The management of tetralogy of Fallot with pulmonary atresia and diminutive pulmonary arteries

Comparison of staged repair versus single-stage complete repair for pulmonary atresia with ventricular septal defect: A systematic review and meta-analysis

AIMS

To evaluate comparative outcomes of the repair of pulmonary atresia with ventricular septal defect (PAVSD), done as staged repair (SR) or single-stage complete repair (CR).

METHODS

A systematic online search was conducted using the following databases: PubMed, Scopus, Cochrane database, The Virtual Health Library, Clinical trials.gov, and ScienceDirect for studies comparing SR versus CR for treatment of PAVSD. Total mortality rate, operative and early post-operative mortality rate, post-operative ventilation duration, duration of post-operative intensive care unit (ICU) stay, need for post-operative extra-corporeal membrane oxygenation (ECMO) support rate, transcatheter re-intervention rate, unplanned re-operation rate, freedom from right ventricular outflow tract (RVOT) re-intervention, and length of hospital stay (LOS) were the evaluated outcome parameters.

RESULTS

Four comparative studies reporting a total of 264 patients who underwent SR (167 patients) or CR (97 patients) were included. Total mortality was higher in the SR group compared to the CR group (odds ratio (OR) 2.58, P = 0.03). Two groups were comparable regarding operative and early post-operative mortality (OR 1.37, P = 0.62), post-operative ventilation duration (mean difference (MD) - 1.58, P = 0.43), need for post-operative ECMO support rate (OR 4.72, P = 0.16), transcatheter re-intervention rate (OR 0.60, P = 0.53), unplanned re-operation rate (OR 0.73, P = 0.57), and LOS (MD - 3.39, P = 0.45). Higher rate of freedom from RVOT re-intervention was observed in the SR group (OR 4.16, P = 0.00001).

CONCLUSION

Single-staged early CR of PAVSD significantly reduced total mortality rate as compared with SR. However, there is life-long risk of frequent need for RVOT re-interventions. Future high-quality randomised studies with robust methodological qualities are encouraged to evaluate the optimal timing and technique for repair of PAVSD, by analysing more outcomes in large patient groups and multi-centre studies.

Pediatric Cardiac MR Imaging:: Practical Preoperative Assessment

Prevalence of patients with congenital heart disease (CHD) is rapidly increasing due to continuous advancements in diagnostic techniques and medical or surgical treatment approaches. Along with cardiac computed tomography angiography, cardiac magnetic resonance (CMR) serves as a fundamental imaging modality for pre-surgical planning in patients with CHD, as CMR allows for the evaluation of cardiac and great vessel anatomy, biventricular function, flow dynamics, and tissue characterization. This information is essential for risk-assessment and optimal timing of surgical interventions. This article discusses the current role of pediatric cardiac MR imaging as a practical preoperative assessment tool in the pediatric population.

Bleeding in the lung complicates a routine intracardiac repair: What went wrong!!!

Cyanotic congenital heart disease presents an increased tendency to bleed in view of subtle coagulation defects. Airway bleeding can be particularly difficult to manage while maintaining an adequate ventilation. An isolated lung bleed with the exclusion of possible traumatic, medical and surgical causes of bleeding, should alert the attending anesthesiologist to the possibility of the collateral-related bleeding. Preoperative coil embolization remains an important initial management step in a case of tetralogy of Fallot (TOF) with major aortopulmonary collaterals. Nevertheless, the coiling of the collaterals in certain specific case scenarios is not feasible, rendering the management of a lung bleed, all the more challenging. We, hereby discuss a case of a 7-year-old girl with a massive endotracheal bleed at the time of weaning from cardiopulmonary bypass after corrective surgery for TOF. The subsequent approach and management are discussed. The optimal management of tetralogy with collaterals mandates an effective communication among the cardiologist, radiologist, anesthesiologist, and the surgeon.

Which cardiovascular magnetic resonance planes and sequences provide accurate measurements of branch pulmonary artery size in children with right ventricular outflow tract obstruction?

Children with right ventricular outflow tract obstructive (RVOTO) lesions require precise quantification of pulmonary artery (PA) size for proper management of branch PA stenosis. We aimed to determine which cardiovascular magnetic resonance (CMR) sequences and planes correlated best with cardiac catheterization and surgical measurements of branch PA size. Fifty-five children with RVOTO lesions and biventricular circulation underwent CMR prior to; either cardiac catheterization (n = 30) or surgery (n = 25) within a 6 month time frame. CMR sequences included axial black blood, axial, coronal oblique and sagittal oblique cine balanced steady-state free precession (bSSFP), and contrast-enhanced magnetic resonance angiography (MRA) with multiplanar reformatting in axial, coronal oblique, sagittal oblique, and cross-sectional planes. Maximal branch PA and stenosis (if present) diameter were measured. Comparisons of PA size on CMR were made to reference methods: (1) catheterization measurements performed in the anteroposterior plane at maximal expansion, and (2) surgical measurement obtained from a maximal diameter sound which could pass through the lumen. The mean differences (Δ) and intra class correlation (ICC) were used to determine agreement between different modalities. CMR branch PA measurements were compared to the corresponding cardiac catheterization measurements in 30 children (7.6 ± 5.6 years). Reformatted MRA showed better agreement for branch PA measurement (ICC > 0.8) than black blood (ICC 0.4-0.6) and cine sequences (ICC 0.6-0.8). Coronal oblique MRA and maximal cross sectional MRA provided the best correlation of right PA (RPA) size with ICC of 0.9 (Δ -0.1 ± 2.1 mm and Δ 0.5 ± 2.1 mm). Maximal cross sectional MRA and sagittal oblique MRA provided the best correlate of left PA (LPA) size (Δ 0.1 ± 2.4 and Δ -0.7 ± 2.4 mm). For stenoses, the best correlations were from coronal oblique MRA of right pulmonary artery (RPA) (Δ -0.2 ± 0.8 mm, ICC 0.9) and sagittal oblique MRA of left pulmonary artery (LPA) (Δ 0.2 ± 1.1 mm, ICC 0.9). CMR PA measurements were compared to surgical measurements in 25 children (5.4 ± 4.8 years). All MRI sequences demonstrated good agreement (ICC > 0.8) with the best (ICC 0.9) from axial cine bSSFP for both RPA and LPA. Maximal cross sectional and angulated oblique reformatted MRA provide the best correlation to catheterization for measurement of branch PA's and stenosis diameter. This is likely due to similar angiographic methods based on reformatting techniques that transect the central axis of the arteries. Axial cine bSSFP CMR was the best surgically measured correlate of PA branch size due to this being a measure of stretched diameter. Knowledge of these differences provides more precise PA measurements and may aid catheter or surgical interventions for RVOTO lesions.

