Pulmonary Artery Anatomy Research Articles

The Importance of Topographical Recognition of Pulmonary Arteries in Diagnostics and Treatment of CTEPH, Based on an Analysis of a Dissected Case Model-A Pilot Study.

Knowledge of the anatomy of pulmonary arteries is essential in many invasive procedures concerning pulmonary circulation. In the diagnosis and treatment of chronic thromboembolic pulmonary hypertension (CTEPH), two-dimensional (2D) pulmonary angiography is used. Recognizing the topographic course of the pulmonary arteries and understanding the status in three dimensions (3D) is paramount. This study aimed to evaluate and describe the branching variant of pulmonary arteries in a single case, as well as morphological parameters of the segmental arteries, like length, diameter and branching angles. One pair of embalmed human cadaver lungs was dissected by a scalpel and surgical forceps and was measured up to the subsegmental arteries. The diameters (ranging from 3.04 to 9.29 mm) and lengths (ranging from 9.09 to 53.91 mm) of the pulmonary segmental arteries varied. The proximal branching angles were wide and close to perpendicular, while distally, the angles between the segmental and subsegmental arteries were narrower (30-45°). Upon evaluating the branching, rare variations were identified and delineated, notably in the lower lobes of both lungs. Utilizing knowledge and data in clinical settings is instrumental for effectively diagnosing and treating CTEPH. Further research is required to explore the complications in invasive procedures related to various anatomical variations.

Pulmonary Arterial Anatomical Patterns: A Classification Scheme Based on Lobectomy and 3D-CTBA.

Preoperative evaluation of pulmonary vascular and tracheal routes and variations is of great importance to the surgeon. Three-dimensional computed tomography bronchography and angiography (3D-CTBA) has evolved in recent years with the optimization of 3D reconstruction techniques and artificial intelligence. We aim to apply CT angiography and Exoview 3D reconstruction technology to assess patients' pulmonary arterial tree and its anatomical variants and to try to summarize a set of anatomical typing of the pulmonary arterial tree that is relatively easy and conducive to promoting teaching based on surgical habits of lobectomy. A total of 358 patients hospitalized in the Department of Thoracic Surgery of the First Affiliated Hospital of Soochow University between July 2020 and August 2021 were included in this study. We carefully analyzed the site of emanation, alignment, and number of branches of the pulmonary artery according to a uniform classification method in conjunction with the two-dimensional CT images and transformed them into 3D reconstruction models. Different types of pulmonary artery were observed in 358 cases. We evaluated the complete pulmonary artery tree and counted the number and frequency of major arteries of the pulmonary based on the surgical habits of anatomical lobectomy. The 3D-CTBA technique enables us to adequately assess the anatomy of the pulmonary arteries. Moreover, we provide a practical classification scheme of pulmonary arterial anatomical patterns based on lobectomy and 3D-CTBA. Our data can be used by clinicians in the teaching of pulmonary artery anatomy and the preoperative preparation for anatomical lobectomy.

Bridge to transplant in single-ventricle anatomy: subpulmonary support with EXCOR ventricular assist device associated with pulmonary artery reconstruction.

Patients with a single ventricle circulation continue to be a challenge for a heart transplant. The patients in this cohort, often in poor clinical condition with frequent hepatic and renal impairment having undergone previous multiple surgical procedures, are often allosensitive and consequently have an increased risk of post-transplant complications. Although the most recently published series results are improved, this group of patients, with preserved ventricular function, continues to have a higher mortality rate. Moreover, the operation can be complicated by anatomical differences among the pulmonary arteries. This case report presents a child with tricuspid atresia and pulmonary vascular resistance contraindicating Fontan surgery, unfavourable anatomy of the central pulmonary arteries and in poor clinical condition. An EXCOR ventricular assist device (Berlin Heart) was used for sub- pulmonary mechanical circulatory support and pulmonary bifurcation reconstruction, as a bridge to a transplant.

