Intraluminal Pulmonary Vein Stenosis in Children

Neonatal Risk Factors for Pulmonary Vein Stenosis in Infants Born Preterm with Severe Bronchopulmonary Dysplasia

OBJECTIVE

To evaluate associations between neonatal risk factors and pulmonary vein stenosis (PVS) among infants born preterm with severe bronchopulmonary dysplasia (sBPD).

STUDY DESIGN

We performed a case-control study of infants born from 2010 to 2022 at <32 weeks' gestation with sBPD among 46 neonatal intensive care units in the Children's Hospitals Neonatal Consortium. Cases with PVS were matched to controls using epoch of diagnosis (2010-2016; 2017-2022) and hospital. Multivariable logistic regression analyses were utilized to evaluate PVS association with neonatal risk factors.

RESULTS

From 10 171 preterm infants with sBPD, we identified 109 cases with PVS and matched those to 327 controls. The prevalence of PVS (1.07%) rose between epochs (0.8% in 2010-2016 to 1.2% in 2017-2022). Relative to controls, infants with PVS were more likely to be <500 g at birth, to be small for gestational age <10th%ile, or have surgical necrotizing enterocolitis, atrial septal defects, or pulmonary hypertension. In multivariable models, these associations persisted, and small for gestational age, surgical necrotizing enterocolitis, atrial septal defects, and pulmonary hypertension were each independently associated with PVS. Among infants on respiratory support at 36 weeks' postmenstrual age, infants with PVS had 4.3-fold higher odds of receiving mechanical ventilation at 36 weeks' postmenstrual age. Infants with PVS also had 3.6-fold higher odds of in-hospital mortality relative to controls.

CONCLUSIONS

In a large cohort of preterm infants with sBPD, multiple independent, neonatal risk factors are associated with PVS. These results lay important groundwork for the development of targeted screening to guide the diagnosis and management of PVS in preterm infants with sBPD.

Incidence and predictors of in-stent restenosis following intervention for pulmonary vein stenosis due to fibrosing mediastinitis

BACKGROUND

Fibrosing mediastinitis (FM) is a rare yet fatal condition, caused by different triggers and frequently culminating in the obstruction of the pulmonary vasculature and airways, often leading to pulmonary hypertension and right heart failure. Percutaneous transluminal pulmonary venoplasty (PTPV) is an emerging treatment for pulmonary vein stenosis (PVS) caused by FM. Our previous study showed as high as 24% of in-stent restenosis (ISR) in FM. However, the predictors of ISR are elusive.

OBJECTIVES

We sought to identify the predictors of ISR in patients with PVS caused by extraluminal compression due to FM.

METHODS

We retrospectively enrolled patients with PVS-FM who underwent PTPV between July 1, 2018, and December 31, 2022. According to ISR status, patients were divided into two groups: the ISR group and the non-ISR group. Baseline characteristics (demographics and lesions) and procedure-related information were abstracted from patient records and analyzed. Univariate and multivariate analyses were performed to determine the predictors of ISR.

RESULTS

A total of 142 stents were implanted in 134 PVs of 65 patients with PVS-FM. Over a median follow-up of 6.6 (3.4-15.7) months, 61 of 134 PVs suffered from ISR. Multivariate analysis demonstrated a significantly lower risk of ISR in PVs with a larger reference vessel diameter (RVD) (odds ratio (OR): 0.79; 95% confidence interval [CI]: 0.64 to 0.98; P = 0.032), and stenosis of the corresponding pulmonary artery (Cor-PA) independently increased the risk of restenosis (OR: 3.41; 95% CI: 1.31 to 8.86; P = 0.012). The cumulative ISR was 6.3%, 21.4%, and 39.2% at the 3-, 6-, and 12-month follow-up, respectively.

CONCLUSION

ISR is very high in PVS-FM, which is independently associated with RVD and Cor-PA stenosis.

TRAIL REGISTRATION

Chinese Clinical Trials Register; No.: ChiCTR2000033153. URL: http://www.chictr.org.cn .

