Atherosclerosis causing recurrent catastrophic aortopulmonary shunt dehiscence in a patient with Alagille syndrome.

Alagille syndrome (ALGS) is an autosomal dominant disorder associated with cholestatic liver disease, pulmonary valvar stenosis or atresia, vasculopathy, and renal disease. Although the liver and cardiac manifestations contribute to overall morbidity and mortality during their life span, these patients also carry a burden of important but often underappreciated vascular abnormalities. This report describes a 3 year-old girl with Alagille syndrome, hepatic cholestasis, systemic hypertension, hypercholesterolemia, hypertriglyceridemia, and tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals (TOF/PA/MAPCAs). She presented for bilateral pulmonary artery plasty and central shunt upsizing. She then experienced three shunt dehiscence episodes, necessitating emergent intervention. Autopsy showed diffuse atherosclerosis and significant atherosclerotic plaque at the site of shunt dehiscence. This is the first reported case of ALGS with TOF/PA/MAPCAs and catastrophic shunt dehiscence due to significant generalized vasculopathy caused by dyslipidemia and atherosclerosis. Dyslipidemia, a known comorbidity in ALGS, is one of few modifiable risk factors that should be screened for and treated, particularly before cardiac surgery.

Improved surgical outcome after fetal diagnosis of hypoplastic left heart syndrome.

BACKGROUND: Hypoplastic left heart syndrome (HLHS) is frequently diagnosed prenatally, but this has not been shown to improve surgical outcome. METHODS AND RESULTS: We reviewed patients with HLHS between July 1992 and March 1999 to determine the influence of prenatal diagnosis on preoperative clinical status, outcomes of stage 1 surgery, and parental decisions regarding care. Of 88 patients, 33 were diagnosed prenatally and 55 after birth. Of 33 prenatally diagnosed patients, 22 were live-born, and pregnancy was terminated in 11. Of 22 prenatally diagnosed patients who were live-born, 14 underwent surgery, and parents elected to forego treatment in 8. Of 55 patients diagnosed postnatally, 38 underwent surgery, and 17 did not because of parental decisions or clinical considerations. Prenatally diagnosed patients were less likely to undergo surgery than patients diagnosed after birth (P:=0.008). Among live-born infants, there was a similar rate of nonintervention. Among patients who underwent surgery, survival was 75% (39/52). All patients who had a prenatal diagnosis and underwent surgery survived, whereas only 25 of 38 postnatally diagnosed patients survived (P:=0.009). Patients diagnosed prenatally had a lower incidence of preoperative acidosis (P:=0.02), tricuspid regurgitation (P:=0.001), and ventricular dysfunction (P:=0.004). They were also less likely to need preoperative inotropic medications or bicarbonate (P:=0.005). Preoperative factors correlating with early mortality included postnatal diagnosis (P:=0.009), more severe acidosis (P:=0.03), need for bicarbonate or inotropes (P:=0.008 and 0.04), and ventricular dysfunction (P:=0.05). CONCLUSIONS: Prenatal diagnosis of HLHS was associated with improved preoperative clinical status and with improved survival after first-stage palliation in comparison with patients diagnosed after birth.

Early and intermediate outcomes after repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries: experience with 85 patients.

BACKGROUND: Pulmonary atresia with ventricular septal defect (VSD) and major aortopulmonary collaterals (MAPCAs) is a complex lesion with marked heterogeneity of pulmonary blood supply. Traditional management has involved staged unifocalization of pulmonary blood supply. Our approach has been to perform early 1-stage complete unifocalization in almost all patients. METHODS AND RESULTS: Since 1992, 85 patients with pulmonary atresia, VSD, and MAPCAs have undergone unifocalization (median age, 7 months). Complete 1-stage unifocalization and intracardiac repair were performed through a midline approach in 56 patients, whereas 23 underwent unifocalization in a single stage with the VSD left open, and 6 underwent staged unifocalization through sequential thoracotomies. There were 9 early deaths. During follow-up (1 to 69 months), there were 7 late deaths. Actuarial survival was 80% at 3 years. Among early survivors, actuarial survival with complete repair was 88% at 2 years. Reintervention on the neo-pulmonary arteries was performed in 24 patients. CONCLUSIONS: Early 1-stage complete unifocalization can be performed in >90% of patients with pulmonary atresia and MAPCAs, even those with absent true pulmonary arteries, and yields good functional results. Complete repair during the same operation is achieved in two thirds of patients. There remains room for improvement; actuarial survival 3 years after surgery is 80%, and there is a significant rate of reintervention. These results must be appreciated within the context of the natural history of this lesion: 65% of patients survive to 1 year of age and slightly >50% survive to 2 years even with surgical intervention.

