TRICUSPID
ATRESIA
DR. PALLAVI
• Defined as congenital absence or agenesis of
the tricuspid valve, with no direct
communication between the right atrium and
right ventricle.
• Incidence : 0.06 per 1000 live births
• Prevalence :in clinical series of congenital
heart disease is 1- 2.4 %.
HISTORY
• First reported by Kreysig in 1817.
• Clinical features reported by Bellet and
Stewart in 1933.
• Also by Taussig and Brown in 1936.
EMBRYOLOGY
• During early embryogenesis,the process of
expansion of the inlet portion of the right
ventricle coincides with development of the
AV valves.
• Failure of this process of inlet expansion is the
pathogenetic mechanism for the usual
muscular variety of tricuspid atresia.
• The less common variety , with well formed
but fused leaflets,occurs if the embryological
insult occurs later in gestation.
• If valve fusion is incomplete, tricuspid stenosis
develops.
ANATOMY
• The most common type of tricuspid atresia is
muscular .
• It is characterized by a dimple or a localized
fibrous thickening in the floor of the right
atrium at the expected site of the tricuspid
valve.
• The muscular variety constitutes 89% of cases.
• In the membranous type (6.6%), the
atrioventricular portion of the membranous
septum forms the floor of the right atrium at
the expected location of the tricuspid valve.
• This particular type appears to be associated
with absent pulmonary valve leaflets.
• Minute valvar cusps are fused together in the
valvar type (1%).
• In the Ebstein type (2.6%), fusion of the
tricuspid valve leaflets occurs; attachment is
displaced downward, and plastering of the
leaflets to the right ventricular wall occurs.
• The atrioventricular canal type is extremely
rare (0.2%). -a leaflet of the common
atrioventricular valve seals off the only
entrance into the right ventricle.
• The right atrium is enlarged and
hypertrophied.
• An interatrial communication is necessary for
survival.
• This communication most commonly is a
stretched patent foramen ovale.
• A true ASD is much less common and when
present is almost always in the ostium
secundum location.
• Rarely, the patent foramen ovale is obstructive
and may form an aneurysm of the fossa ovalis,
which is sometimes large enough to produce
mitral inflow obstruction
• The left atrium may be enlarged, especially
when the pulmonary blood flow is increased.
• The mitral valve is morphologically normal; it
is rarely incompetent and has a large orifice.
• The left ventricle is enlarged and
hypertrophied but usually morphologically
normal
• The right ventricle is small and hypoplastic.
• In patients with a large VSD or TGA, the size
of the right ventricle may be larger, but, even
in these patients, the right ventricle is smaller
than normal.
VSD in tricuspid atresia
• Associated VSD is common with TA, seen in
about 90% of individuals during infancy.
• Is usually perimembranous but also may occur
in the muscular septum or as a component of
an atrioventricular septal defect, although the
latter is rare.
• At birth the VSD is usually
restrictive,permitting adequate but not
excessive pulmonary blood flow .
• This advantage is often lost, as 40% of these
defects close spontaneously/ decrease in size-
”acquired pulmonary atresia”
• The majority of defects close in the first yr of
life.
• These restrictive VSD’S cause subpulmonic
obstruction in pts with normally related great
arteries, and subaortic obstruction in pts with
TGA.
Classification
Proposed by Kuhne and later modified
Type 1 : normally related great arteries (70 –
80%)
a. intact ventricular septum with pulmonary
atresia( 9%)
b. small ventricular septal defect and
pulmonary stenosis( 51%)
c. large ventricular septal defect without
pulmonary stenosis ( 9%)
Type ii : D-transposition of great arteries (12 –
25%)
a. ventricular septal defect with pulmonary
atresia( 2%)
b. ventricular septal defect with pulmonary
stenosis( 8%)
c. ventricular septal defect without
pulmonary stenosis(18%)
Type 3 :L- Transposition or malposition of great
arteries (3-6%)
associated complex lesions, ie., truncus
arteriosus, endocardial cushion defect
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,malattachment of the valve,direct attachment
of the mitral leaflets to papillary muscles.
PHYSIOLOGY-TA WITH NRGA
• Obligatory rt to left shunt at atrial level.
