Bilateral Disease and Early Age at Presentation Are Associated with Shorter Survival in Patients with Congenital Heart Disease and Intraluminal Pulmonary Vein Stenosis

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.

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 Complex Pulmonary Vein Stenosis at Altitude Combining Comprehensive Percutaneous Interventional Treatment with Sirolimus, Pulmonary Hypertension Medications and Intraluminal Imaging with Optical Coherence Tomography

BACKGROUND

Pulmonary vein stenosis (PVS) is a growing problem for the pediatric congenital heart population. Sirolimus has previously been shown to improve survival and slow down the progression of in-stent stenosis in patients with PVS. We evaluated patients before and after initiation of sirolimus to evaluate its effects on re-intervention and vessel patency utilizing Optical Coherence Tomography (OCT).

METHODS

We performed a retrospective study, reviewing the charts of patients with PVS, who had been prescribed sirolimus between October 2020 and December 2021. OCT was performed in the pulmonary vein of interest as per our published protocol. Angiographic and OCT imaging was retrospectively reviewed. Statistical analysis was performed using Chi square and Wilcoxon signed-rank test to compare pre-and post-sirolimus data.

RESULTS

Ten patients had been started and followed on sirolimus. Median age at sirolimus initiation was 25 months with median weight of 10.6 kg and average follow-up of 1 year. Median total catheterizations were 7 for patients prior to starting sirolimus and 2 after starting treatment (p = 0.014). Comparing pre- and post-sirolimus, patients were catheterized every 3 months vs every 11 months (p = 0.011), median procedure time was 203 min vs 145 min (p = 0.036) and fluoroscopy time, 80 min vs 57.2 min (p = 0.036). 23 veins had severe in-stent tissue ingrowth prior to SST (luminal diameter < 30% of stent diameter). Post-sirolimus, 23 pulmonary veins had moderate to severe in-stent tissue ingrowth that responded to non-compliant balloon inflation only with stent luminal improvement of > 75%.

CONCLUSION

Our study suggests that the addition of sirolimus in patients with moderate-severe PVS helps to decrease disease progression with decrease frequency of interventions. Reaching therapeutic levels for sirolimus is critical and medication interactions and side-effects need careful consideration. OCT continues to be important for evaluation and treatment guidance in this patient population.

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.

Lung and Pleural Findings of Children with Pulmonary Vein Stenosis with and without Aspiration: MDCT Evaluation

Purpose: To retrospectively compare the lung and pleural findings in children with pulmonary vein stenosis (PVS) with and without aspiration on multidetector computed tomography (MDCT). Materials and Methods: All consecutive children (≤18 years old) with PVS who underwent thoracic MDCT studies from August 2004 to December 2021 were categorized into two groups: children with PVS with aspiration (Group 1) and children with PVS without aspiration (Group 2). Two independent pediatric radiologists retrospectively evaluated thoracic MDCT studies for the presence of lung and pleural abnormalities as follows: (1) in the lung (ground-glass opacity (GGO), consolidation, nodule, mass, cyst(s), interlobular septal thickening, and fibrosis) and (2) in the pleura (thickening, effusion, and pneumothorax). Interobserver agreement between the two reviewers was evaluated by the proportion of agreement and the Kappa statistic. Results: The final study population consisted of 64 pediatric patients (36 males (56.3%) and 43 females (43.7%); mean age, 1.7 years; range, 1 day−17 years). Among these 64 patients, 19 patients (29.7%) comprised Group 1 and the remaining 45 patients (70.3%) comprised Group 2. In Group 1 (children with PVS with aspiration), the detected lung and pleural MDCT abnormalities were: GGO (17/19; 89.5%), pleural thickening (17/19; 89.5%), consolidation (16/19; 84.5%), and septal thickening (16/19; 84.5%). The lung and pleural MDCT abnormalities observed in Group 2 (children with PVS without aspiration) were: GGO (37/45; 82.2%), pleural thickening (37/45; 82.2%), septal thickening (36/45; 80%), consolidation (3/45; 6.7%), pleural effusion (1/45; 2.2%), pneumothorax (1/45; 2.2%), and cyst(s) (1/45; 2.2%). Consolidation was significantly more common in pediatric patients with both PVS and aspiration (Group 1) (p < 0.001). There was high interobserver agreement between the two independent reviewers for detecting lung and pleural abnormalities on thoracic MDCT studies (Kappa = 0.98; CI = 0.958, 0.992). Conclusion: Aspiration is common in pediatric patients with PVS who undergo MDCT and was present in nearly 30% of all children with PVS during our study period. Consolidation is not a typical radiologic finding of PVS in children without clinical evidence of aspiration. When consolidation is present on thoracic MDCT studies in pediatric patients with PVS, the additional diagnosis of concomitant aspiration should be considered.