Comparison between proximal thoracic vascular measurements obtained by contrast-enhanced magnetic resonance angiography and by transthoracic echocardiography in infants and children with congenital heart disease

Accurate assessment of the proximal thoracic vasculature in infants and children with congenital heart disease (CHD) is vital for deciding the appropriate surgical or interventional procedure and predicting outcomes. This information usually is obtained by transthoracic echocardiography (TTE). Contrast-enhanced magnetic resonance angiography (CE-MRA) frequently is used to obtain diagnostic data when the image quality by TTE is limited. Calculation of z-scores for measurements obtained by CE-MRA in this population currently is not possible due to the lack of normative data. A reasonable agreement between vessel dimensions by CE-MRA and TTE will allow the use of TTE-based z-scores on measurements from CE-MRA. This study examines the accuracy and agreement of proximal thoracic vascular measurements obtained by CE-MRA versus TTE. Infants and children younger than 3 years with CHD who had a CE-MRA between August 2006 and May 2011 were retrospectively identified. Main and branch pulmonary arteries, ascending aorta, distal transverse arch, and aortic isthmus were measured from CE-MRA and TTE in analogous imaging planes and locations by two investigators blinded to each other. The study enrolled 35 subjects with CHD. The median age was 129 days (range, 0-1077 days), and the median weight was 5.8 kg (range, 2.16-17 kg). The median interval between the two imaging methods was 9 days (range, 0-60 days). Data analysis was performed with 129 of the 210 possible paired measurements. The remaining 81 paired measurements could not be performed due to inaccurate visualization of vessel borders or an unavailable imaging plane from TTE, CE-MRA, or both. The range of vessel sizes measured from 2.8 to 23.4 mm. There was excellent correlation between CE-MRA and TTE (r = 0.94, p < 0.001). The mean difference between the measurements was -0.1 ± 1.2 mm, and the limits of agreement were -2.5 to 2.3 mm. Proximal thoracic vascular measurements obtained by CE-MRA and TTE in infants and children with CHD have a strong correlation. The agreement between these two imaging methods is adequate. Until normative data for vessel size measurements obtained from CE-MRA are available for this population, TTE-based z-scores can be applied to the measurements obtained by CE-MRA.

Pulmonary atresia with ventricular septal defect and multifocal pulmonary blood supply: does an intensive interventional approach improve the outcome?

INTRODUCTION

Pulmonary atresia with ventricular septal defect (VSD) continues to be associated with significant morbidity and mortality, with significant institutional variation in therapeutic strategies. This study reports a single center experience utilizing an intensive transcatheter approach to promote pulmonary vascular growth.

METHODS

A retrospective analysis of 20 patients undergoing surgical and transcatheter treatment for pulmonary atresia with VSD between 2002 and 2010.

RESULTS

The median age at initial surgical palliation was 6.3 months (8 days to 2.5 years). Eleven patients (group 1) underwent initial surgical palliation without VSD closure and nine patients (group 2) underwent an initial complete repair with fenestrated or complete VSD closure. Group 1 had a smaller Nakata index (54 mm2/m2 vs. 134 mm2/m2 , P = .04) and a smaller absolute native pulmonary artery diameter (2.7 mm vs. 4.5 mm, P = .01) than group 2. Intraoperative angiography was performed in 10 cases to evaluate if early transcatheter intervention was warranted. The median follow-up during the study period was 2.3 years (1.6 months to 8.3 years). Of the 16 patients who survived the initial early postoperative period, 15 patients (94%) went on to receive surgical (n = 11) and/or interventional (n = 25) catheterization procedures. There was improvement in the mean Nakata index from the initial presurgical evaluation to the most recent catheterization data (38.4 mm2/m2 vs. 169.7 mm2/m2, P ≤ .05). To date, two of 11 (18%) patients in group 1 ultimately underwent surgical VSD closure. Overall mortality was six of 20 (30%) with four deaths in group 1 and two deaths in group 2. There were no procedural deaths.

CONCLUSIONS

Combining surgical unifocalization procedures with subsequent early and intensive catheter-based pulmonary artery rehabilitation may improve vascular growth, ultimately rendering many patients suitable for fenestrated VSD closure. Risk stratification, including intraoperative exit angiography, is essential to determine the need for early transcatheter interventions.

