1. Pulmonary atresia with Ventricular septal defect

2. “Pulmonary atresia-ventricular septal defect is defined as a group of congenital cardiac malformations in whom there is lack of luminal continuity and absence of blood flow from either ventricle and the pulmonary artery, in a biventricular heart that has an opening or a hole in the interventricular septum. ”
Congenital Heart Surgery Nomenclature and Database Project: Pulmonary Atresia—Ventricular Septal Defect
Christo I. Tchervenkov, MD, and Nathalie Roy, MD
Ann Thorac Surg 2000;69:97-105

3. “Tetralogy of Fallot with Pulmonary atresia is a congenital cardiac malformation, characterized by the extreme underdevelopment of the right ventricular infundibulum with marked anterior and leftward displacement of the infundibular septum often fused with the anterior wall of the right ventricle resulting in complete obstruction of blood flow into the pulmonary artery and associated with a large outlet, subaortic ventricular septal defect”

4. TOF, PA is a specific type of PA-VSD where the intracardiac malformation is more accurately defined.

5. Other synonyms -Type IV truncus and Pseudotruncus.
PA-VSD has been proposed by the International nomenclature committee of Congenital Heart Surgery Nomenclature and Database Project as a unifying term.

6. Essence of tetralogy of Fallot with pulmonary atresia is cephalad malalignment of the infundibular septum
Causes anatomic obstruction of the right ventricular outflow tract and a malalignment-type of ventricular septal defect.
The aorta overrides the ventricular septal defect and is rotated in a counter-clockwise direction

7. Embryologic origin of the main, right and left pulmonary arteries, and the intrapulmonary arteries.

8. Embryologic origin of the main, right and left pulmonary arteries, and the intrapulmonary arteries.
The main pulmonary artery (MPA) -septation of the truncus and aortic sac.
Intrapericardial right (RPA) and left (LPA) pulmonary arteries -sixth aortic arches with contribution from the aortic sac.
The intraparenchymal pulmonary arteries - from the vascular plexuses of the lung buds.
Vascular plexuses are supplied by the intersegmental arteries (ISAs) in the early embryonic period.

9. Survival of patients with tetralogy of Fallot and pulmonary atresia depends on the adequacy of pulmonary blood flow
Patients with a duct-mediated pulmonary circulation -early mortality due ductal constriction and closure.
Half this group die by 6 months of age and 90% die by 1 year of age
Kirklin JW, Barratt-Boyes BG. Ventricula septal defect with pulmonary stenosis or atresia. In: Cardiac Surgery, 2nd edn. New York: Churchill Livingstone, 1993; 861–1012.

10. Adequate pulmonary blood flow - a greater longevity is seen.
Survival in to the sixth decade reported in unoperated patient with pulmonary atresia, ventricular septal defect, and multiple aortopulmonary collaterals.

11. The median age at death was 11 months, ranging from 9 days to 30 years.
66% of the patients are alive at age 6 months
50% alive by 1 year
8% alive at age 10 years.

12. Various patterns of pulmonary arterial anatomy and source of blood supply

13. Environmental Factors
Maternal diabetes
Maternal phenylketonuria (PKU)
Maternal exposure to retinoic acids and to trimethadione
Infants of diabetic women.

14. Epidemiology
Baltimore-Washington Infant Study3 (BWIS) recorded 4390 infants with cardiovascular malformations from 1981 – 1989.
Tet-PA accounted for 1.4% of all forms of congenital heart disease and 0.07 per 100 live births.
26% of the patients with PA-VSD had chromosomal abnormality, a recognizable syndrome, or other single organ defects

15. PA-VSD occurs more often
DiGeorge syndrome and associated with Chromosome 22q11 microdeletion.
VACTER
CHARGE
Alagille

16. 22q11 deletion 10% of patients with a 22q11 deletion have PA-VSD .
Right aortic arch, or aberrant subclavian artery -more frequent
Branch pulmonary arteries are smaller in patients with a 22q11.2 deletion

