Pulmonary Vein Stenosis in Infants: A Systematic Review, Meta-Analysis, and Meta-Regression

Hybrid Interventions in Congenital Heart Disease: A Review of Current Practice and Rationale for Use

BACKGROUND

Hybrid interventions have become a common option in the management for a variety of patients with congenital heart disease. In this review, we discuss the data that have driven decision making about hybrid interventions to date.

METHODS

The existing literature on various hybrid approaches was reviewed and summarized. In addition, the key tenants to creating a successful hybrid program within a congenital heart center are elucidated.

RESULTS

Hybrid strategies for single-ventricle patients, pulmonary atresia with intact ventricular septum, branch pulmonary artery stenosis, and muscular ventricular septal defect closure have important benefits and limitations compared with traditional approaches.

CONCLUSION

A growing body of evidence supports the use of hybrid interventions in congenital heart disease. But important questions remain regarding improved survival and other long-term outcomes, such as neurocognition, that might impact widespread adoption as a primary treatment strategy.

Outcomes and Risk Factors of Interventions for Pediatric Post-operative Pulmonary Vein Stenosis

Pulmonary vein stenosis (PVS) in children is a challenging condition with poor outcomes. Post-operative stenosis can occur after repair of anomalous pulmonary venous return (APVR) or stenosis within native veins. There is limited data on the outcomes of post-operative PVS. Our objective was to review our experience and assess surgical and transcatheter outcomes. Single-center retrospective study was performed including patients < 18 years who developed restenosis after baseline pulmonary vein surgery that required additional intervention(s) from 1/2005 to 1/2020. Non-invasive imaging, catheterization and surgical data were reviewed. We identified 46 patients with post-operative PVS with 11 (23.9%) patient deaths. Median age at index procedure was 7.2 months (range 1 month-10 years), and median follow-up was 10.8 months (range 1 day-13 years). Index procedure was surgical in 36 (78.3%) and transcatheter in 10 (21.7%). Twenty-three (50%) patients developed vein atresia. Mortality was not associated with number of affected veins, vein atresia, or procedure type. Single ventricle physiology, complex congenital heart disease (CCHD), and genetic disorders were associated with mortality. Survival rate was higher in APVR patients (p = 0.03). Patients with three or more interventions had a higher survival rate compared to patients with 1-2 interventions (p = 0.02). Male gender, necrotizing enterocolitis, and diffuse hypoplasia were associated with vein atresia. In post-operative PVS, mortality is associated with CCHD, single ventricle physiology, and genetic disorders. Vein atresia is associated with male gender, necrotizing enterocolitis, and diffuse hypoplasia. Multiple repeated interventions may offer a patient survival benefit; however, larger prospective studies are necessary to elucidate this relationship further.

Pulmonary vein stenosis in heart transplant patients

BACKGROUND

Pulmonary vein stenosis (PVS) is a rare pediatric condition associated with significant mortality and morbidity. PVS in patients following heart transplant (HT) has not yet been described.

METHODS

Patients who had clinically significant PVS following a heart transplant during the time period of April 1, 2013 to April 30, 2023, at Seattle Children's Hospital were identified. Clinically significant PVS was defined as an atretic vein or a vein with a gradient of ≥4 mmHg across at least one vein by echocardiogram or during cardiac catheterization. Patients who had a diagnosis of PVS prior to their transplant were excluded. A total of six patients were identified. We collected clinical data on these patients from their pre-transplant course to their most recent status.

RESULTS

The median age at HT was 7.5 months (range 2-13 months). The median time from HT to diagnosis of PVS was 3.5 months (range 0.3-13 months). At the last follow-up, the patients had had two to five pulmonary vein interventions, and there were no mortalities. The donor-to-recipient weight and total cardiac volume (TCV) ratios were less than 2.0 in five of six of the patients.

CONCLUSIONS

PVS is a rare complication that is associated with patients who undergo HT during infancy. PVS develops soon after HT and screening should occur accordingly. Interestingly, high donor-to-recipient weight and TCV ratios are not necessarily associated with the development of PVS. Further work will need to be performed in order to determine the significance of PVS in post-HT patients.

Tracheostomy Timing During Pediatric Cardiac Intensive Care: Single Referral Center Retrospective Cohort

OBJECTIVES

To describe associations between the timing of tracheostomy and patient characteristics or outcomes in the cardiac ICU (CICU).

DESIGN

Single-institution retrospective cohort study.

SETTING

Freestanding academic children's hospital.

PATIENTS

CICU patients with tracheostomy placed between July 1, 2011, and July 1, 2020.

INTERVENTIONS

We compared patient characteristics and outcomes between early and late tracheostomy based on the duration of positive pressure ventilation (PPV) before tracheostomy placement, fitting a receiver operating characteristic curve for current survival to define a cutoff.