Gadolinium-enhanced three-dimensional magnetic resonance angiographic assessment of the pulmonary artery anatomy in cyanotic congenital heart disease with pulmonary stenosis or atresia: comparison with cineangiography

Pulmonary stenosis (PS) or pulmonary atresia (PA) is an important component of complex cyanotic congenital heart disease, especially in tetralogy of Fallot or lesions with ventricular septal defect (VSD)-PS physiology. Management strategy in these patients depends on accurate assessment of PAs and identification of all sources of pulmonary blood flow. X-ray cineangiography is the "gold standard" for this purpose, but it has the inherent risks of an invasive procedure. Gadolinium-enhanced three-dimensional magnetic resonance angiography (Gd-MRA) has been shown to noninvasively and accurately evaluate various lesions of the vascular system. This study was undertaken to evaluate the accuracy of Gd-MRA compared with cineangiography in the evaluation of pulmonary anatomy. Nineteen patients having complex cyanotic heart disease with PS or PA were included in the study. All patients underwent Gd-MRA and cineangiography. Catheterisation and MRA findings regarding the anatomic variable of interest were analysed for agreement by Bland-Altman analysis. There was total agreement between the two modalities in the delineation of confluent PAs. McGoon's ratio and the Nakata index, which are standard measures of the adequacy of PA size, also showed excellent agreement between the two modalities. MRA was able to delineate all aorto-pulmonary collaterals in the setting of PA. MRA can delineate all sources of pulmonary blood supply in cyanotic congenital heart disease with PS and/or PA as well as provide accurate assessment of PA size for planning corrective surgery.

Individualized approach to the surgical treatment of tetralogy of Fallot with pulmonary atresia

BACKGROUND

Tetralogy of Fallot with pulmonary atresia is a heterogeneous group of defects, characterised by diverse sources of flow of blood to the lungs, which often include multiple systemic-to-pulmonary collateral arteries. Controversy surrounds the optimal method to achieve a biventricular repair with the fewest operations while basing flow to the lungs on the native intrapericardial pulmonary arterial circulation whenever possible. We describe an individualized approach to this group of patients that optimizes these variables.

METHODS

Over a consecutive 10-year period, we treated 66 patients presenting with tetralogy of Fallot and pulmonary atresia according to the source of the pulmonary arterial flow. Patients were grouped according to whether the flow of blood to the lungs was derived exclusively from the intrapericardial pulmonary arteries, as seen in 29 patients, exclusively from systemic-to-pulmonary collateral arteries, as in 5 patients, or from both the intrapericardial pulmonary and collateral arteries, as in the remaining 32 patients. We divided the latter group into 9 patients deemed simple, and 23 considered complex, according to whether the pulmonary arterial index was greater than or less than 90 millimetres squared per metre squared, and whether the number of collateral arteries was less than or greater than 2, respectively.

RESULTS

We achieved complete biventricular repair in 58 patients (88%), with an overall mortality of 3%. Repair was accomplished in a single stage in all patients without systemic-to-pulmonary collateral arteries, but was staged, with unifocalization, in the patients lacking intrapericardial pulmonary arteries. Complete repair without unifocalization was achieved in all patients with the simple variant of the mixed morphology, and in 56% of patients with the complex variant. The average number of procedures per patient to achieve complete repair was 1, 2.2, 3.8, and 2.6 in patients with exclusively native intrapericardial, simple and mixed, complex and mixed and exclusively collateral pulmonary arterial flow, respectively.

CONCLUSIONS

An individualized approach based on the morphology of the pulmonary arterial supply permits achievement of a high rate of complete intracardiac repairs, basing pulmonary arterial flow on the intrapericardial pulmonary arteries in the great majority of cases, and has a low rate of reoperation and mortality.

Cardiac defects and results of cardiac surgery in 22q11.2 deletion syndrome

Specific types and subtypes of cardiac defects have been described in children with 22q11.2 deletion syndrome as well as in other genetic syndromes. The conotruncal heart defects occurring in patients with 22q11.2 deletion syndrome include tetralogy of Fallot, pulmonary atresia with ventricular septal defect, truncus arteriosus, interrupted aortic arch, isolated anomalies of the aortic arch, and ventricular septal defect. These conotruncal heart defects are frequently associated in this syndrome with additional cardiovascular anomalies of the aortic arch, pulmonary arteries, infundibular septum, and semilunar valves complicating cardiac anatomy and surgical treatment. In this review we describe the surgical anatomy, the operative treatment, and the prognostic results of the cardiac defects associated with 22q11.2 deletion syndrome. According to the current literature, in patients with tetralogy of Fallot with/without pulmonary atresia and truncus arteriosus, in spite of the complex cardiac anatomy, the presence of 22q11.2 deletion syndrome does not worsen the surgical prognosis. On the contrary in children with pulmonary atresia with ventricular septal defect and probably in those with interrupted aortic arch the association with 22q11.2 deletion syndrome is probably a risk factor for the operative treatment. The complex cardiovascular anatomy in association with depressed immunological status, pulmonary vascular reactivity, neonatal hypocalcemia, bronchomalacia and broncospasm, laryngeal web, and tendency to airway bleeding must be considered at the time of diagnosis and surgical procedure. Specific diagnostic, surgical, and perioperative protocols should be applied in order to provide appropriate treatment and to reduce surgical mortality and morbidity.

Radiofrequency perforation of the right ventricular outflow tract as a palliative strategy for pulmonary atresia with ventricular septal defect

BACKGROUND

Radiofrequency perforation (RF) of the right ventricular outflow tract (RVOT), while an effective management strategy in children with an intact ventricular septum, has not been fully detailed in those presenting with a ventricular septal defect.

OBJECTIVE

To determine whether transcatheter perforation of the atretic pulmonary valve is an acceptable management strategy prior to surgical repair.

RESULTS

Valve perforation was attempted in eight children seen between May 2000 and March 2006, five being infants between 1 and 9 days of age. In five children, this was the first of two procedures, the second a planned surgical correction. The RF was successful in six children with one child requiring additional stenting of the RVOT. Of these children, three attained a biventricular repair within the next year without additional palliative surgical procedures. Of the remaining three patients, one is awaiting surgical correction, one did not require further surgery, and one had this procedure as the only planned palliation. The two children in whom RF was not possible were referred for surgical augmentation of pulmonary blood flow.

