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Ebstein’s Anomaly &
Truncus Arteriosus Dr Tarun Bhatnagar
Consultant AnaesthesiologistNarayana Hrudayalaya, Ahmedabad
dr.tarunbhatnagar@yahoo.co.in
Ebstein’s Anomaly
First described by Dr William Ebstein in 1866
Rare disease, accounts for 0.5% of cases of CHDs
Ch by maldevelopment of of tricuspid valve
Aetiology ?? maternal Lithium ingestion
Associated with Cyanotic congenital heart diseases
Atrial septal defect (ASD)
Cases of severe right heart failure
Isolated severe tricuspid regurgitation
L-transposition of the great vessels
WPW /Preexcitation Syndrome
Ebstein’s Anomaly Wide spectrum of anatomic
malformation
Wide spectrum of clinical presentation
Fetus- HydropsNeonate- Severe cyanosis with circulatory collapseChild- Mild cyanosisAdult- Minimal or no symptoms
Maldevelopment of Tricuspid Valve Embryologically, TV is normally formed by
delamination or exfoliation of inner layer of RV myocardium up towards the tricuspid annulus
If this process is arrested or incomplete, the attachments of the leaflets are apically displaced
Anatomy
Characteristic features The septal & posterior leaflets are displaced
downwards or apically into the RV and are dysplastic
Anterior leaflet is, large, redundant (sail-like), undisplaced & attached to the ventricular free wall rather than to the papillary muscles
Atrialized RV (ARV)- proximal inlet portion of the RV that is above the displaced leaflets but below the annulus
Functional RV (FRV)- remaining part of RV that lies below the displaced TV & is much smaller than usual
Anatomy
Anatomy
Anatomy
The predominant clinical finding is tricuspid insufficiency or regurgitation that leads to Severe cyanosis due to
Dilated RA with R→L shunting thru an interatrial communication (ASD or PFO)
Inadequate function of Distal RV - In severe cases the RV can’t develop adequate force to open the pulmonary valve (Functional Pulmonary Atresia)
Compromised LV filling by the dilated RV
Other causes of cyanosis due to ↓ Antegrade PBF
Anatomic pulmonary stenosis or atresia
Subpulmonary Obstruction due to abnormal TV tissue
Elevated PVR of neonatal period
Pathophysiology
Neonates Cyanosis is the most common presentation in infancy Cyanosis alone can improve by normal postnatal ↓ in PVR
or by conservative management Neonates with severe TR- present with Cyanosis ,CHF ,
Metabolic acidosis or Supraventricular tachyarrythmias High Mortality rate in the neonatal group (20%)
Older children DOE, fatigueability consistent with CHF Supraventricular Tachyarrythmias Neurological complications- CVA , Brain abscess Infective Endocarditis LV Dysfunction secondary to RV dilatation
Clinical course
Physical Examination CXR ECG Echo Cardiac Cath
Preop Evaluation
Cyanosis Active precordium Regurgitant holosystolic murmur Widely split S2 Gallop rhythm
Physical Examination
CXR Massive
Cardiomegaly due to enlarged right atrium
Decreased pulmonary vasculature
Small aortic root and main pulmonary artery shadow
Twelve-lead ECG
RAD +Abnormal largeP waves consistent with right atrial enlargement – “Himalayan P waves”
PR interval ◦ Commonly prolonged ◦ May be normal or short in patients with WPW syndrome
QRS complex ◦ RBBB
Rhythm◦ Paroxysmal SVT, atrial flutter, atrial fibrillation,
ventricular tachycardia
Echocardiogram Two-dimensional
◦ Displaced Septal & Posterior leaflet & the redundant
anterior leaflet are easily seen
◦ Apical displacement of the septal leaflet of greater than 8
mm/m2 - Most specific sign.
◦ Eccentric leaflet coaptation.
◦ Dilated right atrium.
◦ Delayed closure of tricuspid valve leaflet.
◦ Various left heart structural abnormalities
Color flow Doppler studies
◦ Varying degrees of tricuspid regurgitation
◦ R-L atrial shunting
◦ Status of pulmonary blood flow
No longer required to make/confirm the diagnosis
The most diagnostic characteristic- Typical atrial pressure & ventricular intracardiac ECG in the atrialized portion of the RV
Elevated RAP R-L atrial shunting with systemic
desaturation Elevated RVEDP
Cardiac Cath
Hypoxia & Acidosis cause pulmonary vasoconstriction !!
while
Hyperoxia & Alkosis causes pulmonary vasodilatation !!
