Pulmonary vein stenosis: expression of receptor tyrosine kinases by lesional cells

An infant with primary pulmonary vein stenosis, associated with fatal occlusion of intraparenchymal small pulmonary veins

Primary pulmonary vein stenosis (PVS) is rare within the pediatric population and its pathophysiology remains unclear, especially as to how the histopathology relates to its refractoriness to treatment. We report the case of a 4-month-old girl with primary PVS. The lesion in this patient was characterized by fatal obstruction of intraparenchymal small pulmonary veins, associated with localized stenosis at the four pulmonary veno-atrial junctions. All four localized stenoses underwent transcatheter stent implantation. Although the procedure was technically successful, her clinical status failed to improve, and she died 2 months after stenting. Histopathological examination of lung specimens showed severe luminal obstruction by marked intimal proliferation with fibrosis in the intraparenchymal small pulmonary veins, and these findings were present in every lobe. To the best of our knowledge, the histopathological findings and clinical course in this case, including the response to treatments, are extremely rare. We suggest that the histological findings of the small pulmonary veins are important in deciding the indication and appropriate timing of intervention. <Learning objective: The outcome of primary pulmonary vein stenosis has remained poor despite aggressive treatment, while the indication and appropriate timing of intervention has not been clarified. The histological findings of small pulmonary veins are important to predict the response to treatment and outcome, and early intervention might prevent the secondary progression of this disease.>.

Cryo-balloon angioplasty for pulmonary vein stenosis in pediatric patients

This study sought to determine the safety and effectiveness of cryo-balloon angioplasty (CbA) for pulmonary vein stenosis (PVS) in pediatric patients. Current therapy options for PVS are less than satisfactory due to recurrent progressive restenosis and neointimal proliferation. Catheterization database, hospital records, imaging studies, and pathologic specimens were reviewed for procedural-related and outcomes data in all patients who underwent pulmonary vein (PV) CbA using the Boston Scientific PolarCath Peripheral Dilation System between August 2006 and June 2009. Thirteen patients (19 PVs; median age 13 months [range 3.5 months to 18.5 years] and weight 7.9 kg [range 3.8 to 47.7]) underwent CbA. Mean PVS diameter after CbA increased from 2.19 (± 0.6) to 3.77 (± 1.1) mm (p < 0.001). Mean gradient decreased from 14 (± 7.4) to 4.89 (± 3.2) mm Hg (p < 0.001). Mean stenosis-to-normal vein diameter ratio increased from 0.52 (± 0.15) to 0.89 (± 0.33) (p < 0.001). Eight patients underwent repeat catheterization a mean of 5.6 months (± 3.66) later. Improved PVS diameter was maintained in 2 PVs. Four veins had restenosis but maintained diameters greater than that before initial CbA. In 11 PVs, the diameter decreased from 4.28 (± 1.14) to 2.53 (± 0.9) mm (p = 0.001). Mean gradient increased from 3.55 (± 3.0) to 14.63 (± 9.6) mm Hg (p = 0.011). All vessels underwent repeat intervention with acute relief of PVS. Stroke occurred within 24 h of CbA in 1 patient. CbA of PVS is safe and results in acute relief of stenosis. However, CbA appears minimally effective as the sole therapy in maintaining long-term relief of PVS.

A prospective phase II trial of vinblastine and methotrexate in multivessel intraluminal pulmonary vein stenosis in infants and children

OBJECTIVE

To determine the safety and efficacy of the chemotherapeutic agents vinblastine and methotrexate in the treatment of children with progressive multivessel intraluminal pulmonary vein stenosis (PVS).

METHODS

Children received weekly vinblastine and methotrexate for a period of 1 year. Outcomes (for patients receiving ≥1 month of chemotherapy) were classified separately for patients with isolated PVS and PVS with congenital heart disease (CHD). Primary efficacy outcome was "response to treatment" categorized by echocardiographic criteria of response. Survival to 1 year was also evaluated. All adverse events were classified according to Cancer Therapy Evaluation Program, Common Terminology Criteria version 3.0. Events were further classified as related to chemotherapy, cardiac, or other causes.

RESULTS

Among 29 patients enrolled, 28 received at least one dose of chemotherapy and were evaluable for toxicity, while 23 were evaluable for response (21 CHD, 2 isolated). Both patients in the isolated group had progressive disease and died. Overall, 33% (7/21) of patients with PVS and CHD had stable disease; 1-year survival of 38%; and four patients continue in remission (93, 96, 124, and 125 months after treatment initiation). While both cardiac-related (19%) and chemotherapy-related (53%) toxicities were common, most were asymptomatic laboratory changes. Grade 3 (13%) and grade 4 (4%) toxicities were reversible, and no treatment-related grade 5 toxicities were observed.

CONCLUSION

We report on the first prospective trial of chemotherapy for infants and children targeting the presence of myofibroblastic cells within the lesions of PVS based on myofibroblastic proliferation associated with desmoid tumors of infancy. The toxicity profile resulted in numerous treatment delays and interruptions that, combined with limited information on the natural history of PVS in this patient population, hampered our ability to determine the true efficacy of this approach. These results will be important as a baseline for clinical trials in this patient population.