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.

Secondary Pulmonary Vein Stenosis Due to Total Anomalous Pulmonary Venous Connection Repair in Children: Extravascular MDCT Findings

Purpose: To evaluate extravascular findings on thoracic MDCT angiography in secondary pulmonary vein stenosis (PVS) due to total anomalous pulmonary venous connection (TAPVC) repair in children. Materials and Methods: All patients aged ≤18 years with a known diagnosis of secondary PVS after TAPVC repair, confirmed by echocardiography, conventional angiography, and/or surgery, who underwent thoracic MDCT angiography studies between July 2008 and April 2021 were included. Two pediatric radiologists independently examined MDCT angiography studies for the presence of extravascular thoracic abnormalities in the lung, pleura, and mediastinum. The location and distribution of each abnormality (in relation to the location of PVS) were also evaluated. Interobserver agreement between the two independent pediatric radiology reviewers was studied using kappa statistics. Results: The study group consisted of 20 consecutive pediatric patients (17 males, 3 females) with secondary PVS due to TAPVC repair. Age ranged from 2 months to 8 years (mean, 16.1 months). In children with secondary PVS due to TAPVC repair, the characteristic extravascular thoracic MDCT angiography findings were ground-glass opacity (19/20; 95%), septal thickening (7/20; 35%), pleural thickening (17/20; 85%), and a poorly defined, mildly heterogeneously enhancing, non-calcified soft tissue mass (17/20; 85%) which followed the contours of affected pulmonary veins outside the lung. There was excellent interobserver kappa agreement between two independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (k = 0.99). Conclusion: Our study characterizes the extravascular thoracic MDCT angiography findings in secondary pediatric PVS due to TAPVC repair. In the lungs and pleura, ground-glass opacity, interlobular septal thickening, and pleural thickening are common findings. Importantly, the presence of a mildly heterogeneously enhancing, non-calcified mediastinal soft tissue mass in the distribution of the PVS is a novel characteristic thoracic MDCT angiography finding seen in pediatric secondary PVS due to TAPVC repair.

Extravascular MDCT Findings of Pulmonary Vein Stenosis in Children with Cardiac Septal Defect

Purpose: To retrospectively investigate the extravascular thoracic MDCT angiography findings of pulmonary vein stenosis (PVS) in children with a cardiac septal defect. Materials and Methods: Pediatric patients (age ≤ 18 years) with cardiac septal defect and PVS, confirmed by echocardiogram and/or conventional angiography, who underwent thoracic MDCT angiography studies from April 2009 to April 2021 were included. Two pediatric radiologists independently evaluated thoracic MDCT angiography studies for the presence of extravascular thoracic abnormalities in: (1) lung and airway (ground-glass opacity (GGO), consolidation, pulmonary nodule, mass, cyst, septal thickening, fibrosis, and bronchiectasis); (2) pleura (pleural thickening, pleural effusion, and pneumothorax); and (3) mediastinum (mass and lymphadenopathy). Interobserver agreement between the two independent pediatric radiology reviewers was evaluated with kappa statistics. Results: The final study group consisted of 20 thoracic MDCT angiography studies from 20 consecutive individual pediatric patients (13 males (65%) and 7 females (35%); mean age: 7.5 months; SD: 12.7; range: 2 days to 7 months) with cardiac septal defect and PVS. The characteristic extravascular thoracic MDCT angiography findings were GGO (18/20; 90%), septal thickening (9/20; 45%), pleural thickening (16/20; 80%), and ill-defined, mildly heterogeneously enhancing, non-calcified soft tissue mass (9/20; 45%) following the contours of PVS in the mediastinum. There was a high interobserver kappa agreement between two independent reviewers for detecting extravascular abnormalities on thoracic MDCT angiography studies (k = 0.99). Conclusion: PVS in children with a cardiac septal defect has a characteristic extravascular thoracic MDCT angiography finding. In the lungs and pleura, GGO, septal thickening, and pleural thickening are frequently seen in children with cardiac septal defect and PVS. In the mediastinum, a mildly heterogeneously enhancing, non-calcified soft tissue mass in the distribution of PVS in the mediastinum is seen in close to half of the pediatric patients with cardiac septal defect and PVS.