• LA receives both the entire systemic and
pulmonary venous return.
• The entire mixture flows into the LV which is
the sole pumping chamber for the pulmonary
and systemic circulation.
• When the great arteries are normally
related,pulm artery blood flow is usually
reduced as the restrictive VSD, is a zone of
subpulmonic stenosis.
• LV overload is curtailed but at the cost of
cyanosis.
• This is so in 90% of cases.
In TGA
• The VSD is almost always non-restrictive and
pulmonary stenosis is usually absent.
• Low PVR results in abundant pulmonary
arterial blood flow.
• Minimal cyanosis,marked LV volume overload.
• If these pts have a restrictive vsd,or
infundibular narrowing→diminished syst
circulation→metabolic acidosis and shock.
SEX PREDILECTION
• Tr. Atresia with normally related great arteries
have an equal frequency in males and
females.
• If TGA is present→male preponderance.
• No male preponderance with juxtaposition of
atrial appendages.
GENETICS
• Although specific genetic causes of the
malformation remain to be determined in
humans, the FOG2 gene may be involved in
the process.
• This has however been validated only in
animal studies.
• Familial recurrence is low , and recurrence in
siblings is only about 1%.
OVERALL ACTUARIAL SURVIVAL IN
INFANTS WITH TRICUSPID ATRESIA
• 1 year- 72%.
• 5 years- 52%.
• 10 years- 46%
NATURAL HISTORY
• Few infants with tr. Atresia and normally
related gr . Arteries with an intact ventricular
septum survive beyond 6 months of age
without surgical palliation.
• Intense hypoxia and death ensue unless the
ductus is patent, or adequate systemic to PA
collaterals are present , either of which are
unlikely.
TR. ATRESIA WITH NRGA AND
SMALL VSD.
• The VSD in such patients closes
spontaneously or is excessively obstructive, so
that majority of patients die by one year.
• Rarely, a favorable balance is achieved b/w
the presence of VSD and pulm . Blood flow ,
permitting survival from 2nd to 5th decades.
TR. ATRESIA WITH NRGA AND
LARGE VSD.
• Pts with TA , normally related great arteries
and large VSD do not fare well
• Excessive pulmonary arterial flow results in
vol. overload of LV and CCF.
• Pts have lived to ages 4 to 6 years.
• In exceptional cases, long survivals have been
reported between ages 32 and 45 yrs.
TR. ATRESIA WITH TGA
• Same poor longevity patterns hold when TA
occurs with complete transposition and large
VSD.
• TA with TGA with subaortic stenosis(
restrictive VSD) is an ominous combination.
• Exceptional survivals to mid-late teens have
been recorder.
• problems related to increased longevity-
I.E,brain abscess, paradoxical embolism
Physical examination- appearance
• Dysmorphic facies-occasionally “cat-eye”
syndrome or congenital coloboma may
be seen.
JVP
• Increase in the A wave amplitude , due to the
restrictive interatrial communication.
• Y descent is slow
• In LVF, A and V waves increase in amplitude.
Precordium
• LV impulse without a RV impulse in a cyanotic
patient.
• A gentle RV impulse in pt with TA ,complete
transposition and a well dev RV .
• Palpable thrill if VSD is restrictive.
AUSCULTATION
• First heart sound is single .
• Second usually single, but a soft delayed
pulmonic component is occasionally present.
• TA with normally related great arteries,
prominent systolic murmur originates at the
site of restrictive VSD – holosystolic, maximal
at the mid to lower left sternal edge.
TA with complete transposition
and increased pulmonary blood
flow
• Holosystolic murmur – across VSD
• S2 – single but always loud
• S3
• MDM
• 4th heart sounds are rare in any of the
varieties of tricuspid atresia.
Pulmonary vascular resistance –
high
• VSD murmur vanishes
• Soft midsystolic murmur- anterior aortic root
• Rarely, the loud second component from the
dilated hypertensive posterior pulmonary
trunk is heard.
• TA with complete transposition, coexisting
pulmonic or subpulmonic stenosis –
midsystolic murmur – loudness and length
vary inversely with degree of obstruction
ECG
• Tall peaked right atrial P waves are usually
seen
• Biatrial P – if left atrial volume is↑ due to
↑PBF.