The role of surgical therapy for pulmonary vein atresia in childhood

The outcome for children with pulmonary vein atresia has been historically poor. This report describes clinical outcomes after surgical treatment of primary and secondary pulmonary vein atresia. All patients undergoing surgery for pulmonary vein atresia at Children's Hospital Boston from 1 January 2005 to 1 January 2009 were identified. The data available for analysis included demographic characteristics, findings based on cardiac catheterization and other imaging, clinical information, operative surgical intervention, and pulmonary vein histology. The study-specific information included the calculated number of atretic pulmonary veins as well as surgical interventions performed during the study period. The study end points included successful relief of pulmonary vein atresia, recurrence of pulmonary atresia or stenosis, overall pulmonary vein disease progression, and patient survival. A total of 16 patients with one or more pulmonary vein atresias were identified in the cardiac surgery registry database. Of these 16 patients, 5 had primary pulmonary atresia, and 11 had secondary atresia after repair of anomalous pulmonary venous drainage. Surgical recanalization of atretic pulmonary veins was achieved for more than 80% of the patients. At the most recent follow-up assessment, 7 (44%) of the 16 patients had recurrence of atresia. Five of the patients had development of new atresia in other previously healthy pulmonary veins. The median follow-up period was 4 months for primary and 17 months for secondary pulmonary vein atresia. The three main predictors of pulmonary vein disease progression after surgery were the presence of underlying lung disease (P = 0.036), prematurity (P = 0.035), and a history of recurrent pulmonary vein atresia. The overall mortality rate for the patients with primary or secondary pulmonary vein atresia was 56% at the most recent follow-up assessment (100% for the patients with primary vein atresia and 36% for the patients with secondary vein atresia).

CONCLUSIONS

Surgical recanalization of pulmonary vein atresia is possible, but prognosis remains poor. Recurrence of atresia can take place as early as a few months in the presence of underlying lung disease, prematurity, or history of recurrent pulmonary vein atresia. Further research is needed to identify mechanisms for attaining and sustaining pulmonary vein patency after surgery.

Serum levels after everolimus-stent implantation and paclitaxel-balloon angioplasty in an infant with recurrent pulmonary vein obstruction after repaired total anomalous pulmonary venous connection

Everolimus-eluting stents and paclitaxel-coated balloons are used in the interventional treatment of coronary artery disease in adults to reduce the restenosis rate and in small-vessel disease. Both substances are released into the circulation. We report systemic drug exposure after implantation of one everolimus-eluting stent and dilation with one paclitaxel-coated balloon in an 8-month-old infant, which was used as an innovative therapy for recurrent pulmonary vein stenosis.

Pulmonary vein stenosis: prematurity and associated conditions

OBJECTIVE

Pulmonary vein stenosis is a rare, although often lethal, anomaly. Risk factors for the diagnosis of pulmonary vein stenosis are poorly characterized. In this study we sought to identify factors associated with pulmonary vein stenosis, paying particular attention to preterm birth.

METHODS

By review of the cardiac database we identified all of the subjects with pulmonary vein stenosis over a 10-year period at our institution. Those children with anomalous pulmonary venous connection were not included. Patient-related variables were analyzed for their association with pulmonary vein stenosis. Pulmonary vein stenosis was diagnosed by spectral Doppler interrogation of the pulmonary veins (continuous, turbulent flow with calculated mean gradient > 5 mm Hg) and confirmed by cardiac catheterization in nearly all of the cases.

RESULTS

Twenty-six patients with pulmonary vein stenosis were identified. The median age at diagnosis was 7.4 months; range: 1 day to 35 months. Congenital heart defects were present in the majority of subjects. Associated genetic syndromes were present in 8 subjects (31%). The 2-year survival rate from diagnosis was 43%. The majority of subjects (16 [61%]) were preterm. Gestational ages ranged from 24.2 to 41.0 weeks, and birth weights ranged from 460 to 4445 g. Preterm birth was strongly associated with the diagnosis of pulmonary vein stenosis, odds ratio 10.2 (95% CI 4.7-22.6), p < .001. Eleven (42%) of the 26 subjects were treated for bronchopulmonary dysplasia before being diagnosed with pulmonary vein stenosis.

CONCLUSIONS

Prematurity is associated with the diagnosis of pulmonary vein stenosis. It is interesting to note that many of these patients also have intracardiac shunt lesions, which may act in concert with preterm endothelium to produce pulmonary vein stenosis.

Importance of totally anomalous pulmonary venous connection and postoperative pulmonary vein stenosis in outcomes of heterotaxy syndrome

Historically, outcomes of patients with heterotaxy syndrome and congenital heart disease have been poor. Published series include patients treated over many decades or focus on specific patient/operative subgroups. This study was performed to evaluate midterm outcomes and determine anatomic risk factors for death in patients with all types of heterotaxy syndrome treated after 1985. We reviewed all infants with heterotaxy born between 1985 and 1997, presenting to one institution at <6 months age, followed for > or =5 years. Of 102 study patients (46 with asplenia phenotype, 56 with polysplenia phenotype), 48 (47%) died at a median age of 0.6 months, 12 without intervention. Survivors were followed for a median of 12.8 years (5-21.7 years). Independent predictors of mortality included obstructed totally anomalous pulmonary venous connection (TAPVC) (OR, 7.8; 95% CI, 1.9-32.9; p = 0.005), mild or greater atrioventricular (AV) valve regurgitation at presentation (OR, 3.5; 95% CI, 1.0-12.1; p = 0.03), and common AV canal (OR, 3.1; 95% CI, 1.1-8.5; p = 0.03). Sixteen patients developed pulmonary vein stenosis at a median age of 2 months, with 5 (31%) alive at follow-up. In patients with TAPVC, the mean indexed sum of pulmonary vein diameters was lower among patients who died than in survivors (42.3 +/- 8.3 vs 49.5 +/- 10.1 mm/m2; p = 0.02). Mortality remains high among patients with heterotaxy treated in the modern surgical era, particularly those with obstructed TAPVC. Pulmonary vein stenosis is common after repair of TAPVC in patients with heterotaxy, may be diagnosed beyond infancy, and is associated with poor outcomes.