Anatomical characterization of pulmonary artery and implications to pulmonary artery pressure monitor implantation

In patients with heart failure, guideline directed medical therapy improves outcomes and requires close patient monitoring. Pulmonary artery pressure monitors permit remote assessment of cardiopulmonary haemodynamics and facilitate early intervention that has been shown to decrease heart failure hospitalization. Pressure sensors implanted in the pulmonary vasculature are stabilized through passive or active interaction with the anatomy and communicate with an external reader to relay invasively measured pressure by radiofrequency. A body mass index > 35 kg/m2 and chest circumference > 165 cm prevent use due to poor communication. Pulmonary vasculature anatomy is variable between patients and the pulmonary artery size, angulation of vessels and depth of sensor location from the chest wall in heart failure patients who may be candidates for pressure sensors remains largely unexamined. The present study analyses the size, angulation, and depth of the pulmonary artery at the position of implantation of two pulmonary artery pressure sensors: the CardioMEMS sensor typically implanted in the left pulmonary artery and the Cordella sensor implanted in the right pulmonary artery. Thirty-four computed tomography pulmonary angiograms from patients with heart failure were analysed using the MIMICS software. Distance from the bifurcation of the pulmonary artery to the implant site was shorter for the right pulmonary artery (4.55 ± 0.64 cm vs. 7.4 ± 1.3 cm) and vessel diameter at the implant site was larger (17.15 ± 2.87 mm vs. 11.83 ± 2.30 mm). Link distance (length of the communication path between sensor and reader) was shorter for the left pulmonary artery (9.40 ± 1.43 mm vs. 12.54 ± 1.37 mm). Therefore, the detailed analysis of pulmonary arterial anatomy using computed tomography pulmonary angiograms may alter the choice of implant location to reduce the risk of sensor migration and improve readability by minimizing sensor-to-reader link distance.

Clarifying the Pulmonary Arterial Morphology and Pulmonary Blood Supply in Patients with Tetralogy of Fallot and Pulmonary Atresia on Computed Tomography Angiography

Aim. The present study sought to characterize the pulmonary arterial morphology and pulmonary blood supply in patients of tetralogy of Fallot and pulmonary atresia (TOF-PA) on CT angiography. Materials and Methods. We retrospectively reviewed our departmental database to identify patients with TOF-PA evaluated using CT angiography. The images were analysed to detect the presence of main and branch pulmonary arteries and pulmonary arterial confluence, presence of major aortopulmonary collateral arteries (MAPCAs), laterality and relation with pulmonary arterial morphology, and presence of patent arterial duct and associated intra- and extracardiac anomalies. Results. TOF-PA was identified in 177 patients (114 (64.4%) males; median age: 9 months). Pulmonary arteries were confluent in 142/177 (80.2%) patients. According to Somerville classification, type II pulmonary atresia was the most frequent pattern seen in 127/177 (71.8%). Based on McGoon’s ratio, pulmonary arteries were adequate for surgery in 123/177 (69.5%) patients. Patent arterial duct was present in 84/177 (47.5%) patients while MAPCAs were present in 124 (70.1%) patients, of which 72/124 (58.1%) patients had at least 1 essential MAPCA supplying either lung. According to Congenital Heart Surgeons’ Society classification, type B pulmonary arterial anatomy was the most prevalent, seen in 103/177 (57.6%) patients. Conclusion. TOF-PA is associated with marked morphologic variability in the pulmonary arterial arborization to supply the lungs. Cardiac CT angiography can accurately delineate the pulmonary arterial morphology, sources of pulmonary blood supply, and associated cardiovascular anomalies in patients with TOF-PA which aids in planning appropriate surgical management including decisions regarding the need for unifocalization of MAPCAs.

Three-dimensional/four-dimensional spatiotemporal image correlation morphology of the ductus arteriosus in fetuses with pulmonary atresia undergoing neonatal ductal stenting.