Systemic venous collateral channels causing desaturation after bidirectional cavopulmonary anastomosis: evaluation and management.

OBJECTIVES: We sought to characterize the frequency, anatomic details and factors associated with the development of collateral channels between the superior and inferior vena caval systems after bidirectional cavopulmonary anastomosis. BACKGROUND: It is well known that systemic venous collateral channels often develop in patients who have undergone a classic Glenn shunt or bidirectional cavopulmonary anastomosis and that such collateral channels can lead to profound systemic desaturation. However, there have been few reports focusing on this problem. METHODS: Fifty-four patients (median age 1.4 years) who underwent bidirectional cavopulmonary anastomosis and had preoperative and postoperative angiograms available for review were studied retrospectively. Postoperative connections between the superior and inferior vena caval systems were identified and measured. Sites of collateral origin and entry from the superior and inferior venous systems, as well as the course taken in between, were recorded. RESULTS: At follow-up angiography performed 17 days to 46 months postoperatively, a total of 31 venous collateral channels were observed in 18 patients with a wide variety of primary morphologic diagnoses. The majority of these collateral channels (80%) originated from the brachiocephalic vein or its junction with the superior vena cava, and over half of them drained below the diaphragm. In patients who developed venous collateral channels, the mean transpulmonary pressure gradient early after bidirectional cavopulmonary anastomosis was higher (p = 0.005), and mean arterial oxygen saturation at follow-up was lower (p = 0.009). There were trends toward higher superior vena caval pressure early after the operation and at follow-up in patients with collateral channels and a higher likelihood of absent upper lobe pulmonary blood flow in these patients. Successful coll embolization of 10 collateral channels was performed in six patients, with a median increase in arterial oxygen saturation of 16%. CONCLUSIONS: Angiographically detectable systemic venous collateral channels develop after bidirectional cavopulmonary anastomosis in a substantial number of patients (33% in the present series) with a variety of forms of a functional univentricular heart. Patients with venous collateral channels can be treated successfully with coil embolization, but the indications for embolization will depend on individual circumstances.

Accessory and anomalous atrioventricular valvar tissue causing outflow tract obstruction: surgical implications of a heterogeneous and complex problem.

OBJECTIVES: The purpose of this study was to determine the effect of accessory or anomalous atrioventricular valvar apparatus on relief of outflow tract obstruction. BACKGROUND: Outflow tract obstruction due to accessory tissue or anomalous attachments of the atrioventricular valvar apparatus is an unusual but well-recognized problem. In addition to obstruction, anomalous attachments of the atrioventricular valvar apparatus may interfere with procedures to relieve outflow tract obstruction or perform outflow tract reconstruction. METHODS: Since 1992, we have operated on 21 patients (median age 4 years) with systemic (n=13), pulmonary (n=5) or bilateral (n=3) outflow tract obstruction due to accessory atrioventricular valvar tissue and/or anomalous attachments of the subvalvar apparatus. Primary diagnoses were isolated obstruction of the systemic outflow tract or aortic arch (n=7), transposition complexes (n=6), previously repaired atrioventricular septal defect (n=3), functionally single ventricle (n=3) and ventricular septal defect with pulmonary outflow obstruction (n=2). Outflow tract gradients ranged from 20-110 mm Hg (median 58 mm Hg). RESULTS: Complete relief of obstruction due to atrioventricular valvar anomalies was possible in 14 patients. In six patients, the planned procedure either had to be modified or only partial relief of the obstruction was achieved. In the remaining patient, who had borderline functionally single ventricle heart disease (unbalanced atrioventricular septal defect) and systemic outflow obstruction due to accessory and functional valvar apparatus, support was withdrawn because the parents refused univentricular palliation and the valvar anomalies precluded a Ross-Konno procedure. There were two early deaths. At follow-up ranging from 1 to 66 months (median 27 months), there was one death, and there has been no recurrence of outflow tract obstruction or residual atrioventricular valvar tissue. CONCLUSIONS: Outflow tract obstruction caused by accessory or anomalous atrioventricular valvar structures is an uncommon and heterogeneous group of conditions that can have significant surgical implications. In the majority of cases, tailoring of surgical techniques will permit complete relief of obstruction. However, such anomalies may limit standard surgical options and necessitate an innovative approach in some patients.

Outcomes in critically ill neonates with pulmonary stenosis and intact ventricular septum: a multiinstitutional study. Congenital Heart Surgeons Society.

