This document discusses fetal cardiac interventions (FCI). It begins by outlining different types of FCI including transplacental therapy, ultrasound-directed interventions like HIFU, fetal surgeries, and catheter-based interventions. It then discusses the pathophysiology and in utero progression of various cardiac lesions like critical aortic stenosis and hypoplastic left heart syndrome. The rest of the document provides details on established FCIs like balloon aortic valvuloplasty, techniques for various procedures, case selection criteria, counseling considerations, and complications. It emphasizes the importance of a multidisciplinary team and appropriate case selection for improving postnatal outcomes of FCIs.

1. Murtaza Kamal
April 25, 2019
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2. Scope of the talk…
Types of FCI
Pathophysiology of lesions
Individual interventions
Complications
Level of care assessment+ coordinating action plan
Future prospects
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3. Charles S Kleinman
Pioneer
1980: 1st manuscript on
fetal echo
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4. Introduction…
FCI: Important therapy to prevent in utero progression
of simple lesion to complex cardiac condition
Cardiac problems with risk of fetal demise+ those
causing impairment of organ development leading to
significant postnatal mortality+ morbidity—> Potentially
benefit from in utero management
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5. The list is not very limited…
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6. FCT Types…
1. Transplacental therapy:
Antiarrhythmic drugs to mother in tachyarrhythmia
Maternal steroids in fetal heart block
2. Ultrasound directed:
HIFU for TRAP sequence/ Creating IA communication
3. Fetal surgeries:
Tricuspid valve repair in severe Ebstein’s anomaly
4. Fetal cardiac interventions:
Fetal balloon aortic/ pulmonary valvotomy
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7. The pioneers…
1975: 1st transplacental therapy—> Maternal propranolol
for fetal tachycardia
1986: 1st percutaneous fetal intervention—> Attempted in
utero pacing
1989: 1st fetal balloon aortic valvotomy performe by
Allan, Sharland and Tynan in fetus with critical aortic
stenosis
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8. IFCIR
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9. Principals of FCI…

10. Criteria to select for FCI…
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11. Established interventions…
• In utero management of fetal tachycardia/ bradycardia
• Fetal balloon aortic valvotomy for critical AS with
evolving HLHS
• Atrial septal stenting in HLHS with IAS/restrictive
foramen ovale
• Balloon pulmonary valvotomy for PA-IVS11

12. In utero progression of
cardiac lesions…
• Cardiac defects may progress+ evolve into more
complex lesions with advancement of gestation
• Critical AS+ PS—> Progress to HLHS+HRHS
• Intervening at an appropriate stage: Can modify
evolution of disease+ improve postnatal outcome
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13. Catheter based FCIs (AHA
2014)…
13

14. Critical AS
Natural h/o in utero:Variable
Development early in gestation
Result in rapid progression to HLHS+ endocardial
fibroelastosis
In mid- gestation
Result in dilatation of LV—> Progression to LV dysfunction—>
Elevated LA+ LV filling pressures—> Reversal of flow across
foramen ovale—> Redistribution of blood from LA
to right-sided chambers
Reduced blood flow across mitral valve + LV—> Detrimental effect
on LV growth—> ventricular hypoplasia + endocardial fibroelastosis
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15. Critical AS cont…
Fetal balloon aortic valvotomy at appropriate stage—> Improves LV
filling+ help to achieve biventricular circulation in postnatal life
Echo suggesting potential progression to HLHS:
Narrow aortic jet >2 m/sec
Dilated dysfunctional LV
Neo-development of MR
Monophasic mitral inflow Doppler
Lt—> rt shunt across foramen ovale
Reversal of flow in aortic arch
Important to identify cases which have potential to achieve
biventricular circulation following in utero relief of aortic stenosis
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16. Scoring system to predict biventricular circulation
followed by fetal balloon aortic valvotomy:
McElhinney et al.
LV long axis Z- score >0
LV short axis Z- score >0
Aortic annulus Z- score >–3.5
MV annulus Z-score >–2
MR/ AS maximum gradient ≥20 mm Hg
>4: 100% Sn, 53% Sp in predicting biventricular outcome
Postnatal outcomes: Not encouraging fetuses with score <4
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17. HLHS with IAS
Foramen ovale: Essential to decompress LA in HLHS
Restriction of foramen ovale/ IAS: Cause fetal PH—>
Delayed/ non-regression of PVR in postnatal life
IAS+ pulmonary venules: Thickened+ muscular—>
Arterialization of pulmonary veins
Outcome of Norwood procedure in this subset: Poor—>
Pre- existing pulmonary venous hypertension
Neonatal mortality: 48% despite early intervention+
surgery
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18. HLHS with IAS cont…
Echo features of in utero PV hypertension:
Restrictive foramen ovale flow/ IAS
Dilated PVs with prominent atrial
reversal on PV doppler
In utero atrial stenting of IAS to relieve LA
hypertension: May potentially prevent adverse PV
remodeling—> Improving postnatal outcome
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19. PA-IVS
HRHS: Relatively better prognosis
PV atretic: Redistribution of blood through foramen ovale—>lt side
Resultant reduction of flow across TV—> Progressive RV
hypoplasia
Fetal PV perforation/ balloon pulmonary valvotomy: Promotes
growth of RV by improving flow into stiff hypertrophied
ventricle—> Facilitating either biventricular circulation/ at least
1.5 ventricular repair postnatally
Decompression of RV—> Reduces severity of TR—> Preventing
hydrops
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20. PA-IVS cont…
Fetuses with membranous PA with tricuspid valve Z-score < 2:
Ideal candidates for procedure
Poor prognostic features:
TV/ MV ratio <0.7
RV/ LV length ratio <0.6
Tricuspid inflow duration <31.5% of cardiac cycle
length
Presence of RV sinusoids
Presence of 3/4 features predict non- biventricular outcome: Sn
100%, Sp 75%
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21. Development of fetal cardiac
intervention programme…
Initiation and development : Requires several
prerequisites
Trained personnel to plan+ perform procedure
Multidisciplinary team
Financial expenses: Not covered by health insurance
Social+ local governmental policies
PNDT clearance
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22. 22

