What is the current option of first choice for treatment of pulmonary arterial stenosis?

Pulmonary reperfusion injury in post-palliative intervention of oligaemic cyanotic CHD: a new catastrophic consequence or just revisiting the same old story?

Pulmonary reperfusion injury is a well-recognised clinical entity in the setting pulmonary artery angioplasty for pulmonary artery stenosis or chronic thromboembolic disease, but not much is known about this complication in post-palliative intervention of oligaemic cyanotic CHD. The pathophysiology of pulmonary reperfusion injury in this population consists of both ischaemic and reperfusion injury, mainly resulting in oxidative stress from reactive oxygen species generation, followed by endothelial dysfunction, and cytokine storm that may induce multiple organ dysfunction. Other mechanisms of pulmonary reperfusion injury are "no-reflow" phenomenon, overcirculation from high pressure in pulmonary artery, and increased left ventricular end-diastolic pressure. Chronic hypoxia in cyanotic CHD eventually depletes endogenous antioxidant and increased the risk of pulmonary reperfusion injury, thus becoming a concern for palliative interventions in the oligaemic subgroup. The incidence of pulmonary reperfusion injury varies depending on multifactors. Despite its inconsistence occurrence, pulmonary reperfusion injury does occur and may lead to morbidity and mortality in this population. The current management of pulmonary reperfusion injury is supportive therapy to prevent deterioration of lung injury. Therefore, a general consensus on pulmonary reperfusion injury is necessary for the diagnosis and management of this complication as well as further studies to establish the use of novel and potential therapies for pulmonary reperfusion injury.

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.

Initial status and 3-month results relating to the use of biodegradable nitride iron stents in children and the evaluation of right ventricular function

Background

Pulmonary artery stenosis is often associated with congenital heart disease. The aim of the study was to evaluate the efficacy and safety of stenting for branch pulmonary artery stenosis using a biodegradable nitride iron stent (IBS^® Angel™) and right ventricular systolic and diastolic function.

Methods

From July 2021 to February 2022, a total of 11 cases (ages ranged from 36 to 86 months old) were included in this pre and post-intervention, prospective, cohort and preclinical study. All cases underwent transthoracic echocardiographic (TTE), chest radiography, along with computed tomography (256-slice scanner, multiple-detector) and right heart catheterization. Different types of biodegradable nitride iron stents were implanted. TTE was performed serially 1 day, 1 month and 3 months after the procedure to evaluate the rate of restenosis and right ventricular function.

Results

Stenting was successful in 11 patients. There were no major adverse cardiovascular events related to the device or to the procedure. Blood perfusion in the branch pulmonary artery was improved immediately. At follow-up, there was no significant restenosis that required re-intervention. None of the patients suffered from in-stent thrombosis, vascular embolism, stent displacement or heart failure. Compared with normal values, there were statistical with regards to FAC, E/A and E′/A′. Furthermore, we found that TAPSE correlated significantly with pulsed Doppler S wave (p = 0.008) and left ventricular ejection fraction (p < 0.01). The early trans-tricuspid inflow velocities E/E′ (tissue doppler at the lateral tricuspid annulus) correlated significantly with E′/A′ (p = 0.009). FAC and E′/A′ were statistically different from those prior to stenting (p = 0.041 and p = 0.035) when tested one month postoperatively. At three months postoperatively, only E/A showed a statistical difference (p = 0.015).

Conclusion

Our analysis suggests that biodegradable nitride iron stents are feasible, safe, and effective in children. Some small improvements were observed in right ventricular systolic and diastolic function after successful transcatheter intervention, although change was not statistically significant due to the small sample number. (A clinical Trial to Evaluate the Safety and Efficacy of IBS Angel in Patients With Pulmonary Artery Stenosis (IRIS); NCT04973540).

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.

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.

