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Pulmonary atresia with intact ventricular septum Pulmonary atresia and intact ventricular septum was first described in 1784 by Hunter Robert M. Freedom- described the diversity of this malformation and emphasized the complexity of this disorder Epidemiology New England Regional Infant Cardiac Program identified 75 patients with this disorder- 3.1% of all infants enrolled in the study Baltimore-Washington Infant Study defined the prevalence for this disorder as 0.083 per 1,000 live births Levocardia, normal atrial relations, concordant atrioventricular connections, and concordant ventriculoarterial connections Right ventricular outflow tract is imperforate. Either membranous or muscular atresia. The ventricular septum is intact. Pulmonary blood flow is usually mediated by a PDA Multiple direct aortopulmonary collaterals originating from the descending thoracic aorta may be the sole sources of pulmonary arterial supply rarely. Nonconfluent pulmonary arteries, each supplied by a patent arterial duct may also occur rarely. Morphogenesis Kutsche and Van Mierop theory Pulmonary atresia with ventricular septal defect occurs earlier in cardiac morphogenesis than pulmonary atresia and intact ventricular septum. Pulmonary atresia and ventricular septal defect occur early in cardiac morphogenesis, after partitioning of the truncoconal part of the heart but before closure of the ventricular septum. Pulmonary atresia and intact ventricular septum occur after cardiac septation. Reflects a prenatal inflammatory disease rather than a true congenital malformation Kutsche LM, Van Mierop LH. Pulmonary atresia with and without ventricular septal defect: A different etiology and pathogenesis for the atresia in the 2 types? Am J Cardiol 1983;51:932â Few data to support an inflammatory process Histopathological studies provided no evidence of inflammation. Obligatory right-to-left shunt at atrial level-either a patent foramen ovale or true secundum atrial septal defect If the interatrial septum is intact -alternative pathways for systemic venous return - coronary sinus to left atrial fenestration. Tricuspid Valve Ranges from extreme stenosis to severe regurgitation Severely regurgitant valve -dilated annulus. The valve may exhibit Ebstein anomaly. Extremely dysplasia also seen. Patients with the largest right ventricles usually have severe tricuspid regurgitation with valves exhibiting features of Ebstein's anomaly and dysplasia. A major management challenge with a poor overall prognosis. Right Ventricle Congenital Heart Surgeons Study (CHSS)-the use of the tricuspid diameter Z value It is the diameter of the tricuspid valve normalized to body surface area. Data from the CHSS showed that the Z value of the tricuspid valve correlated with the size of the right ventricular cavity (p <0.0001) Relief of outflow tract obstruction with associated pulmonary insufficiency may result in remodeling with regression of hypertrophy that can result in real or perceived growth of the right ventricle Daubeney PE, Delany DJ, Anderson RH, et al. Pulmonary atresia with intact ventricular septum: Range of morphology in a population-based study. J Am Coll Cardiol 2002;39:1670 Freedom RM. How can something so small cause so much grief? Some thoughts about the underdeveloped right ventricle in pulmonary atresia and intact ventricular septum. J Am Coll Cardiol 1992;19:1038 Well developed RV with hypertrophy-inlet,trabecular and outlet well developed -good prognosis. Small RV cavity (66%)-poorer surgical outcomes Markedly increased RV dimensions-severe TR(associated Ebsteins anomaly- 10-15 %) The aortic arch is left sided Aortic valve stenosis has been described in patients with pulmonary atresia and intact ventricular septum Myocardial Abnormalities Ischemia, fibrosis, infarction, and myocardial rupture have been observed Myocardial disarray and ventricular endocardial fibroelastosis also seen. Ventricular to coronary artery communications PA IVS is associated with ventriculo arterial connections(by large sinusoids) Usually seen in association with hypoplastic RV Connections are seen to commonly RCA,LAD (to LCX is rare) Blood flow Systole-High pressure RV to sinusoids Diastole-coronary artery to RV- ‘coronary steal' Development Coronary circulation develops as isolated plexus of vessels. Connections first develop to ventricular cavity and later coronary arteries develop and connect to aorta. Pulmonary atresia-high RV pressure maintains RV to sinusoids patency Coronary artery anomalies 1) right ventricle -to-coronary artery fistulas 2) coronary artery stenoses 3) coronary occlusions Natural History Equal prevalence in male and female 50% newborns die in first month of life Majority die in first 3 months Survival beyond first year is rare. Survival upto 21 years reported. Physical Examination Newborns with pulmonary atresia and intact ventricular septum become cyanotic and hypoxemic –along with closure of the patent arterial duct Cyanosis usually is apparent within hours of birth and is progressive The left ventricle may be enlarged, and at the apex, its impulse may be forceful. The second heart sounds is single.