Tricuspid Atresia with Absent Pulmonary Valve and Intact Ventricular Septum: A Rare Association

The absence of the pulmonary valve in connection with tricuspid atresia and intact ventricular septum is a rare malformation, associated with a poor prognosis. The right ventricle is severely hypertrophied, resembling a cardiac mass protruding into the left ventricular outflow tract. We report such a case that underwent successful palliation with a Blalock–Taussig shunt followed by a superior cavopulmonary anastomosis.     

Longevity of Neonatal Ductal Stenting for Congenital Heart Diseases with Duct‐dependent Pulmonary Circulation

Introduction. Ductal stent (DS) in duct‐dependent pulmonary circulation is less morbid than neonatal Blalock–Taussig shunt. However, there is concern if DS provides an adequately long palliation before definitive repair. Methods. This is a retrospective review of clinical follow‐up of all consecutive infants after successful DS performed by a single operator. They were divided into three anatomic groups. Group A neonates had balloon valvotomy for critical pulmonary stenosis or pulmonary atresia with intact ventricular septum, who needed DS patency until the right ventricle was adequate to provide antegrade pulmonary flows. Group B patients with tetralogy of Fallot and pulmonary atresia suited for later biventricular repair needed ductal patency until conduit surgery was completed. Group C patients with functionally univentricular hearts needed DS patency until bidirectional Glenn shunt completion. Results. Among 22 infants, four Group A patients followed for 26–54 months after balloon pulmonary valvotomy had adequate oxygen saturation and needed only short‐term DS patency. In six out of nine Group B patients, corrective biventricular repair using conduits was performed after 5–14 months at a body weight of 5–7.5 kg. Bidirectional Glenn shunt and confluence repair were performed in seven of nine Group C patients weighing 6–8.5 kg after 8–15 months. The hilar pulmonary artery growth in B and C groups was adequate for surgical repair. No patient needed stent redilatations or additional shunts on follow‐up for hypoxia. Four patients had sudden death. Conclusions. The short‐term patency of DS was adequate after balloon valvotomy for critical pulmonary stenosis or pulmonary atresia with intact ventricular septum. Duration of palliation by DS was also sufficient in univentricular hearts to allow adequate somatic growth before Glenn surgery. In patients with biventricular anatomy treated by DS, conduit repair had to be performed at a relatively early age. Interstage mortality was 18%.     

Pulmonary atresia with an intact septum: indications for the neonatal surgical treatment guided by 2-dimensional and Doppler echocardiography

Twelve neonates with pulmonary atresia and intact ventricular septum underwent surgical treatment based on two-dimensional and Doppler echocardiography. Ten patients with adequate morphology of the right ventricular outflow tract portion shown by means of two-dimensional echocardiography underwent pulmonary valvulotomy and systemic-to-pulmonary shunt. Two neonates with atresia of the right ventricular infundibulum on two-dimensional echocardiography underwent systemic-to-pulmonary artery shunt without valvulotomy. In all patients the qualitative and quantitative echocardiographic diagnosis was confirmed at surgery and/or with the subsequent angiocardiographic study. Two-dimensional and Doppler echocardiography is a precise diagnostic method for planning surgical treatment in neonates with pulmonary atresia and intact ventricular septum.     

Myocardial ischemia in patients with pulmonary atresia and intact ventricular septum

Children who die after operation for pulmonary atresia and intact ventricular septum may have myocardial ischemia. The relation between histologic evidence of myocardial ischemic injury and the presence of a right ventricle to coronary artery fistula, coronary artery dysplasia and operation in 17 autopsy specimens was assessed. Age at death ranged from 1 day to 16 years (median, 11 days). Of the 17 hearts, 6 (35%) had right ventricle to coronary artery fistulas, 5 of which had coronary artery dysplasia. In three cases, there was segmental or complete absence of a coronary artery. Ischemia was present in four of these six hearts, two of which had right ventricular outflow reconstruction. Six of the 11 hearts without right ventricle to coronary artery fistulas also had myocardial ischemia. Of these six cases, four had right ventricular outflow reconstruction and two had shunt operations. Death occurred from 1 to 8 days (mean 3) after operation. Hearts with pulmonary atresia and intact ventricular septum may have myocardial ischemia with or without either right ventricle to coronary artery fistulas or coronary artery dysplasia. Myocardial ischemia may occur after right ventricular outflow reconstruction or shunt operations. Thus, myocardial ischemia occurs commonly in patients with pulmonary atresia and intact ventricular septum and is not always related to coronary abnormalities or operation.     