MEASUREMENTS AND MAIN RESULTS

Sixty-one patients underwent tracheostomy placement (0.5% of CICU admissions). Median age was 7.8 months. Eighteen patients (30%) had single ventricle physiology and 13 patients (21%) had pulmonary vein stenosis (PVS). Primary indications for tracheostomy were pulmonary/lower airway (41%), upper airway obstruction (UAO) (31%), cardiac (15%), neuromuscular (4%), or neurologic (4%). In-hospital mortality was 26% with 41% survival at the current follow-up (median 7.8 [interquartile range, IQR 2.6-30.0] mo). Late tracheostomy was defined as greater than or equal to 7 weeks of PPV which was equivalent to the median PPV duration pre-tracheostomy. Patients with late tracheostomy were more likely to be younger, have single ventricle physiology, and have greater respiratory severity. Patients with early tracheostomy were more likely to have UAO or genetic comorbidities. In multivariable analysis, late tracheostomy was associated with 4.2 times greater mortality (95% CI, 1.9-9.0). PVS was associated with higher mortality (adjusted hazard ratio [HR] 5.2; 95% CI, 2.5-10.9). UAO was associated with lower mortality (adjusted HR 0.2; 95% CI, 0.1-0.5). Late tracheostomy was also associated with greater cumulative opioid exposure.

CONCLUSIONS

CICU patients who underwent tracheostomy had high in-hospital and longer-term mortality rates. Tracheostomy timing decisions are influenced by indication, disease, genetic comorbidities, illness severity, and age. Earlier tracheostomy was associated with lower sedative use and improved adjusted survival. Tracheostomy placement is a complex decision demanding individualized consideration of risk-benefit profiles and thoughtful family counseling.

Echocardiographic characteristics and clinical outcomes in fetuses with pulmonary stenosis or pulmonary atresia with intact ventricular septum

OBJECTIVE

To summarize echocardiographic characteristics of the anatomy and hemodynamic and clinical outcomes in fetuses with isolated pulmonary stenosis (PS) or pulmonary atresia with intact ventricular septum (PA/IVS).

METHODS

This was a single-center retrospective study of fetuses with isolated PS or PA/IVS. Echocardiographic variables and clinical outcomes after delivery were evaluated and compared.

RESULTS

Between 2016 and 2021, 115 livebirths with isolated PS or PA/IVS were included. Proportion of fetuses with mild, moderate and critical PS and PA/IVS was 41.7 %, 18.3 %, 26.1 % and 13.9 %. Fetuses with more severe PS had worse anatomic and hemodynamic profiles. Specifically, the cardiothoracic ratio, pulmonary valve (PV) velocity, degree and velocity of tricuspid regurgitation increased as PS severity increased; and the pulmonary artery/aorta ratio, right ventricle/left ventricle long-axis (TV/MV) ratio, tricuspid valve/mitral valve annulus (TV/MV) ratio, and tricuspid valve inflow duration/cardiac cycle ratio decreased as PS severity increased (P <0.001 for all). PV velocity ≥2 m/s predicted PV pressure ≥40 mm Hg after delivery, with an AUC of 0.81; TV/MV ratio combined with RV/LV ratio predicted clinical outcomes, with an AUC of 0.88. Live births with more severe PS had higher mortality rate (mild 0 vs. moderate 0 vs. critical 11 % vs. PA-IVS 36 %) and lower rate of developing bi-ventricles (mild 100 % vs. moderate 95 % vs. critical 89 % vs. PA-IVS 36 %).

CONCLUSION

Findings of this study help better understand the anatomy and hemodynamic and clinical outcomes in fetuses with isolated PS or PA/IVS, which could have implications for prenatal counseling and prediction of fetal outcome.

Evaluation of paediatric pulmonary vein stenosis by cardiac CT angiography: a comparative study with transthoracic echocardiography and catheter angiogram

AIM

To compare prospective electrocardiogram (ECG)-gated cardiac computed tomographic angiography (CCTA) with transthoracic echocardiography (TTE) and cardiac catheter angiography (CCA) for paediatric pulmonary vein (PV) stenosis.

MATERIALS AND METHODS

Retrospective chart review was undertaken of all patients who underwent CCTA for PV evaluation over a 4-year period. Patient demographics, findings of CCTA, TTE, and CCA, as well as interventions performed, were recorded for each PV.

RESULTS

Thirty-five patients were included (23 male patients). All patients had a prior TTE with time interval between TTE and CCTA ranging from 0 to 90 days. CCTA detected 92 abnormalities in 32 patients. TTE missed 16 PV abnormalities (16/92, 17%), detected 37 abnormalities with certainty (37/92, 40%), and was suggestive in 39 abnormalities (39/92, 42%). CCTA was negative for PV abnormalities when TTE was positive or suspicious in three patients. Nineteen patients underwent CCA (18 patients with 52 abnormalities and one patient with normal PV), confirming CCTA findings. Thirty-nine were treated with angioplasty/stenting (39/52,75%). Failed recanalisation occurred in three PVs (3/52, 6%) and no intervention was attempted for the rest as the gradient was not significant (10/52,19%). Nine patients underwent surgical repair (26/92, 28%). Five patients (14/92, 15%) were managed with no intervention based on CCTA findings and poor clinical prognosis.

CONCLUSIONS

CCTA plays an important role in detecting paediatric PV stenosis and identifies additional findings compared to TTE that have direct surgical/interventional implications. CCTA complements TTE in imaging these patients and helps guide management.

