Hypoplastic left heart syndrome (HLHS) is characterized by underdevelopment of the left side of the heart. It requires multi-stage surgical intervention to establish an adequate circulation. The first stage, known as the Norwood procedure, involves reconstructing the aortic arch and creating a shunt to provide pulmonary blood flow. Subsequent stages include the hemi-Fontan/Glenn procedure and final Fontan completion. Alternative treatments include heart transplantation or hybrid approaches. Long-term survival has improved but remains dependent on surgical expertise and individual patient risk factors. Ongoing management focuses on achieving balanced systemic and pulmonary circulations through each stage of treatment.

1. HYPOPLASTIC
LEFT HEART
SYNDROME

2. Basic Diagnosis
• Intra uterine
• Post natal
Preoperative
Mx
Surgical
evolution
Sx strategies Results

3. HYPOPLASTIC LEFT HEART SYNDROME
VS
HYPOPLASTIC LEFT HEART PHYSIOLOGY

4. HYPOPLASTIC LEFT HEART PHYSIOLOGY
• Inability of the left heart to sustain adequate cardiac
output following birth because of underdevelopment
of one or more left heart structures despite surgical or
medical intervention.

6. BASIC TERMS
• “Atresia” is defined as the congenital absence or closure of a normal body
orifice or tubular organ.
• “Stenosis” is narrowing or stricture of a duct or a canal.
• “Hypoplasia” is the incomplete development or underdevelopment of an
organ or tissue

7. WHAT IS IT??
• Continuum
• By definition incompatible with a biventricular circulation

8. HYPOPLASTIC LEFT HEART SYNDROME
• Defined as a spectrum of cardiac malformations characterized by
underdevelopment of the left heart with significant hypoplasia of the left
ventricle including atresia, stenosis, or hypoplasia of the aortic or mitral
valve, or both valves, and hypoplasia of the ascending aorta and aortic
arch.”

9. HYPOPLASTIC LEFT HEART COMPLEX
• Cardiac malformation at the milder end of the spectrum of hypoplastic left
heart syndrome characterized by underdevelopment of the left heart with
significant hypoplasia of the left ventricle and hypoplasia of the aortic or
mitral valve, or both valves, in the absence of intrinsic valvar stenosis or
atresia, and with hypoplasia of the ascending aorta and aortic arch.”

10. HYPOPLASTIC LEFT HEART VARIANTS OR
RELATED MALFORMATION
• Not truly HLHS
• Previously “Aortic atresia with ventricular septal defect and a well-
developed mitral valve and left ventricle” as a type of hypoplastic left heart
syndrome
• Reclassified as a “hypoplastic left heart syndrome-related malformation”
because it does not include significant left ventricular hypoplasia, which
is considered an essential element of hypoplastic left heart syndrome.

11. MORPHOLOGIC SUBTYPES
• Four can be defined based on the status of the left-sided heart valves:
• Aortic and mitral atresia (AA/MA)
• Aortic atresia and mitral stenosis (AA/MS)
• Aortic stenosis and mitral atresia (AS/MA)
• Aortic and mitral stenosis (AS/MS)
• AA/MA is the most common, AS/MA is the least common, and AA/MS is the
highest-risk subtype.

12. HOW TO
DIAGNOSE??

13. PRENATAL- IN UTERO DIAGNOSIS
• Schedule the delivery
• Regular scans
• Entire team
• Other anomalies
• Fetal intervention

14. FETAL CARDIAC INTERVENTIONS
• Indications:
1. Severe aortic stenosis (AS) in an attempt to prevent
progression to HLHS.
2. Intact atrial septum in an attempt to improve perinatal
survival and surgical outcome.

18. FETAL INTERVENTION
Hoped that successful
intervention in the fetus will
lead to a biventricular
circulation at the time of
birth.

