Tricuspid atresia is a congenital heart defect where the tricuspid valve is absent, preventing blood flow from the right atrium to the right ventricle. It occurs in approximately 1-2.4% of congenital heart defects. Survival depends on the presence of an atrial septal defect to allow blood to bypass the right ventricle. Treatment involves multiple staged surgeries culminating in the Fontan procedure to reroute systemic venous return directly to the pulmonary arteries. Complications can include arrhythmias, ventricular dysfunction, protein-losing enteropathy, and thromboembolic events.

1. TRICUSPID ATRESIA

2. INTRODUCTION
• 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 %
• Survival depends upon the presence of an atrial
septal defect (ASD) to allow egress of blood from
the RA to LA.

4. HISTORY
• First reported by Kreysig in 1817.
• Clinical features reported by Bellet and
Stewart in 1933.
• Also by Taussig and Brown in 1936.
• In 1906, Kuhne initially categorized tricuspid
valve atresia

5. GENETICS
• Associated with microdeletions of 22q11, and
trisomies 13, 18, and 21 (8,9,10).
• Likelihood of a microdeletion of 22q11 is
about 7%.
• Two growth factor pathways areTGF- β/BMP
and Notch pathways

6. EMBROLOGY
• Development of the tricuspid valve is related to the sinus
(inlet) portion of the RV.
• Inlet portion of the RV is absent and infundibular portion is
developed
• Development/size of the trabecular portion of the RV is
variable
• Formation of the atrioventricular cardiac valves:Days 34 to
36
1.Formed from endocardial cushion tissue
2. Tricuspid valve, papillary muscles and chordae tendineae
formed largely from the conus septum.

11. Additional cardiovascular abnormalities occur in 18% of patients with normally related
great arteries and in 63% of patients with transposed great arteries.
These include coarctation of the aorta,patent ductus arteriosus (PDA), and right aortic arch
Extracardiac anomalies occur in 20% of cases.

13. HEMODYNAMICS
Determined by:
• Presence or absence of pulmonary valve atresia
• Severity of subpulmonary/pulmonary stenosis
• Relationship of the great arteries
• Presence of subaortic obstruction.
• Patients with TA and increased pulmonary blood flow
have relatively high systemic arterial oxygen saturation.
• NRGA demonstrate pulmonary or subpulmonary (at
the VSD) obstruction that is progressive

14. HEMODYNAMICS
• Most patients with transposed great arteries (type II-C) have
unobstructed pulmonary blood flow.
• VSD associated with tricuspid atresia has muscular
circumference and tends to become smaller over time.
• Restrictive VSD with NRGA produces progressive
subpulmonary stenosis and increasing hypoxemia.
• Restrictive VSD associated with TGA produces subaortic
obstruction.
• When subaortic obstruction coexists with PA band, LVH
hypertrophy leading to fibrosis and myocardial dysfunction

21. CXR

23. Newborns with prenatal evidence of severe outflow obstruction and those
demonstrating severe hypoxemia and acidosis should be treated promptly with
infusion of prostaglandin E1 to maintain patency of the PDA

24. SURGICAL MANAGEMENT
IST STAGE SURGERY
WITH PULMONARY OBSTRUCTION
WITHOUT PULMONARY OBSTRUCTION
WITH TGA AND SUBAORTIC OBSTRUCTION
SECOND STAGE SURGERY
BIDIRECTIONAL GLENN
THIRD STAGE
FONTAN COMPLETION

30. PA BANDING
• Primary objective : to reduce excessive PBF and
protect pulmonary vasculature from hypertrophy and
irreversible (fixed) pulmonary hypertension.
• PAB was classified as anatomically effective if it
reduced the MPA diameter to 50%
• Functionally effective : reduction of PAP to 50% of
systemic pressure
• Trusler formula aims for adequate PAB in the normally
related great artery (NRGA) group
• 20+WT IN KG
• IN ADMIXTURE LESIONS, 24+WT IN KG

31. Patients with D-TGA and subaortic obstruction
• With type II lesions who have a VSD that
obstructs aortic blood flow
• First stage could be enlargement of the VSD or
a Damus-Kaye-Stansel (anastomosis between
MPA and ascending aorta) with a modified BT
shunt.

