A successful aortic coarctectomy performed beyond early infancy is followed, even in the long term, by persistence of left ventricular hypertrophy and by diastolic dysfunction, although systolic function is often increased. In this study we investigated whether earlier coarctectomy provides better preservation of left ventricular function. Experimental studies on the myocardial response to pressure overload show that neonates and young infants develop a functionally advantageous combination of myocytic hyperplasia (together with mild hypertrophy) and increased angiogenesis. Older patients, in contrast, generate myocytic hypertrophy in isolation, setting the scene for ventricular dysfunction. Cross-sectional echo-Doppler evaluation of left ventricular size, shape, mass and systolic and diastolic function was made in 13 patients a mean of 44±36 months (range 11 days-10 years) after successful coarctectomy in the first year of life. They were compared to 11 age, body surface area and gender-matched control subjects. In all patients, left ventricular mass normalized for body surface area was significantly greater than in the control group (66.2±12.3 vs 43±l2 p=0.0001). There was no correlation between left ventricular mass normalized for body surface area and age at operation, follow-up duration, degree of residual isthmic gradient, peak systolic wall stress, systolic blood pressure or left ventricular shape. No significant differences were noted between the two groups in regard to transverse diameter of the aortic arch, left ventricular afterload (meridional end-systolic wall stress), volume and shape (both in systole and diastole), systolic performance (fractional shortening and ejection fraction) and contractility (rate-corrected velocity of fiber shortening to meridional end-systolic wall stress relationship). Furthermore, no significant differences were found with respect to indices of mitral (including peak filling rate normalized to mitral stroke volume) and pulmonary venous flow, suggesting normal diastolic function. Repair of aortic coarctation in the first year of life promotes a more complete recovery of left ventricular function (particularly diastolic) than that reported after coarctectomy at older age, despite persistence of moderate ventricular hypertrophy.

A new surgical technique is described to reduce the flow through acquired systemic-pulmonary collateral arteries, a complication which has been recognized as a risk factor in patients undergoing the Fontan operation. When systemic-pulmonary collateral arteries have developed subsequent to previous construction of an ipsilateral Blalock-Taussig shunt or a Glenn anastomosis, and are identified by angiography in advance of the Fontan operation, the technique is indicated as a preparative procedure. It consists of rethoracotomy aimed at isolating the lung from the thoracic wall (peeling), and wrapping of the upper half of the lung with expanded polytetrafluoroethylene sheets to avoid redevelopment of collateral vessels into the lung (wrapping). This decreases the systemic-collateral flow through small vessels which cannot be handled by conventional embolization using catheterization techniques, and permits the Fontan operation to be performed more safely.

The purpose of this study was to determine the cause, onset, clinical outcome and treatment of aortic insufficiency developing during treatment of complex cardiac anomalies. Aortic insufficiency associated with ventricular septal defect is a well-recognized entity. Very few studies, in contrast, have addressed the development of aortic insufficiency in the presence of more complex cardiac anomalies. Ten patients were selected from two clinical centers. All patients were diagnosed with a major cardiac anomaly requiring surgical treatment. Each patient developed aortic insufficiency requiring a surgical treatment of the valve after correction or palliation of their cardiac defect. There were six males, and mean age for the series was 17 years (range 5.5 to 33 years). All patients were initially operated for repair (eight patients) or palliation (two patients) of their congenital anomaly. Five patients had tetralogy of Fallot, one had tetralogy associated with pulmonary atresia, and two patients had double outlet right ventricle, and two had complete transposition. The degree of aortic insufficiency, the amount of pulmonary stenosis present before the original procedure and the diameter of the aortic root measured before the aortic surgical procedure on the valve were assessed by angiography and echocardiography. The mean time between the last surgical procedure and the appearance of aortic regurgitation was three years, with a mean time between the last intervention and the aortic procedure of 7.3 years. The etiology of the insufficiency was explained by prolapse of an aortic leaflet in three patients. Four patients had annular dilation with central regurgitation, two patients had traumatic perforation of a leaflet, one patient had lesions consistent with endocarditis. Eight patients had dilation of the aortic root. Surgical procedures included five replacements of the aortic valve, three aortic valvoplasties, one aortic valvar replacement associated with a Glenn shunt, and one Bentall procedure. One patient died two months following an aortic valvar replacement. All patients were assessed by transthoracic echocardiography before discharged. The two main causes of aortic regurgitation, leaflet prolapse and annular dilation are age-related complications. Most patients had dilation of the aortic root from longstanding increases in aortic flow. Early repair of congenital anomalies may decrease these complications.

