1. One & A Half Ventricle Repair
Thank you very much, Mr. chairman, and good morning , ladies and gentlemen.
I’d like , first of all , to thank the organizing committee of this meeting for inviting me here today.
And it is also a great honor to me to present my surgical experience on this complex group of patients.
My topic today is a one and a half ventricle repair.
Yong Jin Kim, M.D.
Department of Thoracic & Cardiovascular Surgery, Seoul National University Hospital, Seoul, Korea

2. One & A Half Ventricle Repair
Anne M. Billingsley et al.
Definitive repair in patients with pulmonary atresia and intact
ventricular septum. J Thorac Cardiovasc Surg 1989;97:746-54
The one and a half ventricle repair instead of a Fontan or biventricular repair would be logical, if it improves patient survival and functional status.
As described by Billingsley and his colleagues in 1989 , in patients with pulmonary atresia with intact ventricular septum, by diverting the superior caval flow directly to the lungs, the pulmonary ventricular volume load is reduced by approximately one third.
A poorly functioning pulmonary ventricle or one that is of marginal size may then be able to adequately cope with the reduced volume load in their report.

3. ONE AND A HALF VENTRICLE REPAIR
Early complications of biventricular repair
Late complications of Fontan repair
BIVENTRICLE
REPAIR
SINGLE
VENTRICLE
REPAAIR
Most children with congenital cardiac disease are amenable to either single ventricle palliation or biventricular repair.
There are a few patients who have a good systemic ventricle, but a pulmonary ventricle that may not be capable of supporting the pulmonary circulation because of ventricular size or function.
Long-term outcomes of the Fontan procedure have been less than ideal.
Late problems of ventricular hypertrophy, dilation, and eventual failure are time-dependent and appear to be inevitable.
It follows that avoidance of the Fontan physiology is preferred.
At the same time, biventricular repair in patients with borderline pulmonary ventricle can result in poorer early and late survival.
ONE AND A HALF VENTRICLE REPAIR
Insufficient long-term data

4. Approach for Inadequate Ventricle
Systemic-pulmonary artery shunt or
bidirectional Glenn shunts
2. Biventricular repair with atrial septal fenestration
3. Fontan- type procedures
Therapeutic goal in the management of lesions that include right ventricular hypoplasia or dysfunction is the establishment of a pulmonary / systemic flow ratio of one without overloading the systemic ventricle.
For such anomalies, 3 classic approaches had been followed : palliative procedures , such as systemic-pulmonary artery or Glenn shunts, biventricular repair with fenestration of the atrial septum, and Fonyan-type procedures.
Systemic-pulmonary artery or bidirectional Glenn shunt , which has proved a useful intermediate step, is probably not an adequate for definitive palliation in most cases.
Atrial septal fenestration during biventricular repair in the setting of inadequate pulmonary ventricle may be effective ; however, volume loading of the heart continue and the appropriate fenestration size may not be predictable, leaving the possibility of right heart failure or systemic desaturation, and risk of paradoxical embolism.
And also the Fontan operation remains a suboptimal form of definitive palliation for many patients with complex congenital heart disease.

5. Small Pulmonary Ventricle
Tricuspid Z-value
Pulmonary ventricular volume
Operation
>-2
<-2
<-5
<-10?
>80%
<80%
<50%
<30%
Biventricular repair
One and a half repair
One and a half, atrial fenestration,
possible delayed fenestration closure
Fontan procedure
Anatomic selection criteria for one and a half ventricle repair are largely based on cohort reports available in the literature.
Minimun right ventricular size necessary to accommodate the entire systemic venous return is less well characterized.
Patients with pulmonary atresia and intact ventricular septum have been shown to have good outcomes with a biventricular repair , provided, there was a tripartite right ventricle and tricuspid z-score of greater than –3.
Poor outcomes occurred when a biventricular repair was performed for tricuspid z-score less than –3.
But the absolute sizes of the right ventricle and tricuspid valve z-scores may not be the only factors for operative success.
Right ventricular compliance, tricuspid regurgitation, right ventricular outflow tract status, relative pulmonary artery hypoplasia, and the pulmonary vascular resistance are important additional considerations in preoperative candidate selection.

