Surgery for Congenital Heart Diseases By: Dr. Shkar R. Saeed

Etiologic Basis of Congenital Heart Diseases 1. Primary genetic factor (10%) 1) Chromosomal; 5-10% 2) Single mutant gene; 3% Recessive Dominant 2. Genetic-environmental interaction (90%) 1) Multifactorial inheritance; majority 2) Risks to offspring of an affected parent 3) Environmental contribution Drugs Infections Maternal conditions

Potential Cardiovascular Teratogens 1. Drugs Alcohol Amphetamines Anticonvulsants Chemotherapy Sex hormone Thalidomide Retinoic acid 2. Infections Rubella Coxsakie virus 3. Maternal conditions Old age Diabetes Lupus Phenylketonuria 4. Others

Maternal Risk Factors Factors Malformation Advanced age Trisomy 21 Maternal CHD Various Diabetes mellitus VSD, TGA, cardiomyopathy SLE Heart block Phenylketonuria TOF, VSD, COA, HLHS Viruses Teratogenic, myocarditis (*cytomegalovirus, herpes, coxsacki B, parvovirus)

Maternal Drug Exposures Drug Malformation Diphenylhydantoin PS, AS Trimetadione VSD, TOF, TGA, HLHS Thalidomode TOF, Truncus arteriosus Lithium Ebstein anomalies Alcohol VSD, ASD, PDA, TOF Amphetamine VSD, ASD, PDA, TGA Birth control pills VSD, TOF, TGA

classification of Congenital Heart Diseases 1. Lt to Rt Shunt ( 53 % ) PDA 17 % ASD 16.5 % VSD 13 % AVSD 3.5 % 2. Rt to Lt Shunt (11 % ) TOF 4.5 % TA 3 % PA+VSD 2.5 % PA+IVS 0.5 % 3. Admixture Lesion ( 15 % ) TGA 5 % Univ. Ht. 5 % DORV < 2 % Truncus 0.8 % Corrected TGA < 0.5 % 4. Obstructive Lesion ( 15 % ) Coarctation 9.5 % PS 2 % MS etc. 1.5 % LVOTO 1.3 % HLHS 0.9 % IAA 0.6 % 5. Valvular Lesion Ebstein < 1 % AR < 0.5 % MR < 0.5 % 6. Miscellaneous Arrhythmia 5 % Vascular ring 0.5 %

Evaluation of CHD by History Taking 1. Infants 1) Murmur 2) Symptoms of CHF poor feeding, low weight gain, tachypnea, tachycardia, sweating, anxiety, irritability, frequent URI 3) Symptoms of hypoxemia cyanosis, hypoxic spell 2. Children 1) Murmur 2) Symptoms of CHF exercise intolerance, dyspnea on exertion, frequent URI, palpitation 3) Syncope, chest pain 4) Symptoms of Hypoxemia cyanosis, hypoxic spell,clubbing

Investigations 1.CXR Integral part of evaluation TOF(boot shaped heart) TGA(egg on side) Dilated PA (PHTN) 2.Echo(TTE,TEE) 3. MRI 4. Cardiac catheterization(exact anatomy, PA pressure messurements,Qp/QA messure, occluders and dilators

To Be Corrected in Neonate Critical AS Hypoplastic left heart syndrome Interrupted aortic arch Symptomatic COA TGA Truncus Arteriosus Other symptomatic complex heart diseases

To Be Corrected in Infancy Cardiac anomalies with pulmonary outflow tract obstruction Critical PS Tricuspid atresia TGA TOF PA with or without VSD Corrected TGA

Surgical Indications and Optimal Timing of Operation

Palliative Surgery Systemic – pulmonary artery shunt Blalock-Taussig shunt Cavopulmonary shunt (BCPS) Hemifontan & Fontan procedures RVOT reconstruction Valvotomy Patch widening Valved conduit Pulmonary artery banding Atrial septectomy

Systemic–Pulmonary Artery Shunt ( Qp<Qs i.e cyanosis) Systemic–pulmonary artery shunt is indicated due to age, size, anatomy or other conditions when: Complex anomaly with severe cyanosis, irritability, hypoxic episode Critically ill neonates or infants due to decreased pulmonary flow Facilitating growth of hypoplastic pulmonary artery

Pulmonary Artery Banding Qp>Qs i.e more Pulm. flow Pulmonary artery banding is indicated to decrease pulmonary blood flow & protect vascular disease when: Control of congestive heart failure Complex or multiple VSD (+/- coarctation) CPB medically contraindicated Protection of pulmonary vascular bed

Atrial Septectomy For the increasing of effective pulmonary flow and systemic oxygen saturation Indication of atrial septectomy : TGA Tricuspid atresia Pulmonary atresia MV and LV hypoplasia Decreasing tendency of indication due to early total correction or intervention

Reparative Surgery Non-open heart surgery Open heart surgery Palliative procedure Corrective procedure Anatomic correction Physiologic correction

Non-open Heart Surgery Corrective procedure PDA COA Vascular ring and sling Coronary artery anomalies Stenotic valvular diseases Instrumental dilatation