Treatment approach to unilateral branch pulmonary artery stenosis

Unilateral proximal pulmonary artery stenosis is often seen in the setting of postoperative congenital heart disease. Accurate assessment of the hemodynamic significance of such a lesion is important so as to determine "When to intervene?" A thorough evaluation should include symptom assessment, anatomical assessment through detailed imaging, functional assessment using differential pulmonary blood flow measurement and cardiopulmonary exercise testing. Symptoms of exertional dyspnea or intolerance, decreased pulmonary blood flow to stenosed lung, and abnormal exertional performance would be factors to pursue therapy in the setting of significant anatomical narrowing. Safe and effective therapy can be offered through transcatheter or surgical techniques and has been shown to improve exertional performance.

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.

Personalized stent design for congenital heart defects using pulsatile blood flow simulations

Stent size selection and placement are among the most challenging tasks in the treatment of pulmonary artery stenosis in congenital heart defects (CHD). Patient-specific 3D model from CT or MR improves the understanding of the patient's anatomy and information about the hemodynamics aid in patient risk assessment and treatment planning. This work presents a new approach for personalized stent design in pulmonary artery interventions combining personalized patient geometry and hemodynamic simulations. First, the stent position is initialized using a geometric approach. Second, the stent and artery expansion, including the foreshortening behavior of the stent is simulated. Two stent designs are considered, a regular stent and a Y-stent for bifurcations. Computational fluid dynamics (CFD) simulations of the blood flow in the initial and expanded artery models are performed using patient-specific boundary conditions in form of a pulsatile inflow waveform, 3-element Windkessel outflow conditions, and deformable vessel walls. The simulations have been applied to 16 patient cases with a large variability of anatomies. Finally, the simulations have been clinically validated using retrospective imaging from angiography and pressure measurements. The simulated pressure, volume flow and flow velocity values were on the same order of magnitude as the reference values obtained from clinical measurements, and the simulated stent placement showed a positive impact on the hemodynamic values. Simulation of geometric changes combined with CFD simulations offers the possibility to optimize stent type, size, and position by evaluating different configurations before the intervention, and eventually allow to test customized stent geometries and new deployment techniques in CHD.

Evaluation of pulmonary artery stenosis in congenital heart disease patients using functional diagnostic parameters: An in vitro study

Congenital pulmonary artery (PA) stenosis is often associated with abnormal PA hemodynamics including increased pressure drop (Δp) and reduced asymmetric flow (Q), which may result in right ventricular dysfunction. We propose functional diagnostic parameters, pressure drop coefficient (CDP), energy loss (E_loss), and normalized energy loss (E¯_loss) to characterize pulmonary hemodynamics, and evaluate their efficacy in delineating stenosis severity using in vitro experiments. Subject-specific test sections including the main PA (MPA) bifurcating into left and right PAs (LPA, RPA) with a discrete LPA stenosis were manufactured from cross-sectional imaging and 3D printing. Three clinically-relevant stenosis severities, 90% area stenosis (AS), 80% AS, and 70% AS, were evaluated at different cardiac outputs (COs). A benchtop flow loop simulating pulmonary hemodynamics was used to measure Q and Δp within the test sections. The experimental Δp-Q characteristics along with clinical data were used to obtain pathophysiologic conditions and compute the diagnostic parameters. The pathophysiologic Q_LPA decreased as the stenosis severity increased at a fixed CO. CDP_LPA, E_loss,LPA (absolute), and E¯_loss,LPA (absolute) increased with an increase in LPA stenosis severity at a fixed CO. Importantly, CDP_LPA and E¯_loss,LPA had reduced variability with CO, and distinct values for each LPA stenosis severity. Under variable CO, a) CDP_LPA values were 14.5-21.0 (70% AS), 60.7- 2.2 (80% AS), ≥ 261.6 (90% AS), and b) E¯_loss,LPA values (in mJ per Q_LPA) were -501.9 to -1023.8 (70% AS), -1247.6 to -1773.0 (80% AS), -1934.5 (90% AS). Hence, CDP_LPA and E¯_loss,LPA are expected to assess the true functional severity of PA stenosis.