6. Assessment of Pulmonary Ventricle
1. Pulmonary ventricular morphology
- Ventricular size
- AV valve apparatus
- Tricuspid Z-value
2. Pulmonary ventricular function
- Functional analysis
- Ventricular wall thickness & diastolic filling
- Dilated ventricle
3. Pulmonary ventricular afterload
- High PVR
- Peripheral PS
Measurements of right ventricular volume are not simple, because of the complex nonconical shape of the right ventricle.
Estimates of ventricular size can be made using the Sympson biplane methods by angiocardiographic or echocardiographic assessment.
Functional analysis of right ventricle can be performed also by echocardiographic or angiocardiographic measurement , and graded as normal , mildly, moderately, or severely decreased.
Thickened ventricles may have good systolic function , but poor filling.
Dilated ventricles may have good filling , but poor function.
The other important determinant for right ventricular ability to handle a volume load is the pulmonary afterload.
The safe upper limit of pulmonary artery pressure and pulmonary vascular resistance for patients undergoing one and a half ventricle repair is unknown.
But patients with elevated pulmonary vascular resistance are not candidates for one and a half ventricle repair , unless there is a repairable anatomic causes.

7. One & A Half Ventricle Repair
Surgical Rationale
1. Recruiting the hypoplastic pulmonary ventricle,
presumably providing kinetic energy and
pulsatility to pulmonary blood flow
2. Reducing the volume or pressure load of the
inappropriate pulmonary ventricle
3. Simplification of complex procedures or to limit
the risk from right AV valve repair
4. Acute and chronic ventricular dysfunction
The one and a half ventricle repair recruits the hypoplastic right ventricle, presumably providing kinetic energy and pulsatility to pulmonary blood flow, while the bidirectional Glenn shunt reduces the volume load of the right ventricle.
The indications for this type of repair have expanded to cover a variety of anomalies that feature a functionally abnormal right ventricle that would not be able to cope with the entire pulmonary circulation.
There are other applications in which it may have a important role, however, such as facilitation of biventricular repair without hypoplasia or functional impairment of the pulmonary ventricle for lesions as DORV, TGA, corrected TGA , left SVC to left atrium, or conversion among patients with complex lesions who have previously undergone bidirectional Glenn shunt.

8. One & A Half Ventricle Repair
Technical Principles
Create a modified in-series circulation with no
left-right or right-left shunting
2. Make the systemic ventricle to pump a single
cardiac output
3. Induce the pulmonary circulation to receive full
cardiac output through the pulmonary ventricle
& the superior cavopulmonary connection
The surgical principles of one and a half ventricle repair are ; to create a modified in-series circulation without left to right , or right to left shunt , and to make the systemic ventricle pumping a single cardiac output, and to induce pulmonary circulation receiving full cardiac output through the pulmonary ventricle and superior cavopulmonary connection.
Possible reasons for application of one and a half ventricle repair include ; volume unloading for small or dysfunctional ventricle , reduced contractility for acute or chronic ventricular dysfunction, correction of cyanosis, facilitation of biventricular repair without hypoplasia, and the pressure considerations for certain complex anomalies .

9. Diagnostic Criteria Atrial isomerism complex Tetralogy of Fallot
AVSD with or without TOF
Congenitally corrected TGA
Double-inlet left ventricle
Double-outlet right ventricle
D-transposition of great arteries
Ebstein’s anomaly
PS, Pulmonary atresia with IVS
VSD with or without straddling AV valve
Those are diagnosis for which a one and a half ventricle repair may be useful such as ; atrial isomerism complex , tetralogy of Fallot , AVSD with or without TOF, atrioventricular & ventriculoarterial discordance, double-inlet left ventricle, double-outlet right ventricle, D-transposition of great arteries , Ebstein’s anomaly , pulmonary stenosis, pulmonary atresia with IVS , VSD with or without straddling AV valve .
For the patients with right ventricular and tricuspid valve dysfunction, especially in Ebstein’s malformation, the right ventricular myocardium is generally abnormal as well , with impaired contractility and histologic dysplasia and various degrees of tricuspid valve malformation.
With a substantial reduction in volume load, as is achieved by bidirectional cavopulmonary anastomosis, alteration in the tricuspid valvar function , allowed for more aggressive tricuspid annuloplasty , is probably attributable largely to combination of geometric changes in the ventricle and valvar apparatus .

10. One & A Half Ventricular Repair
Seoul National University Hospital Experience
Now , I’d like to talk about our intermediate term results of one and a half ventricle repair over the past 10 years.