Management algorithm in pulmonary atresia with intact ventricular septum.

Pulmonary atresia with intact ventricular septum (PAIVS) is a disease with remarkable morphologic variability, affecting not only the pulmonary valve but also the tricuspid valve, the RV cavity and coronary arteries. With advances in interventional techniques and congenital heart surgery, the management of PAIVS continues to evolve. This review is an attempt at providing a practical approach to the management of this disease. The basis of our approach is morphologic classification as derived from echocardiography and angiography. Group A, patients with good sized RV and membranous atresia, the primary procedure at presentation is radiofrequency (RF) valvotomy. Often it is the only procedure required in this group with the most favourable outcome. Patients with severely hypoplastic RV (Group C) are managed along the lines of hearts with single ventricle physiology. The treatment at presentation is patent ductus arteriosus (PDA) stenting with balloon atrial septostomy or conventional modified Blalock Taussig (BT) shunt. Bidirectional Glenn shunt may be done 6-12 months later followed by Fontan completion after a suitable interval. Patients in Group B, the intermediate group, are those with borderline RV size, usually with attenuated trabecular component but well developed infundibulum. The treatment at presentation is RF valvotomy and PDA stenting +/- balloon atrial septostomy. Surgical re-interventions are not uncommonly required viz. bidirectional Glenn shunt when the RV fails to grow adequately (11/2 - ventricle repair) and right ventricular outflow tract (RVOT) reconstruction for subvalvar obstruction or small pulmonary annulus. Catheter based interventions viz. repeat balloon dilatation or device closure of patent foramen ovale (PFO) may also be required in some patients.     

Congenital pulmonary atresia with tricuspid insufficiency: Morphologic study

In an anatomic study of 21 cases of pulmonary atresia with tricuspid insufficiency (pulmonary atresia with intact ventricular septum, type II), the morphologic features of the tricuspid valve and the right ventricle were found to differ greatly from those seen in pulmonary atresia with tricuspid stenosis (pulmonary atresia with intact ventricular septum, type I). Morphologically, pulmonary atresia with tricuspid insufficiency (type II) has a greater resemblance to Ebstein's disease with pulmonary atresia than to type I pulmonary atresia. The anomaly may be more amenable to surgery than pulmonary atresia with tricuspid stenosis because the right ventricle in the former may be converted into a functional chamber by a valvotomy combined with a shunting procedure and atrial septostomy.     

Necrotizing enterocolitis in pulmonary atresia with intact ventricular septum

Necrotizing enterocolitis (NEC) occurred in 2 neonates with pulmonary atresia and intact ventricular septum. Both infants underwent open heart surgery for the insertion of a right ventricular outflow tract patch under profound hypothermia, surface cooling and a fibrillating heart, without circulatory arrest. In both patients the development of NEC preceded both the cardiac catheterization study and open heart surgery. Urgent repair of the cardiac lesion was undertaken in an attempt at improving the critical bowel wall ischemia. Postoperatively, exacerbation of the NEC reached an advanced stage rapidly leading to the death of the patients. Recommendations regarding the management of future cases exhibiting this potentially lethal combination of disease are presented.     

Two-dimensional echocardiographic evaluation of right ventricular size and function in newborns with severe right ventricular outflow tract obstruction

Critical pulmonary stenosis or atresia with intact ventricular septum represents a congenital cardiac lesion for which the long-term prognosis appears to depend partly on the size of the right ventricle. Thus, the capability of noninvasive assessment of right ventricular size to predict operative outcome was examined in 15 infants (aged 1 to 30 days, mean 5.6) with severe right ventricular outflow tract obstruction (either critical pulmonary stenosis [7 patients] or pulmonary atresia with intact ventricular septum [8 patients]). Using echocardiography in two orthogonal subxiphoid views, right ventricular volume, wall thickness, area change fraction, ejection fraction and tricuspid anulus dimension were measured. All patients with a normalized right ventricular enddiastolic volume of less than 5 ml/m2 and a normalized tricuspid anulus dimension of less than 1.0 cm/m2/3 required a shunt operation. Only one patient with a volume of more than 6 ml/m2 and a normalized tricuspid anulus dimension of more than 1.4 cm/m2/3 required more than relief of right ventricular outflow tract obstruction. In this patient, residual severe pulmonary stenosis necessitated the shunt procedure. One patient with a volume of more than 6 ml/m2 had an anulus diameter of less than 1.4 cm/m2/3 and one patient with an anulus diameter of more than 1.4 cm/m2/3 had a volume of less than 6 ml/m2; both required shunt procedures. It therefore appears that if either the ventricular volume or tricuspid anulus size is excessively small, a shunt procedure is necessary. Wall thickness, area change fraction and ejection fraction measurements were not significantly correlated with right ventricular volume or postoperative outcome.(ABSTRACT TRUNCATED AT 250 WORDS)     

