Fontans surgery Its evolution & types of Fontans Pre-requisites before surgery Indications Complications Management of Complications

1. DR.NIHAR MEHTA
J A S L O K H O S P I T A L & R E S E A R C H C E N T R E
FAILING FONTANS

2. Fontan Circulation
 Fontan Procedure
 Fontan Physiology
 Patient Selection
 Post-Fontan Complications
 Fontan Outcomes
 Post-Fontan Pregnancy
 Anesthesia Implications

3. Fontan Procedure
 It is used to treat complex congenital heart diseases with
ONE FUNCTIONAL VENTRICLE that maintains systemic
and pulmonary circulations which are not connected in
series but in parallel
 Bi-ventricular repair is not possible
 Tricuspid atresia
 Pulmonary atresia / Severe pulmonic stenosis with intact IVS
 Double inlet ventricle
 Single ventricle
 Hypoplastic left or hypoplastic right heart
 Heterotaxy syndromes
 Severe Ebstein’s anomaly

4. Fontan Procedure
 A single ventricle parallel circuit creates 2 major
disadvantages:
 Systemic arterial DESATURATION at rest
 Chronic VOLUME OVERLOAD to the ventricle
 Without surgical intervention, there is about a 90%
mortality before age 1
 A completion Fontan is a palliative step in a series
of surgeries used to improve oxygenation and
cardiac function

6. The Original Fontans Procedure
ATRIOPULMONARY FONTANS
 Done for Tricuspid Atresia
 End to end shunt from SVC
to Right Pulmonary artery
 Connection of Left
Pulmonary artery to Right
atrium  diverts IVC blood
to LPA
 Used 2 homograft valves

9. INTRA ATRIAL FONTAN –
LATERAL TUNNEL
 Cavopulmonary
Fontan circulation
 Intraatrial conduit
 IVC to the right
pulmonary artery

10. INTRA ATRIAL FONTANS

12. EXTRA ATRIAL FONTANS
 Extraatrial
cavopulmonary Fontan
circulation,
 Extraatrial conduit
 IVC to the right
pulmonary artery

13. EXTRA ATRIAL FONTANS

16. How to achieve a Fontan Circuit
 At BIRTH, it is impossible to create a Fontan
circulation:
 PVR is elevated for several weeks
 SVC and IVC veins and pulmonary arteries may be too small
 STAGED APPROACH  Adapt to changing
hemodynamics

17. How to achieve a Fontan Circuit
 Neonatal period (1 month)
 Improve the limited flow to the lungs – BT SHUNT / PA
BAND
 The infant is allowed to grow for several months
 Pulmonary vasculature will develop more
 PVR will stabilize
 PROBLEMS
 The heart will be subjected to chronic volume overload / pressure overload
 Ventricular function may deteriorate
 Expect mild progressive desaturation of the infant

18. How to achieve a Fontan Circuit
BT SHUNT PA BAND

19. How to achieve a Fontan Circuit
 At age 4-12 months
 The superior vena cava will be connected to the pulmonary
artery (Glenn)
 This will decrease the volume load to the heart
 The patient will remain cyanotic as the desaturated blood from
the IVC is still allowed to flow to the aorta

20. How to achieve a Fontan Circuit
Single Ventricle – BT
Shunt
Single Ventricle –
Bidirectional Glenn
http://www.cincinnatichildrens.org/health/heart-encyclopedia/anomalies/sv.htm

21. How to achieve a Fontan Circuit
 At 1-5 years of age
 The Fontan circuit is completed by connecting the IVC
to the pulmonary artery
Single Ventricle –
Bidirectional Glenn
Single Ventricle –
Completed Fontan
http://www.cincinnatichildrens.org/health/heart-encyclopedia/anomalies/sv.htm

22. FONTANS STAGING
SUMMARY
 STAGE 1: AT 1 MONTH OF AGE
 OPTIMISE QP/QS :
 BT SHUNT / PA BAND
 STAGE 2: AT 4-12 MONTHS
 OPTIMISE VENTRICULAR VOLUME:
 BD GLENN / HEMI FONTAN
 STAGE 3: AT 1-5 YEARS
 REDUCE ADMIXTURE & DIRECT FUNCTIONAL
VENTRICLE TO SYSTEMIC CIRCUIT
 FONTANS

23. Fontan Modifications
d'Udekem, Y. et al. Circulation 2007;116:I-157-I-164
Fontan surgical techniques: Classical atriopulmonary connection (A), Lateral tunnel (B),
and extracardiac conduit (C)

24. Fontan Physiology
 The sub-pulmonary ventricle is bypassed
 Systemic venous return is diverted directly into the
pulmonary arteries
 Goal is to provide adequate pulmonary blood flow and
cardiac output with minimal elevation in venous pressure
 Systemic and pulmonary venous returns are
separated:
 CYANOSIS is relieved
 VOLUME LOADING on the ventricle is significantly
reduced