The value of prenatal identification of morphology of ductus arteriosus in fetuses with congenital heart defects (CHD) with pulmonary atresia and duct-dependent pulmonary circulation (DDPC) in planning neonatal ductal stenting procedure is untested. The aim of the study is to analyze the utility of three-dimensional/four-dimensional (3D/4D) spatiotemporal image correlation (STIC) fetal echocardiography in delineating the morphology of ductus arteriosus in fetuses with DDPC undergoing neonatal ductal stenting. In this retrospective study (2017-22), prenatal imaging of pulmonary artery (PA) anatomy, aortic arch sidedness, and morphology of ductus arteriosus (ductal origin was classified as vertical/horizontal and ductal course as tortuous/straight) was done using 3D/4D STIC imaging and volume datasets. Prenatal findings were correlated with angiographic findings during stenting and the degree of agreement was calculated. We included 27 fetuses with a prenatal diagnosis of CHD with DDPC who underwent neonatal ductal stenting. The accuracy of prenatal assessment of PA anatomy, branch PA stenosis, and arch sidedness was 100%, 92.6%, and 88.9%, respectively. The accuracy of prenatal assessment of ductal origin and course, compared with angiography, was 85.2% and 88.9%, respectively. Prenatal imaging had a diagnostic accuracy of 100% for vertical straight and horizontal tortuous ducts, 84.6% for vertical tortuous, and 67% for horizontal straight ducts. Duct stenting was successful in 25 (92.6%) babies; two died after the procedure from stent occlusion. Fetal echocardiography using 3D/4D STIC imaging enables accurate delineation of the morphology of ductus arteriosus in fetuses with DDPC, thereby aiding parental counseling and planning neonatal ductal stenting.

Feasibility of an Animal Model for Cavopulmonary Support With a Double-Outflow Pump.

Both single- and double-outflow cavopulmonary assist devices (CPADs) were recently proposed for the Fontan population, whereas single-outflow configurations were evaluated in large animal trials and double-outflow concepts are lacking an equivalent in vivo assessment. The aim of this study was to test the hemodynamic properties of a double-outflow CPAD device in an acute sheep model. The two inflow cannulae of a CPAD were anastomosed to the caval veins. Outflow graft connection was performed via end-to-side anastomosis to the right (RPA) and main pulmonary artery (MPA). Speed ramp protocols were conducted, and hemodynamic effects were monitored in terms of caval flows, cardiac output (CO), central venous pressure (CVP), pulmonary artery pressure (PAP), and left atrial pressure (LAP). Six experiments were conducted (53.35 ± 5.1 kg). In three experiments, the animal model was established, the CPAD was examined, and restoration of biventricular equivalency in terms of venous return was achieved. Venous pressures (CVP) declined linearly with increasing pump speed (r > 0.879), whereas caval flow (r > 0.973), CO (r > 0.993), PAP (r > 0.973), and LAP (r > 0.408) increased. Despite the considerable complexity of the sheep model caused by the sheep pulmonary arterial anatomy that requires substantial graft bending, the CPAD was evaluated in three acute experiments and showed the potential to completely substitute a subpulmonary ventricle.

Ductus arteriosus morphology in duct-dependent pulmonary circulation: CT classification and pattern in different ventricular morphology.

The objective was to study the ductus arteriosus morphology in duct-dependent pulmonary circulation and its pattern in different ventricle morphology using CT angiography. From January 2013 to December 2015, patients aged 6 months and below with duct-dependent pulmonary circulation underwent CT angiography to delineate the ductus arteriosus origin, tortuosity, site of insertion, and pulmonary artery anatomy. The ductus arteriosus were classified into type I, IIa, IIb, and III based on its site of origin, either from descending aorta, distal arch, proximal arch, or subclavian artery, respectively. A total of 114 patients and 116 ductus arteriosus (two had bilateral ductus arteriosus) were analysed. Type I, IIa, IIb, and III ductus arteriosus were seen in 13 (11.2 %), 71 (61.2%), 21 (18.1%), and 11 (9.5%), respectively. Tortuous ductus arteriosus was found in 38 (32.7%), which was commonly seen in single ventricular lesions. Ipsilateral and bilateral branch pulmonary artery stenosis was seen in 68 (59.6%) and 6 (5.3%) patients, respectively. The majority of patients with pulmonary atresia intact ventricular septum had type I (54.4%) and non-tortuous ductus arteriosus, while those with single and biventricular lesions had type II ductus arteriosus (84.9% and 89.7%, respectively). Type III ductus arteriosus was more common in biventricular lesions (77.8%). Ductus arteriosus in duct-dependent pulmonary circulation has a diverse morphology with a distinct origin and tortuosity pattern in different types of ventricular morphology. CT may serve as an important tool in case selection and pre-procedural planning for ductal stenting.