Computed tomographic parenchymal lung findings in premature infants with pulmonary vein stenosis

BACKGROUND

Developmental pulmonary vein pulmonary vein stenosis in the setting of prematurity is a rare and poorly understood condition. Diagnosis can be challenging in the setting of chronic lung disease of prematurity. High-resolution non-contrast chest computed tomography (CT) is the conventional method of evaluating neonates for potential structural changes contributing to severe lung dysfunction and pulmonary hypertension but may miss pulmonary venous stenosis due to the absence of contrast and potential overlap in findings between developmental pulmonary vein pulmonary vein stenosis and lung disease of prematurity.

OBJECTIVE

To describe the parenchymal changes of pediatric patients with both prematurity and pulmonary vein stenosis, correlate them with venous disease and to describe the phenotypes associated with this disease.

MATERIALS AND METHODS

A 5-year retrospective review of chest CT angiography (CTA) imaging in patients with catheterization-confirmed pulmonary vein stenosis was performed to identify pediatric patients (< 18 years) who had a history of prematurity (< 35 weeks gestation). Demographic and clinical data associated with each patient were collected, and the patients' CTAs were re-reviewed to evaluate pulmonary veins and parenchyma. Patients with post-operative pulmonary vein stenosis and those with congenital heart disease were excluded. Data was analyzed and correlated for descriptive purposes.

RESULTS

A total of 17 patients met the inclusion criteria (12 female, 5 male). All had pulmonary hypertension. There was no correlation between mild, moderate, and severe grades of bronchopulmonary dysplasia and the degree of pulmonary vein stenosis. There was a median of 2 (range 1-4) diseased pulmonary veins per patient. In total, 41% of the diseased pulmonary veins were atretic. The right upper and left upper lobe pulmonary veins were the most frequently diseased (n = 13/17, 35%, n = 10/17, 27%, respectively). Focal ground glass opacification, interlobular septal thickening, and hilar soft tissue enlargement were always associated with the atresia of an ipsilateral vein.

CONCLUSION

Recognition of the focal parenchymal changes that imply pulmonary vein stenosis, rather than chronic lung disease of prematurity changes, may improve the detection of a potentially treatable source of pulmonary hypertension, particularly where nonangiographic studies result in a limited direct venous assessment.

Proteomics- and Metabolomics-Based Analysis of Metabolic Changes in a Swine Model of Pulmonary Hypertension

Pulmonary vein stenosis (PVS) causes a rare type of pulmonary hypertension (PH) by impacting the flow and pressure within the pulmonary vasculature, resulting in endothelial dysfunction and metabolic changes. A prudent line of treatment in this type of PH would be targeted therapy to relieve the pressure and reverse the flow-related changes. We used a swine model in order to mimic PH after PVS using pulmonary vein banding (PVB) of the lower lobes for 12 weeks to mimic the hemodynamic profile associated with PH and investigated the molecular alterations that provide an impetus for the development of PH. Our current study aimed to employ unbiased proteomic and metabolomic analyses on both the upper and lower lobes of the swine lung to identify regions with metabolic alterations. We detected changes in the upper lobes for the PVB animals mainly pertaining to fatty acid metabolism, reactive oxygen species (ROS) signaling and extracellular matrix (ECM) remodeling and small, albeit, significant changes in the lower lobes for purine metabolism.

Imaging evaluation of the pediatric mediastinum: new International Thymic Malignancy Interest Group classification system for children

Mediastinal masses are commonly identified in the pediatric population with cross-sectional imaging central to the diagnosis and management of these lesions. With greater anatomical definition afforded by cross-sectional imaging, classification of mediastinal masses into the traditional anterior, middle and posterior mediastinal compartments - as based on the lateral chest radiograph - has diminishing application. In recent years, the International Thymic Malignancy Interest Group (ITMIG) classification system of mediastinal masses, which is cross-sectionally based, has garnered acceptance by multiple thoracic societies and been applied in adults. Therefore, there is a need for pediatric radiologists to clearly understand the ITMIG classification system and how it applies to the pediatric population. The main purpose of this article is to provide an updated review of common pediatric mediastinal masses and mediastinal manifestations of systemic disease processes in the pediatric population based on the new ITMIG classification system.

Prematurity and Pulmonary Vein Stenosis: The Role of Parenchymal Lung Disease and Pulmonary Vascular Disease

Pulmonary vein stenosis (PVS) has emerged as a critical problem in premature infants with persistent respiratory diseases, particularly bronchopulmonary dysplasia (BPD). As a parenchymal lung disease, BPD also influences vascular development with associated pulmonary hypertension recognized as an important comorbidity of both BPD and PVS. PVS is commonly detected later in infancy, suggesting additional postnatal factors that contribute to disease development, progression, and severity. The same processes that result in BPD, some of which are inflammatory-mediated, may also contribute to the postnatal development of PVS. Although both PVS and BPD are recognized as diseases of inflammation, the link between them is less well-described. In this review, we explore the relationship between parenchymal lung diseases, BPD, and PVS, with a specific focus on the epidemiology, clinical presentation, risk factors, and plausible biological mechanisms in premature infants. We offer an algorithm for early detection and prevention and provide suggestions for research priorities.

Pulmonary Vein Stenosis Associated with Germline PIK3CA Mutation

Pulmonary vein stenosis is a rare and frequently lethal childhood disease. There are few known genetic associations, and the pathophysiology is not well known. Current treatments include surgery, interventional cardiac catheterization, and more recently, medications targeting cell proliferation, which are not uniformly effective. We present a patient with PVS and a PIK3CA mutation, who demonstrated a good response to the targeted inhibitor, alpelisib.

