Comprehensive Management of Major Aortopulmonary Collaterals in the Repair of Tetralogy of Fallot

The Hemodynamic Effects of Bolus Dose Calcium in Patients Undergoing Pulmonary Artery Reconstruction and Unifocalization Surgery: A Pilot Study

OBJECTIVES

To determine if bolus administration of calcium increases pulmonary artery pressures after unifocalization procedures or pulmonary artery reconstruction surgery.

DESIGN

Retrospective cohort study using Stanford University's data warehouse.

SETTING

A large pediatric heart center within an academic quaternary care facility.

PARTICIPANTS

All patients undergoing pulmonary artery reconstruction or unifocalization procedures identifiable in the data warehouse.

INTERVENTIONS

Data were collected from Stanford University's data repository and formatted and analyzed using RStudio (v 2023.06.1+524).

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the change in pulmonary artery systolic pressure (PASP) after a bolus administration of calcium. Secondary endpoints include changes in pulmonary arterial-to-systemic arterial pressure ratio, mean arterial pressure, right-sided filling pressure, and left atrial pressure. The Friedman test was used to assess differences and the Durbin-Conover rank-sum for pairwise comparisons. A difference in PASP after a bolus dose of calcium was found (Friedman X2 = 13.67, p = 0.003), with a higher PASP 5 minutes after calcium administration compared with 2 minutes before administration (35 mmHg v 33 mmHg, p = 0.01), and a higher PASP 10 minutes after calcium administration compared with2 minutes before administration (35 mmHg v 33 mmHg, p = 0.008).

CONCLUSIONS

Calcium bolus administration led to an increase in pulmonary arterial pressure in patients after pulmonary artery reconstruction or unifocalization surgeries. It may be prudent to avoid bolus administration in this patient population immediately after repair or in patients with right ventricular dysfunction.

Basic Concepts and Insights into Aortopulmonary Collateral Arteries in Congenital Heart Diseases

Aortopulmonary collateral arteries are persistent embryological vessels supplying lung parenchyma in various cardiopulmonary diseases with underlying pulmonary hypoperfusion. Their identification and mapping are important because of associated clinical implications and tendency to affect the surgical outcome. This article describes the embryological development and clinical relevance of aortopulmonary collaterals in various congenital cardiopulmonary conditions, along with the significance for treatment planning. Roles, strength, and shortcomings of the various imaging options and image-guided interventions are discussed, with a focus on presurgical planning and preparation, as well as postsurgical management.

20-Year Experience With Repair of Pulmonary Atresia or Stenosis and Major Aortopulmonary Collateral Arteries

BACKGROUND

We have followed a consistent, albeit evolving, strategy for the management of patients with pulmonary atresia or severe stenosis and major aortopulmonary collateral arteries (MAPCAs) that aims to achieve complete repair with low right ventricular pressure by completely incorporating blood supply and relieving stenoses to all lung segments.

OBJECTIVES

The purpose of this study was to characterize our 20-year institutional experience managing patients with MAPCAs.

METHODS

We reviewed all patients who underwent surgery for MAPCAs and biventricular heart disease from November 2001 through December 2021.

RESULTS

During the study period, 780 unique patients underwent surgery. The number of new patients undergoing surgery annually was relatively steady during the first 15 years, then increased substantially thereafter. Surgery before referral had been performed in almost 40% of patients, more often in our recent experience than earlier. Complete repair was achieved in 704 patients (90%), 521 (67%) during the first surgery at our center, with a median right ventricular to aortic pressure ratio of 0.34 (25th, 75th percentiles: 0.28, 0.40). The cumulative incidence of mortality was 15% (95% CI: 12%-19%) at 10 years, with no difference according to era of surgery (P = 0.53). On multivariable Cox regression, Alagille syndrome (HR: 2.8; 95% CI: 1.4-5.7; P = 0.004), preoperative respiratory support (HR: 2.0; 95% CI: 1.2-3.3; P = 0.008), and palliative first surgery at our center (HR: 3.5; 95% CI: 2.3-5.4; P < 0.001) were associated with higher risk of death.

CONCLUSIONS

In a growing pulmonary artery reconstruction program, with increasing volumes and an expanding population of patients who underwent prior surgery, outcomes of patients with pulmonary atresia or stenosis and MAPCAs have continued to improve.

