Outcomes After Stent Implantation for the Treatment of Congenital and Postoperative Pulmonary Vein Stenosis in Children

Systemic Sirolimus to Prevent In-Stent Stenosis in Pediatric Pulmonary Vein Stenosis

Evaluate the efficacy of systemic sirolimus (rapamycin) in preventing in-stent stenosis (ISS) in pediatric intraluminal pulmonary vein stenosis (PVS). Report the adverse events related to sirolimus therapy. There is a high incidence of ISS following stent implantation in PVS. The use of sirolimus in preventing ISS has not been reported. Retrospective review of all patients who received sirolimus (8 week course) for treatment of ISS for PVS between January 2013 and June 2018. Forty stents (37 bare metal, 3 drug-eluting) in 20 patients were treated with sirolimus; 20 at the time of implantation (primary prevention [1P]) and 20 following documented ISS requiring transcatheter reintervention (secondary prevention [2P]). Treated patients were young (median 2 y/o [0.7-5.7]) and most had PVS associated with congenital heart disease (75%, 15/20; 4/15 with TAPVC). In the 1P group, 85% (17/20) of stents were without significant (< 50%) ISS at median of 102 days (range 56-527); the growth rate of ISS in this group was 7.5 ± 7.1%/month. In the 2P group, most stents had a slower growth rate of ISS after sirolimus therapy compared to pre-treatment (median 3.7 [- 0.2 to 13.1] vs. 10.4 [1.3 to 19.5] %/month; p < 0.001). One patient developed pneumonia on drug while concurrently taking another immunosuppressive agent. No other serious adverse events were related to sirolimus therapy. Systemic sirolimus slows the growth rate of ISS following stent implantation in PVS compared to pre-treatment rates and was administered safely in a small number of pediatric patients with complex heart disease.

Clinical outcomes after the endovascular treatments of pulmonary vein stenosis in patients with congenital heart disease

BACKGROUND

Pulmonary vein stenosis (PVS) is a condition with challenging treatment and leads to severe cardiac failure and pulmonary hypertension. Despite aggressive surgical or catheter-based intervention, the prognosis of PVS is unsatisfactory. This study aimed to assess the prognosis and to establish appropriate treatment strategies.

METHODS

We retrospectively reviewed endovascular treatments for PVS (2001-2017) from the clinical database at the Okayama University Hospital.

RESULTS

A total of 24 patients underwent PVS associated with total anomalous pulmonary venous connection and 7 patients underwent isolated congenital PVS. In total, 53 stenotic pulmonary veins were subjected to endovascular treatments; 40 of them were stented by hybrid (29) and percutaneous procedures (11) (bare-metal stent, n = 34; drug-eluting stent, n = 9). Stent size of hybrid stenting was larger than percutaneous stenting. Median follow-up duration from the onset of PVS was 24 months (4-134 months). Survival rate was 71 and 49% at 1 and 5 years, respectively. There was no statistically significant difference between stent placement and survival; however, patients who underwent bare-metal stent implantation had statistically better survival than those who underwent drug-eluting stent implantation or balloon angioplasty. Early onset of stenosis, timing of stenting, and small vessel diameter of pulmonary vein before stenting were considered as risk factors for in-stent restenosis. Freedom from re-intervention was 50 and 26% at 1 and 2 years.

CONCLUSIONS

To improve survival and stent patency, implantation of large stent is important. However, re-intervention after stenting is also significant to obtain good outcome.

Outcomes of Reinterventions for Children with Postoperative Pulmonary Venous Restenosis