Perioperative considerations for non-cardiac procedures in patients with congenital heart disease: A practical overview

Providing thorough care for children with congenital heart disease (CHD) undergoing non-cardiac surgery requires a strong understanding of common heart defects and the procedures used to treat them. To care for these patients, multidisciplinary teams must consider the severity of the underlying cardiac disease, comorbid conditions, and preoperative severity of illness. The American Heart Association's Scientific Statement on Perioperative Considerations for Pediatric Patients with Congenital Heart Disease Presenting for Noncardiac Procedures offers valuable guidance.

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.

Predictors of Serious Adverse Events and High-Level Cardiorespiratory Support in Patients Undergoing Transcatheter Pulmonary Vein Interventions

Patients with pulmonary vein stenosis (PVS) often require frequent transcatheter pulmonary vein (PV) interventions for management of restenosis. Predictors of serious adverse events (AEs) and need for high-level cardiorespiratory support (mechanical ventilation, vasoactive support, and/or extracorporeal membrane oxygenation) 48 h after transcatheter PV interventions have not been reported. This is a single-center retrospective cohort analysis of patients with PVS who underwent transcatheter PV interventions from 3/1/2014 to 12/31/2021. Univariate and multivariable analyses were performed using generalized estimating equations to account for within-patient correlation. 240 patients underwent 841 catheterizations involving PV interventions (median 2 catheterizations per patient [1,3]). At least one serious AE was reported in 100 (12%) cases, the most common of which were pulmonary hemorrhage (n = 20) and arrhythmia (n = 17). There were 14 severe/catastrophic AEs (1.7% of cases) including three strokes and one patient death. On multivariable analysis, age less than 6 months, low systemic arterial saturation (< 95% in patients with biventricular [BiV] physiology, < 78% in single ventricle [SV] physiology), and severely elevated mean PA pressure (≥ 45 mmHg in BiV, ≥ 17 mmHg in SV) were associated with SAEs. Age less than 1 year, hospitalization prior to catheterization, and moderate-severe RV dysfunction were associated with high-level support after catheterization. Serious AEs during transcatheter PV interventions in patients with PVS are common, although major events such as stroke or death are uncommon. Younger patients and those with abnormal hemodynamics are more likely to experience serious AEs and require high-level cardiorespiratory support after catheterization.

Management of Pediatric Pulmonary Vein Stenosis

Pediatric intraluminal pulmonary vein stenosis has evolved into a chronic illness, with improving survival. Although significant knowledge gaps remain, medical providers have found success in the management of patients with pulmonary vein stenosis using a comprehensive multimodality treatment strategy. This review discusses the core principles employed by 4 centers dedicated to improving pulmonary vein stenosis outcomes, including how to make the diagnosis, educating the family, treatment strategy, the importance of surveillance, and the management of symptoms and comorbidities.

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 Hypertension in the Population with Down Syndrome

Persons with Down syndrome (DS) have an increased reported incidence of pulmonary hypertension (PH). A majority of those with PH have associations with congenital heart disease (CHD) or persistent pulmonary hypertension of the newborn (PPHN); however, there are likely multifactorial contributions that include respiratory comorbidities. PH appears to be most commonly identified early in life, although respiratory challenges may contribute to a later diagnosis or even a recurrence of previously resolved PH in this population. Currently there are few large-scale, prospective, lifetime cohort studies detailing the impact PH has on the population with DS. This review will attempt to summarize the epidemiology and characteristics of PH in this population. This article will additionally review current known and probable risk factors for developing PH, review pathophysiologic mechanisms of disease in the population with DS, and evaluate current screening and management recommendations while suggesting areas for additional or ongoing clinical, translational, and basic science research.

Malnutrition, poor post-natal growth, intestinal dysbiosis and the developing lung

In extremely preterm infants, poor post-natal growth, intestinal dysbiosis and bronchopulmonary dysplasia are common, and each is associated with long-term complications. The central hypothesis that this review will address is that these three common conditions are interrelated. Challenges to studying this hypothesis include the understanding that malnutrition and poor post-natal growth are not synonymous and that there is not agreement on what constitutes a normal intestinal microbiota in this evolutionarily new population. If this hypothesis is supported, further study of whether "correcting" intestinal dysbiosis in extremely preterm infants reduces postnatal growth restriction and/or bronchopulmonary dysplasia is indicated.