Bifurcating stents in the pulmonary arteries: A novel technique to relieve bilateral branch pulmonary artery obstruction

Balloon angioplasty and stent placement in close proximity to the bifurcation of the branch pulmonary arteries can be challenging. Multiple approaches have been previously described, though none of these approaches both treats bilateral proximal branch pulmonary artery stenosis and provides an anchor for a transcatheter pulmonary valve replacement. We report a novel approach that involves serial stent placement and balloon dilation through the struts of the stent in each pulmonary artery, along with balloon expansion of the proximal portion of the stents to the diameter of the main pulmonary artery. In the two cases we describe, this strategy resulted in significant relief of branch pulmonary artery obstruction without compromising the anatomy of the main pulmonary artery segment. This technique can be an effective way to alleviate stenoses of the bilateral proximal branch pulmonary arteries and provides a landing zone for a future transcatheter pulmonary valve.

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.

Hybrid intraoperative pulmonary artery stenting in redo congenital cardiac surgeries

Objective

Reconstruction of branch pulmonary arteries (PAs) can be challenging in redo congenital heart surgeries. Treatment options like percutaneous stent implantation and surgical patch angioplasty may yield suboptimal results. We present our experience with hybrid intraoperative stenting which may be an effective alternative option.

Methods

We retrospectively analyzed data of all patients with PA stenosis who underwent intraoperative PA branch stenting in our institution between January 2011 and December 2012.

Results

Ten patients [6 females, median age 10 (1.4 to 37) years], underwent hybrid stenting of the PA. Primary cardiac diagnoses were pulmonary atresia with ventricular septal defect (VSD) in three patients, pulmonary atresia with intact ventricular septum in two, Tetralogy of Fallot (TOF) in one, Double outlet right ventricle (DORV) with pulmonary stenosis (PS) in one, complex single ventricle in two and VSD with bilateral branch PA stenosis in one patient. Concomitant surgeries were revision/reconstruction of RV-PA conduit in 4, Fontan completion in 4, repair of TOF with conduit placement in 1 and VSD closure in 1 patient. The left PA was stented in 7, the right in 2 and both in 1, with a total of 11 stents. There were no complications related to stent implantation. Two early postoperative deaths were unrelated to stent implantation. At mean follow-up period of 14.8 (12–26) months, stent position and patency were satisfactory in all survivors. None of them needed repeat dilatation or surgical reintervention.

Conclusion

Hybrid stenting of branch PA is a safe and effective option for PA reconstruction in redo cardiac surgeries. With meticulous planning, it can be safely performed without fluoroscopy.

Strategies for high-risk reoperations in congenital heart disease

Adults with congenital heart disease (CHD) is a rapidly growing group of patients, and part of this is owing to the improvement in survival for the vast majority of infants with CHD who have undergone successful surgery and live well into adult years. Residual or recurrent lesions may precipitate the need for reoperation and some patients require numerous surgical procedures or interventions over a lifetime. This article will review the surgical issues associated with reoperation in patients with CHD and discuss the different perioperative strategies that serve to decrease the risk of reoperation.

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.

Per-operative stent placement in the right pulmonary artery; a hybrid technique for the management of pulmonary artery branch stenosis at the time of pulmonary valve replacement in adult Fallot patients

After having undergone surgical correction at an early age, many patients with tetralogy of Fallot develop long-term complications including progressive pulmonary regurgitation and peripheral pulmonary stenosis. A high percentage of these patients need to undergo a second operation in their adolescence or early adulthood. If simultaneous treatment of both pulmonary regurgitation and peripheral pulmonary stenosis is warranted, a complete surgical approach has several disadvantages. We describe four cases of Fallot patients with severe pulmonary regurgitation and peripheral pulmonary stenosis who were treated using a hybrid approach involving surgical implantation of a pulmonary homograft and peroperative stenting of the pulmonary artery.

Treatment of congenital heart disease: risk-reducing measures in young adults

Adults with congenital heart disease form a new and relatively young population, since surgical treatment of heart defects became available three to four decades ago. Owing to improved survival this population is steadily growing in number and age. Little is known regarding long-term survival; however, late complications occur frequently. During adulthood, almost half of the patients have one or more complication, such as endocarditis, stroke, systemic or pulmonary hypertension, aortic aneurysm or dissection and arrhythmias. Heart failure and sudden cardiac death are the main causes of death. Treatment of adults with congenital heart disease is aimed at the reduction of symptoms, but also at minimizing the risk and severity of late complications. In this article the most recent advances in the treatment of congenital heart disease will be discussed. The main focus of the article will be on pharmacological, interventional and surgical interventions that reduce the risk of heart failure, arrhythmias, vascular complications, pulmonary hypertension and endocarditis.