This report aims to summarize and evaluate the efficacy and experience of reintervention for children with postoperative pulmonary venous restenosis. Clinical data from 61 patients with postoperative pulmonary venous restenosis who underwent reintervention at Shanghai Children's Medical Center (SCMC) from September 2009 to June 2018 were retrospectively analyzed. The patients comprised 38 boys and 23 girls, with a mean age of 15.4 ± 12.6 months (2-83 months) and a mean weight of 8.1 ± 3.4 kg (3.7-18.5 kg). The mean pulmonary venous velocity was 2.31 ± 0.47 m/s (1.86-3.22 m/s). Primary disease included 48 cases of total anomalous pulmonary venous drainage, nine cases of partial anomalous pulmonary venous drainage, and four cases of primary pulmonary venous stenosis. The reintervention procedures included 34 cases using the sutureless technique, ten cases using bovine pericardium enlargement, three cases using blunt enlargement, four cases of balloon dilatation, one case using stent implantation and nine cases involving more than two surgical methods. The early postoperative pulmonary venous velocity was 1.16 ± 0.20 m/s. There were five in-hospital deaths, resulting in a mortality rate of 8.2%. Fifty-six survivors were followed for 52.8 ± 46.5 months (6-103 months) with no delayed deaths. Echocardiography showed pulmonary venous anastomosis and diameter growth after reintervention, exhibiting a mean growth speed of 0.026 ± 0.013 cm/month (p < 0.05) and a mean velocity of 1.24 ± 0.26 m/s; five patients experienced varying degrees of pulmonary venous obstruction (> 1.6 m/s), but did not require reoperation. Postoperative pulmonary venous restenosis is a common complication after surgery for pulmonary venous malformations. Reintervention should be performed in the early period of pulmonary venous obstruction. Growth of pulmonary venous anastomoses was observed after performing the sutureless technique, bovine pericardium enlargement and blunt enlargement. Although balloon dilatation has a good effect in the early postoperative period, its restenosis rate is high, and strict mid- to long-term follow-up is needed.

Rare cause of cardiac failure in an infant

Congenital stenosis of the pulmonary veins is a rare condition whose outcome is guarded despite the available treatment options. We report a case of a 6-month-old infant with significant stenosis of all four pulmonary veins.

Severe hypertriglyceridemia associated with everolimus drug-eluting stent placement in an infant

We report a case of severe hypertriglyceridemia associated with an everolimus drug-eluting stent in an infant with pulmonary vein stenosis. We review from current literature the mechanisms by which everolimus may cause dyslipidaemia, pharmacokinetics of everolimus in drug-eluting stents, and treatments of hypertriglyceridemia. This case demonstrates the need to closely monitor serum triglyceride levels after everolimus drug-eluting stent placement in infants.

Hybrid Pulmonary Vein Stenting in Infants with Refractory to Surgical Pulmonary Vein Stenosis Repair

Pulmonary vein stenosis (PVS) is still a frustrating disease with extremely high mortality, especially in children with multiple severe PVS. Hybrid pulmonary vein stenting (HPVS) is a rescue treatment for recurrent and malignant PVS. The aim of this study is to share our successful experience with intraoperative HPVS for recurrent PVS after total anomalous pulmonary venous connection (TAPVC) repair in infant. Six patients were identified between 2013 and January 2018, who were diagnosed with recurrent PVS and underwent HPVS in the operating room. The mean age at the time of the HPVS was 10.3 ± 2.7 months (range 7-14 months) and the mean body weight was 7.9 ± 2.6 kg (range 4.1-10.5 kg). Prior pulmonary vein surgery had been performed on average 2.7 times (range 2-3) in all patients. We used a bare-metal stent (BMS) of 6-8 mm diameter in 15 veins of five patients and a drug-eluting coronary stent (DES) in two veins of one patient. All patients had undergone several elective further pulmonary vein in-stent balloon dilatations or another stent insertion after HPVS. Over a mean follow-up of 17.3 ± 13.7 months (range 6-44 months), all patients maintained patency of stents although two patients died due to respiratory failure not associated with PVS. HPVS is a useful treatment modality for recurrent PVS patient that could save the life and achieve longer freedom from restenosis than repetitive surgical pulmonary vein widening only. Even though the prognosis of severe multiple PVS is very poor, planned HPVS could be a good palliation in this patients group.

Pulmonary Vein Stenosis: Outcomes in Children With Congenital Heart Disease and Prematurity