Serial Lung Perfusion Scintigraphy After Unifocalization and Repair of Tetralogy of Fallot With Major Aortopulmonary Collaterals

Background

In patients with tetralogy of Fallot and major aortopulmonary collaterals (MAPCAs), pulmonary blood supply is highly variable. Our approach to this condition emphasizes complete unifocalization of the pulmonary circulation, incorporating all lung segments and addressing stenoses out to the segmental level. Post-repair, we recommend serial lung perfusion scintigraphy (LPS) to assess short-term changes in pulmonary blood flow distribution.

Methods

We reviewed post-discharge and follow-up LPS performed through three years post-repair and analyzed serial changes in perfusion, risk factors for change, and the relationship between LPS parameters and pulmonary artery reintervention.

Results

Of 543 patients who had postoperative LPS results in our system, 317 (58%) had only a predischarge LPS available for review, while 226 had 1 (20%) or more (22%) follow-up scans within three years. Overall, pulmonary flow distribution prior to discharge was balanced, and there was minimal change over time; however, there was considerable patient-to-patient variation in both metrics. On multivariable mixed modeling, time after repair ( P = .025), initial anatomy consisting of a ductus arteriosus to one lung ( P < .001), and age at repair ( P = .014) were associated with changes on serial LPS. Patients who had follow-up LPS were more likely to undergo pulmonary artery reintervention, but within that cohort, LPS parameters were not associated with reintervention risk.

Conclusion

Serial LPS during the first year after MAPCAs repair is a noninvasive method of screening for significant post-repair pulmonary artery stenosis that occurs in a small but important minority of patients. In patients who received follow-up LPS beyond the perioperative period, there was minimal change over time in the population overall, but large changes in some patients and considerable variability. There was no statistical association between LPS findings and pulmonary artery reintervention.

The management of newborns with critical congenital heart diseases prior to transport to a cardiac center

Critical congenital heart diseases (CCHD) are important causes of mortality and morbidity in the newborn period. Even after diagnosis, their management could be seriously compromised by the unplanned delivery in hospitals with limited expertise and resources. The newborn may spend days or week before transport putting a significant burden on the neonatal team to manage such challenging diseases. In this review, the management principles of each individual pathology are discussed in the setting before transport to cardiac centers. Understanding these principles will help the treating teams evaluate and manage those complex conditions. The review avoids the advanced discussion on the management of CCHDs not applicable to the pre-transport setup. It highlights the critical elements in the maintenance of normal hemodynamics specific to each pathology and their variation.

Computed tomography in tetralogy of Fallot: pre- and postoperative imaging evaluation

Tetralogy of Fallot (TOF) is the most common cause of cyanotic congenital heart disease (CHD) and the most frequent complex CHD encountered in adulthood. Although children with TOF share four characteristic features (subaortic ventricular septal defect, overriding aorta, right ventricular hypertrophy, pulmonary stenosis), the clinical spectrum and course are in fact greatly heterogeneous. Echocardiography remains the mainstay for diagnosis, presurgical planning and postoperative follow-up. However, with continued technological advances, CT now plays an increasing role in TOF evaluation and management, helping to minimize routine invasive catheter angiography. Preoperatively, CT is uniquely suited to assess associated pulmonary arterial, aortic and coronary anomalies as well as extra-cardiovascular structures and is particularly helpful for delineating complex anatomy in the TOF subtypes of absent pulmonary valve and pulmonary atresia with major aortopulmonary collaterals. Postoperatively, CT is useful for identifying surgical complications and for long-term monitoring including volumetry quantification, especially in children for whom MRI is contraindicated or limited by implanted devices such as pacemakers and stents. In this article, we review key clinical features and considerations in the pre- and postoperative TOF patient and the burgeoning role of CT for facilitating accurate diagnosis and personalized intervention.

Right ventricular outflow tract anomalies: Neonatal interventions and outcomes

Right ventricular outflow tract (RVOT) anomalies comprise a wide spectrum of congenital heart disease, typically characterized by obstruction to flow from the right ventricle to pulmonary arteries. This review highlights important considerations surrounding management strategy as well as clinical outcomes for the neonate with RVOT anomaly, including: pulmonary atresia with intact ventricular septum, congenital pulmonary valve stenosis, tetralogy of Fallot, and Ebstein anomaly with anatomic or physiologic RVOT obstruction.