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.

Hybrid intraoperative pulmonary artery stent placement for congenital heart disease

Percutaneous branch pulmonary artery (PA) stenting can be challenging, especially in patients with stenosis of the right ventricular (RV) outflow tract or tortuous PA branches. In these cases, a hybrid procedure deploying PA stent(s) during cardiac surgery provides an alternative to relieve branch PA stenosis. The Mayo Clinic Congenital Cardiac surgical database was used to identify all patients having hybrid PA stent procedures. Retrospective analysis of clinical data, procedural details, and outcomes was performed. Between January 1997 and November 2006, 24 patients (15 females), median age 15 years (range 3 to 67 years), had hybrid PA stent procedures. A total of 27 stents were deployed. A left PA stent was placed in 13, right PA stent in 8; 3 patients had bilateral PA stents. Primary cardiac diagnoses were pulmonary atresia (9), tetralogy of Fallot (7), tricuspid atresia (2), and others (6). Maximum balloon diameters ranged from 8 to 16 mm (median = 12 mm). Concomitant surgical procedures performed were RV to PA conduit replacement or RV outflow tract reconstruction (14), pulmonary valve replacement (7), and others (3). Two procedures were performed following complications of percutaneous procedure. There were no deaths or PA damage. There were 2 cases of distal stent migration. Repeat stent dilations within 6 months were performed in 3 patients. In conclusion, hybrid PA stenting can play an important role in the management of congenital heart disease with complex branch PA anatomy. It also can be used as an emergency rescue procedure following complications of percutaneous transcatheter procedures, such as stent embolization. Hybrid procedures were safe and effective in most patients, although stent positioning remains critical. Intraoperative fluoroscopy and active suture fixation of the proximal stent may reduce the need for late reintervention.

Perioperative placement of stents for relief of proximal pulmonary arterial stenoses in infants

INTRODUCTION

Stenoses in the pulmonary arterial system can have a significant negative impact on the early postoperative course in infants. Early recognition and aggressive management are mandatory.

PATIENTS AND METHODS

We describe our experience with 8 infants, with ages ranging from 3 to 9 months, weighing from 4.5 to 7.7 kilograms, who presented in the up to 18 days following construction of a shunt from the superior caval vein to the pulmonary arteries with clinical symptoms of obstructed pulmonary flow. We include also 2 infants in whom pulmonary arterial stents were implanted in the operating room. Cardiac catheterization showed significant stenoses or occlusion of the left pulmonary arteries in 9 infants, the right pulmonary arteries in 2, or the superior caval vein in 1, the investigation being prompted by the findings of supraphysiological superior caval venous pressures and systemic hypoxaemia. We implanted a variety of stents mounted on balloons ranging in diameter from 6 to 13 millimetres, with 7 placed across a newly created surgical anastomotic site.

RESULTS

All stenoses were crossed successfully, and stents implanted satisfactorily in all patients, albeit that 1 infant suffered an acute tear of the left pulmonary artery, requiring immediate reoperation. This patient died 72 hours later due to a diffuse coagulopathy. All other patients demonstrated sustained clinical improvement following the procedure. At follow-up, 7 of the 9 survivors have progressed to completion of the Fontan circulation. Redilation of the stents was required in the interim, prior to completion of the Fontan circulation, in 4 of them. In 2 patients, the previously implanted stents were incised during the Fontan completion, permitting placement of the extracardiac Goretex conduit from the inferior caval vein to the pulmonary arteries.

CONCLUSIONS

Stents can successfully be implanted perioperatively in the pulmonary arterial system during infancy, and redilated, with improvement in clinical outcome in the majority of those with clinically relevant obstruction.

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.