Pulmonary Vein Stenosis Research Articles

Unilateral Lung Congestion During Exercise in a Patient With a Single Pulmonary Vein Stenosis

A 55-year-old man underwent exercise stress echocardiography for evaluation of left inferior pulmonary vein stenosis. During exercise, ultrasound B-lines developed in the left lung only. Unilateral pulmonary congestion did not lead to forward or backward failure. The patient was followed up conservatively. (Level of Difficulty: Beginner.)

Systemic Sirolimus Therapy for Infants and Children With Pulmonary Vein Stenosis

BackgroundAnatomic interventions for pulmonary vein stenosis (PVS) in infants and children have been met with limited success. Sirolimus, a mammalian target of rapamycin inhibitor, has demonstrated promise as a primary medical therapy for PVS, but the impact on patient survival is unknown. ObjectivesThe authors sought to investigate whether mTOR inhibition with sirolimus as a primary medical therapy would improve outcomes in high-risk infants and children with PVS. MethodsIn this single-center study, patients with severe PVS were considered for systemic sirolimus therapy (SST) following a strict protocol while receiving standardized surveillance and anatomic therapies. The SST cohort was compared with a contemporary control group. The primary endpoint for this study was survival. The primary safety endpoint was adverse events (AEs) related to SST. ResultsBetween 2015 and 2020, our PVS program diagnosed and treated 67 patients with ≥moderate PVS. Of these, 15 patients were treated with sirolimus, whereas the remaining patients represent the control group. There was 100% survival in the SST group compared with 45% survival in the control group (log-rank p = 0.004). A sensitivity analysis was completed to address survival bias using median time from diagnosis of PVS to SST. A survival advantage persisted (log-rank p = 0.027). Two patients on sirolimus developed treatable AEs. Patients in the SST group underwent frequent transcatheter interventions with 3.7 catheterizations per person-year (25th to 75th percentile: 2.7 to 4.4 person-years). Median follow up time was 2.2 years (25th to 75th percentile: 1.2 to 2.9 years) in the SST group versus 0.9 years (25th to 75th percentile: 0.5 to 2.7 years) in the control group. ConclusionsThe authors found a survival benefit associated with SST in infants and children with moderate-to-severe PVS. This survival benefit persisted after adjusting the analysis for survival bias. There were 2 mild AEs associated with SST during the study period; both patients were able to resume therapy without recurrence.

Real use of a novel automatic motorized laser balloon for the ablation of atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Electric isolation of the pulmonary veins (PVs) can successfully treat patients with atrial fibrillation (AF). Isolation of pulmonary veins can be achieved by several methods: radiofrequency, cryoballoon or laser balloon ablation (LBA). The main procedural challenge with either method is to achieve a continuous circumferential lesion at the left atrium-PVs junction, with the persistence of functional gaps. Purpose A novel endoscopic ablation system equipped with a precise motor control system (MCS) has been evaluated. The balloon is used with an endoscope to directly visualize and ablate tissue at the left atrial-PVs junction with laser energy. This system enables uninterrupted, high-speed, circumferential lesion creation under direct control of the physician. The MCS is intended to reduce procedure time and to ensure continuity of ablation lesions. The feasibility of the motorized ablation in terms of extent of applicability along each PV-left atrium junction and time of use of the manual point-by-point mode has been investigated. Methods sixteen consecutive patients (male 68.7%, age 60.9 ± 7.8 years) with paroxysmal or persistent AF who underwent LBA were enrolled in our institution. Exclusion criteria were any contraindication for the procedure including the presence of intracavitary thrombosis and contraindications to general anesthesia or deep sedation. After transseptal puncture, the balloon-based endoscopic ablation system was advanced to each PV ostium, and laser energy were projected onto the target. Results A total of 62 PVs were treated with LBA; in 3 patients there was a redundant right intermediate pulmonary vein; in 4 patients there was a right common ostium and in one a left common ostium. MCS was used for 41 PVs (66.1%): in particular, MCS was used continuously between 180° and 325° degrees (50 to 90% of PV circumference) for 22 PVs (35.5%) and between 326° and 359° degrees (91 to 99% of PV circumference) for 16 veins (25.8%). In 3 PVs (4.8%) MCS was used for the entire circumference. During 5.659 (23.6%) seconds out of a total of 23.986 seconds, laser energy delivery occurred in the rapid mode by MCS. No clinical complications, either local or systemic (stroke or TIA, pericardial effusion, pericardial tamponade, pulmonary vein stenosis, esophageal injury, temporary or permanent phrenic nerve palsy), were observed neither during the use of MSC nor during the use of manual point-by-point mode. Of note, a pinhole rupture of the balloon occurred in the first 2 cases of our series, during the use of MCS, without harm to the patient and requiring only replacement of the LBA. Conclusions In our case series, laser balloon ablation with the help of motor control system appears safe and feasible in most cases for large portions of pulmonary vein circumference, providing considerable time sparing (66.1% of total ablation extent in 23.6% of total ablation time).

