High pressure balloon angioplasty for branch pulmonary artery stenosis: early experience

Adult-onset idiopathic peripheral pulmonary artery stenosis

BACKGROUND

Peripheral pulmonary artery stenosis (PPS) refers to stenosis of the pulmonary artery from the trunk to the peripheral arteries. Although paediatric PPS is well described, the clinical characteristics of adult-onset idiopathic PPS have not been established. Our objectives in this study were to characterise the disease profile of adult-onset PPS.

METHODS

We collected data in Japanese centres. This cohort included patients who underwent pulmonary angiography (PAG) and excluded patients with chronic thromboembolic pulmonary hypertension or Takayasu arteritis. Patient backgrounds, right heart catheterisation (RHC) findings, imaging findings and treatment profiles were collected.

RESULTS

44 patients (median (interquartile range) age 39 (29-57) years; 29 females (65.9%)) with PPS were enrolled from 20 centres. In PAG, stenosis of segmental and peripheral pulmonary arteries was observed in 41 (93.2%) and 36 patients (81.8%), respectively. 35 patients (79.5%) received medications approved for pulmonary arterial hypertension (PAH) and 22 patients (50.0%) received combination therapy. 25 patients (56.8%) underwent transcatheter pulmonary angioplasty. RHC data showed improvements in both mean pulmonary arterial pressure (44 versus 40 mmHg; p<0.001) and pulmonary vascular resistance (760 versus 514 dyn·s·cm-5; p<0.001) from baseline to final follow-up. The 3-, 5- and 10-year survival rates of patients with PPS were 97.5% (95% CI 83.5-99.6%), 89.0% (95% CI 68.9-96.4%) and 67.0% (95% CI 41.4-83.3%), respectively.

CONCLUSIONS

In this study, patients with adult-onset idiopathic PPS presented with segmental and peripheral pulmonary artery stenosis. Although patients had severe pulmonary hypertension at baseline, they showed a favourable treatment response to PAH drugs combined with transcatheter pulmonary angioplasty.

Ultra-high pressure balloon angioplasty for pulmonary artery stenosis in children with congenital heart defects: Short- to mid-term follow-up results from a retrospective cohort in a single tertiary center

Objective

Balloon angioplasty (BA) has been the treatment of choice for pulmonary artery stenosis (PAS) in children. There remains, however, a significant proportion of resistant lesions. The ultra-high pressure (UHP) balloons might be effective in a subset of these lesions. In this study, we analyzed the safety and efficacy with short- to mid-term follow-up results of UHP BA for PAS in children with congenital heart defects (CHD) in our center.

Methods

This is a retrospective cohort study in a single tertiary heart center. Children diagnosed with PAS associated with CHD were referred for UHP BA. All data with these children were collected for analysis with updated follow-up.

Results

A total of 37 UHP BAs were performed consecutively in 28 children. The success rate was 78.4%. A significantly (P = 0.005) larger ratio of the balloon to the minimal luminal diameter at the stenotic waist (balloon/waist ratio) was present in the success group (median 3.00, 1.64-8.33) compared to that in the failure group (median 1.94, 1.41 ± 4.00). Stepwise logistic regression analysis further identified that the balloon/waist ratio and the presence of therapeutic tears were two independent predictors of procedural success. The receiver operating characteristic curve revealed a cut-off value of 2.57 for the balloon/waist ratio to best differentiate success from failure cases. Signs of therapeutic tears were present in eight cases, all of whom were in the success group. Perioperative acute adverse events were recorded in 16 patients, including 11 pulmonary artery injuries, three pulmonary hemorrhages, and two pulmonary artery aneurysms. During a median follow-up period of 10.4 (0.1-21.0) months, nine cases experienced restenosis at a median time of 40 (4-325) days after angioplasty.

Conclusions

The UHP BA is safe and effective for the primary treatment of PAS in infants and children with CHD. The success rate is high with a low incidence of severe complications. The predictors of success are a larger balloon/waist ratio and the presence of therapeutic tears. The occurrence of restenosis during follow-up, however, remains a problem. A larger number of cases and longer periods of follow-up are needed for further study.

