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Deborah Kozik, DOAssistant ProfessorDivision of Cardiothoracic Surgery
1954 ‐ 1960: Experimental Era 954 9 p 1960’s ‐ 1980’s: Palliation Era 1980’s ‐ present: Early Repair Era
2010 ‐ 2030’s: Fetal InterventionsHybrid Surgery
Robotics and NanotechnologyStem Cell Therapy pyTissue Engineering
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Highly useful clinical tool
Feasible mode of therapy is available Feasible mode of therapy is available
Fetus at risk for demise
Intervention may alter the evolution of the condition
Conditions in which fetus at high risk for prenatal or neonatal death
Disease likely to have major lifelong morbidity Disease likely to have major lifelong morbidity
Modify course of cardiac growth, function, development in utero
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Substantial short term risk to fetus
U i l i k f d hildUncertain long‐term risk to fetus and child
Some risk to mother
No known medical benefits to the mother
McElhinney, Circulation 2010;121
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First reported and most entrenched mode of FCIFCI
Fetal arrhythmia or heart block
Medication taken orally by mother with transplacental passage to the fetus
May be provided directly through umbilical y p y gvein, fetal muscular or intravascular injection
Fetal SVT most common indication
Digoxin mainstay of therapyDigoxin mainstay of therapy
Sotalol, amiodarone, flecainide
Indications depend on fetal age and disease severity
In preterm fetus, treat regardless of cardiac d sf nction or h dropsdysfunction or hydrops
Intermittent tachycardia, treatment unnecessary
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Sinus node dysfunction, long‐QT syndrome, AV block or fetal distress with acidosisblock, or fetal distress with acidosis
Most common is high‐grade AV block
Association with maternal autoimmune disease, malformation syndromes, ccTGA
Dexamethasone, in association with beta‐i t i ll iagonists, improves overall prognosis
Sympathomimetic agents increase heart rate in fetus, do not restore AV synchrony
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Most common closed FCI procedure Alter in utero natural history of midgestation Alter in utero natural history of midgestation
fetal AS with evolving HLHS Physiological features associated with
progression to HLHS Retrograde flow in transverse aortic arch Severe LV dysfunction Abnormal mitral valve inflow Left‐to‐right flow across foramen ovale
Prevent progressive left heart dysfunction and hypoplasia
Aortic and mitral valve growth improved
N diff i LV h l iNo difference in LV growth velocity
Clear beneficial changes in left heart physiology
Goal to alter left heart physiology and growth to allow biventricular circulation
Not a stand‐alone intervention
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Profound hypoxemia after birth
Results in little effective pulmonary blood flow Results in little effective pulmonary blood flow
Chronic pulmonary venous hypertension in utero
results in pulmonary venous thickening
Damage to pulmonary vasculature may contribute to further mortality
FCI i b h j bl d b FCI may improve both major problems posed by restriction of pulmonary venous outflow
If left atrium decompressed before birth, perinatal hypoxemia and acidosis preventedperinatal hypoxemia and acidosis prevented
If left atrial decompression achieved early in gestation, adverse pulmonary venous remodeling prevented
Technical limitations
Currently performed in early‐to‐mid third Currently performed in early‐to‐mid third trimester
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PA/IVS occurs as a spectrum of hypoplastic right heart diseaseright heart disease
In newborns, biventricular repair estimated from Z‐score of tricuspid valve annulus
Tricuspid valve Z‐score in fetuses can also be uses to assess suitability for biventricular outcome
Role of FCI is to promote right heart growth and functional developmentp
Increase chance of biventricular circulation
Identification of potential candidates based on risk of progression to a functionally univentricular circulation
Prenatal pulmonary valve perforation and dilation performed in midgestation fetuses
Maintenance of valvar patency and improved growth of right heart structures
Effects on right heart functional development and postnatal outcome remain to be determined
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Utility of FCI will depend on clinical and technological factorstechnological factors
More frequent, earlier diagnosis of CHD
Characterization of prognostic features
Optimal gestational windows
Improved and focused technology
Advances in imaging and instrumentation
Risk profiles will improve
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Indications Examples
Vascular access Very tortuous course of delivery sheathsVascular access
Better alignment between defect and device
Avoiding circulatory arrest
A i l bl i d d
Very tortuous course of delivery sheaths
Large ASD in patients with small left atrium
Bad angle for deployment
Stent implantation in a hypoplastic arch
Anatomical problem preventing standard surgical procedure
Interventional procedure during scheduled surgery
Poor surgical access in apical VSD
Stent implantation or balloon angioplasty of pulmonary arteries under direct vision
Done surgically, requires right or left ventriculotomyventriculotomy
Right ventriculotomy may not be able to see defect
Left ventriculotomy can cause LV dysfunction, arrhythmias, and apical aneurysms