Patient and Family-Centered Care for Pediatric Intraluminal Pulmonary Vein Stenosis: Case of a 3 Year Old Patient with Focus on Nurse Practitioner Role

A nurse practitioner’s experience in managing children with intraluminal pulmonary vein stenosis. A case study of a 3-year-old patient with multi–vessel intraluminal pulmonary vein stenosis.

Pulmonary Vein Stenosis: Incremental Knowledge Gains to Improve Outcomes

Pulmonary vein stenosis remains a considerable clinical challenge, with high mortality still present in children with progressive disease. In this review, we discuss the clinical spectrum of pulmonary vein stenosis and what is known about the etiology and potential modifying and contributing factors in progressive pulmonary vein stenosis.

Systemic Sirolimus Therapy for Infants and Children With Pulmonary Vein Stenosis

BACKGROUND

Anatomic 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.

OBJECTIVES

The 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.

METHODS

In 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.

RESULTS

Between 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.

CONCLUSIONS

The 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.

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.

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.

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.

Adjunct Targeted Biologic Inhibition Agents to Treat Aggressive Multivessel Intraluminal Pediatric Pulmonary Vein Stenosis

OBJECTIVE

To evaluate the use of imatinib mesylate with or without bevacizumab targeting neoproliferative myofibroblast-like cells with tyrosine kinase receptor expression, as adjuncts to modern interventional therapies for the treatment of multivessel intraluminal pulmonary vein stenosis (PVS). We describe the 48- and 72-week outcomes among patients receiving imatinib mesylate with or without bevacizumab for multivessel intraluminal PVS.

STUDY DESIGN

This single-arm, prospective, open-label US Food and Drug Administration approved trial enrolled patients with ≥2 affected pulmonary veins after surgical or catheter-based relief of obstruction between March 2009 and December 2014. Drug therapy was discontinued at 48 weeks, or after 24 weeks of stabilization, whichever occurred later.

RESULTS

Among 48 enrolled patients, 5 had isolated PVS, 26 congenital heart disease, 5 lung disease, and 12 both. After the 72-week follow-up, 16 patients had stabilized, 27 had recurred locally without stabilization, and 5 had progressed. Stabilization was associated with the absence of lung disease (P = .03), a higher percentage of eligible drug doses received (P = .03), and was not associated with age, diagnosis, disease laterality, or number of veins involved. Survival to 72 weeks was 77% (37 of 48). Adverse events were common (n = 1489 total), but only 16 were definitely related to drug treatment, none of which were serious.

CONCLUSION

Survival to 72 weeks was 77% in a referral population with multivessel intraluminal PVS undergoing multimodal treatment, including antiproliferative tyrosine kinase blockade. Toxicity specific to tyrosine kinase blockade was minimal.

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

OBJECTIVE

To quantify outcomes of infants (<1 year of age) diagnosed with pulmonary vein stenosis (PVS).