Pleuropulmonary MDCT Findings: Comparison between Children with Pulmonary Vein Stenosis and Prematurity-Related Lung Disease

Purpose: To retrospectively compare the pleuropulmonary MDCT findings in children with pulmonary vein stenosis (PVS) and prematurity-related lung disease (PLD). Materials and Methods: All consecutive infants and young children (≤18 years old) who underwent thoracic MDCT studies from July 2004 to November 2021 were categorized into two groups—children with PVS (Group 1) and children with PLD without PVS (Group 2). Two pediatric radiologists independently evaluated thoracic MDCT studies for the presence of pleuropulmonary abnormalities as follows—(1) in the lung (ground-glass opacity (GGO), triangular/linear plaque-like opacity (TLO), consolidation, nodule, mass, cyst(s), interlobular septal thickening, and fibrosis); (2) in the airway (bronchial wall thickening and bronchiectasis); and (3) in the pleura (thickening, effusion, and pneumothorax). Interobserver agreement between the two reviewers was evaluated with the Kappa statistic. Results: There were a total of 103 pediatric patients (60 males (58.3%) and 43 females (41.7%); mean age, 1.7 years; range, 2 days−7 years). Among these 103 patients, 49 patients (47.6%) comprised Group 1 and the remaining 54 patients (52.4%) comprised Group 2. In Group 1, the observed pleuropulmonary MDCT abnormalities were—pleural thickening (44/49; 90%), GGO (39/49; 80%), septal thickening (39/49; 80%), consolidation (4/49; 8%), and pleural effusion (1/49; 2%). The pleuropulmonary MDCT abnormalities seen in Group 2 were—GGO (45/54; 83%), TLO (43/54; 80%), bronchial wall thickening (33/54; 61%), bronchiectasis (30/54; 56%), cyst(s) (5/54; 9%), pleural thickening (2/54; 4%), and pleural effusion (2/54; 4%). Septal thickening and pleural thickening were significantly more common in pediatric patients with PVS (Group 1) (p < 0.001). TLO, bronchial wall thickening, and bronchiectasis were significantly more frequent in pediatric patients with PLD without PVS (Group 2) (p < 0.001). There was high interobserver kappa agreement between the two independent reviewers for detecting pleuropulmonary abnormalities on thoracic MDCT angiography studies (k = 0.99). Conclusion: Pleuropulmonary abnormalities seen on thoracic MDCT can be helpful for distinguishing PVS from PLD in children. Specifically, the presence of septal thickening and pleural thickening raises the possibility of PVS, whereas the presence of TLO, bronchial wall thickening and bronchiectasis suggests PLD in the pediatric population.

Doppler Echocardiography Features of Pulmonary Vein Stenosis in Ex-Preterm Children

BACKGROUND

Echocardiography is used to screen for the presence of pulmonary vein stenosis (PVS) in ex-preterm infants and children. However, there are no standard accepted criteria for the screening or diagnosis of PVS by echocardiography. In this study, we aim to identify Doppler waveform features and Doppler systolic and diastolic velocity cutoff values associated with a diagnosis of PVS by cardiac catheterization.

METHODS

In this retrospective observational study, the echocardiograms of ex-preterm children less than 3 years old who underwent cardiac catheterization at a single institution were reviewed. PVS on cardiac catheterization was defined by a mean pressure gradient of >3mmHg in the pulmonary vein with angiographic evidence of stenosis. Pulmonary vein Doppler waveforms, from echocardiograms performed prior to catheterization, in children with and without PVS were compared. Non-stenosed veins in patients with PVS were excluded. The systolic and diastolic velocities of blood flow, phasic flow and return of the Doppler waveform to baseline were analyzed.

RESULTS

Forty-seven children were included in the study, 18 children with 25 stenosed pulmonary veins and 29 children with 78 non-stenosed pulmonary veins were analyzed. Stenosed pulmonary veins had higher peak systolic and diastolic velocities, and higher peak and mean pressure gradients as measured by spectral Doppler. Peak systolic and diastolic velocities had an area under the ROC curve of 0.89 (confidence interval: 0.79,0.99) and 0.93 (confidence interval: 0.85 ,0.99) for PVS, respectively, and threshold velocity of 0.7 m/sec had sensitivities of 80% and 84% and specificity of 94%. There was no correlation between Doppler-derived pulmonary vein mean gradient and measured pulmonary vein mean gradient during cardiac catheterization in stenosed pulmonary veins. Presence of phasic flow in the pulmonary vein and return of the Doppler waveform to baseline were associated with a non-stenosed pulmonary vein (sensitivity of 94% and 60% and specificity of 52% and 60%, respectively).

CONCLUSIONS

Systolic and diastolic Doppler velocities and features of the waveform can discriminate for stenosed pulmonary veins confirmed by cardiac catheterization in ex-preterm children. Our results suggest lower systolic and diastolic Doppler velocities cutoff values than currently published to screen for PVS in ex-preterm children. These cutoff values require validation in prospective studies.

Pulmonary vein stenosis: Anatomic considerations, surgical management, and outcomes

OBJECTIVE

The study objective was to evaluate outcomes of pulmonary vein stenosis repair in a large single-center cohort.