19. • Successful decompression of the
LA in utero may avoid severe
hypoxemia at birth, and
theoretically, may also reduce
prenatal lung damage and improve
otherwise-dismal outcomes
IN UTERO ATRIAL SEPTOPLASTY

21. POST NATAL DIAGNOSIS
• Varied
• Dependent on the size and presence of an atrial septal defect (ASD) and
patency of the ductus arteriosus.
• Severely restrictive atrial septum - intense cyanosis with respiratory distress.
• Non restrictive atrial defect - relatively pink.
• Ductal closure - lethargic and has respiratory distress, cool extremities, and
pallor

22. • The upper- and lower-extremity pulses are palpable and symmetric early but
are reduced later as ductal closure ensues.
• Auscultation is generally benign, especially in comparison with a sometimes
dramatic clinical picture. The second heart sound is single and loud, reflecting
the absence of the aortic valve component and the associated PA hypertension.
A third heart sound may be heard, especially in the presence of ventricular
dysfunction.
• Murmurs are uncommon, although a soft systolic ejection murmur may be
generated from increased flow across the pulmonary valve. A louder PSM may
be heard if there is significant tricuspid regurgitation

23. CXR
• Nondiagnostic
• Reflect the degree of atrial-level restriction.
1. Severely restrictive atrial septum, the heart size may be
relatively normal; however, there is significant pulmonary
edema.
2. Nonrestrictive, there is pulmonary overcirculation with
cardiomegaly.

24. 2D ECHO
• Small, muscle-bound left ventricular chamber that does not extend to the
cardiac apex .
• The LA is usually small but may be dilated in patients with a restrictive atrial
septal defect.
• The ascending aorta can be well visualized from the long-axis view and is
frequently small (2 to 3 mm in diameter); the aortic valve may or may not be
patent.
• Color Doppler interrogation of the ventricular septum may show
ventriculocoronary arterial connections. Prognostic implications.

25. • Left Ventricular Long Axis To Heart Long Axis Ratio <0.8,
• Indexed Aortic Root Diameter <3.5 Cm/M2 Of Body Surface
Area,
• Indexed Mitral Valve Area <4.75 Cm2/M2, And
• Left Ventricular Mass Index <35 G/M2

27. NOW WE HAVE A CHILD DIAGNOSED WITH
HLH PHYSIOLOGY. SO WHAT NEXT??
MANAGE IT

28. SHORT RECAP OF PHYSIOLOGY
Foetus with HLH
Transition : foetal to
neonatal
physiology are life-
threatening
Ductus arteriosus
closes
systemic perfusion is
impaired
decrease in PVR
volume shift from the
systemic to the
pulmonary
circulation

29. ISSUES FACED
1. PDA closing
2. Balanced circulation
3. Acidosis
4. Additional anamolies
SOLUTIONS
1. Start prostaglandins
2. Maintain Oxygen saturations =
75–80%
3. Bicarbonate and resuscitate
4. Routine pre-operative
ultrasound scans of head +
kidneys.
IMMEDIATE POST NATAL

30. MANAGEMENT OF A LOW SYSTEMIC
CARDIAC OUTPUT
CAUSES
1. Excessive pulmonary blood flow
(high saturations)
2. Impaired systemic ventricular
function +/- significant tricuspid
regurgitation (normal or low
sats)
3. Restrictive ASD (usually low
sats)
4. Restrictive duct (any sats)
SOLUTIONS
1. Control ventilation. consider
careful introduction of a low
dose vasodilator (sodium
nitroprusside 0.5-1mcg/kg/min).
2. Consider dobutamine + /-
vasodilator
3. Needs intervention.
4. Increase prostaglandin.

31. ROLE OF ATRIAL SEPTOSTOMY

32. Restrictive ASD
In utero
Fetal echo
Post natal
severe metabolic acidosis,
poor oxygenation
CXR
Intubate
PGE1
Sedate and ventilate

33. • Decision based on:
1. Child’s oxygen saturation ( <50–60%), and
2. Not simply on an echo-derived pressure gradient.
• If the septum is opened inappropriately or excessively,
torrential pulmonary blood flow can result leading to
a worsening metabolic acidosis as systemic blood flow
becomes inadequate.
BALANCE OF QP AND QS

34. TO ACHIEVE
• Adequte systemic output include
1. normal peripheral perfusion,
2. adequate urine output, and
3. absence of metabolic acidosis.
• Reasonable balance of Qp and Qs
1. PaO2 of about 40 mmHg and
2. Systemic diastolic blood pressure > 30 mmHg.