Complete blalock–taussig shunt obstruction in < 24 hours post‐operative period in a neonate treated emergently using transcatheter angioplasty and low dose local recombinant TPA

A 12‐day‐old infant with pulmonary atresia, intact ventricular septum, and pulmonary blood flow through a ductus arteriosus developed complete shunt obstruction within 12 hr of creation of a modified Blalock–Taussig shunt. Low dose recombinant tissue plasminogen activator was administered locally as two 0.03 mg/kg bolus injections and was followed by balloon angioplasty. This resulted in complete recanalization of the shunt without any hemorrhagic complications. © 2013 Wiley Periodicals, Inc.     

Importance of right ventricular outflow tract angiography in distinguishing critical pulmonary stenosis from pulmonary atresia.

OBJECTIVE: To investigate the spectrum of pulmonary atresia and critical pulmonary stenosis using right ventricular outflow tract angiography and explore its implications for catheter interventional treatment. DESIGN: Prospective clinical study. SETTING: Two paediatric cardiology centres. SUBJECTS: 11 neonates or infants (aged 1 day to 8 months; weighing 2.3 to 7.8 kg) with pulmonary atresia or where the differentiation of pulmonary atresia from critical pulmonary stenosis was unclear on either echocardiography or angiography. METHODS: Right ventricular outflow tract angiography was performed on all patients to distinguish pulmonary atresia from critical pulmonary stenosis before opening the right ventricular outflow tract. RESULTS: Right ventricular outflow tract angiography showed that three of seven patients diagnosed as pulmonary atresia by echocardiography had pin hole jets across the pulmonary valve; another had a probe patent valve that appeared imperforate on both echocardiography and right ventricular outflow tract angiography. Three of the four patients diagnosed by echocardiography as critical pulmonary stenosis were found on right ventricular outflow tract angiography to have pulmonary atresia. The remaining patient had such a tiny orifice that a second orifice had to be created with a radiofrequency catheter. The right ventricular outflow tract was opened successfully in 10 of the 11 patients, six of whom required application of radiofrequency energy. The right ventricular to aortic systolic pressure ratio fell from 1.4 (0.9 to 1.9) to 0.6 (0.2 to 1.1) (P < 0.05). All 11 patients were alive and well with transcutaneous oxygen saturations ranging from 84% to 95% at a median follow up duration of nine months. CONCLUSIONS: Critical pulmonary stenosis and pulmonary atresia cannot always be accurately distinguished by echocardiography. Right ventricular outflow tract angiography helps to distinguish the two groups. In most cases the right ventricular outflow tract can be opened without mortality and with short to medium term survival.     

Risk factors for augmentation of the flow of blood to the lungs in pulmonary atresia with intact ventricular septum after radiofrequency valvotomy

Some patients with pulmonary atresia with an intact ventricular septum, mild to moderate right ventricular hypoplasia, and a patent infundibulum remain duct dependent on the flow of blood through the arterial duct despite adequate relief of the obstruction within the right ventricular outflow tract. The objective of our study was to review the risk factors for stenting of the patent arterial duct, or construction of a Blalock-Taussig shunt, in the patients with pulmonary atresia and an intact ventricular septum who remain duct-dependent following radiofrequency valvotomy and dilation of the imperforate pulmonary valve. We reviewed the data from 53 patients seen between November 1995 and December 2001. Of the 47 patients who survived, 6 required stenting of the patent arterial duct, while 4 needed construction of a modified Blalock-Taussig shunt to augment the flow of blood to the lungs at a mean of 7 plus or minus 5.7 days following the initial intervention. The remaining 37 patients required no additional procedures. We compared the findings in these two groups. The mean diameter of the tricuspid valve in the patients requiring early reintervention was 8.5 plus or minus 3.7 millimetres, giving a Z-score of -1.1 plus or minus 1.47, whilst those in the group without early reintervention had values of 10.7 plus or minus 2.2 millimetres, giving a Z-score of -0.58 plus or minus 1.18 (p equal to 0.003). No statistically significant differences were found in right ventricular morphology, McGoon ratio, or residual obstruction across the right ventricular outflow tract after decompression of the right ventricle. The diameter of the tricuspid valve, therefore, appears to be the only factor predicting the need for augmentation of flow of blood to the lungs. As just over one-fifth of our survivors required such augmentation, we hypothesize that stenting of the patent arterial duct may be performed as an integral part of primary transcatheter therapy in patients with pulmonary atresia and intact ventricular septum who have moderate right ventricular hypoplasia and a small tricuspid valve.     