METHODS

Clinical data from a pulmonary vein stenosis registry were retrospectively reviewed identifying patients who underwent pulmonary vein stenosis repair. The primary/index operation was defined as the patient's first pulmonary vein stenosis operation during the study period.

RESULTS

Between January 2007 and August 2019, 174 patients underwent pulmonary vein stenosis repair. Bilateral pulmonary vein stenosis occurred in 111 patients (64%); 71 patients (41%) had 4-vessel disease. Fifty-nine patients (34%) had primary pulmonary vein stenosis. Median age was 9 months (interquartile range, 5-27) and weight was 6.5 kg (4.7-10.2). Surgical techniques evolved and included ostial resection, unroofing, reimplantation, sutureless, modified sutureless, and a newer anatomically focused approach of pulmonary vein stenosis resection with lateralization or patch enlargement of the pulmonary vein-left atrium connection. Twenty-three patients (13%) required reoperation. Cumulative 2-year incidence of postoperative transcatheter intervention (balloon dilation ± stenting) was 64%. One-, 2-, and 5-year survivals were 71.2%, 66.8%, and 60.6%, respectively. There was no association between surgery type and reoperation rate (hazard ratio, 2.38, P = .25) or transcatheter intervention (hazard ratio, 0.97, P = .95). The anatomically focused repair was associated with decreased mortality on univariate (hazard ratio, 0.38, P = .042) and multivariable analyses (hazard ratio, 0.19, P = .014). Antiproliferative chemotherapy was also associated with decreased mortality (hazard ratio, 0.47, P = .026).

CONCLUSIONS

This large single-center surgical pulmonary vein stenosis experience demonstrates encouraging midterm results. A new anatomically focused repair strategy aims to alleviate pulmonary vein angulation to minimize turbulence and shows promising early outcomes. Continued follow-up is required to understand longer-term outcomes for this surgical approach.

Aspiration Is Associated with Poor Treatment Response in Pediatric Pulmonary Vein Stenosis

Intraluminal pulmonary vein stenosis is a disease with significant morbidity and mortality, though recent progress has been made using multimodal therapy with antiproliferative agents. The aim of this study was to evaluate the association between aspiration and poor treatment response in patients with intraluminal pulmonary vein stenosis. A retrospective, single-center cohort analysis was performed of patients treated with a combination of imatinib mesylate and multimodal anatomic relief between March 2009 and November 2019. Analysis focused on 2-ventricle patients due to small numbers and clinical heterogeneity of single ventricle patients. Among the 84 patients included, 15 had single ventricle physiology and 69 had 2-ventricle physiology. Among the 2-ventricle group, multivariable analysis revealed that patients with clinical aspiration had nearly five times higher odds of poor treatment response than patients without aspiration (OR 4.85, 95% CI [1.37, 17.2], p = 0.014). Furthermore, male patients had higher odds of poor treatment response than their female counterparts (OR 3.67, 95% CI [1.04, 12.9], p = 0.043). Aspiration is a novel, potentially modifiable risk factor for poor treatment response in pediatric multi-vessel intraluminal pulmonary vein stenosis in patients with 2-ventricle physiology.

Thoracic Multidetector Computed Tomography Angiography of Primary Pulmonary Vein Stenosis in Children: Evaluation of Characteristic Extravascular Findings

PURPOSE

The purpose of this study was to investigate the extravascular thoracic multidetector computed tomography (MDCT) angiography findings of pediatric primary pulmonary vein stenosis (PVS) by comparing extravascular thoracic MDCT angiography findings in children with and without PVS.

MATERIALS AND METHODS

All pediatric patients (age 18 y and below) with a known diagnosis of primary PVS, confirmed by echocardiogram and/or conventional angiography, who underwent thoracic MDCT angiography studies from July 2006 to December 2020 were included. A comparison group, comprised of age-matched and sex-matched pediatric patients without PVS who underwent thoracic MDCT angiography studies during the same study period, was also generated. Two pediatric radiologists independently evaluated thoracic MDCT angiography studies for the presence of extravascular thoracic abnormalities in the lung (ground-glass opacity [GGO], consolidation, pulmonary nodule, mass, cyst, septal thickening, fibrosis, and bronchiectasis), pleura (pleural thickening, pleural effusion and pneumothorax), and mediastinum (lymphadenopathy and mass). When a thoracic abnormality was identified, the location and distribution of the abnormality (in relation to the location of PVS) were also evaluated. Extravascular thoracic MDCT angiography findings of pediatric patients with and without primary PVS were compared. Interobserver agreement between the 2 independent reviewers was evaluated with κ statistics.

RESULTS

The study group consisted of 15 thoracic MDCT angiography studies from 15 individual pediatric patients with primary PVS (8 males [53%] and 7 females [47%]; mean age: 10.9 mo; SD: 11.7 mo; range: 1 to 48 mo). The comparison group consisted of 15 thoracic MDCT angiography studies from 15 individual pediatric patients without PVS (8 males [53%] and 7 females [47%]; mean age: 10.2 mo; SD: 11.5 mo; range: 1 to 48 mo). In children with primary PVS, the characteristic extravascular thoracic MDCT angiography findings were GGO (14/15; 93%), septal thickening (5/15; 33%), pleural thickening (14/15; 93%), and ill-defined, mildly heterogeneously enhancing, noncalcified soft tissue mass (14/15; 93%) following the contours of PVS in the mediastinum. There was excellent interobserver κ agreement between 2 independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (κ=0.99 for the study group and κ=0.98 for the comparison group).