36. Second and third stages
• The second stage for type I and II lesions
involves cavo-pulmonary anastomosis wherein
SVC connects to RPA
• Bidirectional Glenn or hemi-Fontan
procedure.
• Results in a passive flow of blood from the
upper body into the pulmonary vessels.
• Usually takes place at around six months.

37. PULSATILE PBF:
• POTENTIAL GROWTH OF PAS, IMPROVED SPO2,PREVENT PULMONARY AV
FISTULAS
•BETTER CAPILLARY RECRUITMENT,DECREASED PVR, PROVIDES HEPATIC FACTOR,
CAN GO FOR EARLY FONTAN
COMPLICATIONS:
INCREASED PLEURAL EFFUSIONS, LONGER HOSPITAL STAY, VOLUME OVERLOADIG
OF SINGLE VENTRICLE,MORE CHANCES OF AVVR

40. • Third stage is the Fontan procedure, first described in
1971 for TA
• Original Fontan involved end to end anastomosis of
right atrial appendage to the proximal end of RPA
• Undergone considerable modification since its
inception.
• In current era, involves either an extra-cardiac or
intra-atrial non-valved conduit between IVC and Pas.
• Conduit may be fenestrated, providing a “pop-off”
valve as lungs adjust to extra blood flow from lower
body.
• Results in total systemic venous return flowing
passively into PAs
• Usually performed after 3yrs.
• Patients with progressive ventricular dysfunction may
eventually require heart transplantation.

41. FONTAN
• The components of the original Fontan operation:
(1) Classic Glenn anastomosis to direct superior vena cava flow to the
right lung
(2) Redirection of inferior vena cava flow to the pulmonary artery with
a valved connection of the RA to the pulmonary artery
(3) Insertion of a valve into the inferior vena cava
(4) Closure of the ASD
(5) Obliteration of the connection between the pulmonary artery and
RV.

42. FONTAN

43. FONTAN
• Understanding of pulmonary artery flow
dynamics has evolved over time.
• Pulmonary flow occurs after Fontan for the
following reasons:
1. Residual kinetic energy from the previous
ventricular contraction
2. Negative intrathoracic pressure due to
spontaneous breathing
3. Low pulmonary arterial resistance
4. Normal atrial and ventricular relaxation

44. FONTAN
• Fontan operation remains as “definitive palliation” for
most patients with single-ventricle physiology.
• First major change was elimination of the valves in the
IVC and RA-PA connection.
• BDCPA became an integral part of the Fontan
operation.
• Marked enlargement of the RA and high incidence of
atrial arrhythmias associated with the atriopulmonary
Connection.
• Extracardiac conduit technique -preferred approach by
many for patients with tricuspid atresia.
• Bridges et al. described the concept and use of
fenestration

46. FONTAN
• In older AP connection, inspiration and
ventricular relaxation augment flow when
systemic AV valve opens.
• Atrial contraction (systemic venous atrium)
also augments flow.
• Relaxation of atrium will permit flow
reversal.
• This to-and-fro flow pattern is not efficient
and contributes to RA dilation.

47. FONTAN
• In extracardiac conduit, RA mechanics have less effect
on flow.
• Flow reversals in pulmonary arteries are not expected
in extracardiac conduit.
• Relaxation of the pulmonary venous (left) atrium draws
blood flow from the pulmonary veins.
• Another important feature of the echocardiographic
assessment of the patient after Fontan is flow through
fenestration.
• Mean pressure in the entire Fontan circuit should be
equivalent: mean SVC, IVC, Fontan conduit, and
pulmonary artery pressures should all be equal.