35. SURGERY SHOULD NOT BE
UNDERTAKEN UNTIL THE CHILD IS
ESSENTIALLY NORMAL WITH RESPECT
TO ALL ORGAN SYSTEMS OTHER THAN
THE CARDIORESPIRATORY SYSTEM

36. SURGICAL OPTIONS
• Staged reconstruction - Norwood and its modifications
• Followed by stage II and III
• Transplantation
• Transplantation
• Hybrid approach

37. HISTORICAL HIGHLIGHTS

38. • 1970 - Cayler and colleagues - Anastomosis between right
pulmonary artery and ascending aorta with placement of
bilateral pulmonary artery bands.
• 1977, Doty and Knott - primary reconstruction that included
atrial septation and a right atrium (RA) to-PA Fontan circuit.

39. • 1980 - William Norwood – 1st successful palliation
• 1983 - Norwood - the first report of a successful staged
approach.

40. • 1985 - Leonard Bailey - Orthotopic cardiac
transplantation.
• 1993 - Hybrid procedure - Gibbs

41. TIMING

42. NORWOOD EVOLUTION-
1980 THE ORIGINAL

43. 1983
MODIFICATION
• A direct aortopulmonary
anastomosis was
performed without the
use of homograft patch
• Central shunt was
constructed.

44. 1988 MODIFICATION
• Introduced to prevent
obstruction in the aortic arch
as seen earlier in the series.

45. WHY SO MANY STAGES??
• At birth the lungs are immature
• Vascular resistance is naturally high, precluding a
Fontan procedure in the neonatal period.

46. NORWOOD PROCEDURE

47. PRIMARY GOALS
1. Unrestricted interatrial communication
2. Reliable source of pulmonary blood flow,
3. Provision of unobstructed outflow to the systemic
circulation

48. ESSENTIAL STEPS
• Establishment of CPB
• Arch reconstruction
• Atrial septectomy
• Construction of pulmonary blood flow

49. SURGICAL TECHNIQUE
• Perfusion techniques
1. DHCA
2. Antegrade continuous cerebral perfusion with hypothermia
3. Innominate artery + DTA cannulation( high flow, no deep
hypothermia)

50. DHCA

51. ANTEGRADE CEREBRAL PERFUSION

52. Imoto Y, Kado H, Shiokawa Y, Minami K, Yasui H. Experience
with the Norwood procedure without circulatory arrest. J Thorac
Cardiovasc Surg. 2001;122:879–82.

53. DISTAL MPA

56. • Femoral vein - Strong though thin and
hemostatic.
• Pulmonary artery homograft - unpredictable in
its tendency to dilate when pressurized.
• Aortic homograft - thick and tends to calcify
aggressively in the neonate.

59. NEOAORTIC RECONSTRUCTION
“CUFF” TECHNIQUE “TUBE” TECHNIQUE

60. ROGER MEE MODIFICATION

63. PULMONARY BLOOD FLOW
MBTS
SANO

64. MBTS
• In most cases, a 3.5-mm-
diameter PTFE tube graft
• less than 2.5 kg, a 3.0-
mm-diameter graft should
be considered
SANO SHUNT
Weight Diameter
< 3 kg 4mm
3-4 kg 5mm
>4 kg 6mm

65. ADVANTAGES/DISADVANTAGES OF THE
MODIFIED BLALOCK-TAUSSIG SHUNT
Advantages Disadvantages
No ventriculotomy Coronary steal
(Increased diastolic runoff)
Myocardial ischemia
Circulatory instability
Decreased right ventricle function
Limits right ventricle overload Inc Qp& Decreased end organ
perfusion
Good pulmonary artery growth Shunt stenosis/thrombosis

66. ADVANTAGES/DISADVANTAGES OF THE SANO
SHUNT
Advantages Disadvantages
No diastolic runoff ->Higher
diastolic pressure
Right ventriculotomy
Arrhythmias
Right ventricle dysfunction
Right ventricle aneurysm
Tricuspid valve dysfunction
Improved coronary perfusion Early or progressive hypoxemia
Lower pulmonary to systemic ratio Free PR -> Increased volume load on
right ventricle
Pulsatile pulmonary blood flow Inadequate pulmonary artery growth/
central PA distortion
Improved end-organ perfusion More chance - Shunt thrombosis
ECMO can be used