CONCLUSION

A treatment strategy that includes pulmonary valve perforation as initial palliation to increase pulmonary blood flow may be effective. Additional experience to better define those children who would benefit from this treatment algorithm is required.

Imaging of aortopulmonary collateral arteries with high-resolution multidetector CT

BACKGROUND

Precise visualization of the pulmonary vasculature is mandatory for adequate treatment of patients with pulmonary atresia and ventricular septal defect (PA-VSD). Aortopulmonary collateral arteries (APCs) can be visualized by selective injections of contrast agent in the catheterization laboratory.

OBJECTIVE

To evaluate multidetector CT (MDCT) and different image postprocessing methods for analysis of complex pulmonary blood supply in patients with PA-VSD.

MATERIALS AND METHODS

Eight patients (6 weeks to 27.8 years of age) with PA-VSD and APCs underwent MDCT and cardiac catheterization. Using multiplanar reformatting, volume rendering and semiautomatic segmentation algorithms, the aorta, pulmonary arteries and APCs were displayed. MDCT and cardiac catheterization were analyzed by two independent observers.

RESULTS

MDCT accurately imaged central pulmonary arteries (n=8), aortopulmonary shunts (n=2), right ventricular to pulmonary artery conduits (n=2) and origin, course and intrapulmonary connections of APCs (n=25), compared to X-ray angiography. A high correlation was found between the MDCT vessel diameter measurements by two independent observers (n=70, r=0.96, P<0.01) and between MDCT and angiographic vessel diameter measurements (n=68, r=0.96, P<0.01).

CONCLUSIONS

Using three-dimensional imaging software, a complex pulmonary blood supply can be non-invasively and accurately imaged with high-resolution MDCT. This technique may help to reduce the number of cardiac catheterizations or guide interventional or surgical therapy.

Risk factors for arrhythmia and late death in patients with right ventricle to pulmonary artery conduit repair—Japanese multicenter study

BACKGROUND

Arrhythmia and late cardiac deaths are thought to be major complications in patients after right ventricle (RV) to pulmonary artery (PA) conduit repair, although the incidence and predictors of these complications remain unknown. The aim of this study was to clarify the incidence and risk factors for arrhythmia and late deaths in patients with the RV to PA conduit repair through a Japanese multicenter study.

METHODS

Three hundred fifty-one hospital survivors who underwent the RV to PA conduit repair before 1995 were studied.

RESULTS

Survival rate after repair was 92% at 10 years, 88% at 20 and 25 years, respectively. Late death was observed in 30 (8.5%) including 4 patients with sudden death (SD). Higher right ventricular pressure (p = 0.02), larger cardio-thoracic ratio after repair (p = 0.02) and higher incidence of brady- or tachy-arrhythmia and SD (9/30) were associated with late death. Six (1.7%) patients developed ventricular tachycardia or ventricular fibrillation (VT/Vf). There were 22 patients who had 23 new-onset supraventricular tachy-arrhythmia (SVT). Right ventricular hypertension (p = 0.04) was associated with VT/Vf or SD. Male sex (p < 0.01), absence of previously aorto-pulmonary shunt (p < 0.05), older age at repair (p < 0.01) or longer length of follow-up (p < 0.01) were associated with SVT.

CONCLUSION

Arrhythmia and late sudden death are relatively common late after the RV to PA conduit repair. Our data support recent surgical strategies of earlier primary operation and timely reoperation for progressive right ventricular outflow stenosis that may reduce the incidence of late arrhythmias and SD.

Delivery of stents to target lesions: techniques of intraoperative stent implantation and intraoperative angiograms

Mullins et al. [6] reported the first use of stent implantation to treat stenotic branch pulmonary arteries in 1988. In the early to mid-1990s, numerous reports confirmed its safety and efficacy, but there were limited stent and balloon designs and stent implantations were performed using relatively large delivery systems (10- to 12-Fr sheaths) [7, 8]. The general accepted patient size was limited to those weighing 12 kg or greater. Intraoperative stent implantation for branch pulmonary artery stenosis was reported in the early to mid-1990s [1-3, 5, 9]. Indications in these early reports included small patient size or difficult anatomy or patients who had additional cardiac lesions and needed surgery independent of the branch stenosis. The idea was to take advantage of the open-heart exposure provided in the operating room to permit direct access to the stenotic segment. Hence, all intraoperative stent implants were performed under direct visualization on bypass. There were no discussions on advantages over the routine percutaneous approach. Currently, with advances in stent and balloon technology as well as increased operator experience, many of those reported cases probably would have undergone cardiac catheterization for a percutaneous stent implant rather than open-heart surgery. The purpose of this report is to review the current indications, advantages, and disadvantages of intraoperative stent implantation as well as to discuss the techniques that are helpful to optimize intraoperative stent positioning. The role and advantages of intraoperative angiography will also be presented.

Assessment of Vasculature Using Combined MRI and MR Angiography

OBJECTIVE

The purpose of this study was to compare combined cine gradient-recalled echo MRI and MR angiography with conventional angiography in the evaluation of the pulmonary vascular supply in patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries.

MATERIALS AND METHODS

Eleven patients who underwent both MRI and conventional angiography were retrospectively reviewed. Contiguous 2D cine gradient-recalled echo images (TR range/TE, 30-80/4.8; flip angle, 20 degrees or 30 degrees ) and 3D MR angiographic images (TR range/TE range, 3.8-5.0/1.3-2.0; acquisition time, 13-32 sec) using gadopentetate meglumine (0.1-0.2 mmol/kg) were obtained. The presence, size, and course of the pulmonary arteries (main, right, left) and major aortopulmonary collateral arteries (>/= 5 mm) were determined. Presence of minor collateral arteries (< 5 mm) was also noted. Results were compared with findings at conventional angiography.