• PR interval- normal.
• QRS axis – left and superior ( type 1 pts)
• Absence of RV forces in precordial leads
ECG
CHEST X-RAY-TA WITH NRGA AND
SMALL VSD
• Pulmonary vascularity reduced.
• Pulmonary artery segment – inconspicuous.
• Heart size – normal.
• Right cardiac border, esp in LAO projection –
superior convexity caused by enlargement of
RA and its appendage.
• Inferior border – flat or receding owing to
absence of RV.
• LAO – Humped appearance of right cardiac
border and a prominent left cardiac silhouette
TA with complete transposition
and no obstruction
• Lungs – plethoric
• LV, LA, RA – enlarged
• Right cardiac border seldom has distinctive
hump-shaped contour – RV is relatively well
developed
Tr. Atresia with TGA
TA with complete transposition
and PS
• Pulmonary blood flow is normal or reduced
• Ascending aorta and pulmonary trunk are not
border forming (narrow vascular pedicle)
ECHOCARDIOGRAM
• Presence of an imperforate linear echo
density in the location of normal TV
• Presence of two great arteries and semilunar
valves
• Confirm the presence and size of the
interatrial communication.
• Confirm the presence of a VSD.
CARDIAC CATHETERIZATION
• Limited role at present.
• Therapeutic role for balloon atrial
septostomy.
• Prior to a Fontan for determining
pulm.vascular resistance.
HEMODYNAMIC DATA
• In infants, the right atrial pressure is slightly
higher than the left atrial pressure.
• prominent ‘a ‘wave in the right atrium,
especially if the interatrial communication is
restrictive.
• LV systolic and EDP – normal.
• LVEDP may increase in patients with large
VSD’s as PVR drops and left heart volume
overload , ensues.
INITIAL MEDICAL MANAGEMENT
• PGE1, should be started in neonates with
severe cyanosis to maintain patency of the
ductus before cardiac catheterization or
planned surgery
• Balloon atrial septostomy may be carried out
as part of the initial catheterization to improve
the RA-LA shunt.
SURGICAL CARE
• Surgical management may be broadly grouped
into palliative and corrective therapy.
PALLIATIVE SURGERY DECIDED IN
TERMS OF
• decreased pulmonary flow
• increased pulmonary flow
• intracardiac obstruction.
FOR ↓ PBF.
• Pulmonary blood flow may be increased by
surgical creation of an aortopulmonary shunt.
• subclavian artery to ipsilateral pulmonary
artery anastomosis by Blalock and Taussig in
1945
• Potts shunt (descending aorta–to–left
pulmonary artery anastomosis),
• Waterston-Cooley shunt (ascending aorta–
to–right pulmonary artery anastomosis
• central aortopulmonary fenestration or Gore-
Tex shunt,
• modified Blalock-Taussig shunt (Gore-Tex
interposition graft between the subclavian
artery and the ipsilateral pulmonary artery),
• Glenn shunt (superior vena cava–to–right
pulmonary artery anastomosis, end-to-end),
↑ PBF
• In patients with tricuspid atresia type II ,
pulmonary artery banding should be
performed following stabilization with
anticongestive measures.
CORRECTIVE SURGERY
• Fontan and Kreutzer- initial description of the
physiologically corrective operation for
tricuspid atresia
• Complete separation of the systemic and
pulmonary circuits
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 (
mean >= 15 mm Hg)
• Low pulmonary vasc resistance (4 woods
units/m2)
• Adequate sized pulm. Arteries with diameter
> 75% of aortic diameter.
• Normal LVEF (>60%)( rel. contraindication)
• Absence of MR( relative contraindication)
• Absence of complicating factors from prev
ious surgeries
EARLY COMPLICATIONS OF
FONTAN
• Low cardiac output,heart
failure or both .
• Persistent pleural effusion.
• Thrombus formation in the
systemic venous pathways.
• Liver dysfunction
LATE COMPLICATIONS OF
FONTAN
• 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
THANK YOU.

Tricuspid atresia

  • 1.
  • 3.
