Pulmonary artery trauma due to balloon dilation: recognition, avoidance and management

Basic Concepts and Insights into Aortopulmonary Collateral Arteries in Congenital Heart Diseases

Aortopulmonary collateral arteries are persistent embryological vessels supplying lung parenchyma in various cardiopulmonary diseases with underlying pulmonary hypoperfusion. Their identification and mapping are important because of associated clinical implications and tendency to affect the surgical outcome. This article describes the embryological development and clinical relevance of aortopulmonary collaterals in various congenital cardiopulmonary conditions, along with the significance for treatment planning. Roles, strength, and shortcomings of the various imaging options and image-guided interventions are discussed, with a focus on presurgical planning and preparation, as well as postsurgical management.

Treatment of Vascular Injury During Balloon Pulmonary Angioplasty in Patients With Chronic Thromboembolic Pulmonary Hypertension

Background

Treatment strategy for vascular injury during balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) was uncertain.

Objectives

This study aimed to identify an optimal therapeutic strategy for vascular injury during BPA in patients with CTEPH.

Methods

This study reviewed 207 patients with CTEPH and 956 BPA procedures between November 1, 2012 and November 30, 2015. Patients who were diagnosed with vascular injury during BPA, which was defined as angiographic signs or sudden respiratory and hemodynamic defects were included in this study. The study investigated the safety and efficacy of the hierarchically systematic treatment strategy including gelatin sponge embolization (GSE).

Results

More than one-half of the 79 patients and 133 procedures with vascular injury were improved by general treatment with reversal of heparin and high-flow oxygen administration. The investigators performed conventional treatment of proximal vessel occlusion using a guiding or balloon catheter in 47 procedures (35%) in which the culprit vessels could be detected under patients' stable conditions. In 32 procedures (24%) without detected culprit lesions or improvement by conventional treatment, GSE could significantly improve patient condition. The treatment strategy obtained successful bailout in 98% of procedures with vascular injury. No patients who underwent GSE died within 30 days after the treatment. There was no significant difference in cumulative mortality rate (median follow-up: 6.6 years) between groups with or without GSE (15.6% vs 8.2%; adjusted HR: 1.47; 95% CI: 0.25-8.69; P = 0.67).

Conclusions

Treatment strategy including GSE would be promising for vascular injury during BPA in patients with CTEPH.

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.

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.

Pulmonary hemorrhage in children with Alagille syndrome undergoing cardiac catheterization

OBJECTIVES

To evaluate the incidence, severity, and outcomes of pulmonary hemorrhage in children with Alagille syndrome (AGS) undergoing cardiac catheterization, and to find variables associated with hemorrhage in this population.

BACKGROUND

Children with AGS have a high incidence of bleeding complications during invasive procedures. It has been our impression that catheterization-associated pulmonary hemorrhage is more common in children with AGS, but there are no published data on this topic.

METHODS

This was a retrospective single institution study of children with AGS undergoing catheterization from 2010 to 2018. Pulmonary hemorrhage was defined as angiographic or fluoroscopic evidence of extravasated blood in the lung parenchyma, or blood suctioned from the endotracheal tube with documentation of pulmonary hemorrhage by the anesthesiologist or intensivist. Univariate comparisons were made between catheterizations that did and did not have pulmonary hemorrhage.

RESULTS

Thirty children with AGS underwent 87 catheterizations, 32 (37%) with interventions on the branch pulmonary arteries (PA). There were 26 (30%) procedures with hemorrhage, the majority (65%) of which were self-limited or required less than 24 hr of mechanical ventilation. Moderate and severe hemorrhage occurred only in children with tetralogy of Fallot (TOF; 5 of 14, 36%). A higher right ventricle to aorta systolic pressure ratio (1.0 [0.85-1.1] vs. 0.88 [0.59-1.0], p = .029) and interventions on the branch PAs (14 of 26, 54% vs. 18 of 61, 30%, p = .032) were associated with hemorrhage.

CONCLUSIONS

Pulmonary hemorrhage was common in children with AGS undergoing both intervention and diagnostic cardiac catheterization, and was associated with TOF, higher RV to aorta pressure ratio, and interventions on the branch PAs.

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.

Extracorporeal cardiopulmonary resuscitation after pulmonary artery rupture

Pulmonary artery rupture during pulmonary balloon valvuloplasty is a rare and life-threatening complication. Here, we present a pulmonary artery rupture in a 10-month-old infant. The patient had a tamponade, ineffective cardiac massage for 40 minutes and extreme hemodilution due to blood loss. Extracorporeal life support was used for three days. The patient was discharged without any neurological sequelae.