Transcatheter management of combined patent ductus arteriosus and left pulmonary artery stenosis in congenital rubella syndrome: A series of three patients and an insight into case selection for intervention

Transcatheter closure of patent ductus arteriosus (PDA) is now the standard of care with some exceptions. Best treatment for peripheral pulmonary artery (PA) stenosis in small children is still debatable. Surgical augmentation, balloon dilatation, and stenting are the available options with each having its own risks and limitations. Here, we are reporting complete transcatheter management of three cases of congenital rubella syndrome who had PDA and left branch PA stenosis by device closure and stent placement, with successful outcome in two cases and complication, leading to surgery in one. We also share our understanding of case selection for a better outcome.

Transcatheter Intervention for Congenital Defects Involving the Great Vessels: JACC Review Topic of the Week

Since the development of balloon angioplasty and balloon-expandable endovascular stent technology in the 1970s and 1980s, percutaneous transcatheter intervention has emerged as a mainstay of therapy for congenital heart disease (CHD) lesions throughout the systemic and pulmonary vascular beds. Congenital lesions of the great vessels, including the aorta, pulmonary arteries, and patent ductus arteriosus, are each amenable to transcatheter intervention throughout the lifespan, from neonate to adult. In many cases, on-label devices now exist to facilitate these therapies. In this review, we seek to describe the contemporary approach to and outcomes from transcatheter management of major CHD lesions of the great vessels, with a focus on coarctation of the aorta, single- or multiple-branch pulmonary artery stenoses, and persistent patent ductus arteriosus. We further comment on the future of transcatheter therapies for these CHD lesions.

Surgical and Percutaneous Interventions for Chronic Thromboembolic Pulmonary Hypertension

The treatment of chronic thromboembolic pulmonary hypertension has expanded considerably. The ability to endarterectomize chronic thromboembolic material, the availability of pulmonary hypertension medical therapy to treat inoperable chronic thromboembolic pulmonary hypertension and/or residual pulmonary hypertension, and the rebirth of pulmonary balloon angioplasty have changed the management landscape. Patient selection requires a multidisciplinary evaluation at an experienced center. What is inoperable chronic thromboembolic pulmonary hypertension to one group may be operable chronic thromboembolic pulmonary hypertension to another. The ultimate challenge then becomes which intervention provides the optimal long-term outcome for any individual patient.

Treatment of Peripheral Pulmonary Artery Stenosis

Peripheral pulmonary artery stenosis (PAS) is an abnormal narrowing of the pulmonary vasculature and can form anywhere within the pulmonary artery tree. PAS is a congenital or an acquired disease, and its severity depends on the etiology, location, and number of stenoses. Most often seen in infants and young children, some symptoms include shortness of breath, fatigue, and tachycardia. Symptoms can progressively worsen over time as right ventricular pressure increases, leading to further complications including pulmonary artery hypertension and systolic and diastolic dysfunctions. The current treatment options for PAS include simple balloon angioplasty, cutting balloon angioplasty, and stent placement. Simple balloon angioplasty is the most basic therapeutic option for proximally located PAS. Cutting balloon angioplasty is utilized for more dilation-resistant PAS vessels and for more distally located PAS. Stent placement is the most effective option seen to treat the majority of PAS; however, it requires multiple re-interventions for serial dilations and is generally reserved for PAS vessels that are resistant to angioplasty.

Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is associated with several risk factors but is most frequently seen as a rare consequence of an acute pulmonary embolism. Surgical pulmonary thromboendarterectomy (PTE) is potentially curative for CTEPH with the best outcomes seen for the treatment of primarily proximal, accessible lobar or segmental disease. For surgically inoperable patients, percutaneous balloon pulmonary angioplasty (BPA) is feasible and has good short- to mid-term efficacy outcomes. This review focuses on the technique and outcomes associated with BPA which has emerged as a new therapeutic option for CTEPH.

