1. Medical College, Calicut
TRICUSPID ATRESIA
Dr Bijilesh u
Senior Resident,
Dept. of Cardiology,
Medical College, Calicut

2. References - Perloff ‘s text book of congenital heart diseases
- Moss and Adams ‘s text book of congenital cardiology
- Rudolph text book of pediatric cardiology
- Freedom’s natural and modified natural history of cong.heart diseases
- Andreson text book of congenital heart disease
- Figenbaum’ text book of echocardiography
- Hurst’s heart disease
- Braunwald’ heart diseases
- Langman’s Embryology

3. Defined as congenital absence or agenesis of the tricuspid valve, with no direct communication between the right atrium and right ventricle

4. Incidence : 0.06 per 1000 live births Prevalence : 1- 3% of CHD
(Report of New England Regional
Infant Cardiac Program – 1980)

5. HISTORY First reported by Kreysig in 1817
Clinical features reported by Bellet and Stewart in 1933
Taussig and Brown in 1936

6. EMBRYOLOGY
Early embryogenesis - process of expansion of inlet portion of right ventricle coincides with development of AV valves
Failure of this process - atresia of tricuspid valve & absent inlet portion of right ventricle
Embryological insult occurring later in gestation - Less common variety - with well formed but fused leaflets
If valve fusion incomplete - tricuspid stenosis

7. ANATOMY
Muscular
Membranous
Atrioventricular

8. Most common type
– muscular (89%)
Dimple or a localized fibrous thickening in the floor of RA at expected site of tricuspid valve.

9. Membranous type - atrioventricular portion of membranous septum forms floor of the RA at the expected location of TV
May be associated with
absent pulmonary valve leaflets.

10. Minute valvar cusps are fused together (1%) Ebstein type (2.6%)
Valvar type
Minute valvar cusps are fused together (1%)
Ebstein type (2.6%)
Fusion of tricuspid valve leaflets
Attachment is displaced downward
Plastering of the leaflets to the RV wall

11. Atrioventricular canal type
Extremely rare (0.2%)
Leaflet of the common AV valve
seals off the only entrance into RV

12. MORPHOLOGICAL
CONSIDERATIONS

13. RA & ASD The right atrium is enlarged and hypertrophied.
Interatrial communication is necessary for survival
Stretched patent foramen ovale - ¾ cases
True ASD less common - ostium secundum type

14. Rarely patent foramen ovale is obstructive and may form an aneurysm of fossa ovalis
Sometimes large enough to produce mitral inflow obstruction

15. LA & LV
Left atrium may be enlarged, especially when pulmonary blood flow is increased.
Mitral valve is morphologically normal - rarely incompetent
LV is enlarged and hypertrophied

16. Right ventricle Size of the RV varies – depends on size of VSD
With a large VSD or TGA - RV larger
When VSD is small - only the conus is present
Small and hypoplastic
Inflow or sinus portion absent
Trabecular portion & outflow or conus region often well developed

17. VSD in Tricuspid Atresia
Associated VSD - 90% of individuals during infancy
Usually perimembranous
Can be muscular /malalignment types
Restrictive VSD’S cause
subpulmonic obstruction in pts with NRGA
subaortic obstruction in pts with TGA

18. Majority of defects close in the first yr of life
At birth VSD is usually restrictive- permitting adequate but not excessive PBF
40% of these defects close spontaneously/ decrease in size - acquired pulmonary atresia
This advantage is often lost, as
Majority of defects close in the first yr of life

19. Classification - KUHNE
Type Normally related great arteries
Type D-transposition of great arteries
Type L- Transposition of great arteries

20. Type 1 Normally related great arteries (70 – 80%)
a. Intact IVS with pulmonary atresia( 9%)
b. Small VSD and pulmonary stenosis( 51%)
c. Large VSD without pulmonary stenosis ( 9%)

22. Type II
D-transposition of great arteries (12 – 25%) a. VSD with pulmonary atresia( 2%) b. VSD with pulmonary stenosis( 8%) c. VSD without pulmonary stenosis(18%)

24. Type 3 L- Transposition or malposition of great arteries (3-6%)
Associated with complex lesions
Truncus arteriosus
Endocardial cushion defect

25. Additional cardiovascular abnormalities- 20%
Coarctation of aorta – 8%
Persistent left SVC
Juxtaposition of atrial appendages
-50% of TA with TGA
Right aortic arch
Abnormalities of mitral apparatus- cleft in AML,MVP ,direct attachment of leaflets to papillary muscles

