1. Double Switch Operation for Failing Systemic Ventricle
Yong Jin Kim, M.D.
Department of Thoracic & Cardiovascular Surgery
Seoul National University Hospital
2001.7

2. Introduction
Conventional managements of AV discordant heart ( Atrial switch operation in TGA) place morphologic right ventricle & tricuspid valve in the systemic position
The morphologic RV shows significant incidence of progressive ventricular dysfunction & TV regurgitation
Double switch operation(conversion switch operation) as an alternative in selected patients
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3. Natural History of CC-TGA
1. Incidence
0.5% of CHD, slightly male predominating
2. Heart Block
1) Complete heart block
5 - 10% at birth % in adolescence, 30% in adult
2) 1st or 2nd degree A-V block ; % at birth
3) 40% retain normal PR interval & QRS through their lives
3. Ventricular function
Not truly normal, but sufficiently good in most
Tendency to deteriorate after 2nd –3rd decade of life.
4. Effect of coexisting cardiac anomalies
VSD, PS, left A-V valve incompetence
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4. Characteristics of Both Ventricles
1. Ventricle Shape
Cylindric vs. crescent-shaped cavity
2. Contraction pattern
Concentric vs. bellow-like contraction
3. Pumping action
Pressure pump vs. low pressure-volume pump
Its large internal surface area-to-volume ratio
4. Coronary artery supply
Two system vs. one system
5. Embryology
Primitive ventricle vs. bulbus cordis
6. Papillary muscles
Two papillary vs. small and numerous(septophylic)
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5. Corrected TGA
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6. Corrected TGA
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7. CC-TGA morphologic left ventricle
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8. CC-TGA morphologic right ventricle
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9. Operative Indications of CC-TGA
The presence of corrected TGA is not an indication
for a reparative operation
1. Ventricular septal defect
· same as normal heart
2. VSD & Important PS
· same as TOF
3. Left-sided tricuspid incompetence
· same as mitral incompetence
4. Complete heart block
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10. Classic Operation of CC-TGA
1. Repair of ventricular septal defect
2. Repair of coexisting VSD & PS
· Extracardiac conduit
· Without extracardiac conduit
3. Correction of incompetent tricuspid valve
· Repair ( annuloplasty )
· Replacement
4. Fontan-type repair
Straddling, A-V canal defect & hypoplastic
ventricle
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11. “ Classic” Repair of Congenitally Corrected TGA and VSD (Termignon JL, et al. Ann Thorac Surg 1996)
From 1974 to 1994, 52 CCTGA patients
CCTGA and VSD + LVOTO(Group I) : 37
CCTGA and Isolated VSD(Group II) : 15
Tricuspid plasty or replacement
1 (3%) in group I, 8 (53%) in group II
Overall operative mortality : 15% (8/52)
Incidence of postop. AV block 27% (14/52)
Redo tricuspid plasty or replacement in 12
The operative mortality and the incidences of TVR & AV block are high
Secondary heart failure is frequent
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12. Tricuspid Regurgitation & RV dysfunction in CC-TGA
High risk of TR development by the 3rd decade of life(20 to 50%)
Most important risk factor for death after classic repairs
Poorly supported tricuspid annulus – RV dysfunction may induce important TR
Measurable deterioration of RV within 3 years of classic repairs
RV dysfunction appears to be almost always secondary to long-standing TR(Prieto, et al. Circulation.1998)
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13. Morphologic RV after Atrial Switch Operation
Natural difference of ventricle
One coronary ventricle
One conduction radiation
Without well-balanced papillary muscle
Tricuspid Regurgitation
Stretching of the originally noncircular tricuspid ring
Organic damage of tricuspid valve as a results of VSD patching
Failure of systolic leaflet coaptation
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14. Surgical Management for Failing Systemic RV
Double Switch Operation
Correction of AV discordance and VA discordance simultaneously
Senning(Mustard) + ASO
Senning(Mustard) + Rastelli
Senning(Mustard) + REV
Conversion Switch Operation
previous atrial switch take-down and ASO
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15. Surgical Considerations
Left Ventricular Outflow Tract
Right Ventricular Size
Atrioventricular Valves
Ventricular Function
Heart Block and Arrhythmias
Coronary Arteries
Atrial Switch Operation
Reoperations