Preop Mx of Critically ill neonates & infants
Measures to reduce PVR-Mechanical Ventilation -High FiO2/ Hyperventillation /PEEP-Sedation +Paralysis –avoids reflex ↑ in PVR secondary to noxious stimuli-Alkalosis-pulmonary vasodilator /pH7.50-7.60/ sodabicarb or THAM-Inhaled NO-starting dose 5-40ppm
PGE1 infusion- to keep the ductus arteriosus patent & maintain the pulmonary blood flow
Correction of Metabolic Acidosis –improves myocardial function
Inotropes- Avoid Adrenaline as far as possible as it ↑es PVR
Avoid Overzealous Volume Infusions-can cause further annular dilatation –worsen the TR
Preop Mx of Critically ill neonates & infants
Indications Severe cyanosis(spO2< 80%) CHF Intractable Arrythmias due to accessory AV
pathway Cardiomegaly (CTR ratio>0.65 on CXR) Paradoxical embolism
Surgery
Surgical Options
Critically ill neonates
Aortopulmonary Shunt
Palliative Sx ECMO Ortho topic Cardiac
Transplantation
Non critical older children
ASD closure
Tricuspid Valvuloplasty /Replacement
Fontan Operation
In neonates with severe Ebstein anomaly, the functional RV is hypoplastic, and the patient is usually best treated by closing the TVand creating a tricuspid atresia physiology (Starnes procedure)
This strategy commits the neonates for future single ventricle palliations like BDG or Fontan
Plication of Rt atrial tissue +
Atrial Septectomy +
Patch closure of tricuspid annulus (surgically creating tricuspid atresia)
+ Insertion of Aortopulmonary shunt
Palliative Sx
Indication: Mild- Moderate Tricuspid insufficiency where chordae & papillary muscles are intact
Median sternotomy/CPB
Surgery-Patch closure of ASD/PFO +-Plication of Atrialized RV +-Plastic repair of TV+-Posterior tricuspid annuloplasty+-Rt atrial redundant tissue excision+-Correction of any associated anomalies(PS / division of accessory conduction pathways)
Tricuspid Valvuloplasty
Tricuspid valve replacement Indication
Complete failure of formation of TV with no chordae or papillary muscles
Disadvantage-Higher incidence of complications-High chances of Redo TVR (pts growth)
Major Concerns↓CO, R→L shunting with cyanosis, Atrial tachyarrythmias
Anaesthetic GoalsMinimizing PVR, Optimizing RV preload, Maintain RV contractility to optimize PBF
Continue PGE1 infusion untill the completion of Aortopulmonary shunt
InductionPrimary Narcotic based technique+ Pancuronium
Atrial tachyarrythmias RxExternal Cardioversion-0.5J/kg in hemodynamically unstable ptsAdenosine 0.1mg/kg for PSVT
MonitoringInvasive Arterial & CVP Atrial & Ventricular pacing wires
Anaesthetic Considerations
Low CO Pulmonary insufficiency Residual TR Dysrhythmias-PSVT, VT,VF, Heart
Block
Postop Problems
364415_NITHAN_20111007_140427_0006.AVI364415_NITHAN_20111007_140427_0007.AVI
364415_NITHAN_20111007_140427_0011.AVI
Truncus Arteriosus
Uncommon lesion, 1.4% CHDs Ch by single arterial trunk arising from
both ventricles due to the failure of truncus arteriosus to divide into the Aorta & PA
Commonly assoc with a VSD & Coronary anomalies
Most infants present with CHF during the first 2 weeks; 85% of untreated children die by 1 year of age.