Pulmonary vein stenosis (PVS) is a rare condition that has been linked to prematurity and congenital heart disease (CHD). Despite these associations, treatment options are limited and outcomes are guarded. We investigated differences in PVS outcomes based on the presence of CHD and prematurity, and risk factors for mortality or lung transplantation in PVS. Single-center retrospective cohort study of patients diagnosed with PVS between January 2005 and May 2016 and identified by ICD codes with chart validation. Cox proportional hazard models assessed risk factors for the composite outcome of mortality or lung transplantation. Ninety-three patients with PVS were identified: 65 (70%) had significant CHD, 32 (34%) were premature, and 14 (15%) were premature with CHD. Sixty-five (70%) underwent a PVS intervention and 42 (46%) underwent ≥2 interventions. Twenty-five subjects (27%) died or underwent lung transplant 5.8 months (interquartile range [IQR] 1.1, 15.3) after diagnosis. There was no difference in age at diagnosis or mortality based on presence of CHD or prematurity. PVS diagnosis before age 6 months and greater than 1 pulmonary vein affected at diagnosis were associated with higher mortality (hazards ratio [HR] 3.4 (95% confidence interval 1.5, 7.5), P = 0.003, and HR 2.1 per additional vein affected (95% confidence interval 1.3, 3.4), P = 0.004, respectively). Survival in children with PVS is poor, independent of underlying CHD or prematurity. Younger age and greater number of veins affected at diagnosis are risk factors for worse outcome. Understanding causal mechanisms and development of treatment strategies are necessary to improve outcomes.

Palliating Premature Infants With Obstructed Total Anomalous Pulmonary Venous Connection via Catheterization

Obstructed total anomalous pulmonary venous connection (TAPVC) involves anomalous drainage of all pulmonary veins to a location other than the left atrium and typically causes significant respiratory symptoms requiring urgent surgical repair. Premature infants born with obstructed TAPVC are often not considered to be suitable surgical candidates due to their size and therefore pose a significant treatment dilemma. Catheter-based interventions provide a temporizing option for infants with obstructed TAPVC, allowing for hemodynamic stabilization and growth until surgical intervention is feasible. We describe the course of two premature infants with obstructed TAPVC who were palliated with stenting of their anomalous pulmonary veins. Both infants required repeat catheter-based intervention for recurrent stenosis and ultimately underwent successful surgical repair at an acceptable weight and corrected gestational age. We propose that a novel catheter-based approach to initial management may be a beneficial option in the premature and low-weight patient population.

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.

Selective pulmonary artery occlusion to treat hemoptysis associated with pulmonary venous obstruction

Hemoptysis may occur in patients with pulmonary venous obstruction and prominent decompressing vessels in the airways adjacent to the affected pulmonary veins. The options for treatment of hemoptysis are limited, particularly when efforts to alleviate pulmonary venous obstruction have failed. Here we describe a patient with hemoptysis associated with stenosis of the central left upper pulmonary vein and occlusion of the central left lower pulmonary vein. The left upper pulmonary vein was dilated with balloon catheters and a vascular plug was placed in the left lower pulmonary artery. Vascular engorgement regressed in the left bronchus and hemoptysis has not recurred for 4 years despite recurrence of left upper pulmonary vein stenosis. Selective occlusion of branch pulmonary arteries may be an effective option for the treatment of hemoptysis from bleeding in lung segments with inoperable pulmonary venous obstruction.

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.

Total Anomalous Pulmonary Venous Connection: Preoperative Anatomy, Physiology, Imaging, and Interventional Management of Postoperative Pulmonary Venous Obstruction

Total anomalous pulmonary venous connection refers to a spectrum of cardiac anomalies where the pulmonary veins fail to return to the left atrium and the pulmonary venous blood returns through a systemic vein or directly to the right atrium. There is a wide anatomical variety of venous connections and degrees of pulmonary venous obstruction that affect the presentation, surgical repair, and outcomes. In this review, we explore the preoperative physiology, echocardiographic diagnosis, and approach to postoperative complications.

Pulmonary Vein Stenosis in a Newborn: A Commonly Overlooked Diagnosis

The diagnosis of primary pulmonary vein stenosis is often overlooked because its symptoms overlap lung diseases and pulmonary arterial hypertension. Its diagnosis may be difficult because the condition is progressive and associated with other defects. We present a case of pulmonary vein stenosis in a newborn with stenosis of the left-sided common pulmonary vein, diffuse hypoplasia of the superior right pulmonary vein, and atresia of the inferior right pulmonary vein.

Cathether-based interventional strategies for cor triatriatum in the adult - feasibility study through a hybrid approach

Background

Cor triatriatum is a rare congenital cardiac abnormality, consisting of an obstructing membrane between the pulmonary veins and the mitral valve in varying patterns. The entitiy can mimick the pathophysiology of mitral stenosis, necessitating surgical resection. Occasionally, percutaneous balloon dilatation of the membrane has been successfully performed.

Case presentation

We report two cases with cor triatriatum where intraoperative balloon dilatation of the membrane was attempted followed by surgical resection, to explore the feasibility of cathether-based interventional strategies for cor triatriatum.