17. Congenital Heart Surgeons Society Classification
Type A: Native PAs present, pulmonary vascular supply through PDA and no APCs.
Type B: Native PAs and APCs present
Type C: No native PAs, pulmonary blood supply through APCs only.
Tchervenkov CI, Roy N. Congenital heart disease nomenclature and database project: Pulmonary atresia - ventricular septal defect. Ann Thoracic Surg 2000; 69:S97-S105

19. Type A pulmonary atresia with ventricular septal defect

20. Type B pulmonary atresia with ventricular septal defect

21. Type C pulmonary atresia with ventricular septal defect

22. PDA in VSD,PA
In PA-VSD, PDA typically originates from either the undersurface of the arch (67%) or from the undersurface of the innominate artery (33%). PDA is S shaped, long and arises at an acute angle from Aorta Unilateral PDA is usually associated with confluent PAs

23. PDA can be bilateral with non-confluent PAs
PDA can be bilateral with non-confluent PAs. When PDA is present, PAs are confluent in 80% of cases. PDA is absent in 1/3 of cases

24. Aortopulmonary collaterals (APCs)
The term MAPCA(s) was first used by Macartney, Deverall and Scott to differentiate them from the bronchial arteries
Aortopulmonary collaterals (APCs) are muscular arteries until they enter the lung parenchyma, the muscular layer is gradually replaced by elastic lamina that resembles true pulmonary arteries.
APCs are seen in 30 – 65% of patients with PA - VSD and are usually 2 – 6 in number.
Macartney F, Deverall P, Scott O. Haemodynamic characteristics of systemic arterial blood supply to the lungs. Br Heart J 1973;35:28–37.

25. Known sites of origin of APCs include
descending thoracic aorta
subclavian arteries
abdominal aorta
coronary arteries.

26. Three types of SCAs
Type I: Bronchial artery branches- arising from one of the normal bronchial arteries.
Type Il: Direct aortic branches- arising directly from the descending thoracic aorta.
Type III. Indirect aortic branches-branches arising from branches of the aorta other than bronchial artery.
e.g:from subclavian, internal mammary and intercostal arteries.

28. PDA is considered a less reliable source beyond the first few days of life due to its tendency to close.
APCs are also prone for stenosis over a period of weeks to months but are more reliable than PDA

29. PDA VS MAPCAS PDA MAPCA’s ORGIN Opposite to LSCA DTA COURSE STRAIGHT
TORTOUS/RETROESOPHAGEAL
BRANCHING NO
STENOSIS
PA end
AORTIC END
DESTINY
CENTRAL PA
JOIN PA at HILUM / LOBAR/SEGMENTAL
FLOW IN CENTRAL PULMONARY ARTERIES
RETROGRADE
ANTEGRADE

30. Clinical Features PA-VSD presents as a cyanotic newborn
Infant becomes increasingly hypoxemic as the ductus constricts.
If the ductus arteriosus remains patent or because systemic collateral vessels are sufficiently developed to provide adequate pulmonary blood flow- not severely hypoxemic

31. Hypoxemia and cyanosis increase as the patient “outgrows” the relatively fixed sources of pulmonary blood flow.
If growth is delayed-suspect the presence of a 22q11.2 microdeletion.
(growth failure due to heart failure caused by excessive pulmonary blood flow is uncommon)

32. Modes of presentation Cyanosis - 50% Heart failure – 25%
Murmur with mild cyanosis – 25%

33. Peripheral pulses
The peripheral pulses and blood pressure usually are normal in the neonatal period(even with a PDA)
Beyond the first 4 to 6 weeks of age - if pulmonary blood flow is through a PDA or collaterals ,the pulses are bounding, and only minimal cyanosis is present.

34. There is a normal first heart sound and a single loud second heart sound.
A systolic murmur may be audible along the lower left sternal border but usually is not more than grade 3/6 in intensity.
The right ventricular outflow tract is atretic-no separate loud systolic ejection murmur at the upper left sternal border -this is in contrast to the finding in TOF with antegrade pulmonary blood flow.

