CASE DISCUSSION Dr. KM Law Fetal Medicine, O&G, CUHK

Fetal Echocardiography

Case 1

Referred to us for discrepancy in size between the 2

outflow tracts of the fetus with a smaller aorta at 21

weeks

• Isolated – no haemodynamic consequences

• Most reported cases – associated with cardiac or

extracardiac anomalies

– Truncus arteriosus, TOF, DORV, TGA; IAA, transverse

AA hypoplasia with or w/o CoA, RAA/DAA; VSD, ASD

– Chromosomal anomalies (T18)

– Genetic syndromes: 22q11.2 microdeletion, Noonan,

Holt Oram

– VACTERL

Crossed PAs

Interrupted Aortic Arch

Type A: Distal to the LSA

Type B: Between LCCA & LSA

Type C: Between IA & LCCA

• Pathogenetically different from type A

– Type A: an extreme form of CoA due to abnormal flow

during embryogenesis

• Conotruncal defect

– Developmental anomaly of the branchial arch system

• Posterior displacement of infundibular septum

– Malalignment subpulmonary VSD

– Subaortic stenosis

• Arch may be left or right, SA may be aberrant

• Strong association with 22q11.2 microdeletion

Type B IAA

Case 2

Referred to us for SUA and RAA of the fetus at 22

weeks

Left

Right

Left

Right

Left

Right

Left

Right

18

Left

Right

Left

Right

Left

Right

Anomalous Left

Brachiocephalic Vein

Left

Right

Normal LBCV

Left internal jugular vein Right internal jugular vein

Left subclavian vein Right subclavian vein

Left brachiocephalic vein

Right brachiocephalic vein

Superior vena cava

Aortic arch

Pulmonary artery Azygos vein

Normal LBCV

• Rare: 0.2 – 1% of patients with CHD

• Isolated: very rare

• 4 types (Takada, et al. 1992)

Anomalous LBCV

• Not cause symptoms by itself

• High association with CHD

– RAA, pul. obstruction: TOF, TOF+PA; ASD, VSD

• Radiologists – structure confusion

– PLSVC, TAPVC asc. vein; RPA, enlarged LN

• Cardiologists – TV pacemaker insertion

• Anaesthetists – CVP line insertion

• Cardiac surgeons – operative difficulty

– surgical approach, cannulation of SVC for CP bypass

Anomalous LBCV Clinical significance

• Not included in Takada’s classification

• Failure of normal or abnormal development of

LBCV above or below the aortic arch

• LSVC not persistent

Anomalous LBCV Retro-esophageal/tracheal

Left superior intercostal vein

Accessory hemiazygous vein

Hemiazygous vein

Azygous vein

Anomalous LBCV Retro-esophageal/tracheal

Ming, et al., 2009

• Very rare

• 1st reported (Yigit, et al., 2008) – 15 y boy (double LBCV): isolated

• 4 Chinese children (Ming, et al., 2009) – 4 m boy: PA VSD, RAA, PDA, ASD

– 6 m boy: VSD

– 6 d girl: PA VSD, PDA

– 6 m girl (double LBCV): VSD, PDA

• Balkman, et al. 2010 – 16 y boy: TOF

Anomalous LBCV Retro-esophageal/tracheal

• Our case

– 1st AN case described

– With chromosomal abnormality (8p inverted

duplication/deletion syndrome)

– With other venous abnormality – double IVC

– ?Genuine association OR chance occurrence

Anomalous LBCV Retro-esophageal/tracheal

Case 3

Normal morphology scan in China at 23 weeks; 28+

weeks: USG in China showed abnormal UA Doppler;

USG by us at 29+ weeks: normal UA PI.

Incidentally…...

• Need to rule out Williams

syndrome (70% with

SVAS)

• Discussed for option of

amniocentesis

• Patient declined

• Sudden IUFD at 38+

weeks

• Placental biopsy after

delivery for karyotype

and aCGH

• Least common form of LVOT obstruction

• Elastin (ELN) gene deletion/mutation – elastin

deficiency in arterial walls

• 3 anatomic forms

– Hourglass constriction at sinotubular junction (60 –

75%)

– Diffuse narrowing of a variable length of ascending

aorta (25 – 40%)

– Discrete membranous obstruction (rare): ?a variant of

the hourglass deformity

Supravalvular AS

Supravalvular AS

Supravalvular AS

• Commonly associated CV anomalies

– Pulmonary artery stenosis (50%): main or branched

– Coronary artery stenosis

– Dysplastic aortic valve

– Coarctation of aorta (unusual sites) and stenosis of

carotid or other peripheral arteries

Supravalvular AS

• Occurs in 3 settings in paediatric population

– Williams syndrome (30%)

• 1.5 – 1.8 Mb deletion at 7q11.23 including ELN gene

– Familial form with AD inheritance (20%) – ELN

mutation

– Sporadic (50%) – ELN mutation

• WS: increased risk of sudden cardiac death

– Higher in biventricular outflow tract obstruction

– Coronary artery obstruction

– Prolonged QTc interval (15% of WS; not in other types)

Supravalvular AS

Case 4

USG at 22 weeks: early onset IUGR with UA AEDV +

mesocardia

• 23 weeks: UA REDV,

couple opted to continue

• 27+3 weeks: UA REDV,

MCA REDV, EFW

R L

RPA

T

LPA

RMB

MPA

AO

RPA

AD

LPA

T

Left Pulmonary Artery Sling

• Importance:

– Frequently associated with tracheobronchial stenosis

• Mechanical compression

• More commonly a congenital stenosis

• Mortality up to 50% if severe but prognosis improving

• Recurrent pulmonary infection

• Hyperinflated right lung

– CHD in 30% of the cases

– RPA stenosis with right pulmonary hypoplasia

• abnormal rotation of cardiac axis to the right

Left Pulmonary Artery Sling

• PND may improve PN outcome but is rare

– Branched PAs not routinely examined

– Abnormal cardiac axis rotation may contribute to

prenatal screening and detection of LPAS

Left Pulmonary Artery Sling

Case 5

Referred to us for suspected fetal CHD at 22 weeks

• Pathogenesis

– PA + IVS + competent TV = no RV outlet RV HT

– RV HT forces an abnormal communication between

ventricular cavity, coronary sinusoids and coronary

arteries (VCC)

• Importance of VCC

– Disturbance of myocardial perfusion

– Affect surgical repair and prognosis

– Present in as many as 40% of PA IVS

PA IVS with VCC

• Large unobstructed VCC coronary steal – Diastole RV pressure decreases Coronary blood

flow preferentially to RV through large VCC

– Myocardial ischaemia

– Retrograde perfusion from RV during systole

• Dilated coronary artery: tortuous + stenosis segmental obstruction – Markedly reduced antegrade perfusion

– Totally rely on retrograde perfusion from RV during systole right ventricular dependent coronary circulation (RVDCC)

PA IVS VCC Myocardial perfusion disturbance

• Large unobstructed VCC: close VCC first

before opening up the MPA

– Diastole: coronary steal compensated by systolic

retrograde perfusion from RV

– MPA open systolic flow to MPA

• RVDCC: VCC cannot be closed

– Very little antegrade coronary perfusion

– VCC closed retrograde perfusion from RV shut off

– MPA cannot be opened

– Biventricular repair not possible

PA IVS VCC Effects on surgical repair