Adult Congenital Interventions in Heart Failure

Congenital heart disease (CHD) is the most common birth defect, occurring in approximately 0.8% to 1.0% of neonates. Advances in medical and surgical therapies for children with CHD have resulted in a growing population of patients reaching adulthood, with survival rates exceeding 85%. Many of these patients, especially if managed inappropriately, face the prospect of future complications including heart failure and premature death. For adults with uncorrected or previously palliated CHD, percutaneous therapies have become the primary treatment for many forms of CHD. In this article, we discuss the role of transcatheter interventions in the treatment of adults with CHD.

Pulmonary artery dissection following balloon valvuloplasty in a dog with pulmonic stenosis

A 3-month-old, 9.9 kg, male pit bull cross was referred for evaluation of collapse. A left basilar systolic heart murmur graded V/VI and a grade IV/VI right basilar systolic heart murmur were ausculted. Echocardiography showed severe pulmonic stenosis characterized by annular hypoplasia, leaflet thickening, and leaflet fusion. After 1 month of atenolol therapy, a pulmonic valve balloon valvuloplasty procedure was performed, and the intra-operative right ventricular pressure was reduced by 43%. Echocardiography, performed the following day, showed apparent rupture of a pulmonary valve leaflet and a membranous structure within the pulmonary artery consistent with a dissecting membrane. Short-term follow-up has shown no apparent progression of the pulmonary artery dissection and the patient remains free of clinical signs.

Iatrogenic aortopulmonary communications after transcatheter interventions on the right ventricular outflow tract or pulmonary artery: Pathophysiologic, diagnostic, and management considerations

OBJECTIVES

To investigate the spectrum, etiology, and management of traumatic aortopulmonary (AP) communications after transcatheter interventions on the pulmonary circulation.

BACKGROUND

An iatrogenic AP communication is an unusual complication after balloon pulmonary artery (PA) angioplasty or stenting, or transcatheter pulmonary valve replacement (TPVR). However, with the increasing application of transcatheter therapies for postoperative PA stenosis and right ventricular outflow tract (RVOT) dysfunction, including percutaneous pulmonary valve replacement, consideration of the etiology, diagnosis, and management of this problem is important for interventional cardiologists performing such procedures.

METHODS AND RESULTS

We present three new cases, as well as gross anatomy and histopathology data, related to AP communications after PA interventions. We also review the literature relevant to this topic. Including these new cases, there have been 18 reported cases of iatrogenic AP communication after transcatheter interventions on the PAs or RVOT, primarily patients with transposition of the great arteries who underwent PA angioplasty after an arterial switch operation, or after TPVR in patients who had undergone a Ross procedure. The likely cause of such defects is PA trauma plus distortion of the neo-aortic anastomosis resulting from angioplasty or stenting of the RVOT or central PAs, with subsequent dissection through the extravascular connective tissue and into the closely adjacent vessel through the devitalized tissue at the anastomosis.

CONCLUSIONS

Cardiologists performing PA or RVOT interventions should be aware of the possibility of a traumatic AP communication and consider this diagnosis when confronted with suggestive signs and symptoms.

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.

Frequency and risk of in-stent stenosis following pulmonary artery stenting

Peripheral and central pulmonary artery (PA) stenoses can result in right ventricular hypertension, dysfunction, and death. Percutaneous PA angioplasty and stent placement relieve obstruction acutely, but patients frequently require reintervention. Within a heterogeneous patient population with PA stents referred for catheterization because of noninvasive signs of PA obstruction, we have observed that in-stent stenosis (ISS) occurs commonly in some groups, challenging previous reports that this phenomenon occurs infrequently. We set out to evaluate the incidence and demographics of patients with previous PA stent placement who develop ISS. Consecutive patients with previously placed stents presenting for catheterization and undergoing PA angiography were reviewed (104 patients, 124 cases). We defined ISS angiographically, as a 25% narrowing of the contrast-filled lumen relative to the fluoroscopically apparent stent diameter at any site along the length of the stent. For inclusion, we required that the stenotic segment be narrower or equal in size to the distal vessel. ISS was diagnosed in 24% of patients, with the highest incidence among patients with tetralogy of Fallot and multiple aortopulmonary collaterals, Williams syndrome, or Alagille syndrome. In conclusion, ISS after PA stent placement is a more frequent problem than previously reported, and patients with inherently abnormal PAs are disproportionately affected. Increased clinical surveillance after stent placement and investigation of innovative preventive strategies may be indicated.

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.

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.

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.