Dual phase multidetector computed tomography angiography in evaluation of pulmonary arteries and collateral vessels in children with cyanotic congenital heart diseases

BackgroundThe purpose of this paper is to compare the efficacy of dual-phase multidetector computed tomography angiography (CTA) with transthoracic echocardiogram (TTE) and cardiac catheterization angiography (CCA) in evaluation of pulmonary arteries and collateral vessels, major aortopulmonary collateral arteries (MAPCAs) in children with cyanotic congenital heart diseases. MethodsThe study was a prospective observational study where 32 pediatric patients (18 males, 14 females and age range 2–116 months) with cyanotic congenital heart diseases (CCHD) were included. All patients underwent TTE, CTA, and CCA. The findings of CTA in evaluation of pulmonary arteries and MAPCAs were compared with TTE and correlated with CCA findings. ResultsAll CTA studies were adequate except in one (3.1%) case in which main pulmonary artery and left pulmonary artery were not visualized on any of the three modalities. Right pulmonary artery anatomy was not clear or not demonstrated in four cases (12.6%) on CCA, whereas CTA was able to demonstrate pulmonary arteries in these cases. TTE was inadequate in 11 cases (34.3 %) in which one or more pulmonary artery was not clearly visualized. In cases with good pulmonary artery diameter (corresponding to Z score between 1 to 2) statistically significant (P < 0.001) correlation was found between pulmonary artery diameters, McGoon ratio, Nakata index, and Z-scores calculated for pulmonary arteries on all three modalities. There was concordance between CTA and CCA in assessment of MAPCAs and patent ductus arteriosus (PDA), whereas TTE failed to demonstrate MAPCAs in six cases (18.8%). ConclusionCTA was found to be superior to TTE and CCA for the assessment of pulmonary arteries and MAPCAs. CTA is also superior to TTE in the detection of extracardiac anomalies.

Reduction of Inter-Observer Variability Using MRI and CT Fusion in Delineating of Primary Tumor for Radiotherapy in Lung Cancer with Atelectasis

<h3>Purpose/Objective(s)</h3> To compare the difference between magnetic resonance imaging (MRI) and computed tomography (CT) in delineating the target area of lung cancer with atelectasis. Accurately identify the outline volume of the tumor and reduce the probability of normal tissue complications. <h3>Materials/Methods</h3> Retrospective analysis was performed on 15 patients with lung cancer accompanied by atelectasis. All patients were scanned with MRI and CT in the same supine position within one week. All positioning images were transferred to treatment planning systems. According to the anatomy of sternum, rib, vertebral body, pulmonary artery and tumor, each MRI sequence (T1WI, T1WI+C, T1WI+C Delay, T1WI+C 10 minutes, T2WI, DWI) was automatically registered with CT through the planning system, and the fusion stability was increased by manual correction. Five radiation oncologists with rich clinical experience delineate tumor boundary to obtain the gross tumor volume (GTV). The boundary between tumor and atelectasis was determined by referring to CT structure, coronal and sagittal MRI images when drawing CT-MRI fusion images. The target areas of CT and MRI images were sketched on the same day. Consistence index (CI) and dice coefficient (DC) were used to measure differences among observers. <h3>Results</h3> The differences of delineation mean volumes, CI and DC among CT and MRI were significant. Multiple comparisons were made between MRI sequences and CT. The mean volume of DWI, T2WI, T1WI + C 10 minutes sequence in the target area is significantly smaller than that on CT sequence, but the consistency is higher than that of CT sequences. <h3>Conclusion</h3> The recognition of atelectasis by MRI was better than that by CT, which could reduce inter-observer variability of primary tumor delineation in lung cancer with atelectasis. Among them, DWI, T2WI, T1WI+C 10 minutes may be a better choice to improve the GTV delineation of lung cancer patients with atelectasis. Abbreviations: CT: Computed tomography; GTV: Gross tumor volume; MRI: Magnetic resonance imaging; T1WI: WATER:BH AX LAVA-Flex; T1WI+C: WATER:BH AX LAVA-Flex-C; T1WI+C Delay: WATER:BH AX LAVA-Flex-C delay; T1WI+C 10 minutes: WATER:BH AX LAVA-Flex-C 10min; T2WI:RTr Ax T2 fs Propeller; CI: Consistence index; DC: Dice coefficient.

