Major Aortopulmonary Collateral Arteries With Anatomy Other Than Pulmonary Atresia/Ventricular Septal Defect

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.

Pulmonary Artery Hypoplasia in Neonates With Tetralogy of Fallot

BACKGROUND

Neonates with symptomatic tetralogy of Fallot (sTOF) with hypoplastic pulmonary arteries (hPA) are considered high risk. Data are needed to inform the impact of hPA on outcomes, and the ideal management strategy.

OBJECTIVES

The objectives of this study were to quantify the impact of hPA on outcomes in neonates with sTOF and measure the impact of strategy on pulmonary artery (PA) growth in this population.

METHODS

Neonates with sTOF from 2005 to 2017 were reviewed from the Congenital Cardiac Research Collaborative. Criteria for hPA included a unilateral PA z score <-2.0 and contralateral PA z score <0. Primary outcome was mortality. Secondary outcomes included reintervention and PA growth.

RESULTS

We included 542 neonates with sTOF, including 188 (35%) with hPA and 354 (65%) with normal PA, with median follow-up of 4.1 years. Median right and left hPA z scores were -2.19 (25th-75th percentile: -2.55 to -1.94) and -2.23 (25th-75th percentile: -2.64 to -1.91), respectively. Staged repair (vs primary TOF repair) was less common in the hPA cohort (36 vs 44%; P = 0.07). Survival was similar between groups (unadjusted P = 0.16; adjusted P = 0.25). Reintervention was more common in the hPA group (HR: 1.28; 95% CI: 1.01-1.63; P = 0.044); there was no difference after definitive repair (HR: 1.21; 95% CI: 0.93-1.58; P = 0.16). PA growth at 1 year was greater in the hPA cohort, particularly for the right PA (P < 0.001).

CONCLUSIONS

Despite perception, the presence of hPA in neonates with sTOF conferred no increase in overall hazard of mortality or reintervention after definitive repair. PA growth was superior in the hPA cohort. These findings suggest that the presence of hPA does not adversely impact outcomes in sTOF.

Major aortopulmonary collateral arteries in association with atrioventricular septal defect with balanced ventricles and trisomy 21

A major aortopulmonary collateral artery is a rare and easily missed diagnosis that is usually associated with Tetralogy of Fallot or pulmonary atresia. We present two cases of major aortopulmonary collaterals associated with trisomy 21 and atrioventricular septal defect with balanced ventricles in which the diagnosis went undetected until after initial cardiac repair.

The Case of a 44-Year-Old Survivor of Unrepaired Tetralogy of Fallot, Right Aortic Arch and Abdominal Aortopulmonary Collateral Vessels

The most common congenital cyanotic heart disease is described in the literature as the Tetralogy of Fallot. This abnormality is characterized by the presence of ventricular septal defect (VSD), obstruction of the right ventricular (RV) outflow tract, right ventricular hypertrophy, and overriding aorta. In patients with pulmonary atresia with ventricular septal defect (PA/VSD), major aortopulmonary collateral arteries (MAPCA) are common; however, although some of them do not have PA/VSD, they do have other particular anatomical variants. The case we are presenting in this article is a rare mild symptomatic adult noncorrected TOF, with preserved RV function, right aortic arch, and MAPCAs (“classic” thoracic MAPCAs but also abdominal MAPCAs). The anatomy of a complex congenital defect is well illustrated by cardiac magnetic resonance (CMR) and computer tomography angiography (CTA), and these imaging techniques are mostly used to understand the relative clinical “silence” TOF. Imaging scans thus play a key role in the evaluation of these patients, being very important to know the indications and limitations of each method, but also to learn to combine them with each other depending on the clinical picture of the patient’s presentation. Additionally, the close collaboration between clinicians and imagers is essential for a correct, complete and detailed preoperative evaluation, being subsequently essential for cardiovascular surgeons, the whole team thus deciding the best therapeutic management.

Major Aortopulmonary Collateral Arteries

Major aortopulmonary collateral arteries (MAPCAs) are congenital vessels that arise from the aorta or its first-order branches and are distally connected to the pulmonary arterial vasculature, thereby providing pulmonary blood flow. MAPCAs are commonly associated with several congenital heart diseases that have compromised pulmonary circulation due to severe stenosis involving pulmonary valves or arteries or due to pulmonary atresia. Embryologically, MAPCAs are presumed to be persistent segmental arteries. MAPCAs can be imaged with CT and MRI, and such imaging findings are important for surgeons and interventionists. The management options for MAPCAs include unifocalization, surgical ligation, and endovascular interventions, such as coil embolization. This review highlights the role of reporting certain critical features of MAPCAs at CT and MRI, which will help to facilitate management decisions for systemic-to-pulmonary collateral vessels observed in patients with congenital heart disease. Keywords: Pediatrics, CT Angiography, Image Postprocessing, Interventional-Vascular, MR Angiography, Embolization, Stents, Cardiac, Vascular, Aorta © RSNA, 2022.