    • Defined ascongenital absence or agenesis of the tricuspid valve, with no direct communication between the right atrium and right ventricle. • Incidence : 0.06 per 1000 live births • Prevalence :in clinical series of congenital heart disease is 1- 2.4 %.
  • 4.
    HISTORY • First reportedby Kreysig in 1817. • Clinical features reported by Bellet and Stewart in 1933. • Also by Taussig and Brown in 1936.
  • 5.
    EMBRYOLOGY • During earlyembryogenesis,the process of expansion of the inlet portion of the right ventricle coincides with development of the AV valves. • Failure of this process of inlet expansion is the pathogenetic mechanism for the usual muscular variety of tricuspid atresia.
  • 6.
    • The lesscommon variety , with well formed but fused leaflets,occurs if the embryological insult occurs later in gestation. • If valve fusion is incomplete, tricuspid stenosis develops.
  • 8.
    ANATOMY • The mostcommon type of tricuspid atresia is muscular . • It is characterized by a dimple or a localized fibrous thickening in the floor of the right atrium at the expected site of the tricuspid valve. • The muscular variety constitutes 89% of cases.
  • 10.
    • In themembranous type (6.6%), the atrioventricular portion of the membranous septum forms the floor of the right atrium at the expected location of the tricuspid valve. • This particular type appears to be associated with absent pulmonary valve leaflets.
  • 11.
    • Minute valvarcusps are fused together in the valvar type (1%). • In the Ebstein type (2.6%), fusion of the tricuspid valve leaflets occurs; attachment is displaced downward, and plastering of the leaflets to the right ventricular wall occurs.
  • 12.
    • The atrioventricularcanal type is extremely rare (0.2%). -a leaflet of the common atrioventricular valve seals off the only entrance into the right ventricle.
  • 14.
    • The rightatrium is enlarged and hypertrophied. • An interatrial communication is necessary for survival. • This communication most commonly is a stretched patent foramen ovale.
  • 15.
    • A trueASD is much less common and when present is almost always in the ostium secundum location. • Rarely, the patent foramen ovale is obstructive and may form an aneurysm of the fossa ovalis, which is sometimes large enough to produce mitral inflow obstruction
  • 16.
    • The leftatrium may be enlarged, especially when the pulmonary blood flow is increased. • The mitral valve is morphologically normal; it is rarely incompetent and has a large orifice. • The left ventricle is enlarged and hypertrophied but usually morphologically normal
  • 17.
    • The rightventricle is small and hypoplastic. • In patients with a large VSD or TGA, the size of the right ventricle may be larger, but, even in these patients, the right ventricle is smaller than normal.
  • 18.
    VSD in tricuspidatresia • Associated VSD is common with TA, seen in about 90% of individuals during infancy. • Is usually perimembranous but also may occur in the muscular septum or as a component of an atrioventricular septal defect, although the latter is rare. • At birth the VSD is usually restrictive,permitting adequate but not excessive pulmonary blood flow .
  • 19.
    • This advantageis often lost, as 40% of these defects close spontaneously/ decrease in size- ”acquired pulmonary atresia” • The majority of defects close in the first yr of life. • These restrictive VSD’S cause subpulmonic obstruction in pts with normally related great arteries, and subaortic obstruction in pts with TGA.
  • 20.
    Classification Proposed by Kuhneand later modified Type 1 : normally related great arteries (70 – 80%) a. intact ventricular septum with pulmonary atresia( 9%) b. small ventricular septal defect and pulmonary stenosis( 51%) c. large ventricular septal defect without pulmonary stenosis ( 9%)
  • 21.
    Type ii :D-transposition of great arteries (12 – 25%) a. ventricular septal defect with pulmonary atresia( 2%) b. ventricular septal defect with pulmonary stenosis( 8%) c. ventricular septal defect without pulmonary stenosis(18%)
  • 22.
    Type 3 :L-Transposition or malposition of great arteries (3-6%) associated complex lesions, ie., 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,malattachment of the valve,direct attachment of the mitral leaflets to papillary muscles.
  • 26.
    PHYSIOLOGY-TA WITH NRGA •Obligatory rt to left shunt at atrial level. • LA receives both the entire systemic and pulmonary venous return. • The entire mixture flows into the LV which is the sole pumping chamber for the pulmonary and systemic circulation.