The angiographic study of right ventricular outflow tract and pulmonary artery anatomy in tetralogy of Fallot

Objective: The objective of the study is to determine various anatomic variations in the pulmonary vasculature and associated cardiac defects in patients with tetralogy of Fallot (TOF). Methods: This was a cross-sectional descriptive study conducted at Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore from January 2009 to December 2017. A total of 100 patients irrespective of age and gender, who were subjected to cardiac catheterization were enrolled in the study which included all age groups. Measurement of pulmonary valve annulus, main pulmonary artery, right pulmonary artery (RPA), left pulmonary artery (LPA), and descending aorta was taken and corresponding z scores were calculated. McGoon ratio and Nakata index were also calculated. Results: The age group in our study varied from 9 months to 49 years of age. Male-to-female gender ratio was 3:2. All patients had subvalvar (infundibular) stenosis and 82% of patients had stenosis at the valvar level. Seven patients had discrete stenosis, another seven patients had disconnection of RPA or LPA and six patients had supravalvar stenosis in the form of diffuse hypoplasia of one of the pulmonary arteries (PA). Significant communicating major aortopulmonary collaterals arteries (MAPCAs) were seen in 5% of patients and 16% of the patients had a persistent patent ductus arteriosus (PDA). Persistent left superior vena cava was present in 9 patients and 13% of the patients had coronary anomalies. Conclusion: Subvalvular stenosis, confluence of PA, discrete, disconnected, and diffuse stenosis of LPA and RPA were the most common PA abnormalities found in patients with TOF. Significant-associated cardiac lesions including communicating MAPCA, PDA, and coronary anomaly were more commonly observed in these patients.

Cardiac Transplantation of the Fontan Patient with a Prior Norwood Procedure

Single-ventricle palliation starting with a Norwood procedure which culminates in a failed Fontan palliation poses certain unique operative challenges for cardiac transplantation. In this manuscript, we describe some of these challenges and our particular approach in management. Single-ventricle palliation starting with a Norwood procedure which culminates in a failed Fontan palliation poses certain unique operative challenges for cardiac transplantation. In this manuscript, we describe some of these challenges and our particular approach in management. Commentary: Transplantation After Norwood Palliation: Proper Preparation Minimizes the RiskOperative Techniques in Thoracic and Cardiovascular SurgeryPreviewAs the population with a Fontan circulation continues to grow, there is an increasing rate of patients with Fontan failure being referred for heart transplantation.1 Importantly, there has been an increase in the proportion of patients with hypoplastic left heart syndrome surviving to achieve Fontan completion, and these patients represent the highest complexity for heart transplantation due to their aortic arch and pulmonary artery anatomy. The mortality rate for transplantation in patients with single ventricle palliation has been reported to be as high as 20-30%,2-4 and it is likely that many have been denied transplantation due to the perceived extremely high risk. Full-Text PDF

Right-to-Left Inverted Living-Donor Lobar Lung Transplantation

In standard bilateral living-donor lobar lung transplantation (LDLLT), right and left lower lobes donated by 2 healthy donors are implanted into a recipient after right and left pneumonectomies. Because only 2 lobes are implanted, the grafts may be too small for an adult recipient. To overcome size mismatch, we have developed a technique of right-to-left inverted LDLLT based upon the fact that the right lower lobe is generally larger than the left lower lobe. In right-to-left inverted LDLLT, 2 donors donate their right lower lobes. The right graft is implanted in the right side of the recipient. The left graft is inverted and implanted in the left side. This operation is indicated when total graft forced vital capacity (FVC) is less than 60% of the recipient's predicted FVC or when donor's left lower lobectomy is technically difficult due to interlobar pulmonary artery anatomy. In standard bilateral living-donor lobar lung transplantation (LDLLT), right and left lower lobes donated by 2 healthy donors are implanted into a recipient after right and left pneumonectomies. Because only 2 lobes are implanted, the grafts may be too small for an adult recipient. To overcome size mismatch, we have developed a technique of right-to-left inverted LDLLT based upon the fact that the right lower lobe is generally larger than the left lower lobe. In right-to-left inverted LDLLT, 2 donors donate their right lower lobes. The right graft is implanted in the right side of the recipient. The left graft is inverted and implanted in the left side. This operation is indicated when total graft forced vital capacity (FVC) is less than 60% of the recipient's predicted FVC or when donor's left lower lobectomy is technically difficult due to interlobar pulmonary artery anatomy.

