Comprehensive diagnostic catheterization in children with major aortopulmonary collateral arteries: A review of catheterization technique and anatomic nomenclature.

Achieving an optimal surgical result in patients with major aortopulmonary collateral arteries (MAPCAs) requires a thorough preoperative evaluation of the anatomy and physiology of the pulmonary circulation. This review provides a detailed description of diagnostic catheterization in patients with MAPCAs, including a summary of catheterization techniques, an overview of commonly used terms, and a review of MAPCA and pulmonary artery angiographic anatomy.

Balloon Angioplasty for Pulmonary Artery Stenosis After Complete Unifocalization and Repair of Tetralogy of Fallot With Major Aortopulmonary Collaterals.

OBJECTIVES: The objective of this study was to assess procedural outcomes of balloon pulmonary artery (PA) angioplasty procedures after complete repair of tetralogy of Fallot with major aortopulmonary collateral arteries (TOF/MAPCAs). BACKGROUND: Our approach to patients with TOF/MAPCAs emphasizes early complete unifocalization and repair. Major PA reinterventions are relatively uncommon. Balloon PA angioplasty is often used, but the effectiveness of balloon PA angioplasty in this population is unknown. METHODS: The study cohort comprised patients who underwent complete unifocalization and repair of TOF/ MAPCAs at our center between 2002-2018 and underwent balloon PA angioplasty after repair. To assess immediate procedural outcomes, pre- and postintervention PA measurements were compared. RESULTS: We reviewed 134 vessels that were dilated a median of 1.1 years after repair in 60 patients (median 2 PA branches per patient). Treated vessels included 15 central, 64 lobar, and 55 segmental branches. The median PA diameter at the level of stenosis increased from 1.9 mm to 3.3 mm (P<.001), and the median diameter increase was 50%. All but 6 treated vessels were enlarged. The stenosis-distal diameter ratio increased from a median of 64% to 89% (P<.001). The median central PA to aortic systolic pressure ratio was 47% before and 39% after intervention (P<.001). CONCLUSIONS: Balloon PA angioplasty was acutely effective at treating most stenoses of reconstructed PA branches after repair of TOF/MAPCAs. Simple angioplasty can be a useful tool in treating isolated or modest stenoses after unifocalization/PA reconstruction surgery using our approach.

Angiographic Anatomy of Major Aortopulmonary Collateral Arteries and Association With Early Surgical Outcomes in Tetralogy of Fallot.

Background Due in part to the heterogeneity of the pulmonary circulation in patients with tetralogy of Fallot and major aortopulmonary collateral arteries (MAPCAs), research on this condition has focused on relatively basic anatomic characteristics. We aimed to detail pulmonary artery (PA) and MAPCA anatomy in a large group of infants, assess relationships between anatomy and early surgical outcomes, and consider systems for classifying MAPCAs. Methods and Results All infants ( <1 year of age) undergoing first cardiac surgery for tetralogy of Fallot/MAPCAs from 2001 to 2019 at Stanford University were identified. Preoperative angiograms delineating supply to all 18 pulmonary segments were reviewed for details of each MAPCA and the arborization and size of central PAs. We studied 276 patients with 1068 MAPCAs and the following PA patterns: 152 (55%) incompletely arborizing PAs, 48 (17%) normally arborizing PAs, 45 (16%) absent PAs, and 31 (11%) unilateral MAPCAs. There was extensive anatomic variability, but no difference in early outcomes according to PA arborization or the predominance of PAs or MAPCAs. Patients with low total MAPCA and/or PA cross-sectional area were less likely to undergo complete repair. Conclusions MAPCA anatomy is highly variable and essentially unique for each patient. Though each pulmonary segment can be supplied by a MAPCA, central PA, or both, all anatomic combinations are similarly conducive to a good repair. Total cross-sectional area of central PA and MAPCA material is an important driver of outcome. We elucidate a number of novel associations between anatomic features, but the extreme variability of the pulmonary circulation makes a granular tetralogy of Fallot/MAPCA classification system unrealistic.

Transcatheter redirection of hepatic venous blood to treat unilateral pulmonary arteriovenous malformations in a Fontan circulation by short-term total exclusion of the unaffected lung.