Relation Between Pulmonary Artery Pressures Measured Intraoperatively and at One-Year Catheterization After Unifocalization and Repair of Tetralogy with Major Aortopulmonary Collateral Arteries

To assess the relationships between pulmonary artery (PA) pressure and the PA:aortic systolic pressure ratio measured intraoperatively and at surveillance catheterization in patients achieving complete unifocalization and repair for tetralogy of Fallot with major aortopulmonary collateral arteries (TOF/MAPCAs). This was a single-center retrospective cohort analysis of all patients who underwent complete repair of TOF/MAPCAs from 2002-2019 and received a postoperative surveillance catheterization at our center 6-24 months after surgery. Associations between intraoperative and catheter hemodynamic data were analyzed. 163 patients were included. Median systolic PA pressure was 30 (quartiles 26, 35) and 35 (28, 42) mmHg intraoperatively and at catherization respectively; systolic aortic pressure 90 (86, 100) and 84 (76, 92); and PA:aortic pressure ratio was 0.33 (0.28, 0.40) and 0.41 (0.34, 0.49). Moderate correlation was found between the intraoperative and catheter-based hemodynamics, with the majority of systolic PA pressures within 10mmHg and PA:Ao systolic ratios within 0.1. Changes in the ratio were influenced to a similar degree by differences in PA and aortic pressures. Surgical and/or catheter reinterventions were more common in patients with both higher intraoperative PA systolic pressure and PA:aortic systolic ratios and in those with greater discrepancy between intraoperative and catheterization values. PA systolic pressure and the PA:aortic systolic pressure ratio measured immediately after repair remain useful metrics for assessing the initial operative PA reconstruction, and as indicators of longer term hemodynamics. Initially elevated and subsequently discrepant PA systolic pressure and PA:aortic systolic pressure ratios were associated with higher rates of reintervention. (Figure 7).

Improvement in exercise capacity after a modified Potts shunt in an adult patient with pulmonary arterial hypertension

For young adults with end-stage idiopathic pulmonary hypertension, a valved graft connecting the central pulmonary artery to the distal aortic arch can provide substantial palliation of symptoms and may defer lung transplantation https://bit.ly/2TvMFFC.

Perioperative and Anesthetic Considerations in Tetralogy of Fallot With Pulmonary Atresia

Tetralogy of Fallot with pulmonary atresia (ToF-PA) is a rare diagnosis that includes an extraordinarily heterogeneous group of complex anatomical findings with significant implications for physiology and prognosis. In addition to the classic findings of ToF, this particular diagnosis is characterized by complete failure of forward flow from the right ventricle to the pulmonary arterial system. As such, pulmonary blood flow is entirely dependent on shunting from the systemic circulation, most frequently via a patent ductus arteriosus, major aortopulmonary collaterals, or a combination of the two. The pathophysiology of ToF-PA is largely attributable to the abnormalities of the pulmonary vasculature. Ultimately, these patients require operative intervention to create a reliable, controlled source of pulmonary blood flow and ideally complete intracardiac repair. Even after operative correction, these patients remain at risk for pulmonary arterial stenoses and pulmonary hypertension. Although there have been significant advances in surgical and interventional management of ToF-PA leading to dramatic improvements in survival and long-term functional status, there is ongoing debate about the optimal management strategy given the risk of development of irreversible abnormalities of the pulmonary vasculature and the morbidity and mortality associated with sometimes multiple, complex operative interventions often occurring early in infancy. This review will discuss the findings in patients with ToF-PA with a focus on the perioperative and anesthetic management and will highlight challenges faced by the anesthesiologist in caring for these patients.

Outcomes After Repair of Pulmonary Atresia With Ventricular Septal Defect and Major Aortopulmonary Collateral Arteries: A Tailored Approach in a Developing Setting

Objectives: Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCAs) is complex and diverse that has led to a variety of treatment strategies. Experience has been largely obtained in the advanced countries. The clinical diversity is greater in China. We evaluated our surgical approaches and outcomes of these patients. Methods: We reviewed 127 patients undergoing varied surgeries in our center in 2010-2019. Results: Thirty patients underwent single-stage complete repair by unifocalizing MAPCAs and VSD closure (aged 3.9-131.4 months, median 22) with 3 (10%) early deaths. Ninety-seven underwent the first-stage rehabilitation strategy including systemic-to-pulmonary shunt in 29 (aged 0.5-144 month, median 8), and palliative RV-PA conduit in 68 (aged 2.2-209.6 months, median 14) with 5 (5.2%) early deaths. Eight-one patients (63.8%) eventually achieved complete repair with a median right/left ventricular (RV/LV) pressure ratio of 0.7 (ranged 0.4-1.0). Fourteen patients (11.0%) accepted palliation as final destination. Survival for the entire cohort was 89.5, 85.2, and 76.1% at 1, 5, and 10 years, respectively. Survival for those undergoing complete repair was 88.2 and 76.6% at 1 and 5 year, respectively. RV/LV pressure ratio ≥0.8 was risk factor for mortality (HR10.3, p = 0.003). Conclusions: Our cohort, the largest from China, had distinctive clinical features with substantially wider age range and higher RV/LV pressure ratio. Using the combined approaches tailored to individual patients, complete repair was achieved in 64% of patients. The early and intermediate outcomes are acceptable compared to many of the previous reports.