Large aortopulmonary collateral artery exclusively supplying the lower lobe of left lung in an infant with common arterial trunk with aortic dominance with confluent pulmonary arteries

INTRODUCTION

Common arterial trunk with aortic dominance has well-developed bilateral pulmonary arterial arborization without any essential major aortopulmonary collateral arteries (MAPCAs), whereas "solitary" arterial trunk is characterized by collateral arterial supply to all bronchopulmonary segments and absent pulmonary arteries.

CASE REPORT

We report a term female neonate with common arterial trunk with aortic dominance with confluent pulmonary arteries with a large MAPCA as the sole blood supply to the lower lobe of the left lung.

RESULTS

Initial diagnostic workup missed this MAPCA from the descending thoracic aorta. It was suspected during surgery due to massive left atrial return and confirmed by cardiac catheterization study in the early postoperative period and treated successfully by unifocalization.

DISCUSSION

A large essential MAPCA supplying an entire lobe in the common arterial trunk with aortic dominance has not been described. It can present as heart failure and inability to wean off the ventilator in the early postoperative period following intracardiac repair.

CONCLUSION

This is a case hitherto undescribed and possibly falling outside the well-entrenched classifications of the common arterial trunk and a large MAPCA could be an addition to the list of lesion modifiers. Our experience with this case underlines the importance of a thorough and open-minded approach to the initial imaging assessment of even well-described conditions.

Risk analysis for patients with a functionally univentricular heart after systemic-to-pulmonary shunt placement

OBJECTIVES

To investigate risk factors for mortality after systemic-to-pulmonary (SP) shunt procedures in patients with a functionally univentricular heart using the Japan Cardiovascular Surgery Database registry.

METHODS

Clinical data from 75 domestic institutions were collected. Overall, 812 patients with a functionally univentricular heart who underwent initial SP shunt palliation were eligible for analysis. Patients with pulmonary atresia with an intact ventricular septum and patients with a SP shunt as part of the Norwood procedure were excluded. Risk factors for 30- and 90-day mortalities were analysed using a logistic regression model.

RESULTS

Median age and body weight at SP shunt placement were 41 days and 3.6 kg, respectively. Modified Blalock-Taussig shunt, central shunt and other types of SP shunts were applied in 689 (84.9%), 94 (11.8%) and 30 (3.7%) patients, respectively. Cardiopulmonary bypass was utilized in 410 patients (51%) for 128 min (median, 19-561). There were 411 isolated SP shunt procedures. Median hospital stay was 27 days, and 742 (91.4%) patients were discharged. The 30- and 90-day mortality rates were 3.4% and 6.0%, respectively. Placement of a central shunt was identified as a risk factor for 30-day mortality, while lower body weight, preoperative ventilator support, right atrial isomerism and coexistence of major aortopulmonary collateral arteries and an unbalanced atrioventricular septal defect were identified as risk factors for 90-day mortality.

CONCLUSIONS

SP shunt carries a high mortality rate in patients with a functionally univentricular heart when it is performed in smaller patients with complex cardiac anomalies.

Aortopulmonary collateral arteries in non-cyanotic congenital heart disease

Development of major aortopulmonary collateral arteries (MAPCAs) are strongly associated with cyanotic congenital heart disease. However, MAPCAs have rarely been reported in non-cyanotic congenital heart disease. We report on a rare case of a newborn originally diagnosed with an atrial septal defect, a ventricular septal defect, and pulmonary arterial hypertension, who underwent complete repair. Failure to progress postoperatively, lead to the delayed diagnosis of aortopulmonary collateral arteries (APC's). Percutaneous embolization and surgical ligation of APC's resulted in rapid recovery.

To Unifocalize or Not to Unifocalize?: A Comparison of Retroesophageal Versus Anterior Collaterals

BACKGROUND

The anatomy of major aortopulmonary collateral arteries (MAPCAs) can be highly variable with regard to number, anatomic origin, course, and relationship to the native pulmonary arteries. Some MAPCAs travel behind the esophagus (retroesophageal) and bronchus before entering the lung parenchyma. This study compared the physiologic and surgical characteristics of retroesophageal vs anterior located MAPCAs.

METHODS

This was a retrospective review of 42 patients who had 1 (n = 36) or 2 (n = 6) retroesophageal MAPCAs. These MAPCAs were then characterized as (1) single supply, meaning no connection to the pulmonary arteries; (2) dual supply, but inadequate connection to the distal pulmonary vascular bed; and (3) dual supply with adequate connection.

RESULTS

The 42 patients presented with 187 MAPCAs, or 4.5 MAPCAs per patient. Of these, 48 MAPCAs were retroesophageal, including 40 that were single supply, 6 were dual supply with inadequate connection, and 2 had dual supply with adequate connection. On the basis of this anatomy and physiology, 96% of retroesophageal MAPCAs were unifocalized. For the 139 anterior MAPCAs, 89 were single supply, 15 were dual supply with inadequate connection, and 35 were dual supply with adequate connection; thus, 75% of anterior MAPCAs were unifocalized (P < .01 compared with retroesophageal MAPCAs).

CONCLUSIONS

The data demonstrate that retroesophageal MAPCAs had very different anatomy and physiology compared with anterior MAPCAs. These results suggest that nearly every retroesophageal MAPCA should be unifocalized to incorporate the lung segments supplied.