OBJECTIVE: This study attempted to determine the optimal therapeutic interventions by risk-adjusted comparisons of early and intermediate-term outcomes. BACKGROUND: The variety of interventions and the small case load at individual institutions have delayed the generation of reliable information concerning therapy for this condition. METHODS: In this prospective 27-institution study, 101 neonates were consecutively enrolled (between January 1, 1987 and January 1, 1991). Treatment was determined by the physicians. Demographic and morphologic details were tabulated. Dimensions of the pulmonary "anulus" and tricuspid anulus were measured on echocardiograms, and right ventricular cavity size was estimated. Right ventricular-pulmonary trunk pressure gradients were tabulated. Numerous analyses were made. RESULTS: Severe pulmonary valve stenosis and an intact ventricular septum were present in all patients. The right ventricular-pulmonary trunk junction ("anulus") was severely narrowed in 15%. Right ventricular cavity size was severely reduced in 4%. The tricuspid valve was small in 15% of patients; its diameter was poorly correlated with right ventricular cavity size. Eighty-nine percent and 81% of patients survived > or = 1 month and 4 years, respectively, after the initial procedure. Multivariable analysis identified no patient-specific risk factors for death. Only open pulmonary valvotomy without a support technique was uniformly a procedural risk factor; under some circumstances, transannular patching without a shunt was a risk factor. The right ventricular-pulmonary trunk gradient immediately after valvotomy was < 30 mm Hg in 81% of patients and was similar after surgical and balloon valvotomy. In 74% of patients, no intervention was required after the first accomplished intervention. CONCLUSIONS: Marked variation in morphology is uncommon in critical pulmonary stenosis in neonates. Percutaneous balloon valvotomy and certain types of surgical valvotomy are optimal initial procedures. The unusual situation of a small pulmonary "anulus" may initially require a transannular patch and a systemic-pulmonary artery shunt.

Echocardiographic diagnosis alone for the complete repair of major congenital heart defects.

OBJECTIVES: The study was done to determine the diagnostic accuracy of echocardiography alone in the preoperative diagnosis of children with major congenital heart defects undergoing primary complete repair. BACKGROUND: Although echocardiography is well established as the first-line imaging technique for the diagnosis of all forms of congenital heart disease, most institutions continue to perform cardiac catheterization prior to complete repair of more complex defects. METHODS: To determine the diagnostic accuracy of echocardiography alone and echocardiography plus catheterization, we reviewed the records of 503 children with major congenital heart defects who underwent primary complete repair at our institution between July 1992 and June 1997. We included children with transposition of the great arteries, tetralogy of Fallot, double-chamber right ventricle, interrupted aortic arch, aortic coarctation, atrioventricular septal defect, truncus arteriosus, aortopulmonary septal defect, and totally anomalous pulmonary venous return. We excluded children with less complex defects such as isolated shunt lesions, as well as those with the most complex defects that would require surgical palliation (e.g., functional univentricular heart). We defined major errors as those that increased the surgical risk and minor errors as those that did not. Errors in diagnosis were determined at surgery. RESULTS: Eighty-two percent of children (412 of 503) underwent surgery after preoperative diagnosis by echocardiography alone. There were 9 major (2%) and 10 minor errors in the echocardiography alone group and 7 major and 5 minor errors in the echocardiography plus catheterization group. The most common type of error was misidentification of coronary artery anatomy in patients with transposition of the great arteries. No error in either group resulted in surgical morbidity or mortality. CONCLUSIONS: This study suggests that echocardiography alone is an accurate tool for the preoperative diagnosis of major congenital heart defects in most children undergoing primary complete repair, and may obviate the need for routine diagnostic catheterization.

Outcomes after bidirectional cavopulmonary shunt in infants less than 6 months old.