  • 27.
    • When thegreat arteries are normally related,pulm artery blood flow is usually reduced as the restrictive VSD, is a zone of subpulmonic stenosis. • LV overload is curtailed but at the cost of cyanosis. • This is so in 90% of cases.
  • 28.
    In TGA • TheVSD is almost always non-restrictive and pulmonary stenosis is usually absent. • Low PVR results in abundant pulmonary arterial blood flow. • Minimal cyanosis,marked LV volume overload. • If these pts have a restrictive vsd,or infundibular narrowing→diminished syst circulation→metabolic acidosis and shock.
  • 29.
    SEX PREDILECTION • Tr.Atresia with normally related great arteries have an equal frequency in males and females. • If TGA is present→male preponderance. • No male preponderance with juxtaposition of atrial appendages.
  • 30.
    GENETICS • Although specificgenetic causes of the malformation remain to be determined in humans, the FOG2 gene may be involved in the process. • This has however been validated only in animal studies. • Familial recurrence is low , and recurrence in siblings is only about 1%.
  • 31.
    OVERALL ACTUARIAL SURVIVALIN INFANTS WITH TRICUSPID ATRESIA • 1 year- 72%. • 5 years- 52%. • 10 years- 46%
  • 32.
    NATURAL HISTORY • Fewinfants with tr. Atresia and normally related gr . Arteries with an intact ventricular septum survive beyond 6 months of age without surgical palliation. • Intense hypoxia and death ensue unless the ductus is patent, or adequate systemic to PA collaterals are present , either of which are unlikely.
  • 33.
    TR. ATRESIA WITHNRGA AND SMALL VSD. • The VSD in such patients closes spontaneously or is excessively obstructive, so that majority of patients die by one year. • Rarely, a favorable balance is achieved b/w the presence of VSD and pulm . Blood flow , permitting survival from 2nd to 5th decades.
  • 34.
    TR. ATRESIA WITHNRGA AND LARGE VSD. • Pts with TA , normally related great arteries and large VSD do not fare well • Excessive pulmonary arterial flow results in vol. overload of LV and CCF. • Pts have lived to ages 4 to 6 years. • In exceptional cases, long survivals have been reported between ages 32 and 45 yrs.
  • 35.
    TR. ATRESIA WITHTGA • Same poor longevity patterns hold when TA occurs with complete transposition and large VSD. • TA with TGA with subaortic stenosis( restrictive VSD) is an ominous combination. • Exceptional survivals to mid-late teens have been recorder. • problems related to increased longevity- I.E,brain abscess, paradoxical embolism
  • 36.
    Physical examination- appearance •Dysmorphic facies-occasionally “cat-eye” syndrome or congenital coloboma may be seen.
  • 37.
    JVP • Increase inthe A wave amplitude , due to the restrictive interatrial communication. • Y descent is slow • In LVF, A and V waves increase in amplitude.
  • 38.
    Precordium • LV impulsewithout a RV impulse in a cyanotic patient. • A gentle RV impulse in pt with TA ,complete transposition and a well dev RV . • Palpable thrill if VSD is restrictive.
  • 39.
    AUSCULTATION • First heartsound is single . • Second usually single, but a soft delayed pulmonic component is occasionally present. • TA with normally related great arteries, prominent systolic murmur originates at the site of restrictive VSD – holosystolic, maximal at the mid to lower left sternal edge.
  • 40.
    TA with completetransposition and increased pulmonary blood flow • Holosystolic murmur – across VSD • S2 – single but always loud • S3 • MDM • 4th heart sounds are rare in any of the varieties of tricuspid atresia.
  • 41.
    Pulmonary vascular resistance– high • VSD murmur vanishes • Soft midsystolic murmur- anterior aortic root • Rarely, the loud second component from the dilated hypertensive posterior pulmonary trunk is heard.
  • 42.
    • TA withcomplete transposition, coexisting pulmonic or subpulmonic stenosis – midsystolic murmur – loudness and length vary inversely with degree of obstruction
  • 43.
