This document discusses the medical management and long-term complications of tetralogy of Fallot (TOF). It covers cyanotic spell management, surgical correction including palliative procedures, and long-term sequelae following TOF repair such as residual lesions, pulmonary insufficiency, ventricular dysfunction, arrhythmias and conduction abnormalities.

1. TOF-MANAGEMENT AND LONG
TERM COMPLICATIONS
PRESENTED BY-Dr SHASHIKANT NILANGE
CHAIR PERSON-Dr KAPIL RANGAN
Dr NATESH B H
Dr VIKRAM PATIL

2. INTRODUCTION
• Move toward early corrective surgery of TOF has
obviated the need for medical management.
• Instances of acute hypercyanotic spells medical
management will be lifesaving.
• Infants with gradual and consistent worsening of
cyanosis usually due to result of increasing RVOTO
and will benefit little from medical therapy.
• Some consider even single hypercyanotic spell is an
indication for surgery.

3. Medical treatment
• The aim of therapy is to reduce the acute
imbalance between systemic and pulmonary
blood flow and disrupt the pathophysiologic
spiral by relieving pain and anxiety (to reduce
HR and systemic oxygen consumption)
• increase systemic vascular resistance, and
increase pulmonary blood flow.

4. Cyanotic spell management
• Knee chest position: Since most hypercyanotic
spells are provoked, or worsened, by crying,
the infant should be picked up and comforted
as soon as an episode begins, ideally while
being held in a position of flexed knees and
hips that kinks or compresses the femoral
arteries and increases peripheral systemic
vascular resistance.

5. Knee chest position

6. Cyanotic spell management
• If no improvement is seen within a few minutes,
oxygen should be administered and intravenous
access obtained.
• The following measures (in order of increasing
intensity of intervention) can then be tried, any of
which may terminate the spell :
• An intravenous bolus of colloid or crystalloid
fluid will increase intravascular volume, maximize
preload, and improve cardiac output (thereby
increasing mixed venous O2 content).

7. Cyanotic spell management
• Intravenous (or intramuscular) morphine (0.1 to
0.2 mg/kg) should be given to relieve pain and
anxiety, thereby reversing endogenous
catecholamine release, reducing HR, and
lowering RR.
• Intravenous propranolol (0.015 to 0.02 mg/kg) or
the shorter-acting esmolol (0.5 mg/kg given over
1 minute, thereafter continued as an infusion).
Beta blockers lower HR and improve diastolic
ventricular filling thus increasing preload.

8. Cyanotic spell management
• Intravenous sodium bicarbonate (1 mEq/kg) may be required if
there is evidence of worsening acidosis despite the measures
above.
• In unremitting cases, intravenous systemic vasoconstrictors,
for example, phenylephrine (boluses of 0.005 to 0.001 mg/kg),
or norepinephrine (0.05 to 1.0 mg/kg/min) may be required.
• Anaesthesia, intubation, and ventilation may ultimately be
required to reduce the work of breathing and reduce oxygen
consumption and improve mixed venous oxygen content.
• Very occasionally, severe life-threatening spells may require
emergent surgical intervention or mechanical circulatory
support.

9. Cyanotic spell management
• Most spells are self-limiting and do not
require intensive medical therapy.
• Many groups consider their onset as an
indication for surgical correction.
• Interval prophylaxis with beta-blockers (oral
propranolol in a dose of 0.25 to 1 mg/kg, 2 to
3 times per day) may be helpful if surgery is
delayed

10. Surgical correction
• Palliative
• Complete repair

11. • Hypoplastic pulmonary arteries
• Significant co- morbidity
• Prematurity/ low birth weight
• Abnormal coronary artery crossing
the RVOT
• Age < 3months
• Good size PA s
• Age > 3months
Symptomatic ?
Yes
No
Palliation
Surgical
• PDA stenting ( if PDA
dependent)
• RVOT stenting ( if
predominant
infundibular PS)
• Balloon pulmonary
valvoplasty (if
predominant valvar
PS)
• Classical BTT
shunt.
• Modified BTT
shunt
• Pott’s shunt
• Waterston
shunt
Percutaneous
Total repair
PV annulus
Z score >- 4
PV annulus
Z score < - 4
Resection
of RVOT
/Infundibul
ar patch +/-
pulmonary
valvotomy
Trans-
annular
patch
Coronary
crossing
RVOT
• RVOT
reconstructi
on with
seperated
patches
• RV-PA
conduit
Complete
repair at 6-
24 months