OBJECTIVES: We sought to assess the results after bidirectional cavopulmonary shunt (BCPS) in infants < 6 months old and to identify risk factors for poor outcome. BACKGROUND: Although BCPS is a well established procedure for the palliation of patients with a single-ventricle heart, there have been very few reports of outcomes after BCPS in young infants. METHODS: Since 1990, 42 infants between 0.8 and 6.0 months of age (mean [+/-SD] 3.7 +/- 1.4) have undergone BCPS for primary (n = 16) or secondary (n = 26) palliation of tricuspid atresia (n = 13), hypoplastic left heart syndrome (n = 10) or other forms of functional single-ventricle heart (n = 19). Accessory pulmonary blood flow was included in 18 patients. Preoperative and perioperative data were gathered on retrospective review of patient records, and follow-up was conducted by means of direct physician contact or record review. RESULTS: The overall hospital mortality rate, including that associated with reoperations, was 4.8% (2 of 42 patients). Seven patients (17%) required reoperation related to the BCPS or pulmonary blood flow in the early postoperative period: Procedures included take-down of the BCPS in four patients, with one early death, and procedures to decrease pulmonary blood flow in three patients. Age < 1 month correlated significantly with early death and with early failure of the BCPS (death or take-down). Follow-up of the 37 patients discharged with intact BCPS was obtained at a mean +/-SD of 14.3 +/- 11.3 months postoperatively, during which time three patients died (at 6.5 +/- 2.5 months). The 2-year actuarial survival rate for patients undergoing BCPS at < 6 months of age was 86%. Overall freedom from death or take-down (including early and late events) was significantly lower in patients < 2 months old than in those > 2 months old. Four patients have undergone successful Fontan completion (18.3 +/- 2.9 months postoperatively), and one patient whose BCPS was taken down subsequently underwent successful restoration of a BCPS. CONCLUSIONS: Outcomes after BCPS in young infants are comparable to those in older infants and children. However, our current preference is to defer this procedure until after 2 months of age.

Elective primary repair of acyanotic tetralogy of Fallot in early infancy: overall outcome and impact on the pulmonary valve.

OBJECTIVES: We sought to determine if early primary repair of acyanotic tetralogy of Fallot (ToF) can be performed safely with low requirement for transannular patching (TAP) and thereafter allow normal right ventricular outflow tract (RVOT) growth. BACKGROUND: Early primary repair of ToF normalizes intracardiac flow patterns, which may allow subsequent normal RVOT growth. Traditionally repair is deferred until symptoms occur or children are deemed of adequate size for operative risk to be acceptable because of a perceived increased requirement for TAP in small infants. METHODS: Between July 1992 and March 1999, 42 acyanotic infants aged 4 to 87 days (median 62) and weight 2.6 to 6.6 kg (median 4.55) underwent complete repair of ToF. Pulmonary annulus measured 4 to 10.5 mm (median 6.5) with "z-value" of-5.6 to +3.0 (median -1.9). RVOT reconstruction was tailored to each patient; pulmonary valvotomy was performed in 26, main pulmonary arterioplasty in 22, and infundibular patching in 2. Only 10 (24%) required TAP. RESULTS: Postoperative RVOT gradient was 0 to 30 mm Hg (median 10) and pRV/pLV ratio 0.3 to 0.6 (median 0.44). Pulmonary insufficiency was trivial/mild. There were no deaths. Junctional ectopic tachycardia developed in seven; only one required treatment. ICU stay was 2 to 14 days (median 4) and hospital stay 4 to 22 days (median 7). At follow-up 12 to 64 months later (median 38) there were no deaths. One child required reoperation for recurrent RVOT obstruction and two required balloon pulmonary arterioplasty. Follow-up RVOT gradient was 0 to 36 mm Hg (median 12), unchanged from early postoperative condition, and median z-value was -1.2 (-2.8 to +2.5); pulmonary insufficiency remained trivial/mild. CONCLUSIONS: Complete repair of acyanotic ToF can be performed in early infancy with low morbidity and mortality and low requirement for TAP. Though results are not statistically significant, early repair may allow normal RVOT growth thereafter.

Hemodynamic effects of epinephrine, bicarbonate and calcium in the early postnatal period in a lamb model of single-ventricle physiology created in utero.

OBJECTIVES: A reproducible fetal animal model of single-ventricle physiology was created to examine the effects of pharmacologic agents commonly used in the perinatal and perioperative intensive care management of patients with a single ventricle. BACKGROUND: Single-ventricle physiology is characterized by parallel pulmonary and systemic circulations, with effective blood flow to each determined by the relative resistances in the pulmonary and systemic vascular beds. Perinatal and perioperative management of these patients is largely based on empiric observations and differs considerably between institutions and is further complicated by the transitional physiology of the newborn. The lack of animal models of single-ventricle physiology has hindered the understanding of this problem. METHODS: A 10-mm, Damus-Kaye-Stansel-type aortopulmonary anastomosis was created in 10 fetal sheep at 140 +/- 1.2 days of gestation. The main pulmonary artery was ligated distally, and pulmonary blood flow (Qp) was provided through a 5-mm aortopulmonary shunt. Eight lambs were delivered at term and placed on cardiopulmonary bypass (30 min) 48 to 72 h after birth. Pharmacologic interventions (0.1 microgram/kg body weight per min of epinephrine, 2 mEq/kg of sodium bicarbonate and 10 mg/kg of calcium chloride) were performed before and after bypass, and hemodynamic responses were observed. The response to the epinephrine bolus was determined only in the postbypass study. RESULTS: Both before and after bypass, epinephrine infusion and calcium and bicarbonate administration increased Qp and systemic blood flow (Qs) (total cardiac output) but produced only small changes in the Qp/Qs ratio (-0.5% to -7.3% change). With the epinephrine bolus, Qp increased enormously, and the Qp/Qs ratio increased by 584% (p < 0.001). CONCLUSIONS: In neonatal lambs with single-ventricle physiology created in utero, epinephrine infusion and calcium and bicarbonate administration increased total cardiac output without significantly compromising the Qp/Qs ratio. However, epinephrine bolus seems to be hemodynamically detrimental in circumstances of single-ventricle physiology and should be used with caution and probably in relatively lower doses in the resuscitation of patients with single-ventricle physiology. Further investigation of the dose-dependent effects and the effects of prolonged administration of common pharmacologic agents will enable better management of patients with single-ventricle physiology.