23. Case selection
Postnatal outcome: Mainly depends on appropriate case
selection
Planning procedure at an appropriate gestational age:
Vital to allow ventricular growth antenatally
Early procedure prior to 22 weeks: Technically
challenging in view of difficulties in imaging
Balance b/w gestational age and procedure time: Crucial
for better outcome
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24. Counselling
Several social+ cultural issues play vital role
Balance b/w maternal risk, fetal risk and procedural success should
be drawn
Family has to be informed about:
Natural in utero progression of lesion
Possibility of procedural failure
Minimal risk of intrauterine death/premature labor
Need for postnatal procedures
Procedure-related maternal risk low:Most centers now prefer to
perform procedure under IV sedation
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25. The team…
Organizing fetal interventional team: Crux of program
Fetal cardiologist, fetal medicine specialist, obstetrician,
anesthesiologist and perinatologist
Role should be pre defined
Prior discussion about procedure, potential complications
and physiology of condition may give an insight to all team
members
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26. Hardware+ technical aspects
Needle for IM Injection:
Fetal anesthetic agents (Vecuronium, fentanyl) +
antiarrhythmic drugs (e.g. digoxin in tachyarrhythmia) can be
given as IM injections to fetal thigh
21G/ 22G spinal needle/aspiration needles generally used
Needle for Procedure:
19G/ 18G (12–15 cm long) Chiba needle, M3 coaxial or Hawkins
Akins needle may be used for entry into ventricle for balloon
valvotomy
20G/ 22G aspiration needle is for fetal pericardiocentesis26

27. Chiba+ Hawkins Atkins
needles
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28. Hardwares cont…
Guidewire:
0.014” coronary guidewire (BMW, Whisper extra support
or Galeo extra support wires)
Balloon for Valvotomy:
Maverick, Hiryu and Relysis coronary balloons: Ideal as
can be advanced through 18G needle
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29. Procedure…
Favorable fetal position: Indispensable
Anterior position of fetal heart+ posterior spine: Ideal
Utero-ventriculo-outflow tract should be in line to coaxial
the needle- balloon catheter assembly
Once position acceptable, fetal anesthesia (vecuronium and
fentanyl) given using 21G spinal needle
Maternal GA/ IV sedation initiated at time of favorable
fetal position
Good imaging: Key factors 29