A review: Percutaneous pulmonary artery stenosis therapy: state-of-the-art and look to the future

Stenosis, or narrowing, of the branches of the pulmonary artery is a type of CHD that, if left untreated, may lead to significant complications. Ideally, interventions to treat stenosis occur before significant complications or long-term sequelae take place, often within the first 2 years of life. Treatment depends on specifics of the condition, the presence of other malformations, and age of the child. Research and recent innovation to address these shortcomings have provided physicians with safer and more effective methods of treatment. This has further continued to push the ceiling of pulmonary arterial stenosis treatment available for patients. Despite continuous advancement in angioplasty - such as conventional and cutting balloon - and stenting, each treatment method is not without its unique limitations. New technological developments such as bioresorbable stents can accommodate patient growth and pulmonary artery stenosis treatment. As more than a decade has passed since the review by Bergersen and Lock, this article aims to provide a contemporary summary and investigation into the effectiveness of various therapeutic tools currently available, such as bare metal stents and potential innovations including bioresorbable stents.

Application of new balloon catheters in the treatment of congenital heart defects

INTRODUCTION

Balloon angioplasty (BAP) and aortic or pulmonary balloon valvuloplasty (BAV, BPV) are well-established treatment options in congenital heart defects. Recently, significant technological progress has been made and new catheters have been implemented in clinical practice.

AIM

To analyze the results of BAP, BAV and BPV with the new balloon catheter Valver and its second generation Valver II, which the company Balton (Poland) launched and developed. These catheters have not been clinically evaluated yet.

MATERIAL AND METHODS

We performed 64 interventions with Valver I and Valver II. With Valver I the following procedures were performed: 17 BPV (including 9 in tetralogy of Fallot - TOF), 10 BAV and 27 BAP in coarctations of the aorta (CoA) - including 9 native and 18 after surgery. With Valver II ten interventions were done - 3 BPV, 2 pulmonary supravalvular BAP (after switch operations), 2 BAP of recoarctations and 3 other BAP. Age of the patients ranged from a few days to 40 years.

RESULTS

All procedures were completed successfully, without rupture of any balloon catheters. The pressure gradient drop was statistically significant in all groups: BPV in isolated pulmonary valvular stenosis 28.1 mm Hg (mean), BPV in TOF 18.7 mm Hg, BAV 32.8 mm Hg, BAP in native CoA 15.4 mm Hg and in recoarctations 18.6 mm Hg. In 3 cases during rapid deflation of Valver I, wrinkles of the balloons made it impossible to insert the whole balloon into the vascular sheath (all were removed surgically from the groin). No such complication occured with Valver II.

CONCLUSIONS

Valver balloon catheters are an effective treatment modality in different valvular and vascular stenoses.

Transcatheter Implantation of Intravascular Stents for Postoperative Residual Stenosis of Peripheral Pulmonary Artery Stenosis

This is a prospective study of transcatheter implantation of 11 intravascular stents in 7 patients with status/post (S/P) surgical correction of major cardiovascular lesions. The safety and efficacy of balloon-expandable stents for treatment of peripheral pulmonary artery stenosis (PPAS) is evaluated and analyzed. Although the transcatheter implantation of intravascular stents has been reported as a possible treatment for stenotic peripheral pulmonary arteries, the results of intermediate follow-up studies on patients with S/P surgical correction for residual PPAS need to be evaluated. From June 1998 to December 2001, a total of 15 patients with PPAS having S/P surgery for major cardiovascular lesions were enrolled in this study. Eight of them had redo surgery after complete evaluation and the other 7 patients who might be at higher risk of mortality or morbidity from redo surgery, underwent transcatheter implantation of stents to dilate significant PPAS. Tetralogy of Fallot, S/P total correction, was done in 6 and transposition of great vessels, S/P Jatene operation, was done in 1. There were 10 stents (P 308 Palmaz stent ×8 and Intrastent™ ×2) implantation for 10 sites of the stenotic PPAS in these 7 patients, who were aged from 3.6 to 17.3 (10.1 ±5.6) years and had body weights ranging from 17 to 72.5 (37.1 ±23.0) kg. The narrowest diameter of the stenotic peripheral pulmonary arteries and pressure gradients across the stenosis were measured before and after implantation of stents. A follow-up catheterization and pulmonary angiography was performed 1 year later to evaluate the intermediate efficacy of stents implantation. All the stenotic peripheral pulmonary arteries of these 7 patients had a significant reduction of pressure gradients immediately after the procedure. The narrowest mean diameter of pulmonary arteries increased from 6.7 ±3.4 to 11.3 ±3.0 mm (p<0.001), and the mean pressure gradient dropped from 31 ±9.9 to 11.4 ±4.6 mm Hg (p<0.001). The follow-up catheterization 1 year later revealed a persistent effect in all but 1 patient. Only a young male presented with a recurrent stenosis with a pressure gradient of ≥20 mm Hg, which was relieved by redilation with implantation of another stent. There was no immediate or intermediate complication. Transcatheter stent implantation for treatment of a significant residual PPAS after surgical correction of complicated congenital heart disease is a safe and effective procedure. Since children are growing with age, a long-term follow-up study to evaluate the effects and possible problems of stent implantation is mandatory.