Intrapulmonary artery septation for pulmonary artery growth in functionally univentricular hearts.

The pulmonary artery anatomy is one of the important determinants of Fontan completion and its outcomes in patients with functionally univentricular hearts. Despite several modifications to Fontan operation, unbalanced pulmonary arteries pose a significant challenge in this subset of patients. Intrapulmonary artery septation is a technique, developed to rehabilitate the unilateral hypoplastic pulmonary artery following various initial palliative procedures in functionally univentricular hearts. Literature is sparse on this technique. This article reviews the basic concepts and literature on intrapulmonary artery septation. We also describe our experience with modified intrapulmonary artery septation.

An unusual case of aortopulmonary window with crossed pulmonary arteries

We report a case of a 4-year-old boy with a distal type of aortopulmonary window with crossed arrangement of the pulmonary arteries. This case highlights the potential clinical implications of this variant pulmonary arterial anatomy in the setting of the aortopulmonary window and the role of computed tomography angiography in accurately defining vascular relationships in patients with complex congenital cardiac defects.

Congenital isolated absence of a single cusp of pulmonary valve.

A 25-year-old, previously asymptomatic female, presented to the outpatient clinic with episodic palpitations for past 6 months. She was acyanotic and showed no peripheral stigmata of infective endocarditis. Transthoracic echocardiography revealed dilated right ventricle with severe low-pressure pulmonary regurgitation. A cardiac computed tomography angiography performed for evaluation of pulmonary arterial circulation and intracardiac anatomy revealed isolated absence of posterior pulmonary cusp. The two other (right anterior and left anterior) cusps were normal and covered only part of the valve orifice, resulting in pulmonary insufficiency. The main pulmonary artery showed asymmetric dilatation. No other structural heart defects were noted.

3D Virtual Reality Imaging of Major Aortopulmonary Collateral Arteries: A Novel Diagnostic Modality.

BackgroundMajor aortopulmonary collateral arteries (MAPCAs), as seen in patients with pulmonary atresia, are arteries that supply blood from the aorta to the lungs and often require surgical intervention. To achieve complete repair in the least number of interventions, optimal imaging of the pulmonary arterial anatomy and MAPCAs is critical. 3D virtual reality (3D-VR) is a promising and upcoming new technology that could potentially ameliorate current imaging shortcomings.MethodsA retrospective, proof-of-concept study was performed of all operated patients with pulmonary atresia and MAPCAs at our center between 2010 and 2020 with a preoperative computed tomography (CT) scan. CT images were reviewed by two congenital cardiac surgeons in 3D-VR to determine additional value of VR for MAPCA imaging compared to conventional CT and for preoperative planning of MAPCA repair.Results3D-VR visualizations were reconstructed from CT scans of seven newborns where the enhanced topographic anatomy resulted in improved visualization of MAPCA. In addition, surgical planning was improved since new observations or different preoperative plans were apparent in 4 out of 7 cases. After the initial setup, VR software and hardware was reported to be easy and intuitive to use.ConclusionsThis study showed technical feasibility of 3D-VR reconstruction of children with immersive visualization of topographic anatomy in an easy-to-use format leading to an improved surgical planning of MAPCA surgery. Future prospective studies are required to investigate the clinical benefits in larger populations.

Heart transplantation for patients with single ventricle physiology.