Reinterventions after repair of common arterial trunk in neonates and young infants.

OBJECTIVES: To determine rates of reintervention after repair of common arterial trunk in the neonatal and early infant periods. BACKGROUND: With improving success in the early treatment of common arterial trunk, the need for reinterventional procedures in older children, adolescents and adults will become an increasingly widespread concern in the treatment of these patients. METHODS: We reviewed our experience with 159 infants younger than four months of age who underwent complete primary repair of common arterial trunk at our institution from 1975 to 1998, with a focus on postoperative reinterventions. RESULTS: Of 128 early survivors, 40 underwent early reinterventions for persistent mediastinal bleeding or other reasons. During a median follow-up of 98 months (range, 2 to 235 months), 121 reinterventions were performed in 81 patients. Actuarial freedom from reintervention was 50% at four years, and freedom from a second reintervention was 75% at 11 years. A total of 92 conduit reinterventions were performed in 75 patients, with a single reintervention in 61 patients, 2 reinterventions in 11 patients and 3 reinterventions in 3 patients. Freedom from a first conduit reintervention was 45% at five years. The only independent variable predictive of a longer time to first conduit replacement was use of an allograft conduit at the original repair (p = 0.05), despite the significantly younger age of patients receiving an allograft conduit (p < 0.001). Reintervention on the truncal valve was performed on 22 occasions in 19 patients, including 21 valve replacements in 18 patients and repair in 1, with a freedom from truncal valve reintervention of 83% at 10 years. Surgical (n = 29) or balloon (n = 12) reintervention for pulmonary artery stenosis was performed 41 times in 32 patients. Closure of a residual ventricular septal defect was required in 13 patients, all of whom underwent closure originally with a continuous suture technique. Eight of 16 late deaths were related to reintervention. CONCLUSIONS: The burden of reintervention after repair of common arterial trunk in early infancy is high. Although conduit reintervention is inevitable, efforts should be made at the time of the initial repair to minimize factors leading to reintervention, including prevention of branch pulmonary artery stenosis and residual interventricular communications.

Is it necessary to routinely fenestrate an extracardiac fontan?

OBJECTIVES: This study was conducted to assess the need for, and use of, fenestration of an extracardiac conduit Fontan. BACKGROUND: Fenestration of a Fontan connection has been proposed as a means of improving outcomes of single ventricle palliation. The benefit of fenestration is likely to be greatest in the early postoperative period when patients may experience increased pulmonary vascular resistance and decreased ventricular function due to the effects of cardiopulmonary bypass, aortic cross-clamping and positive pressure ventilation. However, there are potential drawbacks to fenestration. The utility of fenestration with extracardiac Fontan operation has not been determined. METHODS: Since 1992, 81 patients have undergone a modification of the Fontan procedure in which an extracardiac inferior cavopulmonary conduit is used in combination with a previously staged bidirectional Glenn anastomosis. We conducted a retrospective review of these patients. RESULTS: Fenestration was performed selectively in 32 patients (39%), including only 2 of the last 38 (5%). In seven patients, a fenestration was placed or clipped in the early postoperative period without cardiopulmonary bypass. There were two operative deaths. Prolonged (>2 weeks) pleural drainage occurred in 13 patients, 8 with fenestration and 5 without. In addition to undergoing earlier Fontan in our experience, patients who had a fenestration placed had significantly higher preoperative pulmonary vascular resistance, significantly higher common atrial pressure after Fontan and significantly lower post-Fontan systemic arterial oxygen saturation. Fontan pressure did not differ between nonfenestrated and fenestrated patients. At follow-up ranging to five years, there were two late deaths and no patients developed protein losing enteropathy. CONCLUSIONS: Fenestration is not necessary in most Fontan patients when an extracardiac conduit technique is performed as described in this article, and therefore, should not be performed routinely with the extracardiac conduit Fontan. The need for fenestration should be assessed after cardiopulmonary bypass when hemodynamics can be evaluated accurately. Fenestration can be placed and revised easily without bypass and with minimal intervention in patients with an extracardiac conduit Fontan.