STUDY DESIGN

MEDLINE (PubMed), Scopus, and Web of Science were searched through February 1, 2017, with no language restrictions. Publications including infants diagnosed with primary PVS, defined as the absence of preceding intervention(s), were considered. The study was performed according to Meta-analysis of Observational Studies in Epidemiology guidelines, the Systematic Reviews, and Meta-Analysis checklist, and registered prospectively. The quality of selected reports was critically examined. Data extraction was independently performed by multiple observers with outcomes agreed upon a priori. Data were pooled using an inverse variance heterogeneity model with incidence of mortality the primary outcome of interest.

RESULTS

Forty-eight studies of 185 infants were included. Studies were highly diverse with regards to the participants, interventions, and outcomes reported. The median (range) age at diagnosis was 5.0 (0.1-11.6) months. Pooled mortality was 58.5% (95% CI 49.8%-67.0%, I² = 21.4%). We observed greater mortality incidence among infants with 3 or 4 vein stenoses than in those with 1 or 2 vein stenoses (83.3% vs 36.1%; P < .01). We observed greater mortality among infants with bilateral than unilateral disease (78.7% vs 26.0%; P < .01).

CONCLUSIONS

Studies of primary PVS during infancy are highly variable in their methodological quality and estimates of clinical outcomes; therefore, estimates of prognosis remain uncertain. Multicenter, interdisciplinary collaborations, including alignment of key outcome measurements, are needed to answer questions beyond the scope of available data.

Reintervention Is Associated With Improved Survival in Pediatric Patients With Pulmonary Vein Stenosis

OBJECTIVES

The aim of this study was to evaluate survival following catheter intervention in pediatric patients with pulmonary vein stenosis (PVS).

BACKGROUND

Despite aggressive surgical and catheter intervention on PVS in children, recurrence and progression of stenosis can lead to right heart failure and death. Clinicians continue to seek effective treatment options for PVS.

METHODS

A single-center, retrospective study was performed including all patients <18 years of age who underwent catheter intervention (balloon angioplasty and bare-metal stent and drug-eluting stent insertion) on PVS. Endpoints included death, vein loss, and rate of reintervention.

RESULTS

Thirty patients underwent intervention (balloon angioplasty, n = 9; bare-metal stent, n = 5; drug-eluting stent, n = 16) at a median age of 6.4 months (4.3 to 9.9 months). Median follow-up duration was 30.6 months (77 days to 10.5 years). Fourteen patients (47%) died at a median of 2.0 months (0.4 to 3.2 months) following intervention. There was no association between DES placement and survival (p = 0.067). Reintervention (catheter or surgical) was associated with improved survival (p = 0.001), with a 1-year survival rate of 84% compared with 25% for no reintervention. Vein loss occurred in 34 of 58 (59%) veins at a median of 3.3 months (1.0 to 5.0 months). One-year vein survival was higher with DES implantation (p = 0.031) and with reintervention (p < 0.001).

CONCLUSIONS

DES implantation at first catheter intervention appears to be associated with improved vein survival but may not result in improved patient survival. However, reintervention appears to be associated with improved patient survival and vein patency, suggesting that despite mode of treatment, frequent surveillance is important in the care of these patients.

Lung Pathology in Pediatric Pulmonary Vein Stenosis

Pulmonary vein stenosis is a rare progressive narrowing of the extrapulmonary pulmonary veins, presenting predominantly in infancy and virtually always lethal. It typically arises following repair of congenital heart disease, particularly anomalous pulmonary venous return. Histologic characterization of pediatric pulmonary vein stenosis, not previously well described, may provide insight into the disease pathobiology. We retrieved archival lung specimens (biopsy, explant, or autopsy) from patients with pediatric pulmonary vein stenosis. Medical records were reviewed. Microscopic examination included hematoxylin and eosin (H&E)-stained slides, and for a subset of patients, elastic, trichrome, smooth-muscle actin, and D2-40. Groups with different clinical disease features were compared using Fisher's exact test. A total of 33 patients (median age, 7 months) had available tissue and 52% had congenital heart disease; 18% were premature. Within the lungs, interlobular septal veins showed thickened muscular coats (in 58%), proliferation/tortuosity (in 6%), and fibromyxoid intimal proliferation (in 3%). Associated arterial hypertensive changes were seen in 30 (91%). The one patient with intrapulmonary venous fibromyxoid intimal proliferation was the only patient with apparent primary familial disease. Lymphangiectasia and arterial medial hypertrophy were histologic features that correlated with clinical grouping. We conclude that in pediatric pulmonary vein stenosis, intrapulmonary pulmonary veins commonly show muscular thickening, best interpreted as venous hypertensive remodeling. Fibromyxoid intimal proliferation resembling that of the extrapulmonary pulmonary veins is uncommon. Awareness of intrapulmonary features in various clinical subtypes of pulmonary vein stenosis may be diagnostically and therapeutically informative considering that current catheter-based and surgical therapy is directed at the extrapulmonary component of pulmonary vein stenosis.