First clinical experience using a novel temperature-guided ablation catheter in a routine workflow for atrial fibrillation ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Recently, a novel irrigated RF catheter was designed with a diamond-embedded tip for rapid cooling and 6 surface thermocouples to reflect real-time tissue temperature. The new technology allows for temperature-controlled irrigated ablation, very high-resolution electrograms (EGMs) from the split-tip electrode, as well as real-time rapid lesion assessment. Aim This study aimed to access clinical performance in terms of lesion formation and procedural safety of the novel DiamondTemp (DT) ablation catheter for atrial fibrillation (AF) ablation under routine clinical conditions. Methods In this prospective observational study, 20 patients underwent pulmonary vein isolation (PVI) with the DT catheter in a temperature control mode (60C°/50 W/ 10 seconds). The ipsilateral pulmonary veins (PV) were divided into 6 anatomical segments (12 segments in total) to record ablation data. All patients underwent preprocedural imaging (computer tomography or magnetic resonance imaging (MRI)) and 10 patients received additional postprocedural late gadolinium enhancement (LGE) MRI of the left atrium 3 months after ablation to access lesion formation for each anatomical PV segment and to rule out PV stenosis. Results Acute PVI was achieved in all patients. Two patients received additional ablation at the cavotricuspid isthmus due to typical atrial flutter. No charring at the catheter tip was found and no procedure related complications were observed. The mean procedure duration (skin-to-skin) was 106 ± 31.9 minutes, mean LA dwell time was 83 ± 27.0 minutes. RF time was 13.5 ± 5.5 minutes with a mean of 74 ± 32.8 RF applications. We measured a mean impedance drop per RF application of 10.7 ± 4.1 ohm. Fluoroscopy time was 4.2 ± 2.3 minutes and the fluoroscopy dose was 221 ± 215.3 cGy*cm2 at a. LGE MRI at 3 months after ablation demonstrated a homogeneous and continuous ablation lesion set around the ipsilateral PVs and there was no evidence for PV stenosis. Conclusions This first clinical series demonstrated that temperature-controlled irrigated ablation resulted in rapid, efficient, and durable PV isolation under routine clinical conditions.

Prognostic Significance of Computed Tomography Findings in Pulmonary Vein Stenosis.

(1) Pulmonary vein stenosis (PVS) can be a severe, progressive disease with lung involvement. We aimed to characterize findings by computed tomography (CT) and identify factors associated with death; (2) Veins and lung segments were classified into five locations: right upper, middle, and lower; and left upper and lower. Severity of vein stenosis (0–4 = no disease–atresia) and lung segments (0–3 = unaffected–severe) were scored. A PVS severity score (sum of all veins + 2 if bilateral disease; maximum = 22) and a total lung severity score (sum of all lung segments; maximum = 15) were reported; (3) Of 43 CT examinations (median age 21 months), 63% had bilateral disease. There was 30% mortality by 4 years after CT. Individual-vein PVS severity was associated with its corresponding lung segment severity (p < 0.001). By univariate analysis, PVS severity score >11, lung cysts, and total lung severity score >6 had higher hazard of death; and perihilar induration had lower hazard of death; (4) Multiple CT-derived variables of PVS severity and lung disease have prognostic significance. PVS severity correlates with lung disease severity.