Conclusions

Various anatomical variations exist of cor triatriatum, depending on the drainage of the pulmonary veins and the drainage of the proximal chamber in the right or left atrium. Only isolated forms of cor triatriatum where all pulmonary veins ultimately drain into the left atrium can be recommended for percutaneous strategies. In addition, several anatomical characteristics should be considered to predict technical success of cathether-based interventional strategies, such as the location of the membrane, the degree of pulmonary vein stenosis, the extent of calcification, and the presence of other (congenital) cardiovascular abnormalities. Furthermore, long-term efficacy of these strategies remains to be confirmed. As such, surgical treatment of cor triatriatum remains the mainstay of treatment in adult patients, especially when other cardiovascular anomalies are present which require surgical correction.

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.

“How to Do It”

Pulmonary vein stenosis (PVS) is often progressive and severe. Surgical and percutaneous angioplasty are acutely successful; however, restenosis is common and many patients require multiple reinterventions. We perform intraoperative “hybrid” stent placement to deliver larger, stronger stents. Hybrid stent placement is well described for pulmonary arterial stenosis (PAS). The PAS data demonstrate that smaller stents are associated with rapid in-stent restenosis. Data from PVS in adults demonstrate superior outcomes with larger stents. Hybrid stent placement requires a strong collaborative effort between congenital heart surgeons and interventional cardiologists.

Stents in paediatric and adult congenital interventional cardiac catheterization

A 'stent' is a tubular meshed endoprosthesis that has contributed to the development of interventional catheterization over the past 30 years. In congenital heart diseases, stents have offered new solutions to the treatment of congenital vessel stenosis or postsurgical lesions, to maintain or close shunt patency, and to allow transcatheter valve replacement. First, stents were made of bare metal. Then, stent frameworks evolved to achieve a better compromise between radial strength and flexibility. However, almost all stents used currently in children have not been approved for vascular lesions in children and are therefore used 'off-label'. Furthermore, the inability of stents to follow natural vessel growth still limits their use in low-weight children and infants. Recently, bioresorbable stents have been manufactured and may overcome this issue; they are made from materials that may dissolve or be absorbed in the body. In this review, we aim to describe the history of stent development, the technical characteristics of stents used currently, the clinical applications and results, and the latest technological developments and perspectives in paediatric and adult congenital cardiac catheterization.

Bilateral pulmonary vein stenting through an unligated vertical vein in a postoperative case of TAPVC

We present a case of obstructed supracardiac total anomalous connection (TAPVC) where the vertical vein was left open at surgery because of significant pulmonary artery hypertension. One month following surgery, the patient developed progressive pulmonary venous obstruction at the pulmonary vein-left atrial junction bilaterally. The pulmonary veins were stented using a technique where the unligated vertical vein was utilized to access left atrium.

Angioplasty of acquired pulmonary vein stenosis using covered stent

One of the most serious complications post-catheter ablation of atrial fibrillation is the development of pulmonary vein stenosis. Controversy currently exists about the optimal treatment approach. The use of balloons and larger stents (~10 mm) results in more optimal outcome than just balloon angioplasty alone; however, even with stent implantation, recurrent restenosis may occur in 30 to 50% of patients. We report the case of a 28-year-old man who developed recurrent left inferior pulmonary vein stenosis following radiofrequency ablation for atrial fibrillation. This was initially stented with good result but soon after developed restenosis and required balloon angioplasty. Following the third episode of restenosis, stenting of the pulmonary vein was performed using a covered stent. The pulmonary vein has remained patent for the last 5 years.

Pulmonary vein stenosis and the pathophysiology of "upstream" pulmonary veins

BACKGROUND

Surgical and catheter-based interventions on pulmonary veins are associated with pulmonary vein stenosis (PVS), which can progress diffusely through the "upstream" pulmonary veins. The mechanism has been rarely studied. We used a porcine model of PVS to assess disease progression with emphasis on the potential role of endothelial-mesenchymal transition (EndMT).

METHODS

Neonatal piglets underwent bilateral pulmonary vein banding (banded, n = 6) or sham operations (sham, n = 6). Additional piglets underwent identical banding and stent implantation in a single-banded pulmonary vein 3 weeks postbanding (stented, n = 6). At 7 weeks postbanding, hemodynamics and upstream PV pathology were assessed.