BackgroundThere is a growing population of palliated and unpalliated single ventricle physiology patients for whom heart transplantation is the only treatment option available. There is a paucity of reports of heart transplantation in this challenging and growing subset of patients from our part of the world. The purpose of the article is to briefly review our experience in the subgroup and compare it with the available literature.MethodsThis was a single-institution retrospective observational study of 16 patients with single ventricle physiology who were transplanted between 2016 and 2019 and their outcomes. The study groups were divided into those with ventricular dysfunction (group 1), who fare substantially better than those with normal ventricular function (group 2) whose short-term outcomes were poorer. Worsening cyanosis, poor candidature for completion Fontan procedure due to severe atrioventricular valve regurgitation or pulmonary artery anatomy, protein-losing enteropathy, plastic bronchitis, and worsening systemic venous congestion are indications in those with normal ventricular function.ResultsPatients with ventricular dysfunction as the main indication had excellent early survival with no early mortality compared to 40% mortality in patients with normal ventricular function. Patients who survived to leave the hospital had however similar long-term outcomes. Two patients with protein-losing enteropathy resolved completely by one month. Normal ventricular function, pulmonary artery stenting, early Fontan failure (6 months), ascites, and need for desensitization were risk factors for early mortality. After the early acute phase of increased risk, the mortality risk plateaued off.ConclusionTransplantation in patients with single ventricle and ventricular dysfunction can be offered with a good early and late outcome. There is a need to have multi-institutional and multi-disciplinary collaboration along with work in basic sciences to better understand the effects of failed Fontan physiology with normal ventricular function.

UNILATERAL ABSENCE OF PULMONARY ARTERY COMPLICATED BY SEVERE PULMONARY HYPERTENSION: FAVORABLE RESPONSE TO PARENTERAL THERAPY

TOPIC: Pulmonary Vascular Disease TYPE: Fellow Case Reports INTRODUCTION: Unilateral absence of pulmonary artery (UAPA) is a rare disorder that can present as an isolated lesion or in association with other congenital heart defects. An important complication of UAPA is the development of pulmonary hypertension (PH). Herein, we discuss a patient with severe PH in the setting of congenital UAPA and highlight the hemodynamic response to combination vasodilator therapy that included parenteral treprostinil. CASE PRESENTATION: A 58-year-old female with a history of congenital left UAPA, left lung hypoplasia and severe PH presented for evaluation of repeated syncopal episodes on minimal exertion. Two years prior to presentation, RHC showed mPAP 56 mmHg, PAWP 11 mmHg, CO 3.63 L/min, CI 1.9 L/min/m2, and PVR 12.4 WU. The patient was receiving riociguat 2.5 mg po TID, ambrisentan 10 mg po daily, and selexipag 1600 mcg po BID. She was NYHA FC IV and required oxygen at 6 L/min via oxymizer. Upon presentation, she was severely hypoxic requiring HFNC at 50 L/min and fraction of inspired oxygen of 0.9. Evaluation revealed Pro-BNP of 6170 pg/ml and cardiac echo showed an EF of 45%, severe RV dilation with severe hypokinesis and RVSP of 100 mmHg. Chest CT with contrast showed absence of the left pulmonary artery, enlargement of the main and right pulmonary arteries without pulmonary embolism, hyperinflation of right lung, and hypoplasia of the left lung. PFTs showed TLC 64%, FEV1/FVC 86, FEV1 43%, FVC 39%, and DLco 23% of predicted. VQ scan showed marked decreased perfusion of the left lung, decreased ventilation of the anterior left lung with some patchy ventilation of the posterior aspect of the left lung, and normal right lung perfusion. Repeat RHC showed significant worsening of hemodynamics with mPAP of 76 mmHg and PVR of 28.6 WU. The patient was transitioned from selexipag to IV treprostinil with rapid titration to 40 ng/kg/min over a few days. There was improvement in her dyspnea and oxygenation with weaning of supplemental oxygen from HFNC to 6 L/min oxymizer. Pro-BNP trended down to 332 pg/ml and she had no recurrence of syncopal episodes. The patient was transitioned from IV to SQ treprostinil and further titration of SQ treprostinil was continued at home to 64 ng/kg/min. After 2 months, repeat echo showed improvement with an EF of 67%, moderate RV dilation with mild hypokinesis and RVSP 60 mmHg. Repeat RHC showed hemodynamic improvement with mPAP of 51 mmHg and PVR of 10.5 WU. DISCUSSION: Patients with UAPA and lung hypoplasia who develop PH pose a management dilemma as no treatment consensus exists. Therapeutic approaches should be based on severity of symptoms, pulmonary artery anatomy, associated cardiovascular anomalies, collateral circulation and hemodynamic parameters. CONCLUSIONS: Select patients with severe PH may benefit from a cautious trial of combination vasodilator therapy under close observation. REFERENCE #1: Kruzliak P, Syamasundar RP, Novak M, Pechanova O, Kovacova G. Unilateral absence of pulmonary artery: pathophysiology, symptoms, diagnosis and current treatment. Arch Cardiovasc Dis. 2013;106(8-9):448-454. doi:10.1016/j.acvd.2013.05.004 DISCLOSURES: Speaker/Speaker's Bureau relationship with United therapeutics Please note: $5001 - $20000 by Karim El-Kersh, source=Web Response, value=Honoraria Removed 04/21/2021 by Karim El-Kersh, source=Web Response Advisory Committee Member relationship with United therapeutics Please note: $1001 - $5000 by Karim El-Kersh, source=Web Response, value=Consulting fee Removed 04/21/2021 by Karim El-Kersh, source=Web Response Advisory Committee Member relationship with Actelion Please note: $5001 - $20000 by Karim El-Kersh, source=Web Response, value=Consulting fee Removed 04/21/2021 by Karim El-Kersh, source=Web Response Advisory Committee Member relationship with United Therapeutics Please note: Current Added 04/23/2021 by Karim El-Kersh, source=Web Response, value=Consulting fee Advisory Committee Member relationship with Actelion Please note: 2019 and 2020 Added 04/23/2021 by Karim El-Kersh, source=Web Response, value=Consulting fee Speaker/Speaker's Bureau relationship with United Therapeutics Please note: Current Added 04/29/2021 by Karim El-Kersh, source=Web Response, value=Honoraria Advisory Committee Member relationship with United Therapeutics Please note: Current Added 04/29/2021 by Karim El-Kersh, source=Web Response, value=Honoraria Advisory Committee Member relationship with Actelion Please note: 2019 and 2020 Added 04/29/2021 by Karim El-Kersh, source=Web Response, value=Honoraria Consultant relationship with Acceleron Pharma Please note: Current Added 04/29/2021 by Karim El-Kersh, source=Web Response, value=Consulting fee No relevant relationships by Meliha Hrustanovic-Kadic, source=Web Response