25.  AGE – 4 to 15 years
 Normal SINUS rhythm
 Normal SYSTEMIC VENOUS RETURN
 Normal RIGHT ATIRAL VOLUME
 Mean PULM. ARTERY PRESSURE <15 mmHg
 PULM. VASC. RESISTANCE < 4 Woods units
 PULM ART. TO AORTA DIAMETER RATIO > 0.75
 LVEF = 60%
 COMPETENT MITRAL VALVE
 ABSENCE OF PULMONARY VALVE DISTORTION
Patient Selection
TEN COMMANDMENTS

26. Fontan Physiology

27. Fontan Outcomes
 Despite the abnormal circuit, most patients with a
Fontan circulation can lead a nearly normal life,
including mild to moderate sport activities
 More than 90% of hospital survivors are NYHA
functional class I or II
 Patient’s remain slightly desaturated with values in
the low 90s

28. Fontan FAILURE
Fontan failure is defined as:
 NYHA functional class III or IV
 Death
 Fontan Take-down / Conversion
 Cardiac Transplantation

29. Fontans FAILURE
 MRI is best for postoperative evaluation of
patients with Fontan circulation
 Cardiac Transplantation remains the only
definitive treatment for those with failing
Fontan circulation.

30. Fontan Circulation Complications
 Complications after Fontan repair related to:
 Elevated pulmonary artery pressure,
 Increased venous pressure / Increased venous congestion
 Anatomic abnormalities of the right and left pulmonary
arteries
 Atrial-ventricular valve regurgitation (AVVR)
 Poor LV function
 Stenosis / Dilatation of the Conduit

31. Fontans Complications

32. Fontans Complications - Pathophysiology

33. Fontans Complications - Pathophysiology

35. Fontans Complications
LEFT VENTRICLE
 Volume overload  dilatation, hypertrophy become
hypocontractile.
 Total bypass of the right side of the heart  marked
reduction of preload to the systemic ventricle  systolic
and diastolic dysfunction of the ventricle  impaired
compliance  low cardiac output.
 The congenital malformation itself also may be a
predisposing factor for ventricular dysfunction
 Systemic ventricle may be a morphologic right ventricle /
indeterminate ventricle  may fail after years of
systemic loading

36. Fontans Complications
LEFT VENTRICLE

37. Fontans Complications
LEFT VENTRICLE
 Reduced preload is the dominant factor
contributing to poor ventricular function
 Failure manifests as exercise intolerance
 Inotropes, afterload reducers, vasodilators and B-
blockers are generally ineffective
 Pulmonary vascular resistance will control cardiac
output
 Improving pulmonary blood flow will improve cardiac
output

38. Fontan Complications
PULMONARY CIRCULATION
 Absence of the hydraulic force of the right ventricle
 paradox of Systemic Venous Hypertension (mean
pressure, >10 mm Hg) and Pulmonary Artery
Hypotension (mean pressure, <15 mm Hg).
 Increase pulmonary vascular resistance.
 Pulmonary vascular resistance is an important
determinant of cardiac output in patients with
Fontan circulation
 Stenosis or leakage of surgical anastomoses may
adversely affect pulmonary blood flow.

39. Fontans Complications
INFERIOR VENA CAVA
Chronic congestive heart failure ( CVP)
Increased Hepatic sinusoidal pressure
Cirrhosis
Portal Venous Hypertension
Hepatic Dysfunction.

40. Fontans Complications
RIGHT ATRIUM
 ATRIOPULMONARY FONTAN CIRCULATION
 RA is exposed to elevated systemic and right atrial
pressure dilatation and hypertrophy
 Dilatation
 Arrhythmia
 Stasis & Poor Blood Flow To The Lungs.
 Clot Formation.
 Fontan Surgery may injure the sinus node or
conducting fibers  ATRIAL ARRHYTHMIA.

41. Fontans Complications
RIGHT ATRIUM
 Predisposition to ATRIAL DYSRHYTHMIAS
 Incidence - Up to 40% - 50% of patients 10 years post-op
 Most commonly :
 Intra-atrial Re-entry Tachycardia / Paroxysmal atrial tachycardia
 Atypical Atrial Flutter
 Sinus node dysfunction
 Ventricular arrythmias (rare)
 Safest treatment is immediate DC cardioversion
 Long term treatments include Medication, Ablation,
Pacemaker, Fontan Conversion

42. FONTAN CONVERSION

43. FONTAN CONVERSION
 Extra cardiac Conduit –
IVC to PA
 Bidirectional Glenns Shunt
– SVC to PA
 Resection of the diated
Right Atrium
 Maze Procedure (Anti-
arrythmic)
 Epicardial Pacemaker