RESULTS

Banded piglets developed pulmonary hypertension. The upstream pulmonary veins exhibited intimal thickening associated with features of EndMT, including increased transforming growth factor (TGF)-β1 and Smad expression, loss of endothelial and gain of mesenchymal marker expression, and coexpression of endothelial and mesenchymal markers in banded pulmonary vein intimal cells. These immunopathologic changes and a prominent myofibroblast phenotype in the remodeled pulmonary veins were consistently identified in specimens from patients with PVS, in vitro TGF-β1-stimulated cells isolated from piglet and human pulmonary veins, and human umbilical vein endothelial cells. After stent implantation, decompression of a pulmonary vein was associated with reappearance of endothelial marker expression, suggesting the potential for plasticity in the observed pathologic changes, followed by rapid in-stent restenosis.

CONCLUSIONS

Neonatal pulmonary vein banding in piglets recapitulates critical aspects of clinical PVS and highlights a pathologic profile consistent with EndMT, supporting the rationale for evaluating therapeutic strategies designed to exploit reversibility of upstream pulmonary vein pathology.

Proximal pulmonary vein stenosis detection in pediatric patients: value of multiplanar and 3-D VR imaging evaluation

BACKGROUND

One of the important benefits of using multidetector computed tomography (MDCT) is its capability to generate high-quality two-dimensional (2-D) multiplanar (MPR) and three-dimensional (3-D) images from volumetric and isotropic axial CT data. However, to the best of our knowledge, no results have been published on the potential diagnostic role of multiplanar and 3-D volume-rendered (VR) images in detecting pulmonary vein stenosis, a condition in which MDCT has recently assumed a role as the initial noninvasive imaging modality of choice.

OBJECTIVE

The purpose of this study was to compare diagnostic accuracy and interpretation time of axial, multiplanar and 3-D VR images for detection of proximal pulmonary vein stenosis in children, and to assess the potential added diagnostic value of multiplanar and 3-D VR images.

MATERIALS AND METHODS

We used our hospital information system to identify all consecutive children (< 18 years of age) with proximal pulmonary vein stenosis who had both a thoracic MDCT angiography study and a catheter-based conventional angiography within 2 months from June 2005 to February 2012. Two experienced pediatric radiologists independently reviewed each MDCT study for the presence of proximal pulmonary vein stenosis defined as ≥ 50% of luminal narrowing on axial, multiplanar and 3-D VR images. Final diagnosis was confirmed by angiographic findings. Diagnostic accuracy was compared using the z-test. Confidence level of diagnosis (scale 1-5, 5 = highest), perceived added diagnostic value (scale 1-5, 5 = highest), and interpretation time of multiplanar or 3-D VR images were compared using paired t-tests. Interobserver agreement was measured using the chance-corrected kappa coefficient.

RESULTS

The final study population consisted of 28 children (15 boys and 13 girls; mean age: 5.2 months). Diagnostic accuracy based on 116 individual pulmonary veins for detection of proximal pulmonary vein stenosis was 72.4% (84 of 116) for axial MDCT images, 77.5% (90 of 116 cases) for multiplanar MDCT images, and 93% (108 of 116 cases) for 3-D VR images with significantly higher accuracy with 3-D VR compared to axial (z = 4.17, P < 0.001) and multiplanar (z = 3.34, P < 0.001) images. Confidence levels for detection of proximal pulmonary vein stenosis were significantly higher with 3-D VR images (mean level: 4.6) compared to axial MDCT images (mean level: 1.7) and multiplanar MDCT images (mean level: 2.0) (paired t-tests, P < 0.001). Thus, 3-D VR images (mean added diagnostic value: 4.7) were found to provide added diagnostic value for detecting proximal pulmonary vein stenosis (paired t-test, P < 0.001); however, multiplanar MDCT images did not provide added value (paired t-test, P = 0.89). Interpretation time was significantly longer and interobserver agreement was higher when using 3-D VR images than using axial MDCT images or MPR MDCT images for diagnosing proximal pulmonary vein stenosis (paired t-tests, P < 0.001).

CONCLUSIONS

Use of 3-D VR images in the diagnosis of proximal pulmonary vein stenosis in children significantly increases accuracy, confidence level, added diagnostic value and interobserver agreement. Thus, the routine use of this technique should be encouraged despite its increased interpretation time.