Successful repair of pulmonary atresia with ventricular septal defect without the use of a conduit: a new surgical option. Report of two cases.

A new technique for the restoration of continuity between the pulmonary artery and the right ventricle in pulmonary atresia with ventricular septal defect without the use of a conduit is described. This was accomplished by anastomosing the inferior margin of the distal pulmonary artery to the apex of a T-shaped infundibular ventriculotomy to form the posterior wall of the reconstructed right ventricular outflow tract. A winged patch of bovine pericardium was then used for the anterior wall to complete reconstruction of the transannular right ventricular outflow tract. This technique was used successfully in two patients.     

Ductus arteriosus patency with stenting in critical pulmonary stenosis and pulmonary atresia with intact interventricular septum

We report our experience with stenting of the ductus arteriosus in three neonates. Two patients had pulmonary atresia with an intact interventricular septum and one had critical pulmonary stenosis. Radiofrequency ablation was used to open the atretic pulmonary valve in two patients. In all three patients implanting a stent avoided the need for surgical creation of a Blalock-Taussig shunt. In two patients the procedure was scheduled as elective surgery, and in one it was done as an emergency procedure. Ductus arteriosus stenting is an alternative to palliative cardiac surgery.     

Successful repair of pulmonary atresia with ventricular septal defect without the use of a conduit: a new surgical option: Report of two cases

A new technique for the restoration of continuity between the pulmonary artery and the right ventricle in pulmonary atresia with ventricular septal defect without the use of a conduit is described. This was accomplished by anastomosing the inferior margin of the distal pulmonary artery to the apex of a T-shaped infundibular ventriculotomy to form the posterior wall of the reconstructed right ventricular outflow tract. A winged patch of bovine pericardium was then used for the anterior wall to complete reconstruction of the transannular right ventricular outflow tract. This technique was used successfully in two patients.     

Stenting of a stenosed major aortopulmonary collateral artery in a baby with pulmonary atresia and a ventricular septal defect: Rescue from critical hypoxia in the immediate postoperative stage of unifocalization supported by extracorporeal membrane oxygenation

A 4‐month baby with pulmonary atresia, ventricular septal defect, major aortopulmonary collateral arteries (MAPCAs) and an extremely hypoplastic central pulmonary artery developed critical hypoxia following right unifocalization combined with a right Blalock‐Taussig shunt. To increase pulmonary blood flow we stented the left lower MAPCA during extracorporeal membrane oxygenation (ECMO) support. He was successfully weaned from ECMO 2 days after stenting. Percutaneous intervention for a stenosed MAPCA is an effective means of increasing pulmonary blood flow in critically hypoxic patients following unilateral unifocalization, even in the immediate postoperative stage. © 2008 Wiley‐Liss, Inc.     

Severe tricuspid stenosis presenting as tricuspid atresia. Echocargraphic diagnosis and surgical management.

Two cases of pulmonary atresia with intact ventricular septum and severe tricuspid stenosis are described in which the initial angiographic diagnosis was tricuspid atresia and pulmonary atresia. Two dimensional echocardiography showed the features of an imperforate tricuspid valve because in each case contrast echocardiography failed to show anterograde flow from the right atrium to right ventricle. Successful radical surgical repair was achieved in one patient with performing a tricuspid valvotomy and inserting an external valved conduit between the hypoplastic right ventricle and the main pulmonary artery. In the second case, an infant died four weeks after tricuspid valvotomy and right ventricular outflow tract reconstruction.     

Reconstruction of the right ventricular outflow tract including pulmonary valve replacement in 6 children under two years of age

In 6 children under 2 years of age correction of congenital heart defects required reconstruction of the right ventricular outflow tract including replacement of the pulmonary valve. Outflow tract reconstruction consisted in implantation of a size 14 valved conduit in 2 patients with d-TGA and subpulmonary stenosis and 1-TGA and subpulmonary stenosis, and a size 16 valved conduit in 2 other patients with truncus arteriosus. In 2 children with DOLV, VSD and aneurysm of the pulmonary artery trunk, the pulmonary valve was replaced by porcine heterografts, sizes 19 and 21 respectively, after primary patch reconstruction of the right ventricular outflow tract. There was one operative death in a child with d-TGA, intact ventricular septum and severe subpulmonary stenosis. This child died in low cardiac output, probably because too much contractile muscle was lost at the site of anastomosis with the conduit. For reconstruction of the right ventricular outflow tract, pulmonary valve replacement has proven mandatory in cases with pulmonary hypertension in order to prevent postoperative right heart failure. Similarly, in cases with pulmonary stenosis and hypoplastic pulmonary arteries, postoperative pulmonary insufficiency can be deleterious to the right ventricle.     