Mid-Term Outcomes After Unifocalization Guided by Intraoperative Pulmonary Flow Study

BACKGROUND

Repair of tetralogy of Fallot (TOF) with major aortopulmonary collateral arteries (MAPCAs) requires unifocalization of pulmonary circulation, intracardiac repair with the closure of the ventricular septal defect, and placement of a right ventricle (RV) to pulmonary artery (PA) conduit. The decision to perform complete repair is sometimes aided by an intraoperative flow study to estimate the total resistance of the reconstructed pulmonary circulation.

METHODS

We reviewed patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs to evaluate acute and mid-term outcomes after repair with and without flow studies and to characterize the relationship between PA pressure during the flow study and postrepair RV pressure.

RESULTS

Among 579 patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs, 99 (17%) had an intraoperative flow study during one (n = 91) or more (n = 8) operations to determine the suitability for a complete repair. There was a reasonably good correlation between mean PA pressure at 3 L/min/m² during the flow study and postrepair RV pressure and RV:aortic pressure ratio. Acute and mid-term outcomes (median: 3.8 years) after complete repair in the flow study patients (n = 78) did not differ significantly from those in whom the flow study was not performed (n = 444). Furthermore, prior failed flow study was not associated with differences in outcome after subsequent intracardiac repair.

CONCLUSIONS

The intraoperative flow study remains a useful adjunct for determining the suitability for complete repair in a subset of patients undergoing surgery for TOF/MAPCAs, as it is reasonably accurate for estimating postoperative PA pressure and serves as a reliable guide for the feasibility of single-stage complete repair.

Longevity of Large Aortic Allograft Conduits in Tetralogy With Major Aortopulmonary Collaterals

BACKGROUND

Appropriate conduit selection for right ventricle (RV)-to-pulmonary artery (PA) connection has been extensively studied, with older implantation age, pulmonary (vs aortic) homografts, and true sizing associated with increased longevity. Notably, patients with PA arborization abnormalities (ie, major aortopulmonary collateral arteries [MAPCAs]) are reported to require earlier and more frequent conduit interventions. We aim to understand the behavior of large-diameter aortic homografts in patients with MAPCAs, which are programmatically utilized at our institution.

METHODS

This is a single-center retrospective cohort study including all children less than 12 years of age who underwent RV-PA connection using an aortic homograft greater than or equal to 16 mm diameter between 2002 and 2019, with a primary outcome of freedom from any RV-PA reintervention and a secondary outcome of freedom from surgical reintervention. Patients were grouped by absolute and indexed conduit sizes for further analysis.

RESULTS

A total of 336 conduits were followed for a median of 3.0 years; transcatheter (n = 30) or surgical (n = 35) reintervention was performed on 64 conduits. Estimated freedom from reintervention and surgical replacement was 84% and 90% at 5 years. Younger age and smaller absolute conduit size were associated with earlier reintervention, but conduit Z-score (median 3.5) was not associated with outcome.

CONCLUSIONS

The programmatic use of oversized aortic homograft RV-PA conduits in the surgical repair of MAPCAs provides a focused experience that demonstrates similar longevity to reported best alternatives. Secondarily, conduit oversizing may improve durability and enables an increased likelihood of nonoperative reintervention.

Outcomes in Patients with Alagille Syndrome and Complex Pulmonary Artery Disease

OBJECTIVE

To assess outcomes in a large cohort of patients with Alagille syndrome (ALGS) who underwent pulmonary artery reconstruction surgery for complex pulmonary artery disease.

STUDY DESIGN

Patients with ALGS who underwent pulmonary artery reconstruction surgery at Lucile Packard Children's Hospital Stanford were reviewed. Patients were examined as an overall cohort and based on the primary cardiovascular diagnosis: severe isolated branch pulmonary artery stenosis, tetralogy of Fallot (TOF) without major aortopulmonary collateral arteries (MAPCAs), or TOF with MAPCAs.

