Surgical management of TOF

1. SURGICAL MANAGEMENT OF
TETRALOGY OF FALLOT
Dr.ANUJ MEHTA

2. • Blalock and Taussig described the first systemic artery-to-pulmonary artery
shunt in 1945
• Lillehei and Varco (1954) first repair by an open-heart procedure.
• Surgical mortality decreased from 50% in the late 1950’s to < 2% in the modern
surgical era
• Residual anatomic and haemodynamic abnormalities are nearly universal.
• Repaired TOF, with considerable cardiac and non-cardiac disease burden, is
Evolution of surgical repair of TOF

3. Shunt Anastomosis Year
BT SCA- PA shunt
Classical-1944
Modified- 1982
Pott’s Descending aorta-LPA 1946
Davidson’s Direct anastomosis MPA-> aorta 1956
Waterston
Ascending aorta- RPA posterior to
SVC
1962
Waterston-
Cooley
Ascending aorta- RPA anterior to
SVC
1966
Gazzaniga Aorta to PA using PTFE tube 1976
Melbourne
Direct end to side anastomosis of PA
to ascending aorta

5. BT SHUNT
De Leval
,1982 @
Great
Ormond
Street

6. ● INDICATIONS :
• CCHD not fit for ICR, with severe symptoms.
• TOF with pulmonary artery atresia
• TOF with-
• unresolved spell
• Age <6 months with low weight/ failure to thrive/ repeated spells.
• Hypoplastic pulmonary arteries.
• Underdeveloped LV (<60% of normal)
• Mitral valve annulus < -2 Z
• Institutional criteria for performing ICR.

7. CLASSICAL MODIFIED
Historical current
Prosthetic
material
- +
Dissection ++++ ++
Subclavian artery sacrificed preserved
Upper limb
ischaemia
+ _
Anastomosis opposite to arch any side
Take down challenging easy
Shunt blockage + ++
Growth potential ++ _

8. ● MBTS
● Preferably on same side
● longer length of SCA available
● less chance of damage to RLN.
● Approach-
● right/ left thoracotomy
● median sternotomy- (+) significant desaturation (CPB)
( - ) adhesions during redo
• PTFE graft size
• 2-4 kg - 3.5 mm
• 4-5 kg - 4 mm
• >5 kg - 5 mm BUT, ultimately - SCA size

9. ● Causes of bradycardia
● RPA absent/ ostial stenosis/hypoplastic/nonconfluent
● Vagus nerve included in clamp.
● Signs of good shunt
● Graft sweating
● thrill over PA
● Improved saturation by 10-15%
● Fall in diastolic B.P.
● Heparin is NOT reversed, unless excessive bleeding

10. ● COMPLICATIONS
• Early
• shunt blockade
• oversize-heart failure
• undersize- inadequate
perfusion
• bleeding
• seroma
• kinking of shunt
• limb ischaemia- CBTS
• Late
• distortion of PA
• Chylothorax
• Disparity in arm- CBTS
• Horner’s syndrome

11. Management of blocked BT shunt
• ??????? when to suspect ???????
• Significant desaturation , shunt murmur (-)
• EtCO2 - falls arterial CO2 - rises
• More dangerous- infundibular obstruction has worsened collaterals are
already closed.
• Resuscitate
• urgent echo
• GOAL- to increase SVR Decrease PVR
• hand ventilate sedate and paralyse
• Human albumin start dopamine or noradrenaline

12. Management of Pulmonary overcirculation
● high saturation
● CXR- congested lungs
● low mixed venous saturation
● acidosis
● low diastolic B.P.
● GOAL decrease SVR, Increase PVR
● fluid restriction
● reduce O2 allow PCO2 to rise gently
● increase PEEP
● Reduce vasopressors, consider vasodilators
● Shunt clipping to be considered

13. Indices
● Mc Goon ratio- angiographic
● [d RPA +d LPA (prebranching)/ d DTA (just above diaphragm-
in systole]
● Normal- 2-2.5
● Nakata index echo
● CSA [LPA+ RPA(mm2) / BSA ]
● Normal 330+/- 30
● Kirklin index
● Z value

14. ICR
● Indications
● McGoon ratio > 1.5
● Nataka index >200
● Z value > -3
● LV volume > 60% of the normal(>30 ml/m2)
● Absent peripheral pulmonary artery stenosis
● No major coronaries crossing RVOT

15. ● Unfavourable PA anatomy in infant
● Multiple VSD in infant
● Coronary artery crossing RVOT in infant
● Hypolplastic LV LVEDV < 30 ml/m2
● LVED(D) <60% of normal
● PV annulus <-7 Z
● Institutional criteria
Contraindications for ICR TOF

16. Technical challenges
● Transatrial / trans ventricular
● TAP/valve sparing
● TAP- width of patch
● Preserving or sacrificing RCA branches
● RVOT management when Anomalous coronary is present
● Preserving PV cusps during TAP
● Preserving tricuspid valve function during VSD closure.
● Dividing and resecting obstructing septal and parietal bands

17. Approaches
● RA-PA
● RVOT- longitudinal/ transverse
● PA only
● RA only

19. • The original repairs -
• closure of the VSD through a large right ventriculotomy and correction of
the right ventricular outflow tract (RVOT) obstruction with a transannular
patch (TAP)

20. Repair of tetralogy of Fallot with separate infundibular and pulmonary arterial patches

21. ● Good RVOT coring
● PA-
● complete VSD, Tricuspid valve, apex of RV
● RA-
● PV, aortic across the VSD

23. Pathophysiology of RV complications post TOF
repair

24. Advantages and disadvantages of various
techniques

25. • RV performance
• Acute change from pressure from pressure loaded to volume loaded RV
• Right ventriculotomy
• PR
• The time of greatest instantaneous hazard to survival -
• when the volume overload is first evident after CPB
• the early hours thereafter,
• only the functional myocardial reserve of the RV is available for
adaptation.

26. To eliminate volume overload,
1) valved conduits,
disadvantages are lack of durability, lack of growth, and valvular
dysfunction.
2)in the short term, some groups have advocated monocusp valve
insertion as an effective alternative

27. Monocuspid valve
• Length- distance from apex of RVOT incision to the pulmonary annulus
• Width- free edge equal to circumference of native annulus
• fixed to apex of RVOT incision and the edges sutured to muscle in
continuous fashion, free edge finally opposed to the annulus
• Hegar dilator is passed to check adequacy of the opening
• A liberal transannular patch is placed above it.

28. ment of monocuspid valve. B. showing suturing technique C. Showing mechanism of action of monocuspid valve during diastolic an

29. Post repair RVOTO assessment
• Residual RVOTO
• After repair and seperation from CPB preferably with cannula in
position post repair P RV/LV.
• Valve sparing - P RV/LV > 0.7 —> Transannular patch

32. Adequacy of Repair
TEE/ Pressure measurement : Standard of care

34. Hypolplastic LPA - Double patch technique
To be divided

35. Anomalous LAD crossing RVOT
● Key factor- exact course and morphology of infundibulum
● if Coronary high near the annulus + low infundibular
obstruction + well developed infundibular chamber -
procedure can be done without endangering coronary
● BUT , if severe diffuse hypoplasia- RV to PA conduit.
● Bicuspid PV- to be inspected and incision can be made
through anterior most commisure- reduces PR

36. ICR for MAPCAS
● embolise MAPCAS on day of surgery and Sx
● Dissect and ligate MAPCA

37. RECENT ADVANCES
● Significant risk factors:
● Prematurity
● low birth weight
● poor PA anatomy
● non cardiac comorbidities.
● Bridging options ???

39. THANK YOU