Clinically significant unilateral pulmonary arteriovenous malformations (PAVM) can develop in patients with a Fontan circulation when there is unbalanced distribution of hepatic venous (HV) blood flow to the lungs. There are reported surgical and transcatheter techniques to treat PAVMs by rerouting HV return, with promising short-term results. We report a case of a novel, technically simple transcatheter approach to redirect HV blood flow in an adult Fontan patient with polysplenia syndrome and severe unilateral PAVMs. Our patient had a two-stage procedure, the first to redirect all HV blood flow to the affected lung with a single covered stent, and a second to confirm resolution of PAVMs and to reintroduce HV effluent to the unaffected lung. At 10-month follow-up, her oxygen saturations had increased from 75% to 93% with a marked improvement in her functional status.

Pulmonary reinterventions after complete unifocalization and repair in infants and young children with tetralogy of Fallot with major aortopulmonary collaterals.

BACKGROUND: Our institutional approach to tetralogy of Fallot (TOF) with major aortopulmonary collaterals (MAPCAs) emphasizes unifocalization and augmentation of the reconstructed pulmonary arterial (PA) circulation and complete intracardiac repair in infancy, usually in a single procedure. This approach yields a high rate of complete repair with excellent survival and low right ventricular (RV) pressure. However, little is known about remodeling of the unifocalized and reconstructed pulmonary circulation or about reinterventions on the reconstructed PAs or the RV outflow tract conduit. METHODS: We reviewed patients who underwent complete repair of TOF with MAPCAs at our center at <2 years of age, either as a single-stage procedure or after previous procedures. Outcomes included freedom from conduit or PA intervention after repair, which were assessed by Cox regression and Kaplan-Meier analysis. RESULTS: The study cohort included 272 patients. There were 6 early deaths and a median of follow-up of 3.6 years after complete repair. Reinterventions on the pulmonary circulation were performed in 134 patients, including conduit interventions in 101 patients, branch PA interventions in 101, and closure of residual MAPCAs in 9. The first conduit reintervention consisted of surgical conduit replacement in 77 patients, transcatheter pulmonary valve replacement with a Melody valve in 14, and angioplasty or bare metal stenting in 10. Surgical PA reinterventions were performed in 46 patients and transcatheter reinterventions in 75 (both in 20). Most PA reinterventions involved a single lung, and most transcatheter reinterventions a single vessel. Freedom from conduit replacement or transcatheter pulmonary valve replacement was 70 ± 3% at 5 years and was shorter in patients with smaller initial conduit size. Freedom from any PA reintervention was 64 ± 3% at 5 years, with the greatest rate during the first year. On multivariable analysis, factors associated with longer freedom from any PA reintervention included lower postrepair RV:aortic pressure ratio and larger original conduit size. CONCLUSIONS: We were able to obtain follow-up data for the majority of patients, which demonstrated freedom from PA reintervention for two thirds of patients. The time course of and risk factors for conduit reintervention in this cohort appeared similar to previously reported findings in patients who received RV-PA conduits in early childhood for other anomalies. Relative to the severity of baseline pulmonary vascular anatomy in TOF with MAPCAs, reinterventions on the reconstructed PAs were uncommon after repair according to our approach, and major reinterventions were rare. Nevertheless, PA reinterventions are an important aspect of the overall management strategy.

Programmatic Approach to Management of Tetralogy of Fallot With Major Aortopulmonary Collateral Arteries: A 15-Year Experience With 458 Patients.