(A2) A pansystolic murmur may be audible at the left lower sternal border(of tricuspid regurgitation.) Arterial duct murmur may be heard in the second and third left intercostal space Radiographic Features The chest radiograph may demonstrate a heart that is only mildly enlarged or one that fills the entire chest cavity Electrocardiographic Features Frontal QRS axis of + 30 to + 90 paucity of right ventricular forces left ventricular dominance or left ventricular hypertrophy Right atrial enlargement The Electrocardiogram in Tricuspid Atresia and Pulmonary Atresia with Intact Ventricular Septum Circulation.1966; 34: 24-37 Electrocardiograms were studied in 37 patients with tricuspid atresia and in 20 with pulmonary atresia and intact ventricular septum. The results were correlated with angiocardiographic findings and postmortem examinations Biatrial hypertrophy was noted in 81% of the electrocardiograms in patients with tricuspid atresia, whereas this pattern was seen in only two infants with pulmonary atresia and intact ventricular septum In tricuspid atresia, left axis deviation was more common. Pulmonary atresia - no instances of left axis deviation in the frontal plane. Echocardiographic Features Functional status of the interatrial septum - obligatory right-to-left shunting. The size and morphology of the tricuspid valve ,RV Patency of ductus Degree of TR Ebsteins anomaly Functional pulmonary atresia Lack of forward flow is due to high pulmonary artery pressure with poor right ventricular function or very severe tricuspid insufficiency. Pulmonary valve is morphologically normal but functionally closed Cardiac cathetrisation Groin approach Catheter passed through IVC to RA Easily passes to LA(PFO) RV entry difficult if severe TR/RV hypoplasia Ductus visualised by left ventricular angiogram Visualisation of coronary arteries RV angiogram ventricular coronary communications confirm PA Management • PGE1 infusion to maintain ductal patency • Electively intubated and controlled ventilation • Metabolic acidosis to be corrected and ionotropic support if perfusion is inadequate • Adequately stabilized before any initial procedure Surgical management • Goal is to achieve a two ventricular circulation with the right ventricle providing all blood flow to the lungs at a low filling pressures without residual right to left shunt • Goal should be achieved with • low moratality • promoting the growth of RV • minimizing the need for subsequent surgical procedures RV cavity size and coronary artery anatomy are crucial in selecting appropriate treatment strategy The options available include the following. Surgical opening of the pulmonary valve and the right ventricular outflow tract. Systemic arterial to pulmonary arterial shunt Transcatheter opening of the pulmonary valve. Maintaining ductus arteriosus patency. Systemic venous to pulmonary arterial shunt. Closing the tricuspid valve. Venous to pulmonary arterial shunts Glenn procedure: end-to-end anastomosis of the SVC to the left pulmonary artery. Cavopulmonary anastomosis or bidirectional Glenn procedure: anastomosis of the SVC to the pulmonary artery so that both lungs can be perfused by SVC blood. Atriopulmonary connection or Fontan procedure: Anastomosis of the right atrial appendage to the pulmonary artery to divert all venous return into the pulmonary artery. Severe pulmonary stenosis or pulmonary atresia with well-developed right ventricle and mild or no tricuspid regurgitation Surgical pulmonary valvotomy with patch closure Balloon valvuloplasty Pulmonary atresia with well-developed right ventricle and marked tricuspid regurgitation SVC to pulmonary artery communication (bidirectional Glenn procedure) can be performed in addition to valvotomy. Pulmonary atresia with hypoplastic right ventricle and tricuspid valve Tricuspid valve diameter less than 8 mm in a newborn infant Tricuspid to mitral valve diameter ratio less than 0.7 Tricuspid valve diameter Z-scores of –3 or smaller Management Bidirectional Glenn procedure Pulmonary atresia with hypoplastic right ventricle and coronary sinusoids Attempts to open the RVoutflow tract are contraindicated. Systemic-to-pulmonary arterial shunt or prolonged PGE1 infusion is recommended. After the age of 3–4 months, cavopulmonary anastomosis may be performed. Risk factor for death after initial procedure Low birth weight Small tricuspid valve RV dependent coronary circulation Prognosis and long-term results after procedures Balloon valvuloplasty performed in the neonatal period may not be very effective in relieving stenosis. Cyanosis may persist and repeat valvuloplasty may be necessary within 6–9 months. Residual pulmonary valve insufficiency Pulmonary atresia with intact ventricular septum: Strategy based on right ventricular morphology Naoki Yoshimura, MD, Masahiro Yamaguchi, MD et al J Thorac Cardiovasc Surg 2003;126 Between April 1981 and June 2002, 45 consecutive patients with pulmonary atresia with intact ventricular septum underwent surgical treatment. Open transpulmonary valvotomy was performed in 27 patients and Blalock-Taussig shunt in 18 patients as the initial palliative procedure. Three patients who underwent a successful transpulmonary valvotomy alone in the neonatal period required no further operation. Definitive repair was performed in 32 patients RESULTS There were 1 early and 2 late deaths before the definitive operation in patients who underwent transpulmonary valvotomy. Two patients who had coronary artery interruption died 3 months and 13 years after the initial Blalock-Taussig shunt. There were 1 early and 2 late deaths after the definitive operation. Survival, including noncardiac death, was 91.1% at 5 years after the initial procedure and 81.5% at 10 years OUTCOME AFTER OPERATIONS FOR PULMONARY ATRESIA WITH INTACT VENTRICULAR SEPTUM Jack Rychik MD, Hara Levy MD et al J Thorac Cardiovasc Surg 1998;116 Overall survivals at 1, 5, and 8 years were 82%, 76%, and 76%. Mortality was highest in infancy Prenatal Diagnosis of Pulmonary Atresia with Intact Ventricular Septum Flow through the foramen ovale- moving from the right atrium to the left atrium. Retrograde flow through the ductus arteriosis THANK YOU…..