
capacity
Symptoms such as
deteriorating exercise
performance
Arrhythmia Sustained atrial or ventricular
arrhythmia
Symptomatic or sustained atrial
and/or ventricular
arrhythmias
Atrial or ventricular
arrhythmia
Indications for pulmonary valve replacement

134. Pulmonary valve replacement
• PVR is one of the commonest procedures performed in
adults with CHD with a risk of operative mortality
generally quoted at around 1%
• Given the long-term adverse influences of chronic PR,
insertion of a competent pulmonary valve is clearly an
attractive option
• PVR can even be achieved without recourse to open
heart surgery using percutaneous techniques

135. Pulmonary valve replacement
• The technical aspects of PVR include homograft
replacement, valved conduit replacement, and
bioprosthetic valve insertion in the orthotopic location with
the creation of RVOT hood using Gore-Tex or heterograft
pericardium
• An alternative method for PVR involves the percutaneous
insertion of a bovine jugular valve sewn to an expandable
stent
• After PVR patients require regular (every 1 to 2 years)
echocardiograms to monitor the function of their new
bioprosthetic valve or RV-to-PA conduit

136. Neurological Outcomes
• Children with repaired TOF have
demonstrated full-scale IQ have scores within
the normal limits for age.
• When repaired TOF children were stratified by
presence of a genetic lesion or syndrome,
those without any identified defects had
scores within the normal limits for age

137. Contraception and Pregnancy after
Tetralogy of Fallot Repair
• It should be introduced early to female adolescents with
TOF and discussed regularly
• Issues regarding genetics, recurrence risk, and fetal
screening should be discussed
• Caution with combined hormonal preparations is required
in women with significant ventricular dysfunction or atrial
arrhythmias because of the associated thromboembolic
risks of estrogen
• Pregnancy is well tolerated in women with repaired TOF

138. 1-stage vs 2 stage repair
• If PA anatomy and coronary anatomy are
suitable then 1 stage repair is preferrable
• If PAs are hypoplastic or coronary artery is
crossing RVOT then 2 stage repair is preferable
( palliation followed by complete repair )

140. Egypt

142. Paediatric Protocol for Malaysian
Hospitals: 2nd Edition, 2008