35. If a PDA is present, a continuous murmur usually is heard after the first 4 to 6 weeks of life.
If systemic-to-pulmonary collateral vessels are present, continuous murmurs can be heard-multiple and prominent over the back
(originate from the descending aorta)

36. Electrocardiographic Features
Right ventricular hypertrophy
Right-axis deviation
Increased pulmonary blood flow -combined ventricular hypertrophy and left atrial enlargement may occur.

37. Radiographic Features
Characteristic appearance likened to the shape of a boot (coeur en sabot).
levorotation of the heart, a prominent upturned cardiac apex, secondary to right ventricular hypertrophy.
concavity in the region of the main pulmonary artery produced by underdevelopment of the subpulmonary infundibulum.
The frequency of a right-sided aortic arch is greater in patients with PA-VSD (26% to 50% of these patients) than in those with TOF (20% to 25%).

40. Pulmonary vascular markings have a typical reticular pattern when there are multiple collaterals supplying the lungs.
Extent of pulmonary vascular markings will depend on the extent of pulmonary blood flow.

41. Echocardiographic Features
Parasternal long-axis show a large aortic valve that overrides a malaligned VSD . The infundibular portion of the ventricular septum is anteriorly malpositioned.
Patient with TOF has a patent, although hypoplastic, right ventricular outflow tract anterior to the infundibular septum. This outflow tract is in continuity with the main pulmonary artery.
The infundibular septum is fused with the free wall in patients with PA-VSD, and there is no separate outflow from the right ventricle .

44. Truncus arteriosus - resembles PA-VSD
(in truncus arteriosus, the pulmonary arteries arise directly from the posterolateral aspect of the truncal root prior to the arch.)

45. Suprasternal notch and high parasternal windows - provide important information about the size and status of the proximal pulmonary arteries.
The position of the malalignment VSD, membranous or infundibular, can be determined.
ASDs and additional muscular VSDs can be detected.

46. Short-axis parasternal and subcostal views-detecting coronary artery abnormalities .
Color flow imaging and continuous wave Doppler techniques -assessment of surgically created right ventricular to pulmonary artery conduits

47. Cardiac Catheterization and Angiography
Delineate the size and distribution of the true pulmonary arteries and to ascertain the extent of collateral blood supply to the lungs

48. Because of the large VSD, RV pressure is equal to the left ventricle pressure.
Right ventricular outflow tract is atretic -the catheter will not enter the pulmonary arteries from the right ventricle (manipulated from the right ventricle through the VSD into the aorta.)
Widened pulse pressure may be present if there is a large runoff into the lungs through a PDA or a previously constructed shunt.

49. Ventricular and aortic root angiography should be done
Ventriculography should be performed with an injection into the left ventricular cavity while the cameras are positioned to record a 70-degree left anterior oblique view with 20 degrees of cranial angulation. This projection displays the middle portion and most of the upper interventricular septum tangentially.

50. Coronary artery anatomy can be defined by an aortic root angiocardiogram and a 70-degree left anterior oblique view (with 20 degrees of cranial angulation). An improved angiographic projection (frontal x-ray tube is caudally angled) -"laid-back" position of the image intensifier and cine camera results in superior visualization of the coronary arteries and their relation to the aorta and the pulmonary artery.

51. Surgical importance - origin of the left anterior descending coronary artery from the right coronary artery, which occurs in approximately 5% of patients

52. Angiographic delineation of the anatomy of pulmonary blood supply -
Venous approach by crossing the VSD
Retrograde arterial approach
The image should provide a large field of view, ideally visualizing both lung fields

53. determine which type of pulmonary artery connection is present
Selective injections in the systemic-to-pulmonary collateral arteries -
to delineate the extent of the pulmonary arterial tree supplied by each collateral vessel
determine which type of pulmonary artery connection is present
Evanescent negative washout pattern -stream of unopacified blood from a connecting pulmonary artery flowing into an area of opacified pulmonary arterial tree(may be the only indication of an existing communication)

54. Long-axis oblique view of left ventriculogram

55. Aortogram demonstrates large pulmonary confluence

56. Selective injection into a collateral artery arising from middle portion of descending thoracic aorta

57. Pulmonary vein wedge angiogram demonstrating a hypoplastic pulmonary artery confluence

58. CT / MR angiography
Alternative modality to define RVOT, MPA, branch PAs and APCs
Needs lesser contrast.

59. Evaluation of adequacy of pulmonary arteries
Complexity of pulmonary blood supply determines the extent of surgical exploration necessary to perform unifocalization
Eligibility for complete repair is dependent as RV-PA conduit needs to be placed to the vessel which is connected to maximum possible pulmonary vascular bed.
Closing the VSD at the time of placement of RV – PA conduit needs to be determined.