P t i l l id t ti f RV Perventricular closure avoids transection of RV muscle bundles, avoids CPB, not limited by vascular access or patient weight
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-Intraop ballooning and stenting of PAs helpful in select circumstance-Distal branch PA stenosis-Right pulmonary artery runs underneath aorta-Left pulmonary artery near phrenic nerve-Patch material can become calcified leading to stenosis-Stents balloon-expandable-Placed on beating heart-Can develop in-stent stenosis
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Multiple re‐interventions for right ventricular outflow tract outflow tract
Timing of conduit replacement or pulmonary valve implantation
No “ideal” conduit or valve exists
All are susceptible to degeneration and loss p gof function
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Maximum available size is 22mm
P h li i d i Percutaneous approach limited to patients with RV to PA conduits
Can be placed through direct puncture of the RV apex or free wall
Will reduce the number of interventions required in children with conduit obstruction or pulmonary insufficiency
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Procedure Age
Norwood 1‐2 weeks
• Bidirectional Glenn Shunt 3‐4 months
F P d • Fontan Procedure 3‐4 years
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Operative mortality 10 ‐ 25%
L “i ” li 8 %Late “interstage” mortality 8 ‐ 12%
Glenn Procedure 2‐5% Developmental delay
Neurologic abnormalities
Feeding difficulties
Ventricular dysfunction
Growth delay
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Shock at presentation
Bi th i ht k Birth weight <2.5 kg
Prematurity <34 weeks of gestation
Age >30 days
Aortic atresia
Poor RV function
Tricuspid regurgitation
Intact atrial septum
Presence of noncardiac malformations
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Hospital for Sick Children, Toronto, ON
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Despite improved hospital survival, institution reported interstage death has institution reported interstage death has remained constant over past decade at 7‐20%
Currently neither the STS database nor available administrative databases track patients across admissions
Multi‐center interstage mortality cannot be calculated
Dependence on functionally inferior systemic RV to pump to pulmonary and systemic circuits to pump to pulmonary and systemic circuits (parallel circulation)
Tenuous balance between pulmonary and systemic blood flow
Mild desaturation or intravascular volume loss places these infants with minimal myocardial places these infants with minimal myocardial reserve at greater risk for mortality
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Intercurrent Illness Recurrent/Residual/ P i l i Gastroenteritis, fever,
respiratory tract infections
Concern Hypovolemia
Hypoxemia
Increased SVR
i
Progressive lesions Shunt stenosis/obstruction,
neoaortic arch obstruction, restrictive ASD, coronary insufficiency, PA distortion, AVV insufficiency
Concern anemia
Inadequate pulmonary blood flow
Progressive hypoxemia
Impaired myocardial performance
During late 1990’s, reported anatomic and physiologic variables implicated in interstage death included
Diagnosis of aortic atresia
Ascending aorta <2.0mm
>moderate AV valve insufficiencyy
Post‐op hemodynamics
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Identify S1P infants at greatest risk
O i i h i l i di hOptimize physiologic state pre‐discharge
Monitor infants in‐home for evidence of physiologic variances
Keep “highest” risk S1P infants inpatient until stage 2g
Unable to consistently predict which infants most “at risk” for interstage deathmost at risk for interstage death
Implementation of home monitoring program (HMP)
Hypothesis that decreased arterial saturation from baseline, poor weight gain or weight loss may foretell the presence of serious anatomic may foretell the presence of serious anatomic lesions or intercurrent illness and allow for life‐saving intervention
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Infant scale and pulse oximeters at home
P k d b i d d d il Parents asked to obtain and record daily weight and oxygen saturation in log book
Notification to healthcare provider by parent/caregiver if breach of pre‐determined criteria occurs
•Pulse Oximetry• Infant probes continuous
•Weight• Digital scale sensitive to 10 Infant probes, continuous
monitoring capability, signal verification
• Digital scale sensitive to 10 grams
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Oxygen sat, weight, and enteral intake recorded on daily log sheet in home‐monitoring binderg g
Uniform call parameter
Infant does not gain 10‐20 grams over 3 days
Infant lose >30 grams over 2‐3 days
O2 saturations <75%
Enteral intake <100cc/kg/24 hours
Parents instructed to report any breach
B d id •Bedside parent education
•“Rooming In” prior to discharge
•Anticipatory guidance
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Children’s Hospital of Wisconsin
Potential etiologies contributing to interstage mortality have been identified, however, a lack of proven predictors of been identified, however, a lack of proven predictors of interstage demise remains a concern
At least one‐half of interstage infants encounter an at‐risk physiologic state prior to undergoing S2P
A strategy of keeping patients deemed “high” risk inpatient until S2P can be effective, but costly
I li b d d i d Interstage mortality can be reduced via a structured team approach to in‐home detection of physiological variances
Despite diligent interstage care, some infants remain at‐risk for sudden