44. AFTER FONTAN CONVERSION

45. Fontans Complications
COLLATERALS & SHUNTS
RIGHT-TO-LEFT SHUNTS
 Incomplete Closure Or A Residual Atrial Septal Defect
 Fenestration between surgical conduits & right atrium 
right-to-left shunt
 Surgical Redirection Of Coronary Sinus Blood flow to the
left atrium
 Pulmonary Arteriovenous Malformations (20%) :
 Due to the absence of pulsatile blood flow
 Underfilling of the pulmonary vascular bed
 Reduced hepatic venous factor
 Aortopulmonary Collateral vessels are common
 arise from the thoracic aorta, internal mammary arteries, or
brachiocephalic arteries

46. Fontans Complications
LYMPHATIC SYSTEM
 High venous pressure & impaired thoracic duct drainage
 Lymphatic system dysfunction.
 Increased pulmonary lymphatic pressure  interstitial
pulmonary edema or lymphedema.
 Leakage into the thorax or pericardium 
PERICARDIAL AND PLEURAL EFFUSIONS (often
right-sided) and CHYLOTHORAX
 Rx – Reduce CVP , Fenestration , Fontan Conversion /
Take down

47. Fontans Complications
LYMPHATIC SYSTEM
PROTEIN-LOSING ENTEROPATHY (4%)
 Its cause is unclear
 Elevated systemic venous pressure  Elevated hepatic
and portal venous pressure  Loss of enteric protein
 Interstinal Lymphangiectasis  Loss of enteric protein
 Hypoproteinemia, Immunodeficiency,
Hypocalcemia, And Coagulopathy
 Fatigue, Peripheral Edema, Pleural & Pericardial
Effusions, Ascites & Chronic Diarrhea.
 Low serum albumin level & Increased fecal α1-
antitrypsin levels

48. Fontans Complications
LYMPHATIC SYSTEM
PROTEIN-LOSING ENTEROPATHY (4%)
 Poor prognosis  5-year survival 50%
 Associated with increased Mortality
 Rx: Many treatments tried
 Dietary Modifications with high-protein and high medium-chain
triglycerides,
 Afterload Reducing Agents, Inotropic Agents, Digoxin, diuretics
 Heparin, Albumin Infusions, Octreotide, Prednisone
 Fenestration / Fontan Conversion / Cardiac Transplantation

49. Fontans Complications
LYMPHATIC SYSTEM
PLASTIC BRONCHITIS (< 1%–2%)
 Noninflammatory Mucinous Casts that form in the
tracheobronchial tree and obstruct the airway.
 Cause : unknown;
High Intrathoracic Lymphatic Pressure Or
Obstruction of lymphatic flow Lymphoalveolar
Fistula And Bronchial Casts

50. Fontans Complications
LYMPHATIC SYSTEM
PLASTIC BRONCHITIS (< 1%–2%)
 Clinical manifestations : dyspnea, cough, wheezing, and
expectoration of casts, severe respiratory distress with
asphyxia, cardiac arrest, or death
 Rx
 Repeat bronchoscopy to remove the thick casts ;
 Aerosolized urokinase or tissue plasminogen activator
 Surgical ligation of the thoracic duct may cure by
decreasing intrathoracic lymphatic pressure and flow

51. Fontan Circulation Complications
BLOOD VESSELS
Predisposition to COAGULOPATHIES
 Thrombosis is more likely in patients with low CO and
venous stasis
 Increased incidence of coagulation factor abnormalities
because of Hepatic Congestion
 Protein C
 Protein S
 ATIII deficiency
 Chronic cyanosis–induced Polycythemia
 Leads to chronic / recurrent Pulmonary Embolism
 Anticoagulation / Asprin Prophylaxis of all patients is
controversial

53. FONTANS MORTALITY
Predictors of
ALL CAUSE MORTLITY / CARDIAC TRANSPLANT
 Hypoplastic left heart syndrome
 Protein losing enteropathy
 Raised CVP
 Diuretic treatment

54. FONTANS MORTALITY
 Modes of death were as follows:
 Sudden Cardiac Death
 Thromboembolism
 Heart Failure
 Sepsis
 Others

55. SUMMARY
 The Fontan procedure is considered palliative and
enables survival for several decades
 “Perfect” Fontan Operation Was An Elusive Goal
 Complications after Fontan are related to increased
venous pressure, increased venous congestion, and
chronic low cardiac output

56. SUMMARY
 Fontans failure is difficult to reverse … so it should
be prevented
 Common long-term sequelae include severe right
atrial dilation, atrial arrythmias, thromboemboli,
hepatic dysfunction, progressive ventricular
dysfunction and AV valve regurgitation, and
worsening cyanosis from systemic venous
collateralization, pulmonary arteriovenous
malformations.

57. SUMMARY
 Post-Fontan goals include maintaining adequate
preload and minimizing increases in pulmonary
vascular resistance
 MRI is the best investigation
 Cardiac Transplant is only definitive treatment

58. THANK YOU