Systemic Embolic Complications of Pulmonary Vein Angioplasty in Children

Pulmonary vein stenosis (PVS) carries significant morbidity and mortality for affected children, and its management often requires multiple angioplasty procedures. PVS angioplasty can be complicated by systemic embolic events such as stroke, but incidence and risk factors are poorly understood. We reviewed pediatric catheterizations involving PVS angioplasty and/or stent placement performed at Boston Children's Hospital between July 2005 and February 2014. A total of 406 cases were performed in 144 distinct patients. Patients underwent a median of two catheterizations, at median age 1 year and weight 6.9 kg. Eleven (2.7 %) catheterizations were complicated by clinically apparent systemic embolic events, comprising 10 strokes (one with associated hepatic embolism) and 1 renal infarct. Prevalence of clinically evident stroke among this cohort was 7.6 %. Using a prior (uncomplicated) catheterization to allow each patient to serve as their own control, we sought to identify potentially modifiable risk factors for systemic embolic events. Although this analysis was limited by low power, complicated and uncomplicated angioplasties did not appear to differ in case time, contrast dose, anticoagulation management, use of cutting balloons, number of catheter exchanges, or size of long sheath used. Significant non-embolic adverse events were common, occurring in 25 % of catheterizations. Systemic embolism appears to complicate PVS angioplasty at a rate much higher than that described for other congenital catheterizations. This risk may be inherent to the procedure rather than related to any modifiable or operator-dependent factors.

Outcomes of surgery for young children with multivessel pulmonary vein stenosis

OBJECTIVE

We pursued a multimodality approach to the treatment of patients with pulmonary vein stenosis, incorporating sutureless surgical repair, catheter interventions, and adjunctive chemotherapy. We report our outcomes after surgery.

METHODS

Between January 2007 and August 2013, 49 patients with multivessel pulmonary vein stenosis underwent operations at our institution. We retrospectively reviewed data from a pulmonary vein stenosis registry and the medical records.

RESULTS

At the time of the index operation, the median patient age was 6 months (range, 32 days-48 months) and weight was 4.9 kg (range, 2.1-13.4 kg). Fourteen patients (28%) died during the follow-up period (median follow-up was 0.5 years [range, 0.04-4.9 years]). There were 2 deaths (4%) within 30 days. Age at repair <6 months, weight at repair <3 kg, and a preoperative right ventricular systolic pressure < ¾ systemic were found to be associated with mortality. One patient required repeat operation for recurrent stenosis. Thirty-nine patients (80%) underwent postoperative catheterizations. The median number of catheterizations per patient was 2 (range, 0-14). Twenty-nine patients (59%) underwent catheterizations with pulmonary vein intervention. The median number of catheterizations with intervention per patient was 1 (range, 0-14). There were no identifiable associations with need for or number of catheterizations with intervention. Ten patients were listed for lung transplantation: 4 patients were de-listed, 3 patients died waiting, and 3 patients underwent transplant.

CONCLUSIONS

Using a multimodality approach, we observed acceptable early survival after operation in patients with pulmonary vein stenosis, despite the need for catheter reinterventions. Lung transplantation remains a viable option.