RESULTS

MRI showed all main (n = 4) and branch (n = 17) pulmonary arteries found at conventional angiography and showed the pulmonary confluence in five of six cases. MRI showed all major aortic collaterals (n = 22) with a highly significant correlation between MRI and conventional angiography measurements (r = 0.84, p < 0.001 [95% confidence interval, -0.35 to 0.40]). One coronary artery collateral was not shown on MRI examination. At MRI, 12 of 14 major and four of seven minor brachiocephalic artery collaterals were shown. MRI showed more minor aortic collaterals than angiography (22 vs 18 vessels, respectively).

CONCLUSION

Combined cine gradient-recalled echo MRI and MR angiography is a reliable method for imaging pulmonary vascular supply in patients with these disorders. Additional prospective studies comparing MRI and conventional angiography may determine whether routine preoperative conventional angiography is required.

Techniques and applications of transcatheter embolization procedures in pediatric cardiology

Transcatheter embolization of congenital or acquired superfluous vascular structure has become routine procedures performed by interventional pediatric cardiologists. Embolization procedure is often part of a collaborative effort with cardiac surgeons to palliate complex congenital heart defect, such as in embolizing aortopulmonary collateral arteries in patient with single ventricle physiology. In other cases, the procedure is the definitive treatment as in embolizing coronary artery fistula. Pediatric cardiologists performing embolization procedures should be familiar with available technologies as well as understand the underlying cardiac anatomy and pathophysiology. This article provides a comprehensive review of presently available embolization agents and technologies. Some of the technologies are used only by interventional radiologists but may be useful to pediatric cardiologists. Specific clinical applications in pediatric cardiology are also discussed with summary of current literature. With continue advancement in transcatheter technology and operator expertise, all unwanted vascular communication should be amenable to transcatheter embolization.

Staged repair of tetralogy of Fallot and diminutive pulmonary arteries with a fenestrated ventricular septal defect patch

OBJECTIVES

Patients with tetralogy of Fallot and diminutive pulmonary arteries are at risk for suprasystemic right ventricular pressure and right ventricular failure after complete repair. We report the short-term outcome and medium-term follow-up after using a fenestrated ventricular septal defect patch as a component of staged repair in selected patients.

METHODS

We reviewed 47 patients with tetralogy of Fallot and diminutive pulmonary arteries whose ventricular septal defect patch was fenestrated, either electively or as a rescue technique, at a single institution between 1984 and 2001.

RESULTS

Early mortality was 10.6% and occurred only in patients who underwent rescue fenestration. Review of medium-term follow-up (median, 39 months) revealed 4 late deaths; an additional 4 patients experienced right ventricular failure despite fenestration. Most (7/8) of these late events occurred in patients who underwent planned fenestration. Excessive left-to-right shunt through the fenestration developed in only 2 patients.

CONCLUSIONS

Fenestrated patch closure of the ventricular septal defect in patients with tetralogy of Fallot and diminutive pulmonary arteries resulted in 10.6% early mortality. Used preemptively in selected patients, this technique is associated with no surgical mortality and a low incidence of excessive left-to-right shunt (4%). Early survivors remain at risk for late death and right ventricular failure despite fenestration.

Staged repair of tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries

OBJECTIVE

To assess the results of a staged surgical approach for tetralogy of Fallot with pulmonary atresia, hypoplastic or absent pulmonary arteries, and major aortopulmonary collateral arteries.

METHODS

We retrospectively reviewed a consecutive series of these patients from a single institution.

RESULTS

From July 1993 to April 2001, 46 consecutive patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collateral arteries were treated with staged surgical repair. The operative sequence usually began with a central aortopulmonary shunt followed by unifocalization of aortopulmonary collateral arteries depending on the source and distribution of pulmonary blood flow. Twenty-eight patients (61%) subsequently underwent complete repair with ventricular septal defect closure and right ventricle to pulmonary artery connection. Those patients who underwent complete repair had a median of 3 total operations (range 1-6). The ratio of the mean pulmonary artery pressure to the mean systemic blood pressure at the time of complete repair was 0.36 (range 0.19-0.58). Two of the 28 repaired patients (7.1%) required subsequent fenestration of the ventricular septal defect closure due to later development of supersystemic right ventricular pressure and right ventricular failure. Eighteen patients (39%) have undergone 1 or more staging operations and are considered good candidates for eventual complete repair. There were no hospital deaths. There was 1 late death (2.2%; 95% CI 0.4-11.3%) in a patient born prematurely who developed severe bronchopulmonary dysplasia precluding complete repair.

CONCLUSIONS

For tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries, a staged surgical approach yields low overall mortality and acceptable hemodynamics after complete repair.

Gadolinium-enhanced 3-dimensional magnetic resonance angiography of pulmonary blood supply in patients with complex pulmonary stenosis or atresia: comparison with x-ray angiography

BACKGROUND

In patients with complex pulmonary stenosis or atresia, a detailed delineation of all sources of pulmonary blood supply is necessary for planning surgical and transcatheter procedures and usually requires diagnostic cardiac catheterization. The goals of this study were to determine whether gadolinium-enhanced 3D magnetic resonance angiography (MRA) can provide a noninvasive alternative to diagnostic catheterization and to compare MRA and x-ray angiography measurements of pulmonary arteries and aortopulmonary collaterals (APCs).