CONCLUSIONS

Children with primary PVS have characteristic extravascular thoracic MDCT angiography findings. In the lungs and pleura, GGO, septal thickening, and pleural thickening are common findings. Importantly, in the mediastinum, the presence of a mildly heterogeneously enhancing, noncalcified soft tissue mass in the distribution of PVS is a novel characteristic thoracic MDCT angiography finding unique to pediatric primary PVS. When this constellation of extravascular thoracic MDCT angiography findings is detected, although rare, primary PVS should be considered as a possible underlying diagnosis, especially in symptomatic children.

The Role of Elevated Wall Shear Stress in Progression of Pulmonary Vein Stenosis: Evidence from Two Case Studies

Pulmonary vein stenosis is a serious condition characterized by restriction or blockage due to fibrotic tissue ingrowth that develops in the pulmonary veins of infants or children. It is often progressive and can lead to severe pulmonary hypertension and death. Efforts to halt or reverse disease progression include surgery and catheter-based balloon dilation and stent implantation. Its cause and mechanism of progression are unknown. In this pilot study, we propose and explore the hypothesis that elevated wall shear stress at discrete pulmonary venous sites triggers stenosis. To assess this theory, we retrospectively analyzed cardiac catheterization, lung scan, and X-ray computed tomography data to estimate wall shear stress in the pulmonary veins at multiple time points during disease progression in two patients. Results are consistent with the existence of a level of elevated wall shear stress above which the disease is progressive and below which progression is halted. The analysis also suggests the possibility of predicting the target lumen size necessary in a given vein to reduce wall shear stress to normal levels and remove the trigger for stenosis progression.

Pulmonary Vein Stenosis-Evolving Surgical Management of a Challenging Disease

Pulmonary vein stenosis (PVS) is an extremely challenging clinical problem in congenital heart disease. It has traditionally required multimodal therapy given its complex underlying pathophysiology. As with other modalities, surgical therapy has undergone tremendous evolution since the 1950s. These evolving strategies have been based upon an improved understanding of the substrates that cause PVS and recurrent vein obstruction. More recent anatomic-based surgical strategies have focused on the pulmonary vein course, and how adjacent mediastinal structures can create a fulcrum effect on the pulmonary veins as they pass from the lung parenchyma to the left atrium. The consequent angulation of pulmonary veins creates altered wall shear stress and likely serves as a nidus for recurrent PVS. Encouraging early results suggest that eliminating pulmonary vein angulation and shortening/straightening the pulmonary vein course may prove effective in surgically managing PVS.

Primary pulmonary vein stenosis among premature infants with single-vessel disease

OBJECTIVES

Describe outcomes among preterm infants diagnosed with single-vessel primary pulmonary vein stenosis (PPVS) initially treated using conservative management (active surveillance with deferral of treatment).

STUDY DESIGN

Retrospective cohort study at a single, tertiary-center (2009-2019) among infants <37 weeks' gestation with single-vessel PPVS. Infants were classified into two categories: disease progression and disease stabilization. Cardiopulmonary outcomes were examined, and a Kaplan-Meier survival analysis performed.

RESULTS

Twenty infants were included. Compared to infants in the stable group (0/10, 0%), all infants in the progressive group had development of at least severe stenosis or atresia (10/10, 100%; P < 0.01). Severe pulmonary hypertension at diagnosis was increased in the progressive (5/10, 50%) versus the stable group (0/10, 0%; P = 0.03). Survival was lower among infants in the progressive than the stable group (log-rank test, P < 0.01).

CONCLUSION

Among preterm infants with single-vessel PPVS, risk stratification may be possible, wherein more targeted, individualized therapies could be applied.

Primary pulmonary vein stenosis during infancy: state of the art review

Primary pulmonary vein stenosis (PPVS) is an emerging problem among infants. In contrast to acquired disease, PPVS is the development of stenosis in the absence of preceding intervention. While optimal care approaches remain poorly characterized, over the past decade, understanding of potential pathophysiological mechanisms and development of novel therapeutic strategies are increasing. A multidisciplinary team of health care providers was assembled to review the available evidence and provide a common framework for the diagnosis, management, and treatment of PPVS during infancy. To address knowledge gaps, institutional and multi-institutional approaches must be employed to generate knowledge specific to ex-premature infants with PPVS. Within individual institutions, creation of a team comprised of dedicated health care providers from diverse backgrounds is critical to accelerate clinical learning and provide care for infants with PPVS. Multi-institutional collaborations, such as the PVS Network, provide the infrastructure and statistical power to advance knowledge for this rare disease.