Complications of pediatric cardiac catheterization and system of catheterization laboratories minimizing complications--a Japanese multicenter survey

BACKGROUND

Pediatric cardiac catheterization is sometimes associated with serious complications. However, there are no data regarding the organization of pediatric cardiac catheterization laboratories to minimize complications.

OBJECTIVES

The aim of this study was to determine the current organization of pediatric cardiac catheterization laboratories with regard to patient safety in Japan.

METHODS AND RESULTS

We sent questionnaires to 105 institutions and obtained data from 82. Major complications requiring surgical therapy or death occurred in 22 institutes (27%). The incidence of major complications did not relate to the number of procedures performed. The procedures were performed without written informed consent in 21% of all institutions. The time to inform about the procedures was within 30 min in 43 institutes (52%). A pre-procedure meeting was held in 56 institutions (68%). The anesthetist attended the diagnostic procedures in 23% and the therapeutic procedures in 53%. The drugs and defibrillator for resuscitation were available in almost all institutions, but a pacemaker was not in 23 institutions (28%). The procedures were performed under the "back-up" of cardiovascular surgeons in 38 institutions (46%).

CONCLUSION

There are still large numbers of institutions in Japan, which need much improvement in the organization of pediatric cardiac catheterization laboratories as an aspect of patient safety.

Conservative management of bronchopulmonary artery perforation without associated haemothorax occurring at thoracentesis: a case report

Puncture or laceration of the pulmonary, intercostal, or peripheral vessels is an uncommon, but potentially life-threatening, complication of thoracentesis, which has been reported to result in severe haemothorax in 75% of patients. Damage to these vessels typically requires surgical intervention or intra-arterial embolisation. We report the successful non-surgical management of an unusual case of pulmonary artery perforation without concomitant haemothorax in an 82-year-old man who underwent thoracentesis.

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.

Spontaneous development and rupture of pulmonary artery aneurysm: a rare complication in an infant with peripheral pulmonary artery stenoses due to mutation of the elastin gene

We present a 3-year-old boy with an elastin gene mutation and multiple peripheral pulmonary stenoses, who developed aneurysms of the pulmonary arteries spontaneously. We performed transcatheter occlusion of the aneurysms with detachable coils. While pulmonary arterial aneurysms may develop following pulmonary balloon angioplasty, spontaneous development is exceedingly rare. To the best of our knowledge, this is the first report describing spontaneous development of pulmonary artery aneurysms in a patient with peripheral pulmonary artery stenoses due to mutation of the elastin gene or Williams-Beuren syndrome.

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.

Emergent use of extracorporeal membrane oxygenation during pediatric cardiac catheterization

OBJECTIVES

The goal of this study was to evaluate the utility of extracorporeal membrane oxygenation (ECMO) to resuscitate patients following critical cardiac events in the catheterization laboratory.

DESIGN

Retrospective review of medical records.

SETTING

Cardiac intensive care unit and cardiac catheterization laboratory at a tertiary care children's hospital.

PATIENTS

Pediatric patients cannulated emergently for ECMO in the cardiac catheterization laboratory (n = 22).

INTERVENTIONS

ECMO was initiated emergently in the cardiac catheterization laboratory for progressive hemodynamic deterioration due to low cardiac output syndrome or catheter-induced complications.

MEASUREMENTS AND MAIN RESULTS

Twenty-two patients were cannulated for ECMO in the catheterization laboratory between 1996 and 2004. Median age was 33 months (range 0-192), median weight 14.8 kg (2.4-75), and median duration of ECMO 84 hrs (2-343). Indications included catheter-induced complication (n = 14), severe low cardiac output syndrome (n = 7), and hypoxemia (n = 1). Three patients (14%) were cannulated in the catheterization laboratory before catheterization for low cardiac output or hypoxemia. During cannulation, 19 patients (86%) were receiving chest compressions; median duration of cardiopulmonary resuscitation was 29 mins (20-57). Eighteen patients (82%) survived to discharge (five of whom underwent cardiac transplantation) and four (18%) died. Of 19 patients who received cardiopulmonary resuscitation during cannulation, 15 (79%) survived to discharge and nine (47%) sustained neurologic injury. There was no significant difference between survivors and nonsurvivors in age, weight, duration of cardiopulmonary resuscitation or ECMO support, pH, or lactate levels.

CONCLUSIONS

ECMO is a technically feasible and highly successful tool in the resuscitation of pediatric patients following critical events in the cardiac catheterization laboratory.