BACKGROUND: Tetralogy of Fallot with major aortopulmonary collateral arteries is a complex and heterogeneous condition. Our institutional approach to this lesion emphasizes early complete repair with the incorporation of all lung segments and extensive lobar and segmental pulmonary artery reconstruction. METHODS AND RESULTS: We reviewed all patients who underwent surgical intervention for tetralogy of Fallot and major aortopulmonary collateral arteries at Lucile Packard Children's Hospital Stanford (LPCHS) since November 2001. A total of 458 patients underwent surgery, 291 (64%) of whom underwent their initial procedure at LPCHS. Patients were followed for a median of 2.7 years (mean 4.3 years) after the first LPCHS surgery, with an estimated survival of 85% at 5 years after first surgical intervention. Factors associated with worse survival included first LPCHS surgery type other than complete repair and Alagille syndrome. Of the overall cohort, 402 patients achieved complete unifocalization and repair, either as a single-stage procedure (n=186), after initial palliation at our center (n=74), or after surgery elsewhere followed by repair/revision at LPCHS (n=142). The median right ventricle:aortic pressure ratio after repair was 0.35. Estimated survival after repair was 92.5% at 10 years and was shorter in patients with chromosomal anomalies, older age, a greater number of collaterals unifocalized, and higher postrepair right ventricle pressure. CONCLUSIONS: Using an approach that emphasizes early complete unifocalization and repair with incorporation of all pulmonary vascular supply, we have achieved excellent results in patients with both native and previously operated tetralogy of Fallot and major aortopulmonary collateral arteries.

Postoperative Outcomes of Children With Tetralogy of Fallot, Pulmonary Atresia, and Major Aortopulmonary Collaterals Undergoing Reconstruction of Occluded Pulmonary Artery Branches.

BACKGROUND: Patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals (TOF/PA/MAPCAs) undergoing unifocalization surgery are at risk for prolonged postoperative respiratory failure. We sought to understand whether patients undergoing reconstruction and incorporation of occluded pulmonary arterial branches were at risk for worse postoperative outcomes. METHODS: We performed a retrospective chart review to identify patients who underwent unifocalization or unifocalization revision with incorporation of occluded pulmonary artery branches. Patients with and without occluded branches were compared, with a focus on clinical outcomes. RESULTS: We studied 92 patients who underwent unifocalization procedures between 2010 and 2014, 17 (18%) of whom underwent reconstruction of occluded pulmonary artery branches. Patients with occluded vessels were more likely to require staged unifocalization procedures, although more than two thirds of this cohort eventually underwent complete intracardiac repair. Durations of mechanical ventilation, intensive care, hospital stay, and the need for early reoperation were similar between the two groups. CONCLUSIONS: Occluded pulmonary arterial branches can be safely recruited into the pulmonary vasculature in patients with TOF/PA/MAPCAs without a significant difference in postoperative outcomes compared with patients who did not have an occluded branch. Incorporation of occluded branches may also facilitate ultimate complete intracardiac repair in this complex population of patients.

Mitral Stenosis and Aortic Atresia--A Risk Factor for Mortality After the Modified Norwood Operation in Hypoplastic Left Heart Syndrome.

BACKGROUND: There are conflicting reports regarding the importance of mitral stenosis and aortic atresia as a risk factor for Norwood mortality. This study reviews outcomes of this anatomic subgroup at our institution and examines the utility of preoperative cardiac catheterization and its correlation with clinical outcomes and pathology findings. METHODS: This is a single-center, retrospective review of hypoplastic left heart syndrome patients who underwent modified Norwood operation between October 2005 and May 2013. RESULTS: Fourteen of 74 hypoplastic left heart syndrome patients (19%) had mitral stenosis and aortic atresia. Operative mortality for MS/AA was 29% versus 7% for all other hypoplastic left heart syndrome anatomic subgroups (p = 0.04). Although only 19% of the entire cohort, the mitral stenosis and aortic atresia subgroup constituted 50% of the total operative mortality and the only interstage deaths. Autopsies support myocardial ischemia as the mechanism of death. Although preoperative angiography defined the presence of ventriculo-coronary connections, it did not clearly risk stratify patients in regard to operative mortality. CONCLUSIONS: Mitral stenosis and aortic atresia is a risk factor for perioperative myocardial ischemia and mortality. Further exploration of myocardial reserve is warranted.

Isolation of the right subclavian artery in a patient with d-transposition of the great arteries.

Isolation of the right subclavian artery (RSCA) is rare, and this finding in association with d-transposition of the great arteries (d-TGA) is extremely unusual. We present a case of an isolated RSCA in a newborn with d-TGA in whom the clinical presentation was diagnostic. We discuss the imaging modalities used to confirm the diagnosis, the embryological basis of the finding, and the surgical repair.

Transcatheter device closure of a congenital aortic-left atrial tunnel.