Primary Pulmonary Vein Stenosis: A New Look at a Rare but Challenging Disease

Primary pulmonary vein stenosis (PPVS) represents a rare but emerging, often progressive heterogeneous disease with high morbidity and mortality in the pediatric population. Although our understanding of PPVS disease has improved markedly in recent years, much remains unknown regarding disease pathogenesis, distinct disease phenotypes, and patient- and disease-related risk factors driving the unrelenting disease progression characteristic of PPVS. In the pediatric population, risk factors identified in the development of PPVS include an underlying congenital heart disease, prematurity and associated conditions, and an underlying genetic or congenital syndrome. Continued improvement in the survival of high-risk populations, coupled with ongoing advances in general PPVS awareness and diagnostic imaging technologies suggest that PPVS will be an increasingly prevalent disease affecting pediatric populations in the years to come. However, significant challenges persist in both the diagnosis and management of PPVS. Standardized definitions and risk stratification for PPVS are lacking. Furthermore, evidence-based guidelines for screening, monitoring, and treatment remain to be established. Given these limitations, significant practice variation in management approaches has emerged across centers, and contemporary outcomes for patients affected by PPVS remain guarded. To improve care and outcomes for PPVS patients, the development and implementation of universal definitions for disease and severity, as well as evidence-based guidelines for screening, monitoring, cardiorespiratory care, and indications for surgical intervention will be critical. In addition, collaboration across institutions will be paramount in the creation of regionalized referral centers as well as a comprehensive patient registry for those requiring pulmonary vein stenosis.

Clinical Outcomes Predictors and Surgical Management of Primary Pulmonary Vein Stenosis

BACKGROUND

Surgical outcomes for primary pulmonary vein stenosis (PPVS) remain unfavorable, and risk factors are still poorly understood. The purpose of this study is to evaluate outcomes and risk factors after PPVS repair.

METHODS

Forty patients with PPVS undergoing surgical repair in Fuwai Hospital from 2010 to 2020 were included retrospectively. Adverse outcomes included mortality, pulmonary vein (PV) restenosis and reintervention. A univariate and multivariate risk analysis was performed to determine risk factors.

RESULTS

The mean follow-up duration was 37.5 ± 31.5 months. Sutureless technique was performed in 7 patients (17.5%), endovenectomy in 9 patients (22.5%), and patch venoplasty in 24 patients (60%). Bilateral PV involvement was documented in 12 patients (30%). Overall mortality, PV reintervention, and restenosis occurred in 15%, 12.5%, and 25% of patients, respectively. Freedom from overall mortality, PV reintervention, and restenosis at 5 years was 85%±6.3%, 88.9%±5.2%, and 65.1%±13.2%, respectively. Multivariate analysis revealed that bilateral PV involvement was an independent risk factor for mortality or PV reintervention (hazard ratio, 10.4; 95% confident interval, 1.9-56; p = 0.006), and involvement of left inferior PV was an independent risk factor for postoperative restenosis of left inferior PV (hazard ratio, 13.1; confident interval, 2.2-76.8; p = 0.004).

CONCLUSIONS

Surgical treatment for PPVS remains a challenging issue with imperfect prognosis. Therefore, it is right and appropriate to take close surveillance on mild or moderate stenosis on a single pulmonary vein. Bilateral and left inferior pulmonary vein involvement are independent risk factors for adverse outcomes.

Pulmonary Vein Stenosis: A Rare Disease with a Global Reach

Pulmonary vein stenosis (PVS) is a rare, but high mortality and resource intensive disease caused by mechanical obstruction or intraluminal myofibroproliferation, which can be post-surgical or idiopathic. There are increasing options for management including medications, cardiac catheterization procedures, and surgery. We queried the International Quality Improvement Collaborative for Congenital Heart Disease (IQIC) database for cases of PVS and described the cohort including additional congenital lesions and surgeries as well as infectious and mortality outcomes. IQIC is a quality improvement project in low-middle-income countries with the goal of reducing mortality after congenital heart surgery. Three cases were described in detail with relevant images. We identified 57 cases of PVS surgery, with similar mortality to higher income countries. PVS should be recognized as a global disease. More research and collaboration are needed to understand the disease, treatments, and outcomes, and to devise treatment approaches for low resource environments.

The many faces and outcomes of pulmonary vein stenosis in early childhood

Pulmonary vein stenosis is a rare and poorly understood condition causing obstruction of the large pulmonary veins and of blood flow from the lungs to the left atrium. This results in elevated pulmonary venous pressure and pulmonary edema, pulmonary hypertension, potentially cardiac failure, and death. Clinical signs of the disease include failure to thrive, increasingly severe dyspnea, hemoptysis, respiratory difficulty, recurrent respiratory tract infections/pneumonia, cyanosis, and subcostal retractions. On chest radiograph, the most frequent finding is increased interstitial, ground-glass and/or reticular opacity. Transthoracic echocardiography with pulsed Doppler delineates the stenosis, magnetic resonance imaging and multislice computerized tomography are used for further evaluation. Interventional cardiac catherization, surgical techniques, and medical therapies have been used with varying success as treatment options.

Unique foetal diagnosis of aorto-pulmonary collaterals in right atrial isomerism

Right atrial isomerism is associated with complex cardiac malformations, particularly single-ventricle lesions; right atrial isomerism is rarely associated with aorto-pulmonary collateral arteries. We report a foetal diagnosis of right atrial isomerism, with an unbalanced atrioventricular septal defect, pulmonary stenosis, total anomalous venous drainage, and significant aorto-pulmonary collaterals diagnosed at 22 weeks' gestation.