Restriction of Atrial Septal Defect Leads to Growth of Hypoplastic Ventricle in Patients with Borderline Right or Left Heart

Patients with borderline hypoplastic right or left ventricle and VSD may be candidates for either single ventricle palliation or staged ventricular recruitment (SVR) followed by eventual biventricular conversion. Components of SVR include restriction of atrial septal defects (ASD) without ventricular septal defects (VSD) closure and addition of accessory pulmonary blood flow. This study evaluated the impact of ASD restriction on ventricular growth and function. We retrospectively reviewed patients with borderline ventricular hypoplasia and VSD who underwent a staged ventricular recruitment (SVR) procedure from 2012 to June 2019. Pre- and post-recruitment MRI and echocardiogram data were compared and analyzed. We excluded cases in which we intentionally restricted VSD with simultaneous ASD restriction. Forty-six patients (41 with right-dominant ventricle, 25 with risk factors for Fontan procedure) underwent SVR at a median age of 15.1 months' (interquartile range (IQR), 7.2-37.2 months'). The median indexed ventricular end-diastolic volume, end-systolic volume, and stroke volume according to cardiac MRI significantly increased at median 11.0 months' (IQR:7.8~14.1 months') after recruitment. Among them, except 2 operative mortalities after SVR, 26 patients underwent bi-ventricular repair (56.5% including one and a half ventricle repair) at a median of 8.0 months' (IQR: 6.2-12.2 months') after recruitment. Fifteen patients await biventricular completion, and 3 patients underwent single ventricle palliation. Pulmonary blood flow (Qp) tended to increase after recruitment regardless of type of pulmonary blood flow modification without statistical significance. Six patients died at a median duration of 6.5 months' (IQR: 2.9-11.7) after SVR; 3 patients died after biventricular completion, 2 after recruitment, and 1 after returning to single ventricle palliation. All of them were considered poor Fontan candidates due to severe atrioventricular valve regurgitation, pulmonary hypertension, pulmonary vein stenosis, or airway stenosis. Restriction of the atrial septum leads to the growth of hypoplastic ventricle in patients with ventricular septal defects who undergo SVR regardless of the preoperative characteristics, and eventual biventricular repair can be performed in a subgroup of these patients. Future work is necessary to optimize timing of SVR and method of accessory pulmonary blood flow.

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

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. 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. 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). 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.

Effectiveness of posterior aortopexy for the left pulmonary vein obstruction between the left atrium and the descending aorta.

Left pulmonary vein (PV) obstruction can occur due to compression between the left atrium (LA) and the descending aorta (DA). One of the effective solutions for this problem is posterior aortopexy. In this study, we have reported five cases of posterior aortopexy to relieve left PV obstruction between the LA and the DA. Since August 2012, five patients have undergone posterior aortopexy for compression of the left PV between the LA and the DA. The median age and weight of the patients at the time of operation were 5.5 months (range, 1-131 months) and 5.2 kg (range, 4.2-29.5 kg), respectively. The left PV obstruction was initially diagnosed on echocardiography in four patients and computed tomography angiography in one patient. The median peak pressure gradient across the obstructed left PV was 7.3 mmHg (range, 4-20 mmHg). Concomitant procedures were ventricular septal defect closure in one patient and patent ductus arteriosus ligation in one patient. There was no PV obstruction on echocardiography in any of the patients after the operation except in the case of one patient who had diffuse pulmonary vein stenosis. The median follow-up duration was 34 months (range, 14-89 months), and during follow-up no incidence of the left PV obstruction was observed in any of the surviving patients. The posterior aortopexy technique could be a good surgical option for the left PV obstruction caused by compression between the LA and the anteriorly positioned DA.

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.

Pulmonary vein stenosis after HotBalloon pulmonary vein isolation of paroxysmal atrial fibrillation.