12. Palliative procedures
Primary corrective surgery not be feasible due to e.g.
• hypoplastic pulmonary arteries
• significant co- morbidity
• prematurity
• abnormal coronary artery crossing the RVOT
Possibilities of palliation
Percutaneous
• Balloon valvuloplasty
• PDA stenting
• Stent in RVOT
Surgical
• Systemic- pulmonary shunt (e.g. BT- shunt)
• Enlargement of RVOT

13. Percutaneous palliation
• Balloon valvuloplasty
• Right ventricular outflow tract stent.
• PDA stenting

14. Balloon valvuloplasty
• Balloon pulmonary valvuloplasty is a useful alternative
to an aortopulmonary shunt and may allow later total
correction in some patients with poorly developed
pulmonary arteries or with associated complex
intracardiac defects. (JACC Vol. 18, No.1 July 1991:159-65)
Adv:
• Adequate for valvar PS
Dis adv:
• Not adequate for infundibular or supravalvar PS as
most TOF pt have combined PS.
• Risk of subsequent cyanotic spell.

15. RVOT stent
Adv:
• Useful option in case of - Low weight, Prematurity, Young
age (<3 months), Unfavourable pulmonary arterial anatomy
• Abnormal coronary distribution
• Critical preoperative condition
• Significant noncardiac co-morbid conditions.
Dis adv:
• Distortion of native pulmonary valve
• Stent migration,
• Ventricular arrhythmias,
• Collapse or fracture of the stent
• Recurrent stenosis.
• Neoendothelial or muscular proliferation

17. PDA stenting
• Stent implantation in a patent ductus arteriosus may
be an alternative nonsurgical approach to providing
pulmonary blood flow .
Dis adv:
• Diastolic runoff from the aorta with lower diastolic
blood pressure and end-organ perfusion.
• Not an option in cases of absent ductus arteriosus ,
tortous ductus arteriosus and presence of confluent
pulmonary artery stenosis.
• A higher likelihood of neointimal proliferation.
• The need for arterial vascular access during placement.

18. Surgical palliation
Indications:
• Neonates with TOF and pulmonary atresia
• Infants with hypoplastic pulmonary annulus,
which requires a transannular patch for
complete repair
• Children with hypoplastic PAs
• Unfavorable coronary artery anatomy
• Infants younger than 3 to 4 months old who
have medically unmanageable hypoxic spells
• Infants with low birth weight

19. Surgical palliation

20. Surgical palliation
• Classic Blalock-Thomas- Taussig shunt :anastomosis of subclavian artery
and the ipsilateral PA. A right-sided shunt is performed in patients with left aortic
arch; a left-sided shunt is performed for right aortic arch.
• Modified Blalock-Thomas-Taussig (BT) shunt : A Gore-Tex interposition
shunt is placed between the subclavian artery and the ipsilateral PA. A left-sided
shunt is preferred for patients with a left aortic arch, whereas a right-sided shunt is
preferred for patients with a right aortic arch. The surgical mortality rate is 1% or
less.
• The Waterston shunt: anastomosis of ascending aorta and the right PA.
Complications: too large shunt leading to CHF or pulmonary hypertension, or both,
and narrowing and kinking of the right PA at the site of the anastomosis.
• The Potts operation: anastomosed between the descending aorta and the left
PA. It may result in heart failure or pulmonary hypertension, as in the Waterston
operation. A separate incision (i.e., left thoracotomy) is required to close the shunt
during corrective surgery, which is performed through a midsternal incision.

21. Surgical palliation
Complications:
• Difficult to select appropriate shunt size in a small
infants.
• Diastolic runoff from the aorta with lower diastolic
blood pressure and end-organ perfusion.
• Pulmonary artery distortion.
• Phrenic and vocal cord nerve injury.
• Chylothorax.
• Shunt narrowing, or occlusion.
• Over circulation and left ventricular volume loading
and pulmonary hypertension.