Rare cases of aortic-left atrial tunnel exist in the literature. This case report highlights the echocardiographic characterization of this vascular anomaly and provides the first description of an aortic-left atrial tunnel closed by interventional cardiac catheterization in a pediatric patient.

Late outcomes in patients undergoing aortopulmonary window for pulmonary atresia/stenosis and major aortopulmonary collaterals.

BACKGROUND: Pulmonary atresia with ventricular septal defect (PA/VSD) and major aortopulmonary collateral arteries (MAPCAs) is a complex form of congenital heart defect. One identifiable subset has small (<2.5 mm) intrapericardial branch pulmonary arteries that are (1) confluent, (2) have normal arborization, and (3) have dual-supplied collateral vessels. When this anatomy is associated with limited pulmonary blood flow, the patients are candidates for creation of an aortopulmonary window to stimulate growth of the pulmonary arteries. The purpose of this study was to review our experience with creation of an aortopulmonary window as the initial palliative procedure. METHODS: This was a retrospective review of our surgical experience with 35 children undergoing aortopulmonary window creation from 2002 to 2011. Patients were identified by preoperative cardiac catheterization to define the cardiac and pulmonary artery anatomy. RESULTS: There was no mortality in 35 patients undergoing aortopulmonary window creation. These patients have subsequently undergone 78 cardiac procedures (with 2 operative mortalities). Eighteen of these patients have achieved complete repair, 4 patients in a second procedure, 6 patients in a third procedure, 5 patients in a fourth procedure, and 3 patients in a fifth procedure. CONCLUSIONS: The data demonstrate that patients can undergo creation of an aortopulmonary window with excellent early results. Few patients were amenable to complete repair at the second operation, and most required multiple reoperations to recruit sufficient arborization. We interpret these counterintuitive results to suggest that hypoplastic central pulmonary arteries and diminished pulmonary blood flow are markers for a less well developed pulmonary vascular bed.

Survival after extreme left atrial hypertension and pulmonary hemorrhage in an infant supported with extracorporeal membrane oxygenation for refractory atrial flutter.

OBJECTIVE: We report here the survival of an infant who developed extreme left atrial hypertension and severe pulmonary hemorrhage while supported with extracorporeal membrane oxygenation for refractory atrial flutter. The patient recovered after decompression of the left heart and catheter ablation of the atrioventricular node. SETTING: Lucile Packard Children's Hospital (Stanford, CA). DATA SOURCE: Chart review. CONCLUSIONS: Recovery of lung function is possible despite systemic-level left atrial pressure resulting in pulmonary hemorrhage and complete solidification of lung parenchyma on gross inspection. Resolution of pulmonary hemorrhage despite anticoagulation while on extracorporeal membrane oxygenation can occur after relief of left atrial hypertension.

Surgical management of life threatening events caused by intermittent aortic insufficiency in a native valve: case report.

We describe a case of a patient admitted with apparent life threatening events characterized by hypotension and bradycardia. The patient was ultimately found to have intermittent severe aortic insufficiency. Upon surgical exploration, abnormalities were discovered in the aortic valve, which had a small left coronary cusp with absence of the nodulus of Arantius. Following surgical repair of the valve, aimed at preventing the small cusp from becoming stuck in the open position, the patient has remained episode free for over one year.

Prevention of pediatric graft coronary artery disease: atorvastatin.

Graft coronary artery disease is a significant cause of late graft failure and death after cardiac transplantation. HMG-coenzyme A reductase inhibitors have been used safely in children but their preventative effects against GCAD are not well known. We investigated whether atorvastatin when initiated early could prevent against the development of pediatric GCAD. Pediatric patients (transplanted between October 28, 1992 and July 9, 2004) were stratified into two groups based on whether or not they received atorvastatin early after transplant. Angiograms were reviewed by a single observer blinded to the treatment strategies and clinical outcomes. Actuarial survival method and the Mantel-Cox test were used to assess statistical significance. Freedom from GCAD was higher among those treated with atorvastatin early in the post-transplant course. One, three, and five-yr freedom from GCAD was significantly greater in the early treatment group (97%, 93%, and 93% respectively) compared with the control group (72%, 65%, and 60% respectively, p < 0.005). The early treatment group was also noted for fewer rejection episodes in the first post-transplant year. The use of atorvastatin when initiated early in the post-transplant course appears protective against graft coronary artery disease.