Patent Ductus Arteriosus Open communication usually between upper descending Aorta and proximal portion of LPA Significant PDA : indicated after 1st month Prophylactic closure : 6-12 months Symptoms of heart failure or failure to thrive: indicated at any time Severe pulmonary vascular disease: contraindicated

Coarctation of the Aorta Congenital narrowing of upper thoracic aorta adjacent to the ductus arteriosus Operation is indicated when : Reduction of luminal diameter > 50% Upper body HT > 150mmHg in young infant With CHF at any age COA with VSD COA with other important intracardiac defects One stage repair

Open Heart Surgery

ASD with or without PAPVR A hole of variable size in the atrial septum and is most common cardiac malformation with various location of defect, fossa ovalis, posterior, ostium, primum, coronary sinus, subcaval (sinus venosus) Uncomplicated ASD or of PAPVC with RV volume overload (Qp/Qs>1.5 or 2.0) : is an indication of surgery. Optimal age : under 5 years but recently 1-2 years to avoid RV volume overload

Total Anomalous Pulmonary Venous Connection These are no direct connection between any pulmonary vein and the LA. But rather, all the pulmonary veins connect to the RA or one of its tributaries Diagnosis is an indication of operation Immediate repair with Diagnosis in any ill neonate : Preoperative preparation is not needed Repair should be done nearly always before 6 months Diagnosis at 6-12 months: prompt repair is indicated

Ventricular Septal Defect A hole (or multiple holes) between Lt & Rt ventricle Symptomatic large VSD : an indication of operation Before 3 months: indicated in large VSDs with CHF or respiratory symptoms Moderate sized VSDs (Qp/Qs < 3.0) with few symptoms : observation during infancy Small VSDs (Qp/Qs < 1.5) : not indicated, risk of bacterial endocarditis Subarterial type : early repair is indicated before childhood

Atrioventricular Septal Defect Abnormalities of atrioventricular valve form & function and interatrial & interventricular communication from maldevelopment of the endocardial cushions Presence of AVSD : indicated with Diagnosis Partial AVSD : 1-2 years of age except CHF or growth failure Complete AVSD with good condition : 3-6 months Development of pulmonary vascular obstructive disease : not indicated

Congenital Aortic Stenosis The various forms of LVOTO occur in combination with other cardiac lesions (IAA, COA, MV anomalies, LV hypoplasia) and obstructive types are supravalvular, valvular, subvalvular, intraventricular Critical AS in neonates : urgent (severe CHF, LV dilatation, hypertrophy) Infants and children Pressure gradient > 75mmHg Symtoms of angina, syncope, exercise intolerance, LVH, pressure gradient > 50mmHg Pressure gradient over 40mmHg in subvalvular lesion to prevent progression

Ebsteins anomaly A congenital defect of tricuspid valve in which the origin of septal and posterior leaflets or both are displaced downward into the right ventricle and the leaflets are variably deformed Symptomatic Ebstein’s anomaly is an indication Valve repair and ASD closure : with important TR, moderate and severe cyanosis WPW syndromes : ablation of accessory conduction pathway

Pulmonary Stenosis Percutaneous balloon valvotomy A form of RV outflow obstruction in which stenosis is usually valvar or both valvar & subvalvularor only subvalvular Critical PS in neonate : indicated with Dx Percutaneous balloon valvotomy Valvotomy with CPB Transannular RVOT patch widening PS in infants and children : indicated with Symptoms & Pr gradient over 50mmHg Surgical treatment is not indicated with mild stenosis

Tetralogy of Fallot Characterized by underdevelopment of RV outflow Diagnosis is an indication of operation Symptomatic complicated in early life : Early total correction or Shunt (1-2 months) and total correction (1 year) Asymptomatic uncomplicated : Total correction at 3-24 months Multiple VSDs, LAD from RCA : Initial shunt and total correction

Double Outlet Right Ventricle A congenital cardiac anomalies which both great arteries rise wholly or in large part from the RV. It is, then, a type of ventriculoarterial connection. Dx is an indication of operation Simple DORV with subaortic VSD : repair by 6 mo with PS --- repair like TOF DORV with subpulmonic VSD (Taussig-Bing heart) : arterial switch operation within 1 mo

Transposition of Great Arteries A cardiac anomaly in which the Aorta arises entirely or in large part from the RV, and PA from LV (atrioventricular concordant connection and ventriculoarterial discordant connection) Simple TGA in neonate : arterial switch operation within 1 months Simple TGA beyond 30 days : atrial switch operation (Mustard, Senning) TGA with VSD : arterial switch operation as early

Tricuspid Atresia A cardiac anomaly in which RV fails to open into a ventricle through a AV valve. There is thus a univentricular AV connection PVR is an important indicator > 4 unit -- contraindication 2-4 unit -- BCPS < 2 unit -- Fontan operation Symptomatic in early life early shunt or PAB BCPS or hemi-Fontan at 6-12 months Fontan at 12-24 months Asymptomatic Fontan candidate : 12-30 months

Congenitally Corrected TGA A cardiac anomaly with ventriculoarterial discordant connection & atrioventricular discordant connection. The circulatory pathways are therefore in series The presence of CCTGA per se is not an indication. With VSD : indications for VSD With VSD + PS : indications for TOF With complete heart block : pacing Double Switch operation : anatomic correction