HotBalloon-based pulmonary vein isolation (HBPVI) has yielded encouraging clinical results in the treatment of paroxysmal atrial fibrillation (PAF). However, pulmonary vein (PV) stenosis remains a concern. The influence of longer application duration on PV stenosis has not yet been systematically evaluated. All patients who underwent first HBPVI of PAF with pre- and post-ablation computed tomography (CT) were included. We used single-shot technique with application duration of 180s in the RSPV, 180-240s in the LSPV, and 120s in the lower PV procedures. PV stenosis was analyzed using CT and categorized as moderate (50-70%), and severe (> 70%) reduction in PV diameter. We analyzed imaging of the PV anatomy before ablation and during follow-up in 84 patients. Among them, 7 (8.3%) showed moderate stenosis, and 3 (3.6%) had severe stenosis including one total occlusion patient. All severe stenosis and total occlusion occurred in RSPV and LSPV procedures with longer application duration. No severe stenosis nor total PV occlusion occurred in inferior PV procedures with shorter application duration. The incidence of PV stenosis ≥ 50% or total PV occlusion was significantly lower in inferior PV than RSPV and LSPV procedures (0.6%, 6.0%, 8.0%, p = 0.01, respectively). All cases of PV stenosis including total PV occlusion patients were asymptomatic. No intervention for PV stenosis was performed. The risk of PV stenosis in HBPVI was rare in lower PV procedure with shorter application duration. An application duration setting of 120s in lower PV procedure might be effective to prevent PV stenosis.

The Real Need for Regenerative Medicine in the Future of Congenital Heart Disease Treatment.

Bioabsorbable materials made from polymeric compounds have been used in many fields of regenerative medicine to promote tissue regeneration. These materials replace autologous tissue and, due to their growth potential, make excellent substitutes for cardiovascular applications in the treatment of congenital heart disease. However, there remains a sizable gap between their theoretical advantages and actual clinical application within pediatric cardiovascular surgery. This review will focus on four areas of regenerative medicine in which bioabsorbable materials have the potential to alleviate the burden where current treatment options have been unable to within the field of pediatric cardiovascular surgery. These four areas include tissue-engineered pulmonary valves, tissue-engineered patches, regenerative medicine options for treatment of pulmonary vein stenosis and tissue-engineered vascular grafts. We will discuss the research and development of biocompatible materials reported to date, the evaluation of materials in vitro, and the results of studies that have progressed to clinical trials.

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.

Role of 3D reconstructed images in primary pulmonary vein stenosis.

Primary pulmonary vein stenosis (PPVS) is a rare congenital cardiac anomaly. The surgical management of PPVS requires anatomical delineation of pulmonary venous drainage along with exact localization of the stenosis. Since echocardiography cannot visualize the whole length of pulmonary veins (PV), computed tomography (CT) pulmonary venography becomes necessary. Three-dimensional (3D) reconstruction helps in planning PV augmentation and for prognostication. Here, we present 3D reconstructed CT pulmonary venography images of a 3-month-old child who presented to us with PPVS.

Current Endovascular Approach in Adult Patients with Pulmonary Vein Stenosis: A State-of-the-Art Approach

Regarding to more invasive treatment of atrial arrhythmia (atrial fibrillation ablation) and pulmonary vein isolation (PVI), the rate of acquired pulmonary vein stenosis (PVS) is increasing and at present, PV ablation for AF has become the principal cause of PVS in adult patients. On the other way, by improvement in procedural techniques, equipment, and the experience of the operators, the incidence of PVS has been decreased. There is some controversy about the manner of follow-up of these patients and in most centers, just symptomatic patients are considered for imaging and treatment. Almost always, those with PV stenosis more than 70% or multiple PV involvement become symptomatic and if give them up without treatment, pulmonary symptoms and finally irreversible pulmonary hypertension will occurred. So, intensive pursue after the procedure is highly recommended. Whereas in pediatric patients with congenital or acquired PVS, the best treatment approach is surgery, in adult patients, the preferred type of treatment is the transcatheter intervention with high acute success rate. In this present review, we have scrutinized about the diagnostic modalities, the indications for intervention, the diverse treatment strategies, and principally clarify an accurate stepwise approach during transcatheter procedure.