What Interventional Cardiologists Are Still Leaving to the Surgeons?

Nowadays, development of new technologies is still ongoing with the ultimate goal of maximizing treatment outcomes with less invasiveness and reduced procedural risk. This review is intended to update on when interventionalists need surgical support in common or emerging problems in congenital heart disease.

Peripheral pulmonary artery stenosis as a cause of pulmonary hypertension in adults

Peripheral pulmonary artery stenosis (PPAS) is an underrecognized condition in the adult population. PPAS can lead to pulmonary hypertension but is likely misdiagnosed as either idiopathic pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension. We retrospectively identified adult patients with PPAS either in its isolated form or related to other congenital defects from January 1998 to September 2012. We reviewed the patients' clinical data by using our hospital electronic medical records and/or their paper charts. We identified 6 adult patients with PPAS with an age range of 16-56 years (1 woman and the rest men). Presenting signs and symptoms were thoracic murmurs, progressive dyspnea, and syncope. Three patients had Williams-Beuren syndrome. Pulmonary angiography showed that PPAS was predominantly located in main branches or lobar pulmonary arteries in 5 patients, while in 1 patient the arterial narrowing was at the level of the segmental pulmonary arteries. Right heart catheterization showed a mean pulmonary artery pressure (PAP) ranging from 35 to 60 mmHg. Balloon dilation was performed in all patients, predominantly in the lobar arteries, and it caused a decrease in mean PAP that ranged from 16% to 46% in 5 patients. In 1 patient the mean PAP did not decrease. All but 1 patient had follow-up echocardiograms at 1 year that showed stable echocardiographic findings. Pulmonary hypertension due to PPAS continues to presents a diagnostic challenge. Therefore, a high index of suspicion during the initial evaluation of pulmonary hypertension is essential for its prompt diagnosis and adequate treatment.

Iatrogenic left pulmonary artery to left atrium fistula

Trans-catheter balloon angioplasty is a well-established treatment modality for pulmonary artery (PA) stenosis in children with congenital heart disease. We report a case of an unusual complication where a fistula developed between the left PA and the left atrium during balloon angioplasty in a patient with history of tetralogy of Fallot. This was successfully treated with placement of a covered stent.

Impact of Percutaneous Interventions for Pulmonary Artery Stenosis in Alagille Syndrome

OBJECTIVE

The study aims to examine acute and midterm outcomes after percutaneous interventions for treatment of pulmonary artery stenosis (PAS) in patients with Alagille Syndrome (ALGS).

BACKGROUND

PAS affects up to two thirds of ALGS patients. Responsiveness to transcatheter therapies may differ from other causes of PAS. To date, there has been no study to evaluate outcomes of transcatheter interventions on PAS exclusively in ALGS.

METHODS

In this single-center series, we reviewed procedural, hemodynamic, and angiographic data from patients with ALGS and PAS from 2007 to 2011 who underwent an interventional catheterization. Minimal luminal diameter (MLD) was assessed pre- and postintervention, and at follow-up catheterization(s) when available. Acute and midterm response to high-pressure balloon angioplasty (HBA), bare metal stent (BMS) placement, and cutting balloon angioplasty (CBA) were assessed.