Key role of the alternate complement pathway in hyperacute rejection of rat hearts transplanted into fetal sheep.

Hyperacute rejection (HAR) mediated by xenoreactive natural antibodies (XNA), which are thought to develop in early infancy, is a major impediment to transplantation between widely disparate species. The ability to diagnose certain forms of congenital heart defects early in prenatal life suggests the potential for these defects to be corrected by cardiac transplantation, prior to the development of XNA and host immunocompetence. This study investigated whether discordant cardiac xenotransplantation into fetal and neonatal recipients might obviate HAR due to the relative lack of XNA. Six neonatal lambs at 3 days (n=3) or 7 days (n=3) of life, and two fetal lambs at 125 and 142 days of gestation (term = 145 days) received cardiac grafts from adult Wistar-Furth (275-350 g) rats. All eight cardiac xenografts showed clinical evidence of HAR, with rapid swelling, loss of contractility, and ecchymosis and a mean survival time of 12.5 +/- 6.4 min. Sections of explanted grafts showed classical histologic features of HAR, including interstitial hemorrhages, platelet microthrombi, and edema, without leukocyte infiltration. Immunopathology of grafts harvested from fetal recipients showed a lack of significant intragraft deposition of sheep IgM, IgG, or C1q, but widespread endothelial labeling for C3, factor B, and properdin. In contrast, grafts in neonatal recipients showed IgM, IgG, and C1q deposition, as well as C3, factor B, properdin, and terminal complement (C) components. Fibrin deposition and platelet thrombi were seen in both groups of recipients. Injection of cobra venom factor resulted in prolongation of cardiac xenograft survival in neonatal lambs (n=3) to 12 hr. Analysis by immunohistology showed that normal sera from neonatal and adult, but not fetal, sheep contained IgM and IgG XNA reactive with rat cells. In conclusion, rodent grafts transplanted into fetal sheep undergo HAR, likely through direct activation of the alternate pathway of C, whereas neonatal lambs acquire XNA in the very early postnatal period and reject rat hearts through activation of both the classical and alternate pathways of C. Thus, at least in some species combinations, cardiac transplantation during the early postnatal period, or even in utero, may still be subject to development of HAR.

Early and late results after repair of aortopulmonary septal defect and associated anomalies in infants <6 months of age.

The Richardson classification system for aortopulmonary septal defect (APSD) includes simple defects between the ascending aorta and pulmonary trunk (type I), defects extending distally to include the origin of the right main pulmonary artery (type II), and anomalous origin of the right main pulmonary artery from the ascending aorta with no other aortopulmonary communication (type III). These are rare lesions that must be repaired in early infancy to avoid development of pulmonary vascular disease. Few reports have focused on patients with complex, associated lesions who underwent repair in early infancy. Between 1972 and 1995, 24 patients with Richardson type I (n = 11), II (n = 7), or III (n = 6) defects underwent repair at ages ranging from 2 to 172 days (median 34). Twelve patients had complex, associated anomalies, including interrupted or hypoplastic arch (n = 9), tetralogy of Fallot with (n = 1) or without (n = 1) pulmonary atresia, and transposition of the great arteries (n = 1). The most recent 7 patients were diagnosed by echocardiography without cardiac catheterization. There were no early or late deaths among the 12 patients with simple APSD. Four patients with complex, associated lesions died in the early postoperative period and another died 4 months after surgery. All 6 surviving patients with interrupted arch have had recurrent obstruction at the arch repair site, although reintervention for this reason has been performed in only 2 patients. Altogether, 6 early survivors have required reintervention, and all survivors are in New York Heart Association class I at follow-up ranging from 2 to 25 years. Thus, long-term survival after repair of APSD in early infancy is excellent. Late sequelae are likely to be related either to associated lesions or to obstruction at the APSD repair site. Almost all cases of APSD in young infants can be diagnosed and evaluated by echocardiography without catheterization.

Maturational and hemodynamic factors predictive of increased cyanosis after bidirectional cavopulmonary anastomosis.