67. POSTOPERATIVE CARE
RULE OF FOURTY (40)
- Fi O2 ~ 0.40
- Pa CO 2 ~ 40 mmHg.
- Pa O2 ~ 40 mmHg.
- Hct. ~ 40 %

68. 2 MAJOR CONCERNS
• Tricuspid valve
• Aortic arch obstruction

69. 2ND STAGE
• HEMI-FONTAN
• BD GLENN

70. EARLY 2ND STAGE
• Reduces duration of inefficient mixed circulation
• Maximal preservation of systemic ventricular function by reducing
right ventricular volume work and chance of distortion of the pulmonary
arteries caused by tethering from the PTFE graft
• It allows use of a relatively small-diameter shunt at the time of first-stage
reconstruction.
• Hemodynamic efficiency is markedly improved and mortality risk substantially
reduced

71. BDG HEMI-FONTAN

72. Operative Techniques in Thoracic and Cardiovascular Surgery 2013 18, 124-137DOI: (10.1053/j.optechstcvs.2013.09.001)
Copyright © 2013 Elsevier Inc. Terms and Conditions

73. Operative Techniques in Thoracic and Cardiovascular Surgery 2013 18, 124-137DOI: (10.1053/j.optechstcvs.2013.09.001)
Copyright © 2013 Elsevier Inc. Terms and Conditions

74. Operative Techniques in Thoracic and Cardiovascular Surgery 2013 18, 124-137DOI: (10.1053/j.optechstcvs.2013.09.001)
Copyright © 2013 Elsevier Inc. Terms and Conditions

75. Operative Techniques in Thoracic and Cardiovascular Surgery 2013 18, 124-137DOI: (10.1053/j.optechstcvs.2013.09.001)
Copyright © 2013 Elsevier Inc. Terms and Conditions

76. BDG Hemifontan
simple procedure that can be performed
under short periods of CPB without the
need for aortic cross clamping or
circulatory arrest. It may even be
performed without CPB.
Preserves natural SVC-RA confluence
chances of phrenic nerve injury Less
future lateral tunnel Fontan may be
difficult
Easier
Homograft patch augmentation
Better flow dynamics

77. THIRD STAGE- FONTAN
Extra cardiac Lateral tunnel

78. TRANSPLANTATION
ADVANTAGE
1. Single operation
2. Biventricular physiology
DISADVANTAGES
1. Limited availability of donor
hearts,
2. Requirement for lifelong
immunosuppression, and
3. late graft failure

79. HYBRID STRATEGY

80. • Bilateral PA banding
• Ductal stenting
• Reverse Blalock-Taussig shunt

82. ADVANTAGES
• Avoidance of circulatory arrest in the early neonatal
period
• Shifting the major surgical stage to later period until
the brain is more developed.

83. FUNDAMENTAL WEAKNESS OF HYBRID
• Blood flow to the lungs occurs throughout the cardiac cycle, similar to a Blalock
shunt. Thus the lungs compete with the brain and coronary arteries for flow
during diastole.
• Difficulty of removing the stent from the proximal descending aorta which
complicates arch reconstruction.
• Dilation of the main pulmonary artery as a consequence of the bilateral
pulmonary artery bands. Dilation can lead to neoaortic valve regurgitation
• Retrograde COA is Achilles heel

84. SURVIVAL
• Variable among institutions
• The survival was 76% at 1
month, 60% at 1 year, and 54%
at 5 years.
• In contrast, at less experienced
institutions, hospital mortality
still approached 50%.

85. • 1-year survival was 74% for patients with a right ventricle–to–pulmonary trunk conduit
procedure, and 64% for those with a systemic artery–to–pulmonary artery shunt
procedure

86. RISK FACTORS OF DEATH
1. Intact or highly restrictive
atrial septum
2. MS/AA with LV-coronary fistula
3. Moderate or severe TR
4. Depressed right ventricular
function preoperatively

88. • 25% of listed patients died while
awaiting transplantation
• The mean waiting period for those
receiving an organ was
1.3 months.

89. BIVENTRICULAR REPAIR
• Z-score for the mitral valve of greater than -3, and a left ventricle of normal
size.
• 3 groups :
1. HLHC
2. AA & VSD
3. Critical AS& LV hypoplasia

91. TAKE HOME POINTS
• Management should begin as soon as possible, preferably
prenatally.
• Diagnosis of HLH is made by echocardiography
• Prompt diagnosis& treatment is essential
• Surgical strategies include staged reconstruction,
transplantation& hybrid approach.

92. ‘‘A JOURNEY OF A THOUSAND MILES MUST
BEGIN WITH A SINGLE STEP.’