30. Procedure cont…
USG guidance, 18G long needle (12–15 cm) for puncture
of maternal abdomen, uterus and fetal chest wall to
enter ventricle
Fetal chest wall+ ventricular entry may be difficult if
baby is not immobile
External counter support using hand helps to advance
needle without much effort
Site of ventricular entry should be in line with outflow
tract
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31. Fetal Balloon Aortic
Valvotomy
Guidewire balloon assembly prepared
Apical LV puncture generally aligns well to LVOT
Dilated LV usually gets collapsed after puncture
Transient bradycardia that generally improves on its own
After aligning needle to LVOT: Prepared guidewire balloon
assembly is advanced through needle
Gentle manipulation needed to cross aortic valve under
ultrasound imaging
A balloon annulus size ratio of 1–1.2 usually gives adequate result
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32. FBAV cont…
Semi-compliant balloons used to minimize trauma to aortic
valve
Immediate success:
Demonstration of balloon inflation across valve
Appearance of AR
Good antegrade flow across aortic valve
Balloon catheter-wire assembly should be removed along with
needle to avoid balloon avulsion within fetal heart
Inspection of the balloon integrity after removal: Mandatory
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33. Fetal PV perforation+ balloon
dilatation…
Puncture site at apico- infundibular free wall of RV: Needle aligns to
RVOT to perforate atretic PV
Needle positioned more anteriorly to conform to anatomy of RVOT
18G needle directly advanced through PV for perforation
Alternately, 22G Chiba needle advanced through larger needle for
valve perforation
Wire may be parked either in PA or descending aorta
Balloon-annulus ratio can be more (1.2 to 1.3) compared to aortic valve
dilatation
Shorter balloon lengths of 8 or 10 mm may be used to prevent
accidental dilatation of RV free wall
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34. Stenting Foramen ovale
RA punctured perpendicular to IAS with 18G/17G needle
Needle can directly be advanced to perforate septum/ 22G Chiba
needle may be advanced through it for perforation
Wire is placed in LA or advanced into PV
Short length stents of 3.5 × 13 mm can be easily passed through
17G needle and positioned across septum under ultrasonic
guidance
Stent kept in center and dilated to maximum limits
Complications: Stent malposition+ embolization
Only limited experience in this subset
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36. Fetal tachyarrhythmias…
Direct fetal therapy: Hydropic fetuses with tachycardia
which are resistant to transplacental therapy
Intraumbilical, intra-amniotic, intra- peritoneal,
intramuscular and intracardiac administration of
antiarrhythmic
Intramuscular injections: Most commonly adopted, safe
for fetus
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37. Tachycardias management:
In utero (AHA 2014)…
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38. Tachycardia management: In
utero cont (AHA 2014)…
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39. Antiarrhythmic drugs…
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40. Fetal Ht blocks
Transplacental therapy with maternal steroids+
sympathomimetic drugs: Used in fetal immune-mediated
CHB
Gross hydrops+ FHR< 55/min carries high risk of fetal
demise
Few reports of in utero pacing in such fetuses, with
technical success but unfavorable outcome
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41. Management of bradycardia:
In utero (AHA 2014)…
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42. Management of bradycardia:
In utero (AHA 2014)…
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43. Fetal pericardiocentesis
Pericardial effusion can be isolated or associated with hydrops
Isolated pericardial effusion: Due to maternal lupus
erythematosis, congenital infections, pericardial tumors,
ventricular diverticuli, congenital hypothyroidism and idiopathic
arterial calcification
Massive pericardial effusion: Can result in tamponade and
impaired filling of ventricles
Impairs growth of lungs in utero and hence poses a grim
postnatal prognosis
Performed using 21G/22G aspiration needle
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44. 44

45. Complications…
Pericardial effusion:
Common
Usually self-limiting
Does not need any specific management, rarely aspiration
Persistent bradycardia:
Inevitable during entry into ventricle
Usually transient and needs no treatment
If persists: Intracardiac injection of atropine (20 μg/kg)+
adrenaline (10 μg/kg) through same needle
Placental hemorrhage
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46. Complications cont…
• Fetal loss/premature delivery: 11% of procedures
• Less in recent times with improvement of skills+ technique
• Valve regurgitation: AR 40% of balloon aortic valvotomies
• Well tolerated in view of low SVR in fetus (placenta) and high LVEDP
• Usually resolves in a few weeks
• Avulsion of balloon and injury to other organs
• No maternal mortality/ morbidity reported so far
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47. Outcome+ prognosis
• Depends on severity of cardiac lesion+ timing of intervention
• Technical success and long-term outcome improved over last
decade with refinement of technique+ patient selection
• Follow-up data of first 100 cases of fetal aortic valvuloplasty:
Success in 77%; 45% achieved biventricular circulation postnatally
• Depends on severity of disease at time of intervention
• Larger LV size+ higher LV pressure at time of intervention—> More
likely to be associated with biventricular outcome
• Fetal intervention is never a standalone procedure—> Even when
biventricular circulation is achieved
• Usually need postnatal balloon valvuloplasty
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48. Prognosis cont…
• Some requires additional surgical procedures like COA,
aortic and mitral valve replacements during follow-up
• However survival and morbidity definitely superior to
HLHS
In series of 10 cases of in utero pulmonary valvuloplasty,
Tworetzky, et al. reported technical success in 6; of
which 4 could achieve biventricular circulation
Fetal tricuspid valve Z score below –3 associated with
univentricular outcome
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49. Level of care assessment…

50. Take home message…
Advancement in imaging+ instrumentation—> Resulted in
improved rates of technical success in fetal cardiac
interventions
Proper patient selection+ optimum timing of intervention
can translate technical success into favorable postnatal
outcome
Evidence still evolving in this field—> Much to be learned
Evaluation of long-term outcome from various centers would
help to favorably alter prenatal technique and perinatal
management of this subset of patients50

51. Thanks….
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