Reference Values for Ventricular Volumes and Pulmonary Artery Dimensions in Pediatric Patients with Transposition of the Great Arteries After Arterial Switch Operation.

Pulmonary artery (PA) anatomy in patients with transposition of the great arteries (TGA) after arterial switch operation (ASO) with Lecompte manoeuvre is different compared to healthy subjects, and stenoses of the PA are common. Magnetic resonance imaging (MRI) is an excellent imaging modality to assess PA anatomy in TGA patients. However, disease-specific reference values for PA size are scarce. To establish disease-specific reference ranges for PA dimensions and for biventricular volumes and mass. Retrospective. A total of 69 pediatric patients with TGA after ASO (median age 12.6 years; range 5-17.8 years; 13 females and 56 males). 3.0 T, steady-state free precession (SSFP) and gradient echo cine sequences and four-dimensional time-resolved magnetic resonance angiography with keyhole. Right and left PA (RPA, LPA) were each measured at three locations during its course around the aorta. Ventricular volumes, mass, and ejection fraction were measured from a stack of short axis cine images. The lambda-mu-sigma (LMS) method of Cole and Green, univariate and multivariate linear models, and t-test. Centile graphs and tables for PA dimensions, biventricular volumes, mass, and ejection fraction were created. Univariate linear analysis showed significant associations (P< 0.05) between body surface area (BSA), height, and weight with systolic MPA and RPA diameter. In multivariate linear analysis, only BSA remained a strong predictor for main PA and RPA diameters. For biventricular volumes, the univariate linear model revealed a strong influence of BSA, height, weight, and age (all P< 0.05). On multivariate linear analysis, only body height remained associated. Uni- and multivariate linear analyses showed a strong association between BSA and PA diameters, as well as between height and biventricular volumes, and therefore, centile tables and graphs are presented accordingly. Our data may improve MR image interpretation and may serve as a reference in future studies. 4 TECHNICAL EFFICACY STAGE: 2.