    ECG • Tall peakedright atrial P waves are usually seen • Biatrial P – if left atrial volume is↑ due to ↑PBF. • PR interval- normal. • QRS axis – left and superior ( type 1 pts) • Absence of RV forces in precordial leads
  • 44.
  • 45.
    CHEST X-RAY-TA WITHNRGA AND SMALL VSD • Pulmonary vascularity reduced. • Pulmonary artery segment – inconspicuous. • Heart size – normal. • Right cardiac border, esp in LAO projection – superior convexity caused by enlargement of RA and its appendage.
  • 46.
    • Inferior border– flat or receding owing to absence of RV. • LAO – Humped appearance of right cardiac border and a prominent left cardiac silhouette
  • 48.
    TA with completetransposition and no obstruction • Lungs – plethoric • LV, LA, RA – enlarged • Right cardiac border seldom has distinctive hump-shaped contour – RV is relatively well developed
  • 49.
  • 50.
    TA with completetransposition and PS • Pulmonary blood flow is normal or reduced • Ascending aorta and pulmonary trunk are not border forming (narrow vascular pedicle)
  • 51.
    ECHOCARDIOGRAM • Presence ofan imperforate linear echo density in the location of normal TV • Presence of two great arteries and semilunar valves
  • 52.
    • Confirm thepresence and size of the interatrial communication. • Confirm the presence of a VSD.
  • 54.
    CARDIAC CATHETERIZATION • Limitedrole at present. • Therapeutic role for balloon atrial septostomy. • Prior to a Fontan for determining pulm.vascular resistance.
  • 55.
    HEMODYNAMIC DATA • Ininfants, the right atrial pressure is slightly higher than the left atrial pressure. • prominent ‘a ‘wave in the right atrium, especially if the interatrial communication is restrictive. • LV systolic and EDP – normal. • LVEDP may increase in patients with large VSD’s as PVR drops and left heart volume overload , ensues.
  • 56.
    INITIAL MEDICAL MANAGEMENT •PGE1, should be started in neonates with severe cyanosis to maintain patency of the ductus before cardiac catheterization or planned surgery • Balloon atrial septostomy may be carried out as part of the initial catheterization to improve the RA-LA shunt.
  • 57.
    SURGICAL CARE • Surgicalmanagement may be broadly grouped into palliative and corrective therapy.
  • 58.
    PALLIATIVE SURGERY DECIDEDIN TERMS OF • decreased pulmonary flow • increased pulmonary flow • intracardiac obstruction.
  • 59.
    FOR ↓ PBF. •Pulmonary blood flow may be increased by surgical creation of an aortopulmonary shunt. • subclavian artery to ipsilateral pulmonary artery anastomosis by Blalock and Taussig in 1945 • Potts shunt (descending aorta–to–left pulmonary artery anastomosis), • Waterston-Cooley shunt (ascending aorta– to–right pulmonary artery anastomosis
  • 60.
    • central aortopulmonaryfenestration or Gore- Tex shunt, • modified Blalock-Taussig shunt (Gore-Tex interposition graft between the subclavian artery and the ipsilateral pulmonary artery), • Glenn shunt (superior vena cava–to–right pulmonary artery anastomosis, end-to-end),
  • 61.
    ↑ PBF • Inpatients with tricuspid atresia type II , pulmonary artery banding should be performed following stabilization with anticongestive measures.
  • 62.
    CORRECTIVE SURGERY • Fontanand Kreutzer- initial description of the physiologically corrective operation for tricuspid atresia • Complete separation of the systemic and pulmonary circuits
  • 63.
    CHOUSSAT CRITERIA • Ageat 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 ( mean >= 15 mm Hg)
  • 64.
    • Low pulmonaryvasc resistance (4 woods units/m2) • Adequate sized pulm. Arteries with diameter > 75% of aortic diameter. • Normal LVEF (>60%)( rel. contraindication) • Absence of MR( relative contraindication) • Absence of complicating factors from prev ious surgeries
  • 66.
    EARLY COMPLICATIONS OF FONTAN •Low cardiac output,heart failure or both . • Persistent pleural effusion. • Thrombus formation in the systemic venous pathways. • Liver dysfunction LATE COMPLICATIONS OF FONTAN • 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
  • 67.