Bidirectional cavopulmonary anastomosis (BCA) is thought to be beneficial in the palliation of patients with univentricular congenital heart disease considered at high risk for Fontan repair. Experience with patients undergoing BCA suggested that those who were older or larger at the time of surgery tended to be more cyanotic postoperatively than their younger and smaller counterparts. This study was designed to identify correlates of systemic arterial oxygen saturation after BCA. Specifically, it was postulated that maturational changes in blood flow distribution might be associated with decreasing arterial oxygen saturation. Database records of all 110 patients undergoing BCA at our institution from June 1988 until the end of 1991 were reviewed. Postoperative catheterization data were available for 66 patients. Twenty-one patients were excluded because they had potentially reversible causes of cyanosis yielding inestimable degrees of error in hemodynamic calculations. In the remaining 45 patients, univariate and multivariate regression analyses were used to identify correlates of systemic arterial oxygen saturation. Growth and maturation as represented by body surface area exhibited a highly significant inverse correlation with arterial oxygen saturation (p = 0.005), as did pulmonary vascular resistance (p = 0.003). Patients who underwent BCA when > 3.9 years of age or with body surface area > 0.65 m2 were at significantly increased risk for excessive postoperative cyanosis, defined as systemic arterial oxygen saturation < or = 75% (p < 0.005). The interval between surgery and catheterization correlated directly with arterial oxygen saturation (p = 0.002), indicating a tendency toward earlier study of more cyanotic patients. None of the other variables examined correlated significantly with arterial oxygen saturation.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolated left superior vena cava to the left atrium with situs solitus and dextrocardia: extracardiac repair facilitated by juxtaposition of the atrial appendages.

We describe an extremely unusual case, with isolated left superior vena cava to the left atrium, normal intracardiac anatomy, and left juxtaposition of the atrial appendages. Surgical repair was performed without cardiopulmonary bypass by anastomosing the left superior cava to the superior aspect of the right atrial appendage, and was facilitated by the ectopic location of the appendage.

Exclusion of the placenta during fetal cardiac bypass augments systemic flow and provides important information about the mechanism of placental injury.

The in utero correction of congenital cardiac malformations requires the availability of fetal cardiac bypass. One difficulty with fetal cardiac bypass is that very high flow rates are necessary when the placenta is left in the bypass circuit; the placenta requires about 40% of fetal cardiac output, which results in a normal cardiac output of 400 ml/kg per minute. Previous attempts to perform fetal cardiac bypass failed to consistently achieve these high flow rates because of cannula size limitations. On the basis of previous work done in our laboratory with an isolated-placenta model, which demonstrated that at normothermia the placenta would tolerate at least 30 minutes of cessation of umbilical blood flow, we hypothesized that exclusion of the placenta from the fetal cardiac bypass circuit would reduce fetal cardiac output by one half and allow us to obtain better systemic perfusion without compromising placental function. Cardiac bypass was performed in 20 late-gestation fetal lambs. In 10 lambs, no drugs were given; 5 served as controls in which the placenta was perfused; in the last 5, the placenta was excluded by clamping the umbilical cord during bypass. The latter 10 lambs were treated with indomethacin, which is known to improve placental blood flow after fetal cardiac bypass. We measured blood gases and determined regional blood flow with radiolabeled microspheres to assess placental function after bypass. The 5 control fetuses experienced rapid hypercapnea and hypoxemia after bypass, in association with minimal placental blood flow; when the placenta was excluded, arterial carbon dioxide tension rose somewhat more slowly, and placental blood flow after bypass was significantly better. When indomethacin was given, arterial blood gases in both groups showed a mild increase in carbon dioxide tension and similar placental blood flows (about 30% of baseline) after bypass. Indomethacin is known to block the vasoconstrictive response of the placenta to fetal cardiac bypass, implicating the release of vasoactive cyclooxygenase products as the cause of the adverse effects. In this study, placental perfusion on bypass without indomethacin caused much more severe placental dysfunction than did bypass with the placenta excluded from the circuit. The use of indomethacin improved postbypass placental function in both groups, but this effect was much more dramatic in the placenta-perfused group.(ABSTRACT TRUNCATED AT 400 WORDS)

Prostaglandin synthesis inhibition prevents placental dysfunction after fetal cardiac bypass.