METHODS AND RESULTS

Thirty-two patients with pulmonary stenosis or atresia (median age: 4.7 years, range: 1 day to 46.9 years) underwent both MRA and cardiac catheterization (median time: 1 month). Diagnoses included tetralogy of Fallot (TOF) with pulmonary atresia (n=13), TOF with pulmonary stenosis (n=4), post-Fontan palliation (n=5), and other complex congenital heart disease (n=10). Compared with catheterization and surgical observations, MRA had a 100% sensitivity and specificity for the diagnosis of main (n=10) and branch pulmonary artery (PA) stenosis or hypoplasia (n=38), as well as absent (n=5) or discontinuous (n=4) branch PAs. All 48 major APCs diagnosed by catheterization were correctly diagnosed by MRA. Three additional APCs were diagnosed by MRA but not by catheterization. The mean difference between MRA and catheterization measurements of 33 pulmonary vessel diameters was 0.5+/-1.5 mm, with a mean interobserver difference of 0.4+/-1.5 mm.

CONCLUSIONS

Gadolinium-enhanced 3D MRA is a fast and accurate technique for delineation of all sources of pulmonary blood supply in patients with complex pulmonary stenosis and atresia and can be considered a noninvasive alternative to diagnostic catheterization with x-ray angiography.

Factors determining peripheral pulmonary artery stenosis remodeling in children after percutaneous transluminal balloon angioplasty

The peripheral pulmonary artery stenosis (PPS) that complicates congenital heart anomalies can improve after percutaneous transluminal balloon angioplasty (PTA), despite an initial poor response, but there is little information concerning the factors that determine such remodeling. The present study reviewed the hemodynamic and angiographic data before, immediately after, and at late follow-up after PTA for 17 lesions in 14 patients. Lesions were classified into either the (+) group (with pulmonary artery remodeling) or the (-) group (without remodeling). Remodeling was defined as an increase of more than 30% in the predictive percent of normal (%N) of the peripheral pulmonary artery diameter at late follow-up compared with the diameter immediately after PTA. Remodeling occurred in 6 of 17 lesions (35%), and the pressure gradient immediately after PTA was significantly smaller (<10 mmHg) in the (+) group than in the (-) group. Late expansion of the lesion (remodeling) occurs after PTA in some children with PPS and an adequate initial reduction in the pressure gradient favors subsequent remodeling.

Use of small stents for rehabilitation of hypoplastic pulmonary arteries in pulmonary atresia with ventricular septal defect

Branch pulmonary artery stenosis frequently occurs in pulmonary atresia with ventricular septal defect (PA/VSD). Balloon dilation alone is often unsuccessful in patients with severely hypoplastic pulmonary arteries with residual stenoses after surgical repair. In an attempt to promote distal pulmonary artery growth, 17 stents were placed in 12 severely stenotic pulmonary artery lesions in 10 patients with PA/VSD. All had prior surgery, including pulmonary artery repair, right ventricle to pulmonary artery homograft, and, in 6 of 10, closure of VSD. Median age at stent placement was 16.8 months (range, 13.2-56). Stents were placed using 3.0, 3.5, or 4.0 mm balloons in all but one lesion, in which a 7 mm balloon was used. Following stent placement, there was an increase in the lesion diameter from 1.5 to 3.4 mm (P < 0.05) and an increase in flow to the affected lung from 27% to 34% (P < 0.05). Repeat catheterization 2 to 6 months after stenting in six patients revealed complete occlusion in two of eight lesions. In the other six vessels, there was an increase in distal vessel diameter from 2.96 to 3.94 mm (P < 0.05) even though four had severe restenosis requiring restenting. Two patients underwent surgical pulmonary artery reconstruction and stent removal because of adequate distal vessel growth. Stenting of hypoplastic pulmonary arteries in PA/VSD results in immediate improvement in vessel size and blood flow. Stent restenosis is common although distal vessel growth can be achieved. Stenting of these lesions should be reserved only for those patients unresponsive to other interventions.

Accuracy of MRI evaluation of pulmonary blood supply in patients with complex pulmonary stenosis or atresia

Detailed imaging of pulmonary artery (PA) anatomy and significant aorto-pulmonary collaterals (APCs) is crucial for surgical planning and follow-up in patients with complex congenital heart disease (CHD) and pulmonary stenosis or atresia. Because examination by echocardiography is often technically limited and catheterization is invasive, this study evaluated the diagnostic accuracy of magnetic resonance imaging (MRI) as an alternate non-invasive tool. Thirteen patients (median age 28 years, range: 1-44 years) underwent both cardiac catheterization and MRI within a median of two months (range 0.1-8 months). Diagnoses included tetralogy of Fallot (TOF) with pulmonary atresia (n = 8), TOF with pulmonary stenosis (n = 2), single left ventricle with pulmonary stenosis (n = 2), and complex heterotaxy with pulmonary stenosis (n = 1). The MRI sequences used in this study were ECG-gated spin echo and gradient echo sequences acquired in multiple planes. Compared to catheterization, MRI had 100% sensitivity and specificity for the diagnosis of main PA (n = 6) and branch PA (n = 13) hypoplasia or stenosis, as well as discontinuous (n = 4) or absent (n = 10) branch PAs. There was complete agreement between catheterization and MRI identification of significant APCs (n = 18). Main PA atresia was noted by MRI in four patients but was not definitively seen by catheterization in any. MRI but not catheterization precisely defined the distance between discontinuous PAs and their relationship to other mediastinal structures. In conclusion, cardiac MRI is a reliable non-invasive imaging modality to define PA and APC anatomy in patients with complex pulmonary stenosis or atresia.