50. FONATAN
• Mean fenestration gradient is equivalent to
transpulmonary gradient.
• Normal gradient should be 5 to 8 mm Hg, determined by
PVR.
• Low fenestration gradient is usually the result of
hypovolemia.
• An elevated gradient:Fontan pathway stenosis, intrinsic
pulmonary resistance issues, lung disease, or pulmonary
venous obstruction.
• Elevation of LA or LVEDP will cause elevation in mean PA
and Fontan conduit pressures but will not change
transpulmonary gradient if CO normal.

51. FONTAN
• Echocardiographic evaluation of the patient after Fontan is
challenging.
• Clues to Fontan failure that can be assessed:
1. Inferior vena cava dilation with presence of spontaneous echo
contrast
2. Reduction in ventricular contractility and/or worsening diastolic
function
3. Assessment of anatomic pathway stenosis
• Small gradients in the Fontan circuit and branch pulmonary arteries
are important
• Altered flow patterns can reflect diastolic dysfunction or
dysrhythmia
4. Calculation of the transpulmonary gradient by measuring the
“average” mean fenestration gradient over several cardiac cycles
5. Reduced gradients suggest hypovolemia or reduced cardiac output

53. RESULTS
• Results of the Fontan operation for patients with
TA are superior to those for other forms of
functional single ventricle.
• Operative survival (<30 days) was 80% to 85% in
early series , increased to 95% in recent studies
• Early and late mortality were higher for patients
operated in the 1970s and 1980s

55. COMPLICATIONS
• Glenn surgery has excellent short and long term outcomes
• Operative mortality less than 1% and 5-year survival of
87%.
• Long term complications are not common after this
surgery
• Thrombosis and thromboembolic events carry the highest
mortality.
• Monagle, et al. summarized a number of studies and
reported that the occurrence of thrombosis ranged from
2.2% to 19%
• May occur in the Fontan conduit, right atrium, lungs
(pulmonary embolism), or brain (stroke-systemic arterial
emboli.)

56. COMPLICATIONS
• Other complications include arrhythmias, ventricular
dysfunction, cyanosis, and protein-losing enteropathy.
• Systolic and diastolic ventricular dysfunction is known
to be a long term complication of single ventricle
palliation.
• Gelatt et al. reported the incidence of atrial
arrhythmia 5 years after Fontan with AP connection, a
total caval pulmonary connection, or RA to RV
connection as 33%, 18%, and 11%
• Mostly atrial tachycardias,due to suture lines in RA..
interfere with atrial conduction.

57. COMPLICATIONS
• Protein-losing enteropathy (PLE) is a well-described
complication caused by lymphatic congestion.
• It occurs in 5% to 12% of patients after Fontan.
• Longstanding PLE can affect nutritional status of patient.
• Mainstay of treatment for PLE is supportive.
• Treatment :diuretic therapy, replacing albumin, replacing
immunoglobulin and high protein, low-fat diet, octerotide.
• Enteral corticosteroid use has demonstrated maintainance
albumin levels and decrease symptoms.
• Pleuroperitonial shunt

58. COMPLICATIONS
• Plastic bronchitis is another possible long term
sequelae.
• Thick secretions in the airway lumen
characterize it.
• Occurs in around 4% of patients
• Caused by spillage of proteinaceous lymph
through lymphatic-bronchial communications.

59. COMPLICATIONS
• May have cyanosis for a variety of reasons.
• Some degree of right to left shunting across
the fenestration in a Fontan.
• Systemic venous and pulmonary venous
collaterals may develop.
• Cyanosis exacerbated during exercise.
• May benefit from transcatheter fenestration
closure or venovenous occlusion.

60. COMPLICATIONS
• Fontan associated liver disease (liver fibrosis
and cirrhosis)
• Renal dysfunction
• Somatic growth problems
• Psychosocial and neurodevelopmental issues
• Decreased exercise tolerance

61. THANK YOU
HAVE A NICE DAY