11. Patients Profile Duration : Jun 1993 ~ Dec 2001
Number of patients : 17
Male : Female = 13 : 4
Age : 45 months (6~222 months)
Body wt. : 15.9 Kgs (6~52 Kgs)
Tricuspid Z-value : (-4.8~-2.9)
Between the June , 1993 and the end of 2001, a total of 17 patients underwent one and a half ventricle repair in Seoul National University Children’s Hospital.
The mean age at operation was 45 months ranged from 6 months to 222 months and the mean body weight was 15.9Kgs .
The mean tricuspid z-value who had the hypoplastic pulmonary ventricle was – ranging from to –2.9 .

12. Preoperative Diagnosis
PA with IVS
Ebstein’s anomaly
d-TGA with VSD
DORV with VSD
DORV with c-ECD
VSD with hypoplastic RV 6 4 3 2 1
Preoperative diagnosis included PA with IVS in 6 cases, Ebstein’s anomaly in 4, d-TGA with VSD in 3, DORV with VSD in 2, DORV with c-ECD and VSD with hypoplastic RV in one each.

13. Preoperative Echocardiogram M/13mo
Preoperative Echocardiogram M/13mo. s/p ASO, ASD closure, PAB for TGA, VSD, ASD, PDA, hypoplastic RV
This patient with preoperative diagnosis of transposition of great arteries, VSD, ASD and PDA with hypoplastic right ventricle underwent one and a half ventricle repair.
At the age of one month old, he underwent palliative arterial switch operation , PDA division , primary closure of ASD and pulmonary arterial banding.
At the age of 13 months old, closure of residual ventricular septal defect , bidirectional cavopulmonary anastomosis and debanding of pulmonary artery with angioplasty were done.
Preoperative echocardiography shows a small tricuspid valve annulus, z-value of –3.8 and small pulmonary ventricle .
Postoperative echocardiography shows the closed ventricular septal defect with still small right ventricle and patent bidirectional cavopulmonary anastomosis with good ventricular function.

14. Postoperative Echocardiogram
This patient with preoperative diagnosis of transposition of great arteries, VSD, ASD and PDA with hypoplastic right ventricle underwent one and a half ventricle repair.
At the age of one month old, he underwent palliative arterial switch operation , PDA division , primary closure of ASD and pulmonary arterial banding.
At the age of 13 months old, closure of residual ventricular septal defect , bidirectional cavopulmonary anastomosis and debanding of pulmonary artery with angioplasty were done.
Preoperative echocardiography shows a small tricuspid valve annulus, z-value of –3.8 and small pulmonary ventricle .
Postoperative echocardiography shows the closed ventricular septal defect with still small right ventricle and patent bidirectional cavopulmonary anastomosis with good ventricular function.

15. Preliminary Palliative Operation
12 patients (70.6%)
Operation Name
number
BT shunt
PA valvotomy or valvoplasty
RVOT widening
Palliative ASO and PA banding
Palliative ASO and coarctoplasty
Rastelli operation for DORV + VSD + PS
Pulsatile BCPS
AP Fontan 8 4 3 1
Twelve patients had underwent at least one prior palliative procedures.
Twenty procedures were performed on twelve patients.
The common palliative procedures were Blalock-Taussig shunt in 8 patients , PA valvotomy or valvectomy in 4, RVOT widening in 3 , palliative ASO and PA banding, palliative ASO and coarctoplasty, Rastelli operation with intracardiac baffling for DORV , pulsatile BCPS , and AP Fontan in one patient each.

16. Concomitant Procedures
Number
Previous shunt takedown
ASD closure
VSD closure
Transannular RVOT widening
PA angioplasty
RV-PA conduit interposition
TVP
C-ECD correction with baffling 8 5 4 3 2 1
Concomitant procedures at the time of one and a half ventricle repair were ; previous shunt takedown in 8 patients, ASD closure in 5 , VSD closure in 4 , transannular RVOT widening in 4 , PA angioplasty in 3 , RV-PA conduit in 2 , TVP in 2 and complete-ECD total correction with intracardiac baffling on the previous Fontan procedure in one patient.
The adjustable ASD was not constructed during the procedure in our series.
But we used both the right atrial pressure and the arterial oxygen saturation as monitors of the appropriate size of the ASD , if the postoperative right atrial pressure was more than 15mmHg without other causes.