60. McGoon's ratio
McGoon's ratio is calculated by dividing the sum of the diameters of RPA (at the level of crossing the lateral margin
of vertebral column on angiogram) and LPA (just proximal to its upper lobe branch), divided by the diameter of aorta at the level above the diaphragm
[D RPA + D LPA] / D TAO
An average value of 2.1 is normal
Ratio above acceptable postoperative RV systolic pressure in Tetralogy of Fallot.
Ratio below inadequate for complete repair of PA – VSD

61. Nakata index
Nakata PA index is calculated from the diameter of PAs measured immediately proximal to the origin of upper lobe branches of the respective branch PAs.
The sum of the cross sectional area (CSA) of right and left PAs is divided by the body surface area of the patient
Nakata index = CSA of RPA (mm2)+ CSA of LPA (mm2)/ BSA (m2)
A Nakata index of >150 mm2/m2 is acceptable for complete
repair without prior palliative shunt.

62. Nakata index is widely used in preoperative assessment of adequacy of pulmonary vascular bed
Not useful in patients with multifocal pulmonary blood supply, who are evaluated for single-stage repair of PA - VSD.

63. Total Neo-pulmonary artery index (TNPAI)
APCs index was calculated by addition of CSA of all significant APCs divided by the BSA.
CSA of each APC is calculated from diameter of the respective vessels measured on preoperative cineangiogram

64. The sum of total APC index and PA index is called TNPAI.
A TNPAI index >200 mm2/m2 correlated well with low postoperative RV/LV pressure ratio and identified patients who were candidates for VSD closure at the time of single-stage surgicalrepair.
Reddy MV, Petrossian E, McElhinney DB, Moore P, Teitel DF, Hanley FL: One stage complete unifocalization in infants: When should the ventricular septal defect be closed? J Thorac Cardiovasc Surg 1997;113:

65. These indices are of limited value since they are based on the size of the proximal vessels only.
The nature of the distal pulmonary vascular bed and pulmonary vascular resistance are not expressed in these calculations

66. General principles of surgical therapy of PA-VSD
Connect as many lung segments as possible to the blood flow from RV during early infancy - to avoid significant histologic changes occurs in pulmonary vasculature

67. Complete repair should be attempted within weeks to months during infancy.
Therapeutic catheterization procedures such as balloon angioplasty help to rehabilitate pulmonary arteries with stenosis.

68. Components of surgical repair
Placement of RV – PA conduit
Unifocalization of APCs
VSD closure.
These components are performed in one-stage, or at different operations depending on the anatomy and institutional policy.

69. RV – PA conduit placement
Cadaveric, cryopreserved homograft is used to connect right ventricle to available central pulmonary arteries.
In complex cases, where a central pulmonary artery is absent or the pulmonary blood flow is multifocal, unifocalization of the diminutive native pulmonary arteries and APCs will be performed before RV – PA conduit is placed

70. Unifocalization of APCs
Unifocalize significant APCs during the first 3 months of life
Median sternotomy is the preferred method especially if single stage repair is planned.
In multi stage surgical approach, unifocalization is done through lateral thoracotomies.
During unifocalization, APCs are ligated at the origin and mobilized to maximize their length .
Anastomosed in the mediastinum and connected to RV-PA conduit.

71. Aortic arch angiogram before (A) and main pulmonary arteriogram (B)after 1-stage complete unifocalization

72. VSD closure
Closure of VSD at the time of initial repair avoids the need for further surgery.
If any concerns about the adequacy of the pulmonary vascular bed -defer VSD closure.
Unrepaired VSD avoids supra-systemic RV pressure in the immediate postoperative period by allowing RV to decompress through the VSD.