The impact of interventional cardiology for the management of adults with congenital heart defects

The objective of this study is to assess the impact of interventional cardiology procedures for the management of ACHD. The interventional approach to the management of CHD in the adult population is becoming increasingly recognized as the preferred treatment option for a wide number of congenital cardiac conditions. The files of all consecutive patients over 18 years of age who were hospitalized in our department from January 2000 to December 2004 were reviewed. Over the study period, 1,115 ACHD (583 women; mean age 41 +/- 13.8, years, range 18-72 years) were hospitalized in our department; 752 patients underwent cardiac catheterization and 82.4% of them had an interventional procedure carried out. ASD (329/620) and PFO (159/620) closure account for 78% of all the procedures carried out, with a 2.7% of major complications incidence (all of them closing ASDs). Other procedures such as stenting aortic coarctation (40/620), ventricular septal defect closure (33/620), patent ductus arteriosus embolization (30/620), pulmonary valvuloplasty (12/620), stenting pulmonary artery branches (8/620), etc (5/620) were carried out. The most important complication was one death, which occurred in the case of a 22-year-old woman after stent implantation for a recurrent aortic coarctation. A trivial residual shunt was detected in only 5% of the patients who had a 6-month follow-up after VSD closure; no residual shunt was found after PDA embolization during the 12-month follow-up. In conclusion, we believe that the interventional approach is a safe and successful treatment option for a wide number of congenital cardiac conditions. The increasing use of catheter interventions for these patients will be responsible for an increase of complex cases in surgery.

Recent results of pulmonary arterial angioplasty: the differences between proximal and distal lesions

INTRODUCTION

We sought to establish a modern understanding of the safety and efficacy of trans-catheter pulmonary arterial angioplasty.

METHODS

A review of records in a sample of 104 dilations, out of a total of 711 procedures undertaken between January, 1996 and December, 2000, provided descriptive information regarding technique, adverse events, and changes achieved in luminal diameter. Because evidence during the review of angiograms suggested substantial differences according to whether the stenotic lesions were positioned proximally or distally within the pulmonary arterial tree, all analyses incorporated this classification.

RESULTS

We reviewed stenoses in 203 pulmonary arteries, 38% located proximally and 62% distally, with follow-up available concerning dilation in 92 vessels. Proximal dilations frequently involved a prior surgical site, and appeared more compliant and amenable to conventional angioplasty, as evidenced by more common elimination of the waist, but also more recoil, then requiring placement of stents. In contrast, distal lesions frequently required balloons capable of sustaining high pressures of inflation, and larger balloons relative to the size of the vessels. The proportional increase in diameter was greater for distal sites, at 90 plus or minus 77%, compared to proximal, at 64 plus or minus 70%, p equal to 0.002. Serious adverse events occurred in 3 of 104 procedures, giving a rate of serious adverse events of 2.9%. At follow-up, 9 of 92 vessels (10%), 95% confidence intervals from 5% to 18%, returned to their diameters prior to dilation, with no difference in the rate of restenosis according to the site of dilation.

CONCLUSION

Our findings indicate the need to distinguish, and to consider, the important differences in technical issues and outcomes, when performing dilations at proximal as opposed to distal sites. Although angioplasty is effective therapy for pulmonary arterial stenosis, a subset of vessels, more often distal, remain resistant to conventional techniques.

Pulmonary Artery Interventions: An Overview

Interventional radiologists should be familiar with minimally invasive procedures used to treat various abnormalities of the pulmonary arteries. These well-established techniques, which obviate open surgery, are safe and effective when performed by an experienced interventionalist. Catheter-based thrombolysis with intrapulmonary arterial infusion of thrombolytic drugs, percutaneous thrombectomy, or embolus fragmentation can be performed in patients with life-threatening pulmonary embolism. Pulmonary artery stenoses, mainly encountered in patients with pulmonary vasculitis (as in Behçet disease or Takayasu arteritis), may be treated with balloon angioplasty and stent placement. Transcatheter embolization of pulmonary arteriovenous malformation is the standard treatment for hereditary hemorrhagic telangiectasia and is a very effective alternative to surgery to correct an aneurysm or pseudoaneurysm. In cases of hemoptysis that originates in the pulmonary artery, early diagnosis is mandatory for treatment with embolization. Percutaneous retrieval of foreign bodies from the heart or the pulmonary arteries and endovascular biopsy should also be part of the armamentarium of interventional radiologists.