Cyanotic congenital heart disease with decreased pulmonary blood flow in children

Of the "five T's" of cyanotic congenital heart disease--tetralogy of Fallot, TGA, TAPVC, truncus, and tricuspid valve abnormalities (tricuspid atresia, stenosis, and displacement)--the first and last are commonly associated with diminished PBF. The four features that comprise tetralogy of Fallot--right ventricular hypertrophy, VSD, overriding aorta, and subpulmonary stenosis--are all secondary to a single morphogenetic defect: failure of expansion of the subpulmonary conus. This also explains the variability in clinical presentation. When neonates need intervention, shunts are usually performed. Coronary arterial anatomy must be defined before repair, which is usually done after these infants are 3 months of age. Although children with repaired tetralogy of Fallot are not completely "normal," markedly increased longevity and improvement in quality of life can be achieved. When major associated defects are present, such as atrioventricular canal defect, diminutive pulmonary arteries or collateral vessels, or left heart lesions, the prognosis changes from excellent to merely good. Tetralogy of Fallot with absent pulmonary valve syndrome is physiologically different from other tetralogy of Fallot conditions and characterized primarily by airway obstruction from massive dilatation of the central and perihilar pulmonary arteries; repair with pulmonary artery reduction is necessary. Tricuspid valve abnormalities include atresia, hypoplasia (i.e., pulmonary atresia with intact ventricular septum), and displacement (i.e., Ebstein anomaly). The pathophysiology that dictates these children's clinical condition (and prognosis) relates to three factors: (1) status of the tricuspid valve, (2) presence and size of a VSD, and (3) TGA or normally related great arteries. Virtually all children with tricuspid valve abnormalities can be palliated; reparative options include repair using two-ventricle, one-ventricle, or 1-1/2 ventricle repair. Children with critical pulmonary stenosis generally have a normal tricuspid valve and right ventricle. Balloon dilation is usually the only therapy necessary.

Interventional cardiac catheterization

Over the past decade, transcatheter interventions have become increasingly important in the treatment of patients with congenital heart lesions. These procedures may be broadly grouped as dilations (e.g., septostomy, valvuloplasty, angioplasty, and endovascular stenting) or as closures (e.g., vascular embolization and device closure of defects). Balloon valvuloplasty has become the treatment of choice for patients in all age groups with simple valvar pulmonic stenosis and, although not curative, seems at least comparable to surgery for congenital aortic stenosis in newborns to young adults. Balloon angioplasty is successfully applied to a wide range of aortic, pulmonary artery, and venous stenoses. Stents are useful in dilating lesions of which the intrinsic elasticity results in vessel recoil after balloon dilation alone. Catheter-delivered coils are used to embolize a wide range of arterial, venous, and prosthetic vascular connections. Although some devices remain investigational, they have been successfully used for closure of many arterial ducts and atrial and ventricular septal defects. In the therapy for patients with complex CHD, best results may be achieved by combining cardiac surgery with interventional catheterization. The cooperation among interventional cardiologists and cardiac surgeons was highlighted in a report of an algorithm to manage patients with tetralogy of Fallot or pulmonary atresia with diminutive pulmonary arteries, involving balloon dilation, coil embolization of collaterals, and intraoperative stent placement. In this setting, well-planned catheterization procedures have an important role in reducing the overall number of procedures that patients may require over a lifetime, with improved outcomes.

Total repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals: an integrated approach

OBJECTIVE

Predicting postrepair right ventricular/left ventricular pressure ratio has prognostic relevance for patients undergoing total repair of pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries. To this purpose, we currently rely on 2 novel parameters: (1) preoperative total neopulmonary arterial index and (2) mean pulmonary artery pressure changes during an intraoperative flow study.

METHODS

Since January 1994, 15 consecutive patients (aged 64 +/- 54 months) with pulmonary atresia, ventricular septal defect, and major aortopulmonary collaterals were managed according to total neopulmonary arterial index. Seven patients with hypoplastic pulmonary arteries and a total neopulmonary arterial index less than 150 mm(2)/m(2) underwent palliative right ventricular outflow tract reconstruction followed by secondary 1-stage unifocalization and ventricular septal defect closure. The other 8 patients with a preoperative index of more than 150 mm(2)/m(2) underwent primary single-stage unifocalization and repair. The ventricular septal defect was closed in all cases (reopened in 1). In 9, such decision was based on an intraoperative flow study.

RESULTS

Patients treated by right ventricular outflow tract reconstruction had a significant increase of pulmonary artery index (P=.006) within 22 +/- 6 months. Repair was successful in 14 cases (postrepair right ventricular/left ventricular pressure ratio = 0.47 +/- 0.1). One hospital death occurred as a result of pulmonary vascular obstructive disease, despite a reassuring intraoperative flow study. Accuracy of this test in predicting the postrepair mean pulmonary artery pressure was 89% (95% CI: 51%-99%). At follow-up (18 +/- 12 months), all patients are free of symptoms, requiring no medications.

CONCLUSIONS

The integrated approach to total repair of pulmonary atresia, ventricular septal defect, and major aortopulmonary collaterals by preoperative calculation of total neopulmonary arterial index, right ventricular outflow tract reconstruction (when required), and intraoperative flow study may lead to optimal intermediate results.

Conotruncal repair for tetralogy of Fallot: midterm results

OBJECTIVE

Because of the left-sided location of the main atrioventricular conduction axis, the membranous flap can be safely used for closure of the ventricular septal defect in tetralogy of Fallot.

METHODS

Conotruncal repair consists of (1) precise closure of the defect using the membranous flap and (2) outflow reconstruction of the right ventricle by a wide monocusp patch. This method has been followed in 233 patients from October 1985 to March 1997. The age of patients ranged from 2 months to 53 years, with a mean of 4.6 years; 44% were younger than 2 years of age, and 11% were less than 12 months of age.