RESULTS

Fifty-one patients with ALGS underwent pulmonary artery surgery at our center, including 22 with severe branch pulmonary artery stenosis, 9 with TOF without MAPCAs, and 20 with TOF and MAPCAs. Forty-one patients (80%) achieved a complete repair. Five of the patients with TOF with MAPCAs (25%) underwent complete repair at the first surgery, compared with 8 (89%) with TOF without MAPCAs and 19 (86%) with isolated branch pulmonary artery stenosis. At a median follow-up of 1.7 years after the first surgery, 39 patients (76%) were alive, 36 with a complete repair and a median pulmonary artery:aortic systolic pressure of 0.38. Nine patients (18%), including 8 with isolated branch pulmonary artery stenosis, underwent liver transplantation.

CONCLUSIONS

Most patients with ALGS and complex pulmonary artery disease can undergo complete repair with low postoperative right ventricular pressure. Patients with TOF/MAPCAs had the worst outcomes, with higher mortality and more frequent pulmonary artery interventions compared with patients with TOF without MAPCAs or isolated branch pulmonary artery stenosis. Complex pulmonary artery disease is not a contraindication to liver transplantation in patients with ALGS.

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.

Unifocalization and pulmonary artery reconstruction in patients with tetralogy of Fallot and major aortopulmonary collateral arteries who underwent surgery before referral

OBJECTIVE

The study objective was to characterize and analyze outcomes in patients with tetralogy of Fallot and major aortopulmonary collateral arteries who had undergone surgery elsewhere before referral (prereferral surgery).

METHODS

Patients with tetralogy of Fallot and major aortopulmonary collateral arteries who underwent surgery between 2001 and 2019 at our center were reviewed. Prereferral surgery and unoperated patients were compared, as were subsets of prereferral surgery patients who had undergone different types of prior procedures. Primary outcomes included complete repair with survival to 6 months, death, and perioperative metrics.

RESULTS

Of 576 patients studied, 200 (35%) had undergone a wide range and number of prior operations elsewhere, including 92 who had pulmonary blood supply through a shunt and 108 who had a right ventricle pulmonary artery connection. Patients who underwent prereferral surgery with an existing right ventricle pulmonary artery connection had undergone more prereferral surgery procedures than those with a shunt and were more likely to have a right ventricle outflow tract pseudoaneurysm or pulmonary artery stent (all P < .001) at the time of referral. The cumulative incidences of complete repair and death were similar regardless of prereferral surgery status, but the cumulative incidence of complete repair with 6-month survival was higher (P = .002) and of death lower (P = .18) in patients who had prior right ventricle pulmonary artery connection compared with those who had received a prior shunt only.

CONCLUSIONS

Our comprehensive management strategy for tetralogy of Fallot and major aortopulmonary collateral arteries can be applied with excellent procedural results in both unoperated patients and those who have undergone multiple and varied procedures elsewhere.

Major aortopulmonary collateral arteries in a case of unrepaired tricuspid and pulmonary atresia with single ventricle physiology

Tricuspid and pulmonary atresia with single ventricle physiology and major aortopulmonary collateral arteries (MAPCAs) is a complex cyanotic congenital heart disease with heterogeneous pulmonary artery morphology and arborization. The complex anatomy and physiology, coupled with a dearth of existing literature, pose imitable challenges to treatment. Although the exact surgical algorithm is still unclear, the goal is a well-developed, low-resistance pulmonary vascular bed. A precise understanding of the blood supply to each lung is a requisite for successful surgery, and a multimodality and multidisciplinary approach is compulsory. Herein, we describe a case of tricuspid and pulmonary atresia with single ventricle, MAPCAs and aortopulmonary collateral arteries.

Imaging of Pulmonary Atresia With Ventricular Septal Defect

The aim of this article was to review computed tomography angiography and magnetic resonance angiography of pulmonary atresia with ventricular septal defect. This disorder is a rare complex congenital heart disease. Preoperative imaging of pulmonary atresia with ventricular septal defect with computed tomography angiography and magnetic resonance angiography is important for complete anatomical delineation and planning for treatment. Preoperative imaging used for assessment of the main pulmonary artery (its size, valve, and confluence), aortopulmonary collaterals (its origin, insertion, course, and size), presence of patent ductus arteriosus, other sources of collaterals as bronchial and coronary arteries, and pattern of pulmonary arborization. Imaging can detect associated aortic, pulmonary venous and coronary anomalies, and other congenital heart disease. Postoperative imaging after unifocalization and stent is for assessment of patency, stenosis, and occlusion of stent or perivascular lesions as seroma.