Three children with pulmonary atresia and ventricular septal defect with absent central pulmonary arteries underwent successful complete correction following preliminary staging procedures for unifocalization and deletion of multiple major aortopulmonary collateral arteries. The unifocalization procedures were accomplished using valveless pulmonary arterial cryopreserved allografts. This technique was found to facilitate and simplify the final repair. All patients survived the complete correction. The patients have been followed for 1½-4 years following the final surgery. One child died two years after repair from pneumonia complicated by asthma. One patient appears to have progression of pulmonary vascular disease despite the complete repair, and one patient continues to do well both symptomatically and hemodynamically. The results suggest that this method of unifocalization solves many of the problems inherent to more classical techniques, but the overall prognosis of patients in this diagnostic entity has yet to be completely defined.

The number of neonates who undergo intracardiac repair for congenital heart disease has increased in recent years. In considering appropriate surgical options in such circumstances, normal values for various cardiovascular dimensions are needed. We measured 19 parameters for the heart and great arteries (four valves, pulmonary tree, aortic arch, ascending and descending aorta, ventricular septum, left ventricular internal and posterior wall dimensions) using cross-sectional echocardiography in 55 premature and full-term infants (ranging in gestational age from 23 to 41 weeks, in body weight from 543 to 3966 g). The increase in each dimension correlated closely with body weight (r=0.62 to 0.87) and was found to follow a linear regression. The diameter of the isthmus was found to be smaller, and the size of mitral valve annulus larger, than previously published values.

A one-stage repair was performed for correction of the intracardiac malformations associated with coarctation of aorta in five pateints or interrupted aortic arch in eight patients. The ages ranged from four to 294 (median 35) days. The anomalies within the heart were a ventricular septal defect with or without subaortic stenosis (n=7), an aortopulmonary window (n=2), common arterial trunk (n=2), aortic valvar stenosis (n=1) and the TaussigBing anomaly (n=1). Surgery was performed through a median sternotomy employing cardiopulmonary bypass with moderate to deep hypothermia. In terms of the aortic reconstruction, an extended direct anastomosis was performed in 10 patients, while a vascular graft was interposed in three. So long as the aortic cannula did not interfere with the proximal anastomotic site on the aorta, circulatory arrest was avoided. As for surgery within the heart, the ventricular septal defects were closed via the right atrium with myotomy and myectomy if a morphological substrate for subaortic stenosis was confirmed (n=4). There were two hospital deaths (15.4%) due to low cardiac output. In patients who underwent myotomy and myectomy for subaortic stenosis, the postoperative pressure gradient across the aortic valve was negligible. We conclude that surgical results of one-stage repair for the intracardiac malformations associated with interrupted aortic arch or aortic coarctation are reasonable. We suggest that the early relief of obstruction within the left ventricular outflow tract may have played some role in the favorable outcome.

Replacement of the mitral valve was performed in 130 children less than 15 years of age—115 for rheumatic and 15 for congenital disease. Early mortality was 5.4%. Of 123 survivors, 112 were followed postoperatively for a mean period of nine years, with 80 of them on anticoagulants. Thromboembolism is the major late problem, with 25 thromboembolic accidents noted in 25 patients (22.3%). Anticoagulation was ineffective or lacking in 72% of them. Bacterial endocarditis was noted in five cases (4.4%) and a prosthetic leak in three (2.6%). Particular problems are observed in this group of young patients. First, recurrence of rheumatic fever in nine patients with an increasing severity of aortic valvar incompetence; second, with growth the prosthesis can become small as observed in six of our patients. A reoperation was needed in 15 patients, with one requiring two reoperations. Late mortality was 21%. Optimal timing for replacement of the valve is crucial. Appropriate anticoagulation and correct prophylaxis of rheumatic fever and bacterial endocarditis is mandatory. Conservative surgery is certainly preferable to valvar replacement, but if replacement proves necessary, large prostheses should be used.

Believing early repair to offer major benefits, we have repaired tetralogy of Fallot with pulmonary atresia in five infants aged less than six months. The ventricular septal defect was closed via a right atriotomy. The right ventriculotomy was 30±3% of the right ventricular length. The posterior wall of the right ventricular outflow tract was created by anastomosing directly the pulmonary trunk to the right ventriculotomy, or either by interposition of the left atrial appendage or an autologous pericardia! flap. The pathway was then roofed over with an equine pericardia! patch. All patients survived and are now doing well from 18 to 41 (31±11) months after the repair, although one patient required reoperation for relief of stenosis at the site of an anastomosis between the pulmonary arteries and the interposed left appendage. In the other patients, postoperative sequential echocardiography has shown no obstruction in the right ventricular outflow tract, nor significant pulmonary or tricuspid regurgitation. We conclude that primary repair in early infancy is an excellent option for surgical treatment of tetralogy of Fallot with pulmonary atresia.