RESULTS

A membranous flap was present in 86%, 12% had a muscle bar between the defect and the tricuspid valve, and only 2% had neither a membranous flap nor a muscle bar. There was no early death; two late deaths occurred over a mean follow-up period of 7.3 years. The actuarial survival was 99.1%. No patients required reoperation except for two with residual anomalously connecting pulmonary veins. All 233 patients were in sinus rhythm postoperatively. No patient has had a significant residual defect. The mobility of the polytetrafluoroethylene monocusp was echocardiographically detected in 85% and pulmonary regurgitation was less than mild in 82% at the late phase. The late right and left ventricular pressure ratio was 0.40 +/- 0.14 (n = 30) and the late central venous pressure was 5.6 +/- 2.2 mm Hg (n = 30).

CONCLUSION

Conotruncal repair has provided good midterm results with a low central venous pressure, well-reconstructed outflow tract of the right ventricle, no residual defect, and no heart block.

Usefulness of MRI for the pre-operative evaluation of the pulmonary arteries in Tetralogy of Fallot

Adequate pre-operative evaluation of patients with Tetralogy of Fallot (TF) includes cine-angiography to delineate the pulmonary vasculature and the coronary artery anatomy and to demonstrate the presence of multiple ventricular septal defects (VSDs). All other information is obtained from color-Doppler-echocardiography. Magnetic resonance imaging (MRI), using the spin-echo sequence and cine-angiography was employed on 18 patients with TF, four of whom had aorto-pulmonary shunts. Mean age at MRI was 12.9 m (SD 2.3 m) and 14.3 m (SD 2.8 m) at cine-angiography. To compare MRI and cine-angiography we measured the ascending aorta, the main, the left and right pulmonary arteries and each structure at three levels. Diagnostic agreement between the two imaging methods was found if, for each modality, one of the three measurements in one structure differed by more than 40% from the other two measured in case of a local stenosis, and the diameter of the main pulmonary artery was less than 60% of the aorta to diagnose hypoplasia of the main pulmonary artery. There was close agreement between cine-angiography and MRI. With regard to the intracardiac anatomy, MRI was superior to color-Doppler-echocardiography in the depiction of aortic override and of right ventricular hypertrophy. In three cases local stenoses in the pulmonary arteries were detected by MRI and cine-angiography. Hypoplasia of the main pulmonary artery was detected by MRI in six patients and by cine-angiography in five patients. Cine-angiography missed one case of hypoplasia. In the remaining 11 patients normal findings were found by MRI and cine-angiography. For the demonstration of shunts, gradient-recalled-echo MRI is expected to give better results than the spin-echo sequence which depicted two out of four shunts in this series. Cine-angiography can be substituted by MRI in delineating the pulmonary arteries. New developments in MRI indicate the feasibility of delineating the coronary arteries.

Valve perforation and balloon pulmonary valvuloplasty in an infant with tetralogy of Fallot and pulmonary atresia

We report an infant who had tetralogy of Fallot, hypoplastic pulmonary arteries, and membranous pulmonary atresia who underwent successful perforation of the atretic valve and subsequent balloon pulmonary valvuloplasty. Because of the inability to access the pulmonary arteries via a patent ductus arteriosus, two-dimensional echocardiography was used to confirm wire position prior to perforation. The branch pulmonary arteries initially measured 1.5 mm in diameter and enlarged to 2.8 mm immediately after valvuloplasty. Four months postprocedure, the patient underwent a successful repeat balloon pulmonary valvuloplasty. The pulmonary arteries had grown to approximately 6 mm in diameter. Although it is a rare occurrence, patients with tetralogy of Fallot and membranous pulmonary atresia can be dilated with successful growth of the pulmonary arteries.

The clamshell incision for bilateral pulmonary artery reconstruction in tetralogy of Fallot with pulmonary atresia

BACKGROUND

Patients with tetralogy of Fallot/pulmonary atresia often have bilateral pulmonary artery lesions, including diminutive central and peripheral vessels, major aortopulmonary collaterals, and distortion from previous operations. Staged procedures through lateral thoracotomies and median sternotomies have traditionally been used for repair.

METHODS

Between October 1993 and December 1995, 10 patients 3 months to 15 years old with complex tetralogy of Fallot/pulmonary atresia underwent repair via a clamshell approach. Nine had undergone a mean of 2.8 +/- 0.8 previous operations (range 1 to 4). Indications for operation were repair of pulmonary artery arborization anomalies in 10 (4 unilateral, 6 bilateral), with unifocalization in 6 (2 unilateral, 4 bilateral).

RESULTS

Eight of 10 patients had concomitant complete repair. There were no deaths at a mean follow-up of 17.1 +/- 4.0 months (range 12 to 26). Mean ventilation time was 3.7 +/- 2.1 days (range 1 to 14) and hospital stay 8.7 +/- 4.6 days (range 4 to 19). At follow-up, the peak right ventricular/left ventricular pressure ratio in patients who received complete repair was 0.44 +/- 0.13 (0.30 to 0.67). One patient (10%) required reoperation because of pseudoaneurysm of the main pulmonary artery 14 months after repair, and one had successful stent placement because of recurrent left and right pulmonary artery stenosis 8 months after repair. Two infants who underwent complete unifocalization and central pulmonary artery reconstruction are awaiting completion of repair.

CONCLUSIONS

The clamshell approach to complex tetralogy of Fallot/ pulmonary atresia provides simultaneous exposure of bilateral central and peripheral pulmonary artery lesions and intracardiac pathologic conditions. This procedure appears safe and may decrease the number of operations required to complete repair of tetralogy of Fallot/pulmonary atresia in selected patients.