73. VSD closure
Alternative strategy - closing VSD with a fenestrated patch and the fenestration can be closed later either by surgery or transcatheter technique.
When VSD closure is deferred at initial repair, it is surgically closed after 6 – 12 months- when left to right shunt is established via the VSD with Qp/Qs exceeding 2:1 by catheter evaluation .
Reddy MV, Petrossian E, McElhinney DB, Moore P, Teitel DF, Hanley FL: One stage complete unifocalization in infants: When should the ventricular septal defect be closed? J Thorac Cardiovasc Surg 1997;113:

74. Multi-stage versus single-stage approach

75. The choice between multi-stage and single-stage repair is dependent on various factors:
Nature of PAs (small vs good size)
Duct-dependent or collateral-dependent PBF
Status of APCs
Availability of surgical skills and results of the institution.

76. Multi-stage approach:
Traditional approach - palliative shunt in patients with good size, confluent central PA during neonatal period or early infancy to relieve cyanosis and allow for growth of distal pulmonary arteries.
With diminutive PAs, RV – PA continuity is established by placing a RV – PA conduit

77. The VSD is typically left open at this first stage.
Unifocalization of APCs
A subsequent surgery -
VSD closure
Relieve any residual right ventricular outflow tract obstruction
Placement of a valved conduit.

78. Right Unifocalization

79. Left unifocalization

80. Definitive repair in a patient with a previous bilateral unifocalization

81. Single-stage approach
Attempts to perform APCs unifocalization and cardiac repair at the same operation, through median sternotomy

82. Comparison of outcome between multi and single-stage repair
The ultimate results are comparable but patients in the single stage group undergo one or two operations less than the patients in multi-stage group do.
Tchervenkov CI, Salasidis G, Cecere R, Beland MJ, Jutras L, Paquet M, Dobell ARC: One-stage midline unifocalization and complete repair in infancy versus multiple-stage unifocalization followed by repair for complex heart disease with major aortopulmonary collaterals. J Thorac Cardiovasc Surg 1997;114:
Murthy KS, Rao SG, Krishnanaik S, Coelho R,Krishnan US, Cherian KM: Evolving surgical management for ventricular septal defect, pulmonary atresia, and major aortopulmonary collateral arteries. Ann Thoracic Surg 1999;67:

83. Early 1-stage complete unifocalization can be performed in >90% of patients with pulmonary atresia and MAPCAs, and yields good functional results.
Complete repair during the same operation is achieved in two thirds of patients.
Actuarial survival 3 years after surgery is 80%, and but there is a significant rate of reintervention.
Early and Intermediate Outcomes After Repair of Pulmonary Atresia With Ventricular Septal Defect and Major Aortopulmonary Collateral Arteries
Experience With 85 Patients :V. Mohan Reddy, MD; Doff B. McElhinney, MD; Zahid Amin, MD; Phillip Moore, MD; Andrew J. Parry, MD; David F. Teitel, MD; Frank L. Hanley, MD
Circulation. 2000; 101:

84. Outcome of surgical repair
Early mortality %
Late mortality - 16%
Ten- and 20-year survival - 86% and 75%
Freedom from reoperation of 55%.
Early and long-term results of the surgical treatment of tetralogy of Fallot with pulmonary atresia, with or without major aortopulmonary collateral arteries: John M. Cho et al
J Thorac Cardiovasc Surg 2002;124:70-81

85. Perioperative complications
Phrenic nerve injury-0.3 %
Reoperation for bleed-3%
Sepsis-5%
Heart block-0.5%
Pulmonary infarction-0.4%

86. Complementary role of interventional catheterization
Dilation of Distal stenosis within lung parenchyma (inaccessible to the surgeon. )
Coil occlusion of APCs
Stent placement in RVOT
Palliative stenting of stenotic APC’S

87. Long term sequelae
Patients on palliative shunts, develop progressive cyanosis and polycythemia
Aortic regurgitation
Deterioration of conduit and valve function by loss of luminal diameter, calcification, peel formation
Pulmonary regurgitation worsens with RV dilatation and dysfunction

88. THANK YOU