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.

Selected 2020 Highlights in Congenital Cardiac Anesthesia

This article is a review of the highlights of pertinent literature published during the 12 months of 2020 that are of interest to the congenital cardiac anesthesiologist. After a search of the US National Library of Medicine's PubMed database, several topics emerged for which significant contributions were made in 2020. The authors of the present article considered the following topics noteworthy to be included in this review: pediatric cardiac care in the coronavirus disease 2019 era, the use of mechanical circulatory support in coronavirus disease 2019-related multisystem inflammatory syndrome in children, transfusion and coagulation management in children undergoing congenital heart surgery, and pulmonary vein stenosis.

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.

Correlation of Intravascular Ultrasound with Histology in Pediatric Pulmonary Vein Stenosis

Preliminary intravascular ultrasound (IVUS) images of suspected pediatric intraluminal pulmonary vein stenosis (PVS) demonstrate wall thickening. It is unclear how the IVUS-delineated constituents of wall thickening correlate with the histology. We analyzed six postmortem formalin-fixed heart/lung specimens and four live patients with PVS as well as control pulmonary veins using IVUS and light microscopic examination. In PVS veins, IVUS demonstrated wall thickening with up to two layers of variable echogenicity, often with indistinct borders. Histologically, the veins showed fibroblastic proliferation with areas rich in myxoid matrix as well as areas with abundant collagen and elastic fibers. Discrete vein layers were obscured by scarring and elastic degeneration. A lower reflective periluminal layer by IVUS corresponded with hyperplasia of myofibroblast-like cells in abundant myxoid matrix. The hyper-reflective layer by IVUS extended to the outer edge of the vessel and corresponded to a less myxoid area with more collagen, smooth muscle and elastic fibers. The outer less reflective edge of the IVUS image correlated with a gradual transition into adventitia. Normal veins had a thin wall, correlating with histologically normal cellular and extracellular components, without intimal proliferation. IVUS may provide further understanding of the anatomy and mechanisms of pediatric pulmonary vein obstruction.

Pulmonary Vein Stenosis: Moving From Past Pessimism to Future Optimism

Pulmonary Vein Stenosis (PVS) is a rare disease with a prevalence of around 1. 7 cases per 100,000 children under 2 years old. Treatment options for this disease have not provided great results and pathophysiology of this condition is still poorly understood. Here, we will review the history of PVS including diagnostic tools and treatments, the current management approach, and what the future holds for this devastating disease.

Superior Cavopulmonary Connection: Its Physiology, Limitations, and Anesthetic Implications

The superior cavopulmonary connection (SCPC) or "bidirectional Glenn" is an integral, intermediate stage in palliation of single ventricle patients to the Fontan procedure. The procedure, normally performed at 3 to 6 months of life, increases effective pulmonary blood flow and reduces the ventricular volume load in patients with single ventricle (parallel circulation) physiology. While the SCPC, with or without additional sources of pulmonary blood flow, cannot be considered a long-term palliation strategy, there are a subset of patients who require SCPC palliation for a longer interval than the typical patient. In this article, we will review the physiology of SCPC, the consequences of prolonged SCPC palliation, and modes of failure. We will also discuss strategies to augment pulmonary blood flow in the presence of an SCPC. The anesthetic considerations in SCPC patients will also be discussed, as these patients may present for noncardiac surgery from infancy to adulthood.

Is This My Home? A Palliative Care Journey Through Life and Death in the NICU: A Case Report

BACKGROUND

With advancements in neonatology, patients in the neonatal intensive care unit (NICU) are living in the hospital with complex life-limiting illnesses until their first birthday or beyond. As palliative care (PC) becomes a standard of care in neonatology, a level IV NICU developed an interdisciplinary PC team with the mission to ease the physical, mental, and moral distress of the patients, families, and staff. This case report highlights the teamwork and long-term palliative care and ultimately end-of-life care that an infant received by this dedicated NICU palliative care team.

CLINICAL FINDINGS

This case discusses a premature ex-27-week gestation male infant who initially presented to the emergency department at 5 months of age with significant tachypnea, increased work of breathing, and poor appetite.

PRIMARY DIAGNOSIS

The primary diagnosis was severe pulmonary vein stenosis resulting in severe pulmonary hypertension.