Morphological studies of pulmonary arteriovenous shunting in a lamb model of superior cavopulmonary anastomosis.

We sought to identify and characterize the abnormal vascular structures responsible for pulmonary arteriovenous shunting following the Glenn cavopulmonary shunt. Superior cavopulmonary shunt is commonly performed as part of the staged pathway to total cavopulmonary shunt to treat univentricular forms of congenital heart disease, however, clinically significant pulmonary arteriovenous malformations develop in some patients after the procedure. The causes of pulmonary arteriovenous malformations and other pulmonary vascular changes that occur after cavopulmonary shunt are not known. Using a juvenile lamb model of superior cavopulmonary anastomosis that reliably produces pulmonary arteriovenous malformations, we performed echocardiography and morphological analyses to determine the anatomic site of shunting and to identify the vascular structures involved. Pulmonary arteriovenous shunting was identified by contrast echocardiography in all surviving animals (n = 40) following superior cavopulmonary anastomosis. Pulmonary vascular corrosion casts revealed abnormal tortuous vessels joining pulmonary arteries and veins in cavopulmonary shunt animals but not control animals. In conclusion, unusual channels that bridged pulmonary arteries and veins were identified. These may represent the vascular structures responsible for arteriovenous shunting following the classic Glenn cavopulmonary shunt. Detailed analysis of these structures may elucidate factors responsible for their development.

Ketamine does not increase pulmonary vascular resistance in children with pulmonary hypertension undergoing sevoflurane anesthesia and spontaneous ventilation.

BACKGROUND: The use of ketamine in children with increased pulmonary vascular resistance is controversial. In this prospective, open label study, we evaluated the hemodynamic responses to ketamine in children with pulmonary hypertension (mean pulmonary artery pressure >25 mm Hg). METHODS: Children aged 3 mo to 18 yr with pulmonary hypertension, who were scheduled for cardiac catheterization with general anesthesia, were studied. Patients were anesthetized with sevoflurane (1 minimum alveolar anesthetic concentration [MAC]) in air while breathing spontaneously via a facemask. After baseline catheterization measurements, sevoflurane was reduced (0.5 MAC) and ketamine (2 mg/kg IV over 5 min) was administered, followed by a ketamine infusion (10 microg x kg(-1) x min(-1)). Catheterization measurements were repeated at 5, 10, and 15 min after completion of ketamine load. Data at various time points were compared (ANOVA, P < 0.05). RESULTS: Fifteen patients (age 147, 108 mo; median, interquartile range) were studied. Diagnoses included idiopathic pulmonary arterial hypertension (5), congenital heart disease (9), and diaphragmatic hernia (1). At baseline, median (interquartile range) baseline pulmonary vascular resistance index was 11.3 (8.2) Wood units; 33% of patients had suprasystemic mean pulmonary artery pressures. Heart rate (99, 94 bpm; P = 0.016) and Pao2 (95, 104 mm Hg; P = 007) changed after ketamine administration (baseline, 15 min after ketamine; P value). There were no significant differences in mean systemic arterial blood pressure, mean pulmonary artery pressure, systemic or pulmonary vascular resistance index, cardiac index, arterial pH, or Paco2. CONCLUSIONS: In the presence of sevoflurane, ketamine did not increase pulmonary vascular resistance in spontaneously breathing children with severe pulmonary hypertension.

Homograft valved right ventricle to pulmonary artery conduit as a modification of the Norwood procedure.