17. Early Surgical Results
Mortality : 2 cases ( 2/17 )
Causes of death
1. Low cardiac output , acute renal failure with
previous AP Fontan procedure on POD # 3
2. Low cardiac output , acute renal failure with
PA + IVS, LCA-RV fistula on POD # 3
Early postoperative hemodynamics
CVP : 18.4 mmHg (10 – 31 mmHg)
RAP : 12.0 mmHg ( 7 – 19 mmHg)
LAP : 11.9 mmHg ( 8 – 29 mmHg)
Early death occurred in 2 patients and the causes of death were low cardiac output , acute renal failure in patient with previous AP Fontan procedure operated due to increased cyanosis, right-side heart failure , and also low cardiac output , acute renal failure in patient with PA + IVS, LCA-RV fistula with previous BT shunt .
In these two patients , aortic clamp time reached around 3 hours with prolonged cardiopulmonary bypass more than 4 hours .
Early mean postoperative central venous pressure was 18.4mmHg , right atrial pressure 12.0mmHg, and left atrial pressure 11.9 mmHg.
There were two patients whose central venous pressure was more than 20mmHg and also 2 patients whose right atrial pressure more than 15mmHg.
One patient with previous Fontan procedure whose postoperative central venous pressure of 31mmHg, right atrial pressure of 18mmHg and left atrial pressure of 29mmHg died , and another patient of PA, IVS with postoperative right atrial pressure of 19mmHg died.

18. Operative Complications
Morbidity : 9 patients (52.9%)
Prolonged effusion
Acute renal failure
Low cardiac output syndrome
Chylothorax
Arrhythmia
Diaphragmatic palsy
3 cases
2 cases
1 case
Postoperative complications included ; prolonged effusion in 3 cases , acute renal failure in 2 , low cardiac output syndrome in 2 , chylothorax in 2 , arrhythmia in 2, diaphragmatic palsy in one case.
The pathogenesis of early and late onset pleural drainage among the patients in this series probably reflects an even more complex interaction of physiological variables, such as , loss of pulsatilie blood flow , systemic and pulmonary venous pressure, plasma atrial natriuretic peptide , and the imbalance of homeostatic mechanisms during ventricular recovery and the hemodynamic evolution of pulmonary circulation .

19. Late Surgical Results Follow-up duration : 40 months (2~ 116)
Reoperation during follow-up : 1 case
Conduit change 7 years after Rastelli operation
and BCPS at 21 mo of DORV with VSD and PS
Postoperative medications
No medication in 9, diuretics or digitalis or both in 6
NYHA functional status : Class I in 15
Late complications
No evidence of cyanosis, protein-losing enteropathy,
arrhythmia, SVC syndrome
Mean follow-up duration was 40 months in this series
There was one reoperation due to conduit failure 5 years after initial Rastelli procedure with good result.
During follow-up period, most surviving patients showed good functional status without common late complications of Fontan procedure such as, cyanosis, protein-losing enteropathy, arrhythmias and SVC syndrome.
Pulmonary valve incompetence would probably help in increasing right ventricular diastolic dimension in some patients but , the presence of free pulmonary regurgitation would theoretically compromise even further the functional efficiency of an already abnormal right ventricle.
We have to wait and see in patients with right ventricular outflow tract reconstruction whether this will be deleterious or not in the long-term periods.

20. Conclusion
The one & a half ventricle repair appears to be a valid alternative to Fontan & biventricular repair
in patients with right ventricular dysfunction or hypoplasia.
Early and intermediate follow-up results compare favorably with those of the Fontan procedure ; however, more follow-up is needed to establish the long-term results of this procedure.
In conclusion, the patients with one and a half ventricle repair resulted in favorable early and late survival in this series.
Surgical mortality and morbidity has improved by technical advances and preoperative , postoperative management.
The one & a half ventricle repair appears to be a valid alternative to Fontan and biventricular repairs in patients with right ventricular dysfunction or hypoplasia.
Early and intermediate follow-up results compare favorably with those of the Fontan procedure.
Of particular interest in comparing this strategy with a modified Fontan procedure are exercise tolerance, rhythm status, and the effect on cerebral function of pulsatile and mildly elevated pressure in the superior vena cava.
However, more follow-up is needed to establish the long-term results of this procedure before the merits of this approach can be assessed with respect to other forms of intermediate palliation.
Thanks for your attention.