The aim of the study was to determine the optimal size and technique for construction of the systemic-to-pulmonary arterial shunt which will provide suitable pulmonary blood flow in first-stage Norwood palliation for hypoplastic left heart syndrome in neonates. Our clinical experience suggested that an arterial oxygen tension of about 30 mm Hg immediately after cardiopulmonary bypass, with the patients being ventilated at the lowest possible mean airway pressure with an FiO2 of 1.0, provided a suitable pulmonary-to-systemic flow ratio. We also aimed to clarify the characteristics of pulmonary blood flow in accordance with the size of the shunt and the change in the pulmonary vascular resistance in a simplified rigid model of the Norwood procedure. A hole of2.0 mm diameter proved adequate to provide a suitable pulmonary blood flow of 200−300 mlx002F;min in the presence of a pressure gradient of 20−40 mm Hg between the systemic and pulmonary circulations in neonates weighing 3 kg. A short central shunt with a prosthesis of4 mm in diameter produced an excessive flow of pulmonary blood. Our data suggest that using a smaller shunt than that commonly used is necessary to decrease the early and intermediate postoperative mortality. A prosthesis of 3.0 or 3.5 mm in diameter arising from the brachiocephalic artery would be acceptable and can be recommended for first-stage Norwood palliation in small infants, especially in view of the operative difficulties encountered in taking down the shunt at the time of subsequent operations.

The morphology of the aortic valve was studied in 1,022 heart specimens belonging to the collection of the Institute of Pathological Anatomy, University of Padua. Twenty specimens were found to have a unicommissural aortic valve, characterized by the presence of a single leaflet with only one functional commissure; however, the presence of two raphes enabled the recognition of a basically three-sinus arrangement. Age and gender were known in 19 cases: 14 male and five female, mean age nine days. In 19 cases, the unicommissural valve was dysplastic and resulted in a severe congenital aortic valvar stenosis. Only in two hearts was the unicommissural nature of the aortic valve an isolated finding; among the remaining 18, left ventricular fibroelastosis in 11, malformation of the mitral valve in 11, hypoplasia of the left ventricle in eight, ventricular septal defect in four, mitral atresia in three, and subaortic fibrous diaphragm in one. Furthermore, seven (35%) of these 20 unicommissural aortic valves were associated with coarctation of the aorta. Statistical analysis shows that this association is not a random event. Our findings support the hypothesis that the unicommissural aortic valve originates from the early fusion of the three mesenchymal valvar cushions or leaflet primordia. Although the present data do not exclude the possibility that reduction of the blood flow through the aorta during fetal life may play a role in the formation of the unicommissural aortic valve, they rather point in the direction that another etiologic factor, such as an anomalous migration of neural crest cells, may be responsible for the fusion of the valvar cushions.

Between January 1990 and March 1992, a bidirectional cavopulmonary shunt was performed in seven patients under one year of age for palliation of complex cyanotic congenital heart disease. Five cases had tricuspid atresia with a restrictive ventricular septal defect. One case presented with complete mirror imagery, right-sided heart, double inlet and double outlet right ventricle with pulmonary stenosis. Another case had isomerism of the left atrial appendages with common atrioventricular valve and double outlet right ventricle. All had a pulmonary arterial index greater than 250 mm/m2 (Nakata index). Age and weights before surgery averaged five months (one to 11 months) and 5.6 kg (range 2.8 to 8.5 kg) respectively. Preoperative mean arterial oxygen saturation measured by cardiac catheterization was 60.05±14% and postoperative mean arterial oxygen saturation on room air was 79.85±6.03% (p<0.05). There were no deaths, although postoperative complications occurred in three patients, namely pleural effusion and pneumothorax. Mean follow-up was 10±4.2 months. The cardiothoracic ratio decreased in all cases. On subsequent echocardiographic studies with pulsed Doppler sampling, low velocity systolic-diastolic forward flow was registered in the pulmonary trunk. The velocity of flow increased clearly during inspiration. The bidirectional cavopulmonary shunt can be considered as primary palliation for complex cardiac malformations with restricted pulmonary flow independent of age and body weight.