RESULTS

Nine patients (median age 9.1 years) underwent 16 cardiac catheterizations with 34 interventions performed (20 HBA, 11 BMS, 3 CBA). There was a significant acute increase in MLD for all three modalities (42% HBA, P < .01; 91% BMS, P < .01; 58% CBA, P = .04). Follow-up data were available for 19 treated lesions at a median of 11 months. There was no significant difference in the improvement of MLD from baseline between the HBA and BMS groups, although in contrast to the BMS group, the HBA group showed continued interval vessel growth.

CONCLUSIONS

Transcatheter intervention for PAS in ALGS is generally safe and acutely effective. Although BMS implantation was associated with the greatest immediate improvement in MLD, HBA-treated vessels demonstrate interval growth, whereas BMS-treated lesions do not.

Hypoplastic left heart syndrome - a review of supportive percutaneous treatment

Due to the complex anatomical and haemodynamic consequences of hypoplastic left heart syndrome (HLHS), patients with the condition require multistage surgical and supportive interventional treatment. Percutaneous interventions may be required between each stage of surgical palliation, sometimes simultaneously with surgery as hybrid interventions, or after completion of multistage treatment. Recent advances in the field of interventional cardiology, including new devices and techniques, have significantly contributed to improving results of multistage HLHS palliation. Knowledge of the potential interventional options as well as the limitation of percutaneous interventions will enable the creation of safe and effective treatment protocols in this highly challenging group of patients. In this comprehensive review we discuss the types, goals, and potential complications of transcatheter interventions in patients with HLHS.

Pulmonary artery stents in the recent era: Immediate and intermediate follow-up

BACKGROUND

Long-term follow-up after stent dilation of native and acquired pulmonary artery stenosis is scarce in the pediatric population. Most cohorts include a myriad of anatomies and associated conditions.

METHOD

In order to establish objective performance criteria, we performed a retrospective review of all patients who underwent unilateral pulmonary artery stenting in biventricular physiology at three centers from June 2006 to June 2011.

RESULTS

Fifty-eight patients received 60 stents with Palmaz Genesis stent used most commonly (78%). Average age at implantation was 10.4 ± 10.3 years and weight 31.6 ± 21.8 kg. The immediate success rate was 98%, with improvement in minimal diameter from 5.1 ± 2 cm to 10.6 ± 3 cm (P < 0.01). There were 10 complications (7 major and 3 minor) and no acute mortality. One-year follow-up studies were available in 48 patients (83%), including echocardiogram (60%), catheterization (28%), MRI (29%), and lung perfusion (31%). Follow-up echocardiogram showed mild increase in stent gradient, from 5.7 ± 6.7 mm Hg post-procedure to 17.1 ± 11.7 mm Hg. Follow-up catheterization showed no significant change in minimal stent diameter (8.8 ± 2.6 to 7.8 ± 2.3 mm), gradient (7.7 ± 8.4 to 12.6 ± 12.2 mm Hg), or right ventricular pressures (43.7 ± 9 to 47.7 ± 10.5 mm Hg). Nine patients (16%) underwent scheduled stent redilation over a period of 12 days to 25 months.

CONCLUSION

In conclusion, stent implantation shows excellent immediate and 1-year follow-up results with maintenance of improved caliber of the stented vessel and lowered right ventricular systolic pressures.

State of the art catheter interventions in adults with congenital heart disease

Catheter interventions in adults with congenital heart disease have rapidly advanced. Transcatheter valve repair and replacement techniques have been added to the existing spectrum of well-established procedures. This review summarizes current transcatheter management strategies for congenital cardiac anomalies seen in the adult population.

Outcomes After Primary Transcatheter Therapy in Infants and Young Children With Severe Bilateral Peripheral Pulmonary Artery Stenosis

Background—

Angioplasty and stent implantation have become accepted therapies for isolated peripheral pulmonary stenosis, and have been shown to increase vessel diameter and reduce right ventricular (RV) pressure acutely in patients with pulmonary artery (PA) stenosis. The purpose of this study was to assess long-term outcomes after primary transcatheter therapy for peripheral pulmonary stenosis.