Longer Exposure to Left-to-Right Shunts Is a Risk Factor for Pulmonary Vein Stenosis in Patients with Trisomy 21

We conducted a study to determine whether patients born with Trisomy 21 and left-to-right shunts who develop pulmonary vein stenosis (PVS) have a longer exposure to shunt physiology compared to those who do not develop PVS. We included patients seen at Boston Children’s Hospital between 15 August 2006 and 31 August 2017 born with Trisomy 21 and left-to-right shunts who developed PVS within 24 months of age. We conducted a retrospective 3:1 matched case–control study. The primary predictor was length of exposure to shunt as defined as date of birth to the first echocardiogram showing mild or no shunt. Case patients with PVS were more likely to have a longer exposure to shunt than patients in the control group (6 vs. 3 months, p-value 0.002). Additionally, PVS patients were also more likely to have their initial repair ≥ 4 months of age (81% vs. 42%, p-value 0.003) and have a gestational age ≤ 35 weeks (48% vs. 13%, p-value 0.003). Time exposed to shunts may be an important modifiable risk factor for PVS in patients with Trisomy 21.

Intervening with the Nitric Oxide Pathway to Alleviate Pulmonary Hypertension in Pulmonary Vein Stenosis

Pulmonary hypertension (PH) as a result of pulmonary vein stenosis (PVS) is extremely difficult to treat. The ideal therapy should not target the high-pressure/low-flow (HP/LF) vasculature that drains into stenotic veins, but only the high-pressure/high-flow (HP/HF) vasculature draining into unaffected pulmonary veins, reducing vascular resistance and pressure without risk of pulmonary oedema. We aimed to assess the activity of the nitric oxide (NO) pathway in PVS during the development of PH, and investigate whether interventions in the NO pathway differentially affect vasodilation in the HP/HF vs. HP/LF territories. Swine underwent pulmonary vein banding (PVB; n = 7) or sham surgery (n = 6) and were chronically instrumented to assess progression of PH. Pulmonary sensitivity to exogenous NO (sodium nitroprusside, SNP) and the contribution of endogenous NO were assessed bi-weekly. The pulmonary vasodilator response to phosphodiesterase-5 (PDE5) inhibition was assessed 12 weeks after PVB or sham surgery. After sacrifice, 12 weeks post-surgery, interventions in the NO pathway on pulmonary small arteries isolated from HP/LF and HP/HF territories were further investigated. There were no differences in the in vivo pulmonary vasodilator response to SNP and the pulmonary vasoconstrictor response to endothelial nitric oxide synthase (eNOS) inhibition up to 8 weeks after PVB as compared to the sham group. However, at 10 and 12 weeks post-PVB, the in vivo pulmonary vasodilation in response to SNP was larger in the PVB group. Similarly, the vasoconstriction to eNOS inhibition was larger in the PVB group, particularly during exercise, while pulmonary vasodilation in response to PDE5 inhibition was larger in the PVB group both at rest and during exercise. In isolated pulmonary small arteries, sensitivity to NO donor SNP was similar in PVB vs. sham groups irrespective of HP/LF and HP/HF, while sensitivity to the PDE5 inhibitor sildenafil was lower in PVB HP/HF and sensitivity to bradykinin was lower in PVB HP/LF. In conclusion, both NO availability and sensitivity were increased in the PVB group. The increased nitric oxide sensitivity was not the result of a decreased PDE5 activity, as PDE5 activity was even increased. Some vasodilators differentially effect HP/HF vs. HP/LF vasculature.

Natural course of acquired pulmonary vein stenosis after radiofrequency ablation for atrial fibrillation-Is routine follow-up imaging indicated or not?

INTRODUCTION

Thermal injury during radiofrequency ablation (RFA) of atrial fibrillation (AF) can lead to pulmonary vein stenosis (PVS). The aim of the present study was to analyze the natural course of RFA-induced PVS with regard to the grade of stenosis, clinical symptoms, and mortality during long-term follow-up.

METHODS AND RESULTS

All patients with follow-up imaging for radiofrequency-induced untreated PVS were retrospectively assessed. From 2004 to 2017, the total rate of PVS following AF ablation in our center was 0.78% (87 of 11 103). Thirty-eight patients with a total of 54 untreated PVS underwent follow-up including imaging scan. The mean degree of stenosis at the time of diagnosis was 57% ± 27% vs 45% ± 35% (P = .05) after a mean follow-up of 43 ± 31 months. There was a shift in severity of the PVS: 18 of 54 (33%) vs 16 of 54 (30%) severe PVS, 19 of 54 (35%) vs 10 of 54 (18%) moderate PVS, and 17 of 54 (32%) vs 28 of 54 (52%) mild PVS (P = .0001). The mean symptom score decreased significantly during follow-up (1.8 ± 1.0 vs 0.4 ± 0.5, P = .0001). Each of the four patients with progression of PVS underwent another pulmonary vein isolation for AF recurrence following pulmonary vein reconduction during follow-up period.

CONCLUSION

This study showed a spontaneous reduction in stenosis grade and symptoms of PVS over a 3.5-year follow-up. Consequently, routine follow-up imaging of PVS seems not to be necessary. However, additional RF energy delivery to stenotic pulmonary veins should be avoided if possible. In case of conduction recovery, the ablation line should be done wide-antrally and follow-up imaging of PVS is recommended.