The records of nine patients with double-chambered right ventricle, ventricular septal defect and subaortic narrowing were reviewed to clarify the natural history of the components of this pathological combination. All nine patients presented with heart failure related to a perimembranous ventricular septal defect, which underwent spontaneous reduction in eight and closed in one. Echocardiographic diagnoses of double-chambered right ventricle and subaortic narrowing were delayed in eight of the nine cases. The ratio of the distances from the pulmonary valve to moderator band/tricuspid valve annulus (the displacement index) was less than one in all patients. Subaortic narrowing was always discrete and was present at the diagnosis of double-chambered right ventricle. The subaortic narrowing was always recognized echocardiographically, and was seen in eight of nine patients at angiography. The subaortic gradient was 0–20 mm Hg and the subpulmonary gradient 0–110 mm Hg at catheterization. Five patients demonstrated aortic regurgitation. Subaortic narrowing should be diligently sought among patients with double-chambered right ventricle, and vice versa, even in the absence of a ventricular septal defect which may have closed. Both the subaortic narrowing and subpulmonary obstruction may progress, but probably at different rates. Patients with a perimembranous ventricular septal defect, particularly with a displacement index of less than one, should be monitored carefully for evolving subpulmonary obstruction, subaortic narrowing and aortic regurgitation. The subpulmonary obstruction should be resected at the time of any other surgical intervention. The indications for resection of the subaortic narrowing remain ill-defined.

In neonates with duct-dependent congenital heart defects, a reliable non-pharmacological, non-surgical method of maintaining flow through the arterial duct may simplify the management. Stent implantation into the arterial duct has been proposed as such a method. In order to evaluate the technical difficulties which may accompany clinical application, stent implantation into the arterial duct was attempted in 32 newborn lambs aged two to nine days (mean 4.2±1.4) weighing 2.4–7.3 kg (mean 4.6±1.0). Four different types of stent were implanted and the ease of implantation and outcomes were assessed. Stent implantation was technically successful in 28 of the 32 lambs (88%). Of these, 11 lambs died shortly after stent implantation with patent ducts, five lambs had early occlusion of the duct and 12 lambs were entered into a long-term study. The Gianturco-Roubin stent was too rigid and too long to enable successful implantation. The Palmaz-Schatz stent was poorly radio-opaque and was difficult to place accurately. When the aortic orifice was not completely covered, the duct occluded within a few days of implantation. The articulation gap also allowed duct tissue to prolapse into the middle of the stent. The Medinvent and Tower stents were simpler to position due to their superior radio-opacity. The Tower stent had an additional advantage in being a single strand stent which could be easily retrieved if misplaced.

Long-term left atrioventricular valvar function was evaluated in 95 of 110 survivors following surgical repair of atrioventricular septal defect between 1975 and 1984. A common or complete form was present in 40 and a partitioned or partial form in 55 patients. The patients have been followed for three to 13 years with a mean of 8.3 years. Pulmonary arterial banding was performed in 17 patients with a common atrioventricular valve prior to complete repair. The left atrioventricular valvar regurgitation was evaluated by clinical examination, Doppler and/or angiography. Three patients required valvar replacement postoperatively. Previous pulmonary arterial banding, pulmonary hypertension or pulmonary-to-systemic flow ratio did not affect the incidence or severity of left atrioventricular valvar regurgitation postoperatively. In this series left atrioventricular valvar regurgitation increased in the early postoperative period but rarely progressed at late follow-up.

Stenoses of the systemic venous pathways are a potentially dangerous complication after the Mustard operation. The acute and intermediate-term efficacy of balloon dilation of these stenoses has not previously been studied in a large group of patients. A retrospective analysis of clinical and angiographic data, with prospective clinical and echocardiographic follow-up, was performed in a consecutive group of 25 patients (17 male, 8 female) who underwent balloon dilation of the superior or inferior caval venous pathways. For 17 dilations of stenoses in the superior pathway, the mean pressure gradient decreased from 9.1±5.7 to 3.4±2.3 mm Hg (p<0.01), while the diameter of the stenosis increased from 5.9±2.9 to 11.2±3.0 mm (p<0.01). For 25 dilations of the inferior pathway, the mean gradient decreased from 4.3±1.8 to 1.4±1.1 mm Hg (p<0.01), while the diameter of the stenosis increased from 7.3±1.5 to 10.6±2.3 mm (p<0.01). Over a median follow-up of 3.5 years, 16 patients have been without symptoms or signs suggestive of recurrence of stenoses. In the remaining nine patients, 11 further procedures were performed at a median of 3.1 years after initial dilation. In five patients who had previously undergone dilation of the superior (3), inferior (1) or both (1) pathways, further dilations of the same pathway(s) and/or stent implantations were performed. Three patients, including one in whom superior caval venous stenosis had recurred, had developed a new stenosis of a previously undilated pathway, while in two patients no further dilations were required. Balloon dilation offers an alternative to reoperation for stenoses of the systemic venous pathways after the Mustard operation, and appears to provide satisfactory intermediate-term palliation. Recurrences of stenoses in previously dilated pathways, and new stenoses in previously unobstructed pathways, are commonly seen at follow-up. Alternative measures, such as placement of stents, need to be considered in the long-term management of these patients.

