1. Pulmonary Atresia and Intact Ventricular Septum
Seoul National University Hospital
Department of Thoracic & Cardiovascular Surgery

2. Pulmonary Atresia and Intact Ventricular Septum
1. Definition
Congenital malformation in which pulmonary valve is atretic,
coexisting with variable degrees of RV & TV hypoplasia
2. Historical Note
Hunter : 1st case report in 1783
Peacock : Collected 7 patients report in 1839
Grant : Coronary sinusoid & fistula recognized in 1926
Davignon : Suggest systemic-pulmonary artery shunt in 1961
Bowman : Shunt and RV outflow operation in 1971

3. PA+IVS Pathophysiology
Atretic pulmonary valve combined with varying degrees of tricuspid valve and right ventricular hypoplasia, leading to inadequate pulmonary blood flow(supported by PDA) and hypoxia.
Right ventricular-to-coronary artery fistulae are seen in 50~60% of patients, resulting in a right ventricular-dependent coronary circulation in 10~20%

4. Surgical Morphology of PA+IVS
1. Pulmonary valve : remnant fibrous component
2. Pulmonary artery : usually normal in size
3. Right ventricle
Variable, enlarged in 5%, severely reduced capacity in 60 %
Ebstein malformation & severe TR in enlarged thin RV.
Diffuse fibrosis of hypertrophied small RV & fibroelastosis
4. RV-coronary fistula
Coronary sinusoid in 50%, dependent circulation in 10%
5. Tricuspid valve : always abnormal
6. Right atrium
Intraatrial communication in all cases, & enlarged
7. Left-sided chambers
LV compliances is depressed in many cases.
LA enlarged & hypertrophy
8. Coexisting cardiac anomalies ; uncommon

5. RV-Coronary Artery Fistula

6. Clinical Features & Diagnosis
1. Symptoms & signs
Cyanosis after birth & becomes rapidly more severe
as the ductus closes, respiratory distress, metabolic acidosis,
Absence of RV impulse, no typical murmur
2. Chest radiography
Diminished (or normal) vascular marking
3. Electrocardiography
Prominent right atrial P-wave ( RA enlargement )
4. Echocardiography
5. Cardiac catheterization & cineangiography

7. Natural History of PA+IVS
1. Incidence
Uncommon malformation
1~1.5% of CHD
3% of critically ill infants with CHD
2. Survival
50% survival in 2weeks of life
15% survival in 6months of life
3. Modes of death
Severe hypoxia & metabolic acidosis
(Coincides with spontaneous closure of PDA)
Rarely survival into young adult life

8. Technique of Operation for PA+IVS
1. Concomitant placement of patch & shunt
2. Isolated procedure
Valvotomy only
Placement of transannular patch
Systemic-pulmonary artery shunt only
3. Definitive procedures
Separated two-ventricle repair
Single-ventricle repair ( Fontan )
*One & a half ventricle repair
Overhauling RV cavity

9. Operation for PA+IVS Concomitant placement of patch & shunt

10. PA + IVS – Hemi Fontan

11. PA + IVS – Hemi Fontan Alternative Method

12. Lateral Tunnel with Fenestration

13. Surgical Results of PA+IVS
1. Survival
Early death
Time-related survival
2. Modes of death
3. Incremental risk factors for death
1) Dimension of TV
2) RV dependent coronary circulation
3) Systemic-pulmonary shunt
4) Birth weight
4. Interim Intervention after the initial procedure
Transannular patch is better than valvotomy
5. Definitive procedures ; two ventricle repair

14. Surgical Indications of PA+IVS
The presence of the malformation is generally an
indication for operation because of highly lethal nature
of the condition. As soon as diagnosis is suspected,
neonate is intubated, and an infusion of PGE1 is begun.
Selection of the initial intervention is based in large part
on estimated probability( Z value, -3 ) that a separated
two-ventricle system will ultimately be possible
The initial goals of correction are to improve pulmonary
blood flow with a systemic-to- pulmonary shunt & to
promote RV development by relieving RVOTO

15. Special Situation & Controversies
1. Percutaneous valvotomy
Laser valvotomy followed by balloon dilatation
2. Formalin infiltration of ductus arteriosus
3. Right ventricle to aorta conduit
4. Tricuspid valve closure in RV-coronary fistula
5. Tricuspid valve growth
- TV and RV cavity tend to increase in size as the
patients grow with forward flow across valve.
- With growth of RV, fistulae may disappear.
- Abnormality of RV compliance usually remains.