Deborah Kozik, DO Assistant Professor Division of Cardiothoracic Surgery s present: Early Repair Era

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1 Deborah Kozik, DO Assistant Professor Division of Cardiothoracic Surgery : Experimental Era 1960 s 1980 s: Palliation Era 1980 s present: Early Repair Era s: Fetal Interventions Hybrid Surgery Robotics and Nanotechnology Stem Cell Therapy Tissue Engineering 1

2 Highly useful clinical tool 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 Modify course of cardiac growth, function, development in utero 2

3 Substantial short term risk to fetus Uncertain long term risk ik to fetus and child Some risk to mother No known medical benefits to the mother McElhinney, Circulation 2010;121 3

4 First reported and most entrenched mode of FCI Fetal arrhythmia or heart block Medication taken orally by mother with transplacental passage to the fetus May be provided directly through umbilical vein, fetal muscular or intravascular injection Fetal SVT most common indication Digoxin mainstay of therapy Sotalol, amiodarone, flecainide Indications depend on fetal age and disease severity In preterm fetus, treat regardless of cardiac dsfnction dysfunction or hydrops Intermittent tachycardia, treatment unnecessary 4

5 Sinus node dysfunction, long QT syndrome, AV block, or fetal distress with acidosis Most common is high grade AV block Association with maternal autoimmune disease, malformation syndromes, cctga Dexamethasone, in association with betait improves overall prognosis Sympathomimetic agents increase heart rate in agonists, fetus, do not restore AV synchrony 5

6 Most common closed FCI procedure 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 No 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 6

7 Profound hypoxemia after birth 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 may improve both major problems posed by restriction of pulmonary venous outflow If left atrium decompressed before birth, perinatal 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 trimester 7

8 PA/IVS occurs as a spectrum of hypoplastic right 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 development 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 8

9 Utility of FCI will depend on clinical and technological 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 9

10 Indications Examples Vascular access Very tortuous course of delivery sheaths Better alignment between defect and device Large ASD in patients with small left atrium Bad angle for deployment Avoiding circulatory arrest Stent implantation in a hypoplastic arch Anatomical problem preventing standard d surgical procedure Poor surgical access in apical VSD Interventional procedure during scheduled surgery Stent implantation or balloon angioplasty of pulmonary arteries under direct vision Done surgically, requires right or left ventriculotomy Right ventriculotomy may not be able to see defect Left ventriculotomy can cause LV dysfunction, arrhythmias, and apical aneurysms Perventricular closure avoids transection ti of RV muscle bundles, avoids CPB, not limited by vascular access or patient weight 10

11 -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 11

12 Multiple re interventions for right ventricular outflow tract Timing of conduit replacement or pulmonary valve implantation No ideal conduit or valve exists All are susceptible to degeneration and loss of function 12

13 Maximum available size is 22mm Percutaneous approach limited i 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 13

14 Procedure Norwood Age 1 2 weeks Bidirectional Glenn Shunt 3 4 months Fontan Procedure 3 4 years 14

15 Operative mortality 10 25% Late interstage mortality 8 12% Glenn Procedure 2 5% Developmental delay Neurologic abnormalities Feeding difficulties Ventricular dysfunction Growth delay 15

16 Shock at presentation 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 16

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20 Hospital for Sick Children, Toronto, ON 20

21 Despite improved hospital survival, 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 (parallel circulation) Tenuous balance between pulmonary and systemic blood flow Mild desaturation or intravascular volume loss places these infants with minimal myocardial reserve at greater risk for mortality 21

22 Intercurrent Illness Gastroenteritis, fever, respiratory tract infections Concern Hypovolemia Hypoxemia Increased SVR anemia Recurrent/Residual/ Progressive lesions Shunt stenosis/obstruction, neoaortic arch obstruction, restrictive ASD, coronary insufficiency, PA distortion, AVV insufficiency Concern 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 insufficiency Post op hemodynamics 22

23 Identify S1P infants at greatest risk Optimize i physiologic i state pre discharge Monitor infants in home for evidence of physiologic variances Keep highest risk S1P infants inpatient until stage 2 Unable to consistently predict which infants most 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 lesions or intercurrent illness and allow for lifesaving intervention 23

24 Infant scale and pulse oximeters at home Parents asked kd 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 monitoring capability, signal verification Weight Digital scale sensitive to 10 grams 24

25 Oxygen sat, weight, and enteral intake recorded on daily log sheet in home monitoring binder Uniform call parameter Infant does not gain grams over 3 days Infant lose >30 grams over 2 3 days O 2 saturations <75% Enteral intake <100cc/kg/24 hours Parents instructed to report any breach Bedside Bdid parent education Rooming In prior to discharge Anticipatory guidance 25

26 Children s Hospital of Wisconsin Potential etiologies contributing to interstage mortality have 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 Interstage mortality can be reduced d via a structured team approach to in home detection of physiological variances Despite diligent interstage care, some infants remain at risk for sudden 26