Methods and Results—

We studied 69 patients who underwent primary transcatheter intervention for severe isolated peripheral pulmonary stenosis at ≤5 years of age. Genetic/syndromic diagnoses included Williams syndrome (n=23), non-Williams familial arteriopathy (n=12), and Alagille syndrome (n=3). At the initial PA intervention, median RV:aortic pressure ratio decreased from 1.00 to 0.88 (median decrease, 0.18; P <0.001). Patients with a higher preintervention RV:aortic pressure ratio had a greater reduction ( P <0.001). During follow-up (median, 8.5 years), 10 patients died, 5 from complications of PA catheterization (all before 1998). Thirteen patients underwent surgical PA intervention, most within 1 year and along with repair of supravalvar aortic stenosis. Freedom from any PA reintervention was 38±6% at 1 year and 22±6% at 5 years. The median RV:aortic pressure ratio decreased from 1.0 at baseline to 0.53 at the most recent catheterization ( P <0.001), and 82% of patients with available clinical follow-up were asymptomatic.

Conclusions—

Transcatheter therapy for infants with severe peripheral pulmonary stenosis has become safer, regardless of genetic condition. Coupled with reintervention and surgical relief in selected cases, RV:aortic pressure ratios decrease substantially and most patients are asymptomatic at late follow-up.

Catheter Interventions for Pulmonary Artery Stenosis: Matching the Intervention with the Pathology

Pulmonary artery (PA) stenosis represents a heterogeneous defect with a wide morphology and etiology. Interventions to treat PA stenosis should be based on the location, severity, and cause of stenosis as well as the size of the patient at presentation. Specialized dilation balloons, stents, and delivery techniques have been developed to treat a variety of PA stenoses in small infants through adulthood. Early and intermediate results of angioplasty and stenting are superior to surgical results, while long-term data on angioplasty and stenting are becoming available for these proven safe and effective techniques.

Wire-related pulmonary artery injury during pediatric and adult congenital interventional cardiac catheterization

OBJECTIVES

Guidewires used in pediatric catheterization are typically floppy, soft, or J-tipped, and are generally assumed to be atraumatic. A recent sentinel case suggested that such wires may cause clinically significant pulmonary artery (PA) injury. We sought to determine the incidence of wire-related PA injury as a cause of "idiopathic" airway bleeding (endobronchial blood) during interventional cardiac catheterization in patients with congenital heart disease.

DESIGN

The Children's Hospital Boston database of cardiac catheterizations was reviewed for adverse events (AEs) indicating possible PA injury occurring between September 2006 and August 2011. Procedure notes were reviewed, and when the clinical scenario was suggestive of wire injury or was not clear, relevant angiograms were reviewed.

RESULTS

One thousand forty-seven cases involving PA dilation were performed in the period of interest. Five cases of probable wire injury were identified, suggesting an incidence of approximately 0.5 per 100 cases. Of these five cases, trauma was judged due to floppy-tipped wires in two, soft-tipped wires in two, and a J-tipped wire in one. In three cases, the distal wire was looped such that the leading segment was stiffer than the wire tip. Clinical manifestations of wire injury comprised contrast within the airway, vessel aneurysm/tear, obstructive intimal flap, blood from the endotracheal tube, hemothorax, and wedge defect on lung scan. These injuries were relatively benign and did not result in instability or prolonged bleeding.

CONCLUSIONS

Wire injury to the PAs is relatively uncommon, although possible with even floppy-tipped wires. The mechanism and implications of such injuries are markedly different than balloon-mediated vascular tears.

Randomized Trial of Cutting Balloon Compared With High-Pressure Angioplasty for the Treatment of Resistant Pulmonary Artery Stenosis

Background—

We sought to determine the safety and efficacy of Cutting Balloon therapy (CB) compared with conventional high-pressure balloon therapy (HPB) for the treatment of pulmonary artery stenosis.

