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 the 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. Congenitally Corrected Transposition of Great Arteries
1. Incidence
0.5% of CHD, slightly male predominating
2. Heart block
1) Complete heart block
5-10% at birth, 10-15% 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. Coexisting cardiac anomalies
VSD, PS, left A-V valve incompetence ( tricuspid )
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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
4. Coronary artery supply
Two system vs. one system
5. Embryology
Primitive ventricle vs. bulbus cordis
6. Papillary muscles
Two papillary vs. small & numerous (septophylic)
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5. Congenitally Corrected TGA
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6. CC-TGA Morphologic left ventricle
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7. CC-TGA Morphologic right ventricle
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8. Classic 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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9. 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 , hypoplastic ventricle
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10. “ Classic” Repair of Congenitally Corrected TGA and VSD (Termignon JL, et al. Ann Thorac Surg 1996)
From 1974 to 1994, 52 CC-TGA patients
CC-TGA & VSD + LVOTO (Group I) : 37
CC-TGA & 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 valve plasty or replacement in 12
The operative mortality , the incidences of TVR
& AV block are high
Secondary heart failure is frequent
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11. 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
Measurable deterioration of RV within 3 years of classic repairs
RV dysfunction appears to be almost secondary to long-standing TR ( Prieto, et al. Circulation.1998 )
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12. Major Problems after Atrial Switch Operation in TGA
Right ventricular failure
7-10% per 10 years , high with VSD closure
Tricuspid regurgitation
Rhythm disturbance
1/3 of patients lost sinus rhythm after 10 years
& atrial flutter is risk factor for late death
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13. Morphologic RV after Atrial Switch Operation
Nature of right ventricle
One coronary ventricle
One conduction radiation
Without well-balanced papillary muscle
Not suitable to systemic ventricular function
Tricuspid regurgitation
Stretching of originally noncircular tricuspid ring
Poorly supported tricuspid annulus –
RV dysfunction may induce important TR
2. Damage of TV valve as a result of VSD patching
3. Failure of systolic leaflet coaptation
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14. Surgical Management for Failing Systemic RV
Double switch operation
Correction of AV and VA discordance simultaneously
Senning(Mustard) + ASO
Senning(Mustard) + Rastelli
Senning(Mustard) + REV
Conversion switch operation
Previous atrial switch take-down & ASO
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15. Surgical Considerations
Left ventricular outflow tract
Status of atrioventricular valves
Ventricular size & its function
Heart block & arrhythmias
Patterns of coronary arteries
Status of atrial switch operation
Technical problems for ASO
LV training & timing of operation
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16. Proposed Patient Selection Criteria
Unobstructed LV-PA & RV-Ao connections
Balanced ventricular & AV valve sizes
Septatable heart, without AV valve straddling
Translocatable coronary arteries
Current 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
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. Senning plus ASO
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21. 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 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 : 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 & VSD closure
1 late death(43.5 mo) due to LV dysfunction
Survivors : improved FS, NYHA class I – II
Alternative to cardiac transplantation in children
Long-term morbidity caused by rhythm disturbance
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25. Experience in SNUCH From 1990 to 2001 ( 21 patients )
20 double switch operations
1 conversion switch operation
Age : ranged 1 month to 16 years (mean 46months)
M : F = 12 : 9
Dx : CC-TGA (with VSD, PS or PA) – 18
DORV(l–loop), PS, VSD – 2
d-TGA, VSD – 1 ( Conversion switch after Senning )
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26. Experience in SNUCH Preoperative procedures (13 )
Pulmonary artery banding : 2
LMBTS : 3
RMBTS : 1
LMBTS + RMBTS : 2
VSD closure : 2
Atral septostomy : 1
PPM insertion : 1
RV-PA conduit : 1
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27. Experience in SNUCH Operative techniques in 21 patients
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 & PAB
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28. Experience in SNUCH Overall operative mortality : 6 / 21 (28.5%)
Number of death according to period
: 5 / 10 (23.8%) in initial period
LCOS 4 , sepsis 1
* 3 early myocardial failure
: 1 / 11 ( 4.8%)
Sepsis 1
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29. Experience in SNUCH Complications Reoperation in 3
AV block : permanent pacemaker 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 in survivors - Postoperative TR
: all survivors in minimal or grade I
- Preserved ventricular function
: all in NYHA functional class I or II
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31. Operative Procedure
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32. Conclusion
TR and the subsequent RV dysfunction represent the major risk factor for CC-TGA patients.
Double switch operation in selected patients in optimal anatomic & physiologic subsets has encouraging early outcomes with its theoretical advantages.
Conversion switch operation can be performed with an acceptable risk , and may provide long-term survival if adequate patient preparation is warranted.
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