Potential Technical Problems for ASO
Timing of Operation
Role of Left Ventricular Retraining
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16. Proposed Patient Selection Criteria
Unobstructed LV to PA and RV to aortic connections
Balanced ventricular and AV valve sizes
Septatable heart, without major AV valve straddling
Translocatable coronary arteries
Current(or recent) LV/RV pressure ratio greater than 0.7
Competent mitral valve with good LV function
(Karl TR, et al. ATS 1997)
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17. Preparation for Systemic Left Ventricle
Naturally occurring preparation
Pulmonary Artery Banding
age
banding(LV retraining) duration
Preoperative Selection Criteria
Age
Wall thickness
LV/RV pressure ratio
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18. Senning Procedure
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19. Mustard Procedure
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20. Operative Technique - Senning plus ASO
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21. Operative Technique – Conversion Switch Operation
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22. Senning Plus Arterial Switch Operation for Congenitally Corrected Transposition (TR Karl, et al. Ann Thorac Surg 1997)
From 1989 to 1996
14 Senning + ASO : age ranged 0.5 to 120mo
1 hospital Mortality
Actuarial survival beyond 10 months : 81%
Median grade of TR : preop ¾ to ¼ postop
Normal RV function : 11/12 current survivors
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23. Results of the Double Switch Operation in the Current Era (Imamura, et al. Ann Thorac Surg 2000)
From 1993 to 1998
22 Double Switch Operations in 27 CCTGA patients : age ranged 3mo to 55yrs
Senning & ASO : 10
Senning & Rastelli : 12
No early and late Mortality
Epicardial pacemaker insertion in 2
Significantly improved degree of TR with normal LV and RV function
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24. Systemic Right Ventricular Failure After Atrial Switch Operation: Midterm Results of Conversion Into an Arterial Switch (Daebritz SH, et al. Ann Thorac Surg 2001)
4 patients age 38 to 59 months of RV failure underwent arterial switch operation
previous operation : Senning and VSD closure
1 late death(43.5 mo follow up) due to LV dysfunction
Survivors : improved FS, NYHA class I – II
Conversion switch operation is an alternative to cardiac transplantation in children
Long-term morbidity is caused by rhythm disturbance
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25. Experience in SNUCH From 1990 to 2001 20 double switch operations
1 conversion switch operation
Age : ranged 1month to 16 years (mean 46months)
M : F = 11 : 9
Dx : CCTGA(with VSD, PS or PA) – 18
DORV, PS, VSD – 2
dTGA, VSD – 1
(Conversion switch after Senning procedure)
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26. Experience in SNUCH Preop. procedures PAB : 2 LMBTS : 3 RMBTS : 1
VSD closure : 2
BAS : 1
PPM insertion : 1
RV-PA conduit interposition : 1
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27. Experience in SNUCH Operative technique
Senning + ASO : 6
Senning + Rastelli : 9
Mustard + ASO : 1
Mustard + Rastelli : 1
Senning + REV : 2
Mustard + REV : 1
* 1 conversion arterial switch operation after Senning and PAB
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28. Experience in SNUCH Operative mortality : 7 (33%)
Number of death according to period
: 5 (23.8%) / 10 initial learning period
LCOS 4 / sepsis 1
* 3 immediate myocardial failure
: 2 (9.5%) / 11
LCOS 1 / sepsis 1
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29. Experience in SNUCH Complications Reoperation in 3
Postop. AV block : permanent pacemaker insertion in 3
Chylothorax in 4
Reoperation in 3
Senning pathway reaugmentation
Redo Rastelli op d/t residual PS
Conduit change with Homograft
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30. Experience in SNUCH Overall outcomes
Postoperative TR : all survivors in minimal or grade I
Preserved postoperative ventricular function in survivors : NYHA functional class I or II
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31. Operative Technique
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32. Conclusion
Double switch operation in selected patients in optimal anatomic & physiologic subsets has encouraging early outcomes with its theoretical advantage.
TR and subsequent RV dysfunction represent the major risk factor for CCTGA patients.
Conversion switch operation can be performed with acceptable risk and may provide long-term survival advantage if adequate patient preparation is warranted.
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