Surgical therapy of certain congenital heart lesions in utero may have advantages over postnatal repair or palliation. For fetal heart operations to be done, it will be necessary to devise a method of fetal cardiac bypass. Previous studies in which standard cardiopulmonary bypass techniques were used have reported fetal death resulting from increased placental vascular resistance, which causes decreased placental blood flow and depressed respiratory gas exchange. The mechanism responsible for this increase in placental vascular resistance has remained unknown. In a series of 10 fetal cardiac bypass experiments we examined the role of prostaglandins as the mediators of this response. Observations were made during a 1-hour prebypass period, a 30-minute bypass period, and a 2-hour postbypass period. The cardiac bypass circuit consisted of a centrifugal pump, and bypass flows were adjusted to equal a normal fetal cardiac output of 400 ml/min/kg. In six of the experiments indomethacin (3 mg/100 ml) was added to the pump priming to block prostaglandin synthesis. By means of the microsphere technique, fetal cardiac output, placental blood flow, individual organ blood flow, and placental vascular resistance were determined at five times during the experiments: presternotomy, poststernotomy, during cardiac bypass, at 5 minutes after cessation of bypass, and 30 minutes after cessation of bypass. Fetal arterial blood gas measurements were made every 15 to 30 minutes. When indomethacin was used to inhibit prostaglandin synthesis, placental vascular resistance did not increase, placental blood flow did not decrease, and fetal blood gases remained at normal prebypass levels during and after fetal cardiac bypass. We propose that production of vasoactive prostaglandins is responsible for the increased placental vascular resistance and decreased placental blood flow observed after fetal cardiac bypass. An understanding of the mechanism responsible for the increased placental vascular resistance seen after fetal cardiac bypass will be an important first step before clinical application.

Midline one-stage complete unifocalization and repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals.

Traditionally patients with pulmonary atresia, ventricular septal defect, diminutive or absent central pulmonary arteries, and multiple aortopulmonary collaterals have been managed by staged procedures necessitating multiple operations. We have taken a different approach to this lesion. Between August 1992 and March 1994, ten patients aged 1.43 months to 37.34 years (median 2.08 years) at the severe end of the morphologic spectrum of this lesion underwent a one-stage complete unifocalization and repair from a midline sternotomy approach. The median Nakata index of true pulmonary arteries was 50.0 (range 0 to 103.13) and they provided vascular supply to up to nine lung segments (median 5 segments). The number of collaterals per patient ranged from two to five with a median of four. The collaterals provided vascular supply to a median of 15 lung segments per patient (range 11 to 20). Complete unifocalization was achieved in all patients with emphasis on native tissue-to-tissue connections via anastomosis of collaterals to other collaterals and to the native pulmonary arteries. In only one patient (37.34 years old) was it necessary to use a non-native conduit for peripheral pulmonary artery reconstruction. The ventricular septal defect was left open in one patient (5 years old) because of diffuse distal hypoplasia and stenosis of the pulmonary arteries and the collaterals. The postrepair peak systolic right ventricular/left ventricular pressure ratio ranged from 0.31 to 0.58 (median 0.47). There were no early deaths. Complications were bleeding necessitating reexploration in one patient, phrenic nerve palsy in three patients, and severe bronchospasm in three patients. Follow-up (median 8 months, range 2 to 19 months) was complete in all patients. One patient was reoperated on for pseudoaneurysm of the central homograft conduit and then again for stenosis of the left lower lobe collateral. After this last operation at 13 months after the initial repair she died of a preventable cardiac arrest caused by pneumothorax. The patient with open ventricular septal defect underwent balloon dilation of the unifocalized pulmonary arteries, with a current pulmonary/systemic flow ratio of 1.4 to 1.8:1, and is awaiting ventricular septal defect closure. One other patient underwent balloon dilation of the reconstructed right pulmonary artery, with a good result. All survivors (9/10) are clinically doing well. This approach establishes normal cardiovascular physiology early in life, eliminates the need for multiple systemic-pulmonary artery shunts and use of prosthetic material, and minimizes the number of operations required.(ABSTRACT TRUNCATED AT 400 WORDS)

Regression of tricuspid regurgitation after two-stage arterial switch operation for failing systemic ventricle after atrial inversion operation.

The cases of five patients with previous Senning (n = 4) or Mustard (n = 1) operations and failing systemic ventricles in whom banding of the pulmonary artery was performed as an interim step toward an arterial switch procedure are reported. The rise in the ratio of left to right mean systolic ventricular pressure, from 0.35 before operation to 0.90 during operation and 0.80 on the first postoperative day, caused a shift of the ventricular septum from a leftward to a midline or nearly midline position. This shift was associated with a reduction of tricuspid regurgitation. At a median interval of 5.1 months after pulmonary artery banding, the mean left ventricular posterior wall thickness had increased to 8.2 mm, versus 5 mm before operation, and the mean left ventricular myocardial mass index had increased to 90 gm/m2, versus 55.6 gm/m2 before operation. After the arterial switch operation, which was performed in four patients, the tricuspid regurgitation decreased to a trivial amount (n = 1) or disappeared completely (n = 3).