The role of cross-sectional echocardiography is demonstrated in defining the anatomy of the coronary arteries in 29 patients with complete transposition (concordant atrioventricular and discordant ventriculoarterial connections). The study revealed a relationship between some of the less frequent patterns and the spatial relationship of the arterial trunks, along with the presence or absence of a ventricular septal defect. It suggests that a side-by-side relationship of the arterial trunks due to infundibular maldevelopment may be related to some of the less common patterns.

The anatomic and pathophysiologic features of tricuspid valvar dysplasia are discussed in the light of two cases observed during fetal life which progressed with an unexpectedly favorable course. Some fetal echocardiographic features are proposed to explain this outcome. First, absence of associated cardiovascular abnormalities; second, clear separation between well represented right ventricular walls and the tricuspid valvar leaflets; third, normal proximal insertion of the tricuspid leaflets and, fourth, normal dimensions of the pulmonary trunk. We recommend karyotyping because of the possible association of this malformation with an aneuploid karyotype. We also describe transitory functional atresia of the pulmonary valve at birth, as far as we know for the first time, in a neonate that had normal forward flow of blood as seen on Doppler sampling in fetal life.

In 10 neonates with critical aortic stenosis who were treated with balloon dilation, we investigated retrospectively the predictive value for mortality of three echocardiographic parameters: early diastolic mitral valvar diameter, left ventricular end-diastolic diameter, and diameter of the aortic root. Valvoplasty was technically successful in each patient and the peak systolic ejection gradient decreased from 85±42 to 22±13 mm Hg, but clinical success was achieved in only six neonates, with four dying. The diameter of the aortic root was similar in survivors and non-survivors. The mitral valvar diameter and the left ventricular end-diastolic diameter, in contrast, were significantly smaller in non-survivors. The mitral valvar diameter and the left ventricular end-diastolic diameter, in contrast, were significantly smaller in non-survivors. The association of a mitral valvar diameter equal to, or less than, 9 mm with a left ventricular end-diastolic diameter equal to, or less than, 14 mm identified clearly all those who did not survive. In the future, we will recommend patients with these anatomical features for primary Norwood palliation. Neonates with a mitral valvar diameter equal to or greater than 12 mm and a left ventricular end-diastolic diameter equal to or greater than 17 mm, in contrast, are good candidates for balloon dilation. All our patients with these anatomical features survived and are doing well at follow-up (30±14.8 months). Simple echocardiographic measurements, therefore, can help in predicting outcome and choosing the best treatment in neonates with critical aortic stenosis.

There is little information on the indications for balloon dilation angioplasty for aortic coarctation. To determine the indications for balloon dilation in aortic coarctation, we evaluated prospectively the outcome of children treated according to our therapeutic protocol. The protocol included patients with postoperative recoarctation and isolated native coarctation with risks for surgical repair as conditions for which balloon intervention was absolutely indicated, and native coarctation without a significant arterial duct as a condition possibly qualifying for balloon dilation. Patients with duct-dependent coarctation and diffuse hypoplasia of the aortic arch were not considered to require balloon intervention and were treated surgically. We entered 47 patients into this protocol between January 1988 and December 1993. In 21, dilation was performed successfully and provided significant relief of pressure gradients. The peak systolic pressure gradients across the coarcted site in native coarctation and postoperative recoarctation decreased significantly from 40±19 to 13±10 mm Hg (p<0.0001) and 38±24 to 14±75 mm Hg (p<0.01) immediately after the procedure, respectively. Similarly, the diameters of the coarcted site increased significantly from 3.8±1.8 to 6.6±2.43 mm (p<0.0001) and 4.6±1.9 to 6.0±2.0 mm (p<0.005), respectively. Five patients with native coarctation, and one with postoperative recoarctation, developed restenosis during the period of follow-up and were treated successfully with repeat dilation. It may be possible to change the therapeutic strategy for aortic coarctation with advances in the use of balloon dilation. Our protocol for this technique appears to be reasonable, but further evaluation of its indications is needed.