INTERVENTIONS

The severity of the infant's pulmonary vein stenosis was incurable. He required substantial life-extending surgical procedures and daily intensive care interventions. In addition to his life-extending therapies, the infant and his family received palliative care support by the NICU PC team and the hospital-wide PC team (REACH team) throughout his admission. This was specialized care that focused on easing pain and suffering while also addressing any social/emotional needs in the infant, his family, and in the hospital staff. The PC teams also focused on protecting the families' goals of care, memory making, and providing a positive end-of-life experience for the infant and his family. The infant's end-of-life care involved providing adequate pain and symptom management, education, and communication to his family about the dying process and allowing unlimited family time before and after his death.

OUTCOMES

After 11 months in the NICU and despite aggressive therapies, he required more frequent trips to the cardiac catheterization laboratory for restenosis of his pulmonary veins. He was dependent on iNO to treat his pulmonary hypertension and he continued to require an ICU ventilator. His parents ultimately decided to pursue comfort care. He died peacefully in his mother's arms.

PRACTICE RECOMMENDATIONS

The American Academy of Pediatrics and the National Association of Neonatal Nurses both have statements recommending that palliative care be standard of care in NICUs. Establishing a NICU-dedicated interdisciplinary PC team can improve outcomes for infants and families living in the NICU with complex life-limiting illnesses.

Mitochondrial Fission-Mediated Lung Development in Newborn Rats With Hyperoxia-Induced Bronchopulmonary Dysplasia With Pulmonary Hypertension

Background: Bronchopulmonary dysplasia (BPD) is the most common chronic respiratory disease in premature infants. Oxygen inhalation and mechanical ventilation are common treatments, which can cause hyperoxia-induced lung injury, but the underlying mechanism is not yet understood. Mitochondrial fission is essential for mitochondrial homeostasis. The objective of this study was to determine whether mitochondrial fission (dynamin-related protein 1, Drp1) is an important mediator of hyperoxia lung injury in rats. Methods: The animal model of BPD was induced with high oxygen (80-85% O₂). Pulmonary histological changes were observed by hematoxylin-eosin (HE) staining. Pulmonary microvessels were observed by immunofluorescence staining of von Willebrand Factor (vWF). Protein expression levels of Drp1 and p-Drp1 (Ser616) were observed using Western Blot. We used echocardiography to measure pulmonary artery acceleration time (PAT), pulmonary vascular resistance index (PVRi), peak flow velocity of the pulmonary artery (PFVP), pulmonary arteriovenous diameter, and pulmonary vein peak velocity. Mitochondrial division inhibitor-1 (Mdivi-1) was used as an inhibitor of Drp1, and administered through intraperitoneal injection (25 mg/kg). Results: Pulmonary artery resistance of the hyperoxide-induced neonatal rat model of BPD increased after it entered normoxic convalescence. During the critical stage of alveolar development in neonatal rats exposed to high oxygen levels for an extended period, the expression and phosphorylation of Drp1 increased in lung tissues. When Drp1 expression was inhibited, small pulmonary vessel development improved and PH was relieved. Conclusion: Our study shows that excessive mitochondrial fission is an important mediator of hyperoxia-induced pulmonary vascular injury, and inhibition of mitochondrial fission may be a useful treatment for hyperoxia-induced related pulmonary diseases.

Pulmonary Hypertension Associated with Bronchopulmonary Dysplasia: A Review

Early pulmonary vascular disease (PVD) and established pulmonary hypertension (PH) are common associations of bronchopulmonary dysplasia (BPD). Diagnosis of PH is often made by echocardiography because of technical and logistic difficulties with the neonatal population. Optimization of respiratory support is the focus of treatment, however, medical therapies are being used with increased frequency. The prognosis for PH associated with BPD (PH-BPD) is tied to the child's respiratory status. PH is associated with increased risk of death in this population, so active screening and treatment is recommended to minimize morbidity and mortality. In this review, we discuss the pathophysiology of PH in infants with BPD, evaluate the current understanding of screening, diagnosis, and follow-up evaluation; describe comorbid conditions; and provide a framework for targeted physiology-based management strategies.