Diagnosis of right ventricular outflow obstruction in infants by cross sectional echocardiography.

Cross sectional echocardiographic studies were assessed prospectively in 58 infants in whom right ventricular outflow obstruction was subsequently shown angiographically. A subcostal cut was used to display simultaneously the short axis of the aortic root and the long axis of the right ventricular outflow tract. This facilitated the differentiation of the common right ventricular outflow tract obstructive lesions. Tetralogy of Fallot was diagnosed correctly in 22 of 26 infants; pulmonary atresia with intact septum in all of 14 neonates; isolated severe pulmonary valve stenosis in all of nine infants; and pulmonary atresia with ventricular septal defect in eight of nine infants. The subcostal approach is the technique of choice for evaluating right ventricular outflow tract obstruction as it is more reliable than the left parasternal approach.     

The risk of surgical treatment of tetralogy of Fallot: an appraisal

The risk of surgical treatment of tetralogy of Fallot was analyzed with multivariate statistical techniques in a recent surgical series (1975-1983) of 159 corrected and 59 palliated patients. The overall mortality of correction was 12.6% and that of palliation was 15.3%. The significant and independent risk factors that increased the mortality of palliation were the use of a shunt other than the Blalock or its modifications (mostly Waterston) (P = 0.01), and very young age (P = 0.02). Risk factors that increased the mortality of correction were high left over right ventricular pressure ratio (P-RV/LV) (P = 0.02), persistent patency of the arterial duct (P = 0.02), other major associated lesions (P = 0.02), and the use of a transannular patch (P = 0.04). Cardioplegia significantly decreased the risk (P = 0.03). With present techniques, correction can be performed in favorable cases with a mortality approaching zero. Staged procedures neutralized the age related risk of correction, but Blalock shunts carried a mortality rate ranging from 9.5% at 1 month to 1.7% at 12 months of age. This was due to the lack of prostaglandins along with technical faults. Predicted two-stage mortality rates ranged in infants (less than 12 months) from 6.2 to 16% and compared favorably with our observed 27% mortality of primary correction. Our results show that the transannular patch becomes a fully expressed risk only in those patients with restrictive pulmonary arteries or isolated branch stenosis. This is because it decreases the force the right ventricle can generate in maintaining the cardiac output. The chances of survival, when compared with those of patients without transannular patch, are significantly less when the P-RV/LV is between 0.6 and 1.0. We therefore discuss the measures to decrease or neutralize this risk related to insertion of a transannular patch. Among the associated lesions, we discuss briefly the potential for residual right outflow tract stenosis, anomalous origin of the left anterior descending coronary artery and anomalous muscle bundle of the right ventricle.     

Echocardiographic assessment of neonates with pulmonary atresia and intact ventricular septum

In this prospective study, 27 consecutive neonates suspected to be suffering from pulmonary atresia and intact ventricular septum underwent detailed two-dimensional echocardiographic examination before cardiac catheterization. Of the 27 neonates 25 had pulmonary atresia and intact ventricular septum and the remaining 2 had "functional pulmonary atresia" secondary to severe Ebstein's anomaly of the tricuspid valve. In all 25 neonates with pulmonary atresia and intact ventricular septum, the diagnosis and right ventricular morphology based on the tripartite approach were correctly established by echocardiography. The associated Ebstein's anomaly in two babies with pulmonary atresia and intact ventricular septum was also correctly identified by echocardiography. Among the five babies who had a sinusoidal-coronary artery communication, echocardiography demonstrated the fistula in one and provided clues for its diagnosis in two others. In the 25 neonates with pulmonary atresia and intact ventricular septum, the echocardiographic dimensions of their tricuspid anulus, right ventricular infundibulum and main pulmonary artery correlated well with the angiocardiographic measurements (r greater than 0.8). The results of this study suggest that, in the management of neonates with pulmonary atresia and intact ventricular septum, preoperative evaluation by echocardiography is usually sufficient and cardiac catheterization should be reserved for selected cases.