26. PHYSIOLOGY- TA Obligatory rt to left shunt at atrial level
LA receives both the entire systemic and pulmonary venous return
Entire mixture flows into LV - sole pumping chamber
for pulmonary and systemic circulation

27. PHYSIOLOGY TA WITH NRGA Pulm artery blood flow is usually reduced
Restrictive VSD - zone of subpulmonic stenosis.
LV overload is curtailed but
at the cost of cyanosis
90% of cases
When the great arteries are normally related,

28. TA WITH NRGA PHYSIOLOGY
When VSD is non restrictive and pulmonary vascular resistance is low
PBF and LV volume over load - excessive
Cyanosis is mild

29. TA with TGA
PHYSIOLOGY
VSD is almost always non-restrictive and PS usually absent
Low PVR > abundant pulmonary arterial blood flow
Minimal cyanosis,marked LV volume overload
With restrictive vsd or infundibular narrowing
→diminished syst circulation
→metabolic acidosis and shock
If these pts have a

30. SEX PREDILECTION TA with NRGA - Equal frequency in males & females
TA with TGA
- male preponderance
- no male preponderance with
juxtaposition of atrial appendages

31. GENETICS Specific genetic causes - remain to be determined in humans
FOG2 gene may be involved
Validated only in animal studies
22q11 deletion
Familial recurrence is low
Recurrence in siblings is only about 1%

32. Overall survival in infants with TA
1 year- 72%.
5 years- 52%.
10 years- 46%

33. NATURAL HISTORY TA with NRGA with an intact IVS
Few infants survive beyond 6 months without surgical palliation
Intense hypoxia and death ensue
unless ductus is patent
unless adequate systemic to PA collaterals
present

34. Aquired pulmonary atresia
Due to spontaneous closure of VSD
Usually in the first year
Survival depends on patency of the ductus

35. TA with NRGA & SMALL VSD
NATURAL HISTORY
VSD closes spontaneously or become excessively obstructive - majority die by one year
Rarely a favorable balance achieved b/w VSD & PBF permitting survival from 2nd to 5th decades

36. TA with NRGA & LARGE VSD.
NATURAL HISTORY
Excessive PBF > vol. overload of LV and CCF
Patients usually do not fare well
Some have lived to ages 4 to 6 years
Long survivals reported between ages 32 and 45 yrs - in exceptional cases

37. TR. ATRESIA WITH TGA
NATURAL HISTORY
Same poor longevity patterns hold for TA with TGA and large VSD
Exceptional survivals to mid-late teens reported
TA with TGA with subaortic stenosis
( restrictive VSD) - ominous combination
problems related to increased longevity-I.E,brain abscess, paradoxical embolism

38. Physical examination- appearance
Dysmorphic facies
- Cat-eye syndrome
- congenital coloboma
JVP
- a wave amplitude increase due to restrictive
interatrial communication.
- Y descent is slow

39. Precordium LV impulse without an RV impulse in a cyanotic patient
Gentle RV impulse - TA with non restrictive VSD and a well developed RV
Palpable thrill if VSD is restrictive
Key to clinical recognition of ta

40. AUSCULTATION First heart sound is single
Second usually single - soft pulmonic component - occasionally present
TA with NRGA
- prominent murmur of restrictive VSD
– holosystolic maximal at mid to lower LSB

41. TA with TGA & increased PBF
AUSCULTATION
Holosystolic murmur – across VSD
S2 – single & loud S3
MDM

42. Pulmonary vascular resistance – high
AUSCULTATION
VSD murmur vanishes
Soft midsystolic murmur- anterior aortic root
Rarely, the loud second component from the dilated hypertensive posterior pulmonary trunk is heard

43. - coexisting pulmonic or subpulmonic stenosis
AUSCULTATION
TA with TGA
- coexisting pulmonic or subpulmonic stenosis
- midsystolic murmur – loudness and length vary
inversely with degree of obstruction

44. ECG Tall peaked right atrial P waves - Himalayan P waves QRS axis
LV hypertrophy
Absence of RV forces in precordial leads
QRS axis
- left and superior - type 1
- LAD or normal - type 2

45. CHEST X-RAY- TA WITH NRGA AND SMALL VSD
Pulmonary vascularity reduced
Pulmonary artery segment – inconspicuous
Heart size – normal
Right cardiac border
superior convexity
- enlarged RA
Inferior part
flat or receding
- absence of RV

46. LAO – Humped appearance of right cardiac border

47. CXR - TA with TGA - no obstruction
Lungs – plethoric
LV, LA, RA – enlarged
Right cardiac border
no hump-shaped contour
– RV is relatively well developed