Three-Dimensional Printing, Virtual Reality and Mixed Reality for Pulmonary Atresia: Early Surgical Outcomes Evaluation

BACKGROUND

Single-stage unifocalisation for pulmonary atresia (PA) with ventricular septal defect (VSD) and major aortopulmonary collateral arteries (MAPCA) requires a high degree of three-dimensional (3D) anatomical imagination. A previous study has reported the application of a 3D-printed heart model with virtual reality (VR) or mixed reality (MR). However, few studies have evaluated the surgical outcomes of the 3D model with VR or MR in PA/VSD patients.

METHODS

Three-dimensional (3D) heart models of five selected PA/VSD patients were derived from traditional imageology of their hearts. Using VR glasses, the 3D models were also visualised in the operating room. Both the 3D-printed heart models and preoperative evaluation by VR were used in the five selected patients for surgical simulation and better anatomical understanding. Mixed reality holograms were used as perioperative assistive tools. Surgical outcomes were assessed, including in-hospital and early follow-up clinical data.

RESULTS

The use of these three new technologies had favourable feedback from the surgeons on intraoperative judgment. There were no in-hospital or early deaths. No reintervention was required until the last follow-up. Three (3) patients developed postoperative complications: one had right bundle branch block and ST-segment change, one had chest drainage >7 days (>40 mL/day) and one had pneumonia.

CONCLUSION

The preoperative application of a 3D-printed heart model with VR or MR helped in aligning the surgical field. These technologies improved the understanding of complicated cardiac anatomy and achieved acceptable surgical outcomes as guiding surgical planning.

Intraoperative Flow Study Predicted the Postoperative Pulmonary Artery Pressure in the Bidirectional Glenn Operation

Background:

The aim of this study was to evaluate the predictability of postoperative pulmonary artery pressure (PAP) using intraoperative flow study in patients undergoing bidirectional Glenn operation.

Methods:

Patients who underwent Glenn operation under cardiopulmonary bypass (CPB) were included in the study. During the operation, after the completion of additional procedures under CPB, an intraoperative flow study was performed prior to Glenn anastomosis. After the completion of bidirectional Glenn, the patient was separated from the CPB and PAP was measured. The relationship between this pressure and flow study measurement was analyzed.

Results:

Nine patients who underwent bidirectional Glenn operation with additional procedures under CPB between July 2018 and January 2019 were included in the study. The median PAP was 9 mm Hg (interquartile range [IQR]: 7-10 mm Hg) in the flow study and 10 mm Hg (IQR: 8-11 mm Hg) after CPB, and the median difference between these pressures was 1 mm Hg (IQR: 1-3 mm Hg). There was a strong correlation between these two measurements ( r = 0.732; P = .025).

Conclusion:

The results of this study show that PAP after the Glenn procedure can be estimated using an intraoperative flow study. We believe that this method may be useful in intraoperative decision-making for Glenn operation in single ventricular patients who require extensive pulmonary artery (PA) reconstruction due to limited PA development, branch PA stenosis, or nonconfluent PAs. Also, this method can be used as a sort of intraoperative pulmonary resistance reversibility study in patients with high preoperative pulmonary vascular resistance due to surgically correctable pulmonary venous hypertension.

Long-term outcomes in adults with repaired tetralogy of Fallot and pulmonary atresia

BACKGROUND

There are limited outcome data in adults with tetralogy of Fallot and pulmonary atresia. The purpose of this study was to describe re-operations and all-cause mortality in adults with tetralogy of Fallot and pulmonary atresia.

METHODS

Retrospective review of adults with repaired tetralogy of Fallot and pulmonary atresia who received care at the Mayo Adult Congenital Heart Disease Clinic, 1990-2016. All-cause mortality was calculated as events per 100 patient-years from the time of first presentation to the Adult Congenital Heart Disease Clinic.

RESULTS

Of the 221 patients, the age at initial tetralogy of Fallot repair was 6 (5-13) years, and the age at first presentation to the clinic was 27 - 8 years. All patients had at least one right ventricular to pulmonary artery conduit re-operation. There were 31 deaths (14%) at mean age of 41 - 14 years. The causes of death were end-stage heart failure (n = 17), sudden cardiac death (n=9), post-operative death after cardiac surgery (n = 2), sepsis with multi-system organ failure (n = 2), and unknown (n = 1). All-cause mortality rate was 1.7 per 100 patient-years. The risk factors for all-cause mortality were older age (>12 years) at the time of repair (hazard ratio 1.41, 95 confidence interval 1.06-2.02, p = 0.033), non-sustained ventricular tachycardia (hazard ratio 1.36, 95 confidence interval 1.17-2.47, p = 0.015), and left ventricular ejection fraction <50% (hazard ratio 1.39, 95 confidence interval 1.08-2.31, p = 0.031).

CONCLUSION

Based on a review of 221 adults with repaired tetralogy of Fallot and pulmonary atresia, all patients had re-operations and all-cause mortality rate was 1.7 events per 100 patient-years. The current study provides important outcomes data for risk stratification in adults with tetralogy of Fallot and pulmonary atresia.