Methods and Results—

This prospective, randomized, multicenter, investigational device exemption trial compared CB with HPB. Patient eligibility was determined at the precatheterization assessment; vessel eligibility was determined at catheterization. In all vessels, low-pressure balloon dilation to 8 atm was performed, and if it was not successful, the vessel was randomized to CB or HPB. The primary efficacy outcome was percent change in minimum lumen diameter. A core laboratory performed all vessel measurements and angiographic assessment of vessel damage. The primary safety outcome was any serious adverse event attributable to vessel dilation as assessed by the Data and Safety Monitoring Board. Seventy-three patients from 8 institutions were enrolled between 2004 and 2008. In these patients, 72 vessels responded to low-pressure balloon dilation. Of the 173 vessels that met eligibility criteria, 107 were randomized to CB and 66 to HPB. In randomized vessels, CB therapy was associated with greater percent increase in lumen diameter (85% versus 52%; P =0.004). After crossover was introduced, 26 of 47 vessels treated with HPB underwent CB therapy and experienced an additional 48% increase in lumen diameter; the final diameter after CB was 99% greater than the initial diameter. There were no serious adverse events related to treatment in a study vessel.

Conclusion—

CB therapy for pulmonary artery stenosis not responsive to low-pressure balloon is more effective than HPB therapy and has an equivalent safety profile.

Transcatheter rehabilitation of pulmonary arteries

Pulmonary arterial stenoses commonly occur in patients with congenital heart disease. Indications for treatment are based around reduction of right ventricular hypertension and equalization of flow to each lung and its constituent segments. There are many treatment approaches for these lesions depending on the anatomy, location and the age of the patient. Although surgical reconstruction remains an option, it is technically challenging and in many cases, the results are disappointing. In the modern era, the majority of these patients are treated with transcatheter therapy, including balloon angioplasty, and increasingly, the use of intravascular stents. In this article, we discuss these issues and deal with both the technical approach to transcatheter therapy and up-to-date results.

Balloon Angioplasty and Stenting of Branch Pulmonary Arteries

Background—

Pulmonary artery (PA) balloon angioplasty and/or stenting (PA rehabilitation) is one of the most common procedures performed in the cardiac catheterization laboratory, but comprehensive and consistently reported data on procedure-related adverse events (AE) are scarce.

Methods and Results—

Data were prospectively collected using a multicenter registry (Congenital Cardiac Catheterization Project on Outcomes). All cases that included balloon angioplasty and/or stent implantation in a proximal or lobar PA position were included. Multivariate analysis was used to evaluate for independent predictors of AE and need for early reintervention. Between February 2007 and December 2009, 8 institutions submitted details on 1315 procedures with a PA intervention. An AE was documented in 22% with a high severity (level 3 to 5) AE in 10% of cases. Types of AE included vascular/cardiac trauma (19%), technical AE (15%), arrhythmias (15%), hemodynamic AE (14%), bleeding via endotracheal tube/reperfusion injury (12%), and other AE (24%). AE were classified as not preventable in 50%, possibly preventable in 41%, and preventable in 9%. By multivariate analysis, independent risk factors for level 3 to 5 AE were presence of ≥2 indicators of hemodynamic vulnerability, age below 1 month, use of cutting balloons, and operator experience of <10 years. Reintervention during the study period occurred in 22% of patients undergoing PA rehabilitation.

Conclusions—

PA rehabilitation is associated with a 10% incidence of high-level severity AE. Hemodynamic vulnerability, young age, use of cutting balloons, and lower operator experience were significant independent risk factors for procedure-related AE.

A case of isolated peripheral pulmonary artery branch stenosis associated with multiple pulmonary artery aneurysms

Selective right pulmonary arteriography and 3-dimensional computed tomography revealed multiple severe stenoses of the peripheral pulmonary artery associated with poststenotic aneurysms in a 65-year-old woman. She was referred to the hospital for evaluation of dry cough, gradually increasing dyspnea and multiple nodular shadows on a chest radiograph. Echocardiography and cardiac catheterization showed severe pulmonary hypertension, though other structural heart diseases or well-characterized congenital syndromes were ruled out. She was diagnosed as isolated peripheral pulmonary artery branch stenosis. Recent advances in CT technology enable a less-invasive assessment of pulmonary artery, and can be useful in the management of pulmonary arterial hypertension.