48. CXR - TA with TGA and PS Pulmonary blood flow is normal or reduced
Prominent RA
Convex LV
Narrow vascular pedicle

49. ECHOCARDIOGRAM
Presence of an imperforate linear echo density at the location of normal TV
Presence and size of the interatrial communication
Presence and size of a VSD
Relationship of the aorta and pulmonary artery

50. Size of the RV and pulmonary arteries
Presence and severity of infundibular or pulmonary stenosis
Presence and size of the ductus arteriosus
Presence of aortic isthmus narrowing or coarctation
Degree of mitral regurgitation
Left ventricular function

51. CARDIAC CATHETERIZATION
Limited role at present
Newborn
Define sources of pulmonary blood flow
Associated anomalies not clearly defined by echo
TA with TGA - Obstruction at VSD or infundibulum
Therapeutic role for balloon atrial septostomy
that will result in obstruction to systemic blood flow

52. CARDIAC CATHETERIZATION
Prior to Fontan
- Pulm.Vascular resistance
- Pulmonary artery size
- Pulmonary artery distortion - by previous surgery
Older patients without definitive palliation
- detect collaterals from aorta - lungs

53. HEMODYNAMIC DATA Right atrial pressure is slightly higher than LAP
Prominent ‘a ‘wave in the right atrium
-interatrial communication is restrictive
LV systolic and EDP – normal
LVEDP may increase with large VSD as PVR drops and LV volume overload ensues

54. Oxygen saturation (Sao2) in systemic venous return - lower than normal
- diminished Sao2 in
systemic arterial blood
Sao2 of pulmonary venous
return - normal
LA and LV saturations
- diminished
- obligatory R-L shunt
Oxygen saturation in the systemic venous return will be lower than normal as a result of diminished oxygen saturation in the systemic arterial blood. oxygen saturation of pulmonary venous return will be normal. of the obligatory right-to-left atrial-level shunt, left atrial and left ventricular saturations will be diminished.

55. INITIAL MEDICAL MANAGEMENT
PGE1
Maintain patency of the ductus before cardiac catheterization or planned surgery
Given as an infusion
.025 – 0.1 mg/kg/mt
Potential for apnea
Fever , siezure, hypotension
REFER
should be started in neonates with severe cyanosis to

56. Balloon atrial septostomy may be done as part of initial catheterization to improve the RA-LA shunt

57. SURGICAL CARE
Palliative
Corrective therapy

58. PALLIATIVE SURGERY DECIDED IN TERMS OF
Decreased pulmonary flow
Increased pulmonary flow

59. FOR ↓ PBF
PBF - increased by surgical creation of an aortopulmonary shunt
Blalock & Taussig - Subclavian artery - ipsilateral PA
Potts - Descending aorta – LPA
Waterston-Cooley - Ascending aorta – RPA

60. Modified Blalock-Taussig shunt
- Gore-Tex interposition graft
- Subclavian artery - PA
Central aortopulmonary fenestration
- Gore-Tex shunt

61. Glenn shunt
Superior vena cava – RPA
End-to- end
Improves PBF and Sa o2
No risk of pulmonary HTN
Pulmonary AV malformations later

62. ↑ PBF Pulmonary artery banding - In patients with
tricuspid atresia type II

63. CORRECTIVE SURGERY Fontan and Kreutzer
- physiologically corrective operation
- complete separation of the systemic and
pulmonary circuits

64. CHOUSSAT CRITERIA Age at operation – 4 and 15 yrs
- not strictly followed nowadays
Normal sinus rhythm
Normal systemic venous connections
Normal right atrial size
Normal pulmonary arterial mean pressure
- > = 15 mm Hg

65. Low pulmonary vasc resistance - 4 woods units/m2
Adequate sized PA with diameter > 75% of aorta
Normal LVEF (>60%)
Absence of MR
Absence of complicating factors from previous surgeries
Normal LVEF (>60%)( rel. contraindication) Absence of MR( relative contraindication)

67. Low cardiac output,heart failure or both Persistent pleural effusion
LATE COMPLICATIONS OF FONTAN
EARLY COMPLICATIONS OF FONTAN
Low cardiac output,heart failure or both
Persistent pleural effusion
Thrombus formation in the systemic venous pathways
Liver dysfunction
Hepatomegaly and ascites.
Supraventricular arrythmias
Progressive decrease in oxygen saturation( obstn. of venous pathways, leakage in intra- atrial baffle, dev of pulm av fistula)
Protein losing enteropathy

68. THANK YOU.