Clinical Outcomes, Predictors, and Surgical Management of Primary Pulmonary Vein Stenosis

BackgroundSurgical outcomes for primary pulmonary vein stenosis (PPVS) remain unfavorable, and risk factors are still poorly understood. This study evaluated outcomes and risk factors after PPVS repair. MethodsThis retrospective study included 40 patients with PPVS who underwent surgical repair in Fuwai Hospital from 2010 to 2020. Adverse outcomes included overall death, pulmonary vein (PV) restenosis, and reintervention. A univariate and multivariate risk analysis was performed to determine risk factors. ResultsThe mean follow-up duration was 37.5 ± 31.5 months. Sutureless technique was performed in 7 patients (17.5%), endovenectomy in 9 (22.5%), and patch venoplasty in 24 (60%). Bilateral PV involvement was documented in 12 patients (30%). Overall death, PV reintervention, and restenosis occurred in 15%, 12.5%, and 25% of patients, respectively. Freedom from overall death, 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 death or PV reintervention (hazard ratio, 10.4; 95% confidence interval, 1.9-56; P = .006) and that involvement of the left inferior PV was an independent risk factor for postoperative restenosis of the left inferior PV (hazard ratio, 13.1; 95% confidence interval, 2.2-76.8; P = .004). ConclusionsSurgical 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 PV. Bilateral and left inferior PV involvement are independent risk factors for adverse outcomes.

Comparison between cryoballoon and hot balloon ablation in patients with paroxysmal atrial fibrillation.

Pulmonary vein (PV) isolation using balloon ablation was developed as a technique for patients with paroxysmal atrial fibrillation (PAF). While most studies examined cryoballoon ablation (CBA), there have also been many reports on hot balloon ablation (HBA). We aimed to evaluate the clinical characteristics and outcomes between HBA and CBA. In a total of 103 consecutive patients with PAF who underwent catheter ablation, 60 propensity score-matched (30 CBA and 30 HBA) patients were enrolled. The procedural differences and clinical outcomes between the two groups were analyzed. The requirement for additional touch-up ablation was more frequent in the left superior pulmonary vein (LSP) in the HBA group than in the CBA group. Pre-procedural computed tomography (CT) images showed that a thicker left pulmonary vein ridge and larger cross-sectional area of the LSPV were significantly associated with residual PV potentials after HBA. However, post-procedural CT images showed that PV stenosis (> 25%) was higher in the HBA group (33%) than in the CBA group (0%). PV stenosis after HBA was observed most frequently in the right superior PV (50%). The atrial fibrillation/atrial tachycardia-free survival rate during follow-up (365 ± 102 days) was similar between the two groups (CBA vs. HBA, 83% vs. 90%). Although both balloon modalities can relieve atrial arrhythmia after the procedure, careful attention is required during HBA procedures, especially for the right superior PV, to avoid PV stenosis.

Outcomes in Establishing Individual Vessel Patency for Pediatric Pulmonary Vein Stenosis.

The purpose of this study was to determine what patient and pulmonary vein characteristics at the diagnosis of intraluminal pulmonary vein stenosis (PVS) are predictive of individual vein outcomes. A retrospective, single-center, cohort sub-analysis of individual pulmonary veins of patients enrolled in the clinical trial NCT00891527 using imatinib mesylate +/− bevacizumab as adjunct therapy for the treatment of multi-vessel pediatric PVS between March 2009 and December 2014 was performed. The 72-week outcomes of the individual veins are reported. Among the 48 enrolled patients, 46 patients and 182 pulmonary veins were included in the study. Multivariable analysis demonstrated that patients with veins without distal disease at baseline (odds ratio, OR 3.69, 95% confidence interval, CI [1.52, 8.94], p = 0.004), location other than left upper vein (OR 2.58, 95% CI [1.07, 6.19], p = 0.034), or veins in patients ≥ 1 y/o (OR 5.59, 95% CI [1.81, 17.3], p = 0.003) were at higher odds of having minimal disease at the end of the study. Veins in patients who received a higher percentage of eligible drug doses required fewer reinterventions (IRR 0.76, 95% CI [0.68, 0.85], p < 0.001). The success of a multi-modal treatment approach to aggressive PVS depends on the vein location, disease severity, and drug dose intensity.

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.

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.

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.