BACKGROUND: The use of a right ventricle to pulmonary artery (RV-PA) conduit in the Norwood procedure has been proposed to increase postoperative hemodynamic stability. A valve within the conduit should further decrease RV volume load. We report our clinical experience with this modification. METHODS AND RESULTS: From February 2002 through August 2005, we performed 88 consecutive Norwood procedures using RV-PA conduits. We used composite valved conduits made from cryopreserved homograft and polytetrafluoroethylene (PTFE) in 66 cases (54 pulmonary, 12 aortic homografts), other valved conduits in 14, and unvalved PTFE in 8 cases. Hospital survival was 88.6% overall and increased to 93.1% after the initial year. Early interventions were required in 18 patients (16 for cyanosis). Prestage II cardiac catheterization was performed at a mean age of 126 days. Mean Qp/Qs was 1, with mean aortic saturation 71%, mean O2 extraction 24%, and mean right ventricular end-diastolic pressure 9 mm Hg. Patient weight, use of an aortic homograft valve in the conduit, stage I palliation within the first year of our experience, and low O2 extraction and high transpulmonary gradient prestage II were risk factors for overall death. Early interventions were more frequent in aortic valve conduits compared with all other conduits. CONCLUSIONS: The valved RV-PA conduit was associated with low early mortality after the Norwood procedure. The majority of these patients had normal cardiac output and well-maintained RV function. There may be a higher risk for early conduit interventions and death when aortic valve homografts are used in the RV-PA conduit.

Percutaneous pulmonary valve placement in a 10-month-old patient using a hand crafted stent-mounted porcine valve.

Percutaneous replacement of the pulmonary valve in a right ventricle to pulmonary artery (RV-PA) conduit using bovine jugular valves has recently been described as an alternative to surgical options in selected patients weighing >or=20 kg. We report the first case of transcatheter pulmonary valve implantation in an infant and the first use of "off the shelf" components. A 12-mm (Hancock) porcine valve was sutured into a predilated Genesis 2510b stent. The valved stent was manually crimped and mounted on a 12-mm balloon. Snare-assisted deployment in the middle of the RV-PA conduit was accomplished without the use of a long sheath. After the initial deployment, a 14-mm balloon was used to further approximate the stent to the walls of the conduit. Short-term (11 month) follow-up has demonstrated continued valve integrity, markedly decreased right ventricular size and improved function and symptomatic improvement. At 10 months of age, this case represents the youngest patient to undergo percutaneous valve placement and documents the technical feasibility of the procedure.

Angiojet catheter-based thrombectomy in a neonate with postoperative pulmonary embolism.

A 2-day-old male with pulmonary atresia and an intact ventricular septum underwent central aortopulmonary shunt placement and right ventricular outflow tract reconstruction. Postoperatively, the patient had difficulty weaning from mechanical ventilation and was found to have a large thrombus occluding the entire right lower pulmonary artery. The patient underwent successful percutaneous catheter-based thrombectomy in the early postoperative period with the Possis AngioJet catheter. The patient had immediate improvement in gas exchange and was able to be weaned from the ventilator shortly thereafter. This represents the first published use of mechanical thrombectomy in a postoperative neonate.

Balloon dilation of severe aortic stenosis in the fetus: potential for prevention of hypoplastic left heart syndrome: candidate selection, technique, and results of successful intervention.

BACKGROUND: Preventing the progression of fetal aortic stenosis (AS) to hypoplastic left heart syndrome (HLHS) requires identification of fetuses with salvageable left hearts who would progress to HLHS if left untreated, a successful in utero valvotomy, and demonstration that a successful valvotomy promotes left heart growth in utero. Fetuses meeting the first criterion are undefined, and previous reports of fetal AS dilation have not evaluated the impact of intervention on in utero growth of left heart structures. METHODS AND RESULTS: We offered fetal AS dilation to 24 mothers whose fetuses had AS. At least 3 echocardiographers assigned a high probability that all 24 fetuses would progress to HLHS if left untreated. Twenty (21 to 29 weeks' gestation) underwent attempted AS dilation, with technical success in 14. Ideal fetal positioning for cannula puncture site and course of the needle (with or without laparotomy) proved to be necessary for procedural success. Serial fetal echocardiograms after intervention demonstrated growth arrest of the left heart structures in unsuccessful cases and in those who declined the procedure, while ongoing left heart growth was seen in successful cases. Resumed left heart growth led to a 2-ventricle circulation at birth in 3 babies. CONCLUSIONS: Fetal echocardiography can identify midgestation fetuses with AS who are at high risk for developing HLHS. Timely and successful aortic valve dilation requires ideal fetal and cannula positioning, prevents left heart growth arrest, and may result in normal ventricular anatomy and function at birth.