Truncus Arteriosus
Truncus Arteriosus
Truncal valve
VSD
Embryology
Classification & Anatomy
Collet & Edwards Classification-Type I
Collet & Edwards Classification-Type II
Collet & Edwards Classification-Type III
Collet & Edwards Classification-Type IV
Truncus-Longer than normal aorta-Overrides the ventricular septum more towards RV-The Coronaries & one or two PAs arise from it-Branch PA stenosis when present protect pul vasculature from pulmonary overcirculation & pulmonary vascular disease
Truncal Valve-Dysmorphic, stenotic, regurgitant-Tricuspid(60-70%), quadrcuspid(25%), bicuspid(5%)
Coronary artery Anomalies(50%)Clinically imp variations are-High origin of LCA: makes it vulnerable to surgical injury when explanting the PAs)- Large infundibulae or anterior descending artery crossing the RVOT making it vulnerable at the time of RVOT conduit placement
VSD- large, lies immediately beneath the truncal valve
Anatomy
Aortic Coarctation Type B interrupted Aortic Arch Persistent LSVC ASDs Digeorge Syndrome
Associated Anomalies
Pathophysiology
Pulmonary Over circulation
Coronary Ischemia
After the 1st/2nd wk of life PVR falls →Qp/Qs >1
↓ Pulmonary Overcirculation
↓ Volume Overload (LV) + Pressure
Overload (RV)
↓ CHF ↑ Truncal Valve Insufficiency
Pulmonary Circulation Runoff during diastole
↓ Low systemic diastolic
pressure ↓ Low coronary perfusion
pressure ↓ Coronary Ischemia &
Impaired myocardial function
Pulmonary Overcirculation
Progressive Pulmonary Vascular Disease
Lethal Increase in PVR as early as 3rd mth of age
Pathophysiology
Physical Examination S/s of CHF : tachycardia, tachypnea,
irritability, poor feeding, recurrent pulmonary infections
Jerky collapsing arterial pulse Systolic thrill over LSB Loud Ejection Click & holosystolic murmur Early diastolic murmur – if truncal valve
insufficiency present
Preop Evaluation
CXRCardiomegaly, ↑ Pulmonary vascular markings
ECGBVH
Echo- diagnostic-Single great artery with a semilunar valve that overrides the ventricular septum & is continuity with the mitral valve-Enlarged LA-Origins of PAs -Conotruncal VSD -Competence of truncal valve- Caliber of aortic arch
Cardiac Cath- Indicated in older infants with significant PVD-Type IV truncus to delineate MAPCAs & PA anatomy- SaO2<84% indicates significant PVD the child may not tolerate the operative correction
Sx is recommended within the first 2 mths of life as PVD develops by 3-6 mths of age
Infants with CHF are mx by fluid restriction, diuretics , digitalis & afterload reduction
Infants with persistent severe CHF- Complete repair immediately
Surgery is not recommended-Fixed PVD with PVR > 8 Woodunits/m2
Surgery is recommended -Reactive PVD responding to O2 & hyperventillation
Timing of Surgery
Airway abnormalities-Small mouth, micrognathia: Difficult Intubation
CHF-occur due to torrential PBF that can be exacerbated by hyperoxia & hypocapnia-FiO2 of 0.21 + Ventilatory adjustment to maintain SaO2 of 85-95% & pCO2 of 40mmHg is desirable
-Afterload reduction (Milrinone) may improve Systemic CO & reduce PBF
Myocardial Ischemia- can occur before & after induction of anaesthesia
-↑ myocardial wall tension on LV due to volume overload ↑ diastolic runoff to pulmonary circulation
- Mx by Temporary PA banding followed by Complete repair once BP & ECG settles
Anaesthetic Considerations
CPB-Deep Hypothermia-Cardioplegic arrest The PAs are removed from the truncus- site is
oversewn with a running suture VSD is closed allowing the LV to eject thru the
truncal valve to the aorta A valved conduit (cryopreserved valved
pulmonary or aortic homograft) is placed from the RV into the distal main PA
Moderate truncal insufficiency –Valve repair+ commissural annuloplasty
Severe truncal insufficiency- Valve replacement
Surgical Technique- Repair of Truncus
Operative technique for type I truncus arteriosus.
Operative technique for types II and III truncus arteriosus
Pulmonary Hypertensive Crisis-Commonly occur in 3-6 mths old infants after truncus repair-Ch by hypotension, bradycardia & cyanosis-Triggered by hypoxia , hypercapnia, acidosis, pain airway stimulation ,LVF- Rule out Large residual VSD before medical mx- Mx by Mechanical ventilation/NMB/Sedation- Refactory cases-ECMO
Low Cardiac OutputCauses: RV failure (m/c) due to Rt ventriculotomy & wide swings in PVR Others -Truncal valve insufficiency, inadequate myocardial protection , Coronary artery compression- Mx by optimizing preload, Adjusting ventilation to reduce airway pressures, Inotropes/Inodilator
Major Late Complication – Obstruction or Stenosis of Conduit
Postop Problems
Early Truncus repair (within 6 wks) at University of California Sanfrancisco (UCFS) have achieved 86% survival in their series of 244 pts since1975
All children were followed carefully to watch for the development of complications
Outcome
Thanks
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