22. Total repair
• Goal :
VSD closure
Relief of RVOT obstruction
• While maintaining as competent a pulmonary
valve as possible
• Modest degree of RVOT obstruction with less
regurgitation is currently preferred over
complete relief of obstruction with severe PR
Correction of other major associated defects
(ASD/PDA)

23. Early repair v/s late repair
Age at
complete repair
Neonatal
Increased ICU stay
Hypoxic brain injury
Infancy
Lowest morbidity is in
patients with 3-11
months age
Late (>2yr)
RV hypertrophy and
fibrosis
Longer duration of
hypoxia
Van Arsdell G et al: Circulation 2000
Age at
complete repair
Neonatal
Increased ICU stay
Hypoxic brain injury
Infancy
Lowest morbidity is in
patients with 3-11
months age
Late (>2yr)
RV hypertrophy and
fibrosis
Longer duration of
hypoxia

24. Types of complete repair
VSD closure
+
Resection of
infundibulum
+/- pulmonary
valvotomy
Infundibular
patch
+/- valvotomy
Tran annular
patch
RV to PA conduit

25. Trans annular patch v/s valve sparing
repair
Trans annular patch
• No residual stenosis
• Late pulmonary
insufficiency, Ventricular
dysfunction.
• PV annulus Z- score < -4
Valve sparing repair
• Risk of residual stenosis but
improves through time.
• Minimizes pulmonary
regurgitation (PR)
• PV annulus Z- score > -4

27. Transatrial v/s trans ventricular
approach

28. Trans atrial v/s trans ventricular
approach
• Traditionally, TOF was repaired through an RV incision
providing an excellent exposure for closure of the VSD
and relief of RVOT obstruction.
• RV function is impaired after ventriculotomy due to a
reduction in the regional wall motion around the
incision which may increase the incidence of
ventricular arrythmias and sudden death.
• The right atrial approach (combined with a
transpulmonary approach) to repair of TOF avoids the
impairment of RV function caused by ventriculotomy.

32. Long-term complications or sequelae
following TOF repair
• Residual RVOTO
• Residual VSD
• Pulmonary insufficiency (PI)-This is commonly
associated with placement of a transannular
patch. The degree of PI is exacerbated by
coexisting proximal or distal pulmonary artery
stenosis.

33. Long-term complications or sequelae following TOF repair
• RV dilation -This is most commonly associated
with severe and/or prolonged PI.
• RV dysfunction -Many factors may contribute
to this. Chronic volume loading due to severe
PI, RV dilatation, ischemia and fibrosis,
increased wall stress, RV aneurysm or akinesis,
or poor myocardial protection during repair
are possible contributing factors.

35. Long-term complications or sequelae following TOF repair
• LV dysfunction -This may be due to inadequate
myocardial protection during initial repair,
residual VSDs, long-standing systemic to
pulmonary shunts, or impairment by altered RV
mechanics as ventricular-ventricular interactions.
• Aortic regurgitation - This may be due to damage
to the aortic valve during VSD closure or
dilatation of the aortic root

36. Long-term complications or sequelae following TOF repair
• Ventricular tachycardia -Sustained ventricular
tachycardia is thought to be the underlying cause
of sudden death in this population. Risk factors
for sudden death include marked RV dilation, QRS
duration of > 180msecs, progressive prolongation
of the QRS complex(>5ms per year over a 10 yr
period), and LV dysfunction .
• Atrial tachyarrhythmias -Atrial flutter and atrial
fibrillation are most commonly seen and may
occur in as many as 1/3 of adult patients.

37. Long-term complications or sequelae following TOF repair
• Conduction abnormalities
• Right bundle branch block (RBBB) is nearly
universal in repaired TOF patients.
• 15% of patients will have RBBB and a left anterior
hemiblock but this does not predict complete
heart block.
• Complete heart block rarely occurs in the late
postoperative period but can occur in the
immediate perioperative period and is secondary
to damage to the AV node during VSD repair.
• A small percentage will require permanent pacing
postoperatively

38. Long-term complications or sequelae following TOF repair
• Although echocardiography and magnetic
resonance imaging (MRI) are complimentary
modalities in assessing PI and RV form and
function, MRI has become the preferred
method for longitudinally following patients
with repaired TOF