How we approach peripheral pulmonary stenosis in Williams-Beuren syndrome

Williams-Beuren syndrome is associated with supravalvar aortic stenosis and peripheral pulmonary artery stenosis in the majority of affected individuals. Among patients in whom surgery for supravalvar aortic stenosis is contemplated, stenosis of the branch pulmonary arteries is common. For asymptomatic patients with subsystemic right ventricular pressure, the natural history is favorable and no intervention is necessary. For patients with important proximal branch pulmonary artery, stenoses patch arterioplasty can be accomplished at the time of surgery for supravalvar aortic stenosis. For patients with important peripheral pulmonary stenosis, preoperative catheter-based therapy is indicated. Surgical repair of peripheral pulmonary stenosis is indicated when preoperative intervention is unsuccessful and can include a combination of patch arterioplasty as well as intraoperative application of catheter-based techniques. This report will address the approach to this lesion with catheter-based approaches, surgical approaches, and their combination.

The role of stents in the treatment of congenital heart disease: Current status and future perspectives

Intravascular or intracardiac stenoses occur in many forms of congenital heart disease (CHD). Therefore, the implantation of stents has become an accepted interventional procedure for stenotic lesions in pediatric cardiology. Furthermore, stents are know to be used to exclude vessel aneurysm or to ensure patency of existing or newly created intracardiac communications. With the further refinement of the first generation of devices, a variety of "modern" stents with different design characteristics have evolved. Despite the tremendous technical improvement over the last 20 years, the "ideal stent" has not yet been developed. Therefore, the pediatric interventionalist has to decide which stent is suitable for each lesion. On this basis, currently available stents are discussed in regard to their advantages and disadvantages for common application in CHD. New concepts and designs developed to overcome some of the existing problems, like the failure of adaptation to somatic growth, are presented. Thus, in the future, biodegradable or growth stents might replace the currently used generation of stents. This might truly lead to widening indications for the use of stents in the treatment of CHD.

Ultra-high-pressure balloon angioplasty for treatment of resistant stenoses within or adjacent to previously implanted pulmonary arterial stents

BACKGROUND

Stents are essential tools in the management of pulmonary arterial (PA) stenosis in patients with congenital heart disease. Although stents can usually be reexpanded as children grow, resistant in-stent or peri-stent obstruction can complicate the management of PA stents. Angioplasty with ultra-high-pressure (UHP) balloons may facilitate successful treatment of stent-associated PA stenoses that are resistant to high-pressure dilation.

METHODS AND RESULTS

We reviewed patients who underwent UHP angioplasty of in-stent or peri-stent PA stenoses that were resistant to high-pressure redilation. A resistant stenosis was defined as a residual balloon waist during high-pressure redilation of the stent, along with a pressure gradient and/or angiographic stenosis. Thirty-four lesions in 29 patients, including 8 with multiple concentric, overlapping, or adjacent stents, were included. The median age at UHP angioplasty was 9 years, and a median of 4 years had elapsed since unsuccessful high-pressure angioplasty. Thirty-one of the 34 (91% [81% to 100%]) UHP angioplasty procedures were successful in relieving the resistant stenosis. Balloon:waist diameter ratios were conservative (median 1.26), reflecting the ability of UHP balloons to "fracture" nearly all obstructions. After UHP dilation, lesion diameter increased by a median of 3.1 mm (36%), significantly more than after previous high-pressure dilation (1.3 mm, 19%; P<0.001). In 5 lesions, UHP angioplasty fractured the stent, allowing further vessel expansion. There were no vascular or other complications.

CONCLUSIONS

UHP angioplasty was safe and effective for treatment of stent-related resistant PA stenosis in this series; the ability to fracture maximally expanded stents may extend the utility of stents in the pediatric population.

Balloon angioplasty for branch pulmonary artery stenosis--cutting balloons

Pulmonary artery stenosis can cause right ventricular strain but intrapulmonary lesions are inaccessible to surgery; moreover, some are also resistant to high pressure balloon angioplasty. An alternative is the use of microsurgical devices mounted on balloons for transvenous delivery, including cutting balloons. The current literature is sparse but seems to indicate a role for cutting balloons in specific situations. The higher cost of these devices does not merit routine use instead of high pressure balloons but a randomised controlled study is underway to address this issue. Until the results of this become available, the role of cutting balloons for pulmonary artery stenosis remains limited to specific situations. The recommendations for the safe use of these devices must be adhered to by all operators.