Bladed balloon angioplasty for peripheral pulmonary artery stenosis

Treatment for peripheral pulmonary artery stenosis is challenging, and conventional balloon angioplasty has not proved to be universally effective. Evaluated was the efficacy of bladed balloon (BB) dilation to address vessels resistant to conventional high-pressure (10-15 atm) balloon angioplasty (BA). Thirty-one procedures were performed on 14 children with age range 1 month to 15 years. The diameter of the BB ranged from 3 to 8 mm. After BB dilation, all children had subsequent conventional BA (balloon size range, 3-10 mm). The minimal lumen diameter (MLD) before and after the procedure, whether there was a waist at initial BA, and BB diameter-to-MLD ratio before the procedure were measured. A > 50% increase in MLD was considered successful. Four children had Williams syndrome, two children Alagille syndrome, five children Fallot's tetralogy, and three miscellaneous lesions. The resistant stenosis was located in the right central pulmonary artery in 6, right branch pulmonary artery in 7, left central pulmonary artery in 6, and left branch pulmonary artery in 12 lesions. Median BB diameter was 253% (117-440%) of the MLD and increased from 2.0 +/- 0.7 to 3.2 +/- 0.8 mm (P < 0.0001), with a mean increase of 73% +/- 62%. There was an inverse relationship between the MLD before and increase after the procedure (r = 0.75; P < 0.001). The BB diameter-to-MLD ratio before procedure was significantly associated with the increase in MLD (r = 0.70; P < 0.001). After the procedure, 18 of the 31 procedures were considered successful. In all successful procedures, the BB diameter was greater than twice the MLD before the procedure. Comparing children with Williams and Alagille syndrome with the remaining eight children, there were no significant differences in the increase in MLD. A small aneurysm and thrombus were noticed in two and three children, respectively, but no fatal complications were reported. BB angioplasty is effective for resistant peripheral pulmonary artery stenosis when conventional BA fails. The diameter of the BB should be larger than twice the minimal luminal diameter of the stenotic lesion.

Staged repair of tetralogy of Fallot and diminutive pulmonary arteries with a fenestrated ventricular septal defect patch

OBJECTIVES

Patients with tetralogy of Fallot and diminutive pulmonary arteries are at risk for suprasystemic right ventricular pressure and right ventricular failure after complete repair. We report the short-term outcome and medium-term follow-up after using a fenestrated ventricular septal defect patch as a component of staged repair in selected patients.

METHODS

We reviewed 47 patients with tetralogy of Fallot and diminutive pulmonary arteries whose ventricular septal defect patch was fenestrated, either electively or as a rescue technique, at a single institution between 1984 and 2001.

RESULTS

Early mortality was 10.6% and occurred only in patients who underwent rescue fenestration. Review of medium-term follow-up (median, 39 months) revealed 4 late deaths; an additional 4 patients experienced right ventricular failure despite fenestration. Most (7/8) of these late events occurred in patients who underwent planned fenestration. Excessive left-to-right shunt through the fenestration developed in only 2 patients.

CONCLUSIONS

Fenestrated patch closure of the ventricular septal defect in patients with tetralogy of Fallot and diminutive pulmonary arteries resulted in 10.6% early mortality. Used preemptively in selected patients, this technique is associated with no surgical mortality and a low incidence of excessive left-to-right shunt (4%). Early survivors remain at risk for late death and right ventricular failure despite fenestration.

Recanalization of a discrete atretic right pulmonary artery segment with a new radiofrequency system

We describe a case in which a discrete atretic segment of the right pulmonary artery (due to a Blalock-Taussig shunt) was reconstructed using a new radiofrequency system, balloon dilation, and stent implantation in an 18-month-old patient. The shunt was coil-occluded. The technique and applications of this novel approach are discussed.

Interventional strategies in the management of peripheral pulmonary artery stenosis

Peripheral pulmonary artery stenosis challenges therapeutic algorithms for the management of congenital heart malformations. Surgical repair of the proximal pulmonary artery lesion remains with a high recurrence rate while the distal lesions are difficult to access. With the development of transcatheter interventional strategies in the early 1980s, a number of transcatheter treatment options became available. In this review, we summarize the current state of the art for interventional strategies in the management of peripheral pulmonary artery stenosis.

Effect of cutting balloon angioplasty on resistant pulmonary artery stenosis

The effectiveness of cutting balloon (CB) therapy was evaluated in severe pulmonary artery (PA) stenosis resistant to high-pressure balloon angioplasty in children with tetralogy of Fallot and pulmonary atresia. Thirty-eight pulmonary vessels (initial diameter 0.4 to 4.0 mm) resistant to high-pressure balloon angioplasty, as evidenced by a persistent waist, were treated with CB angioplasty in 12 patients. Thirty-two vessels underwent standard CB angioplasty and 6 vessels were treated with a CB catheter augmenting technique. Of the vessels treated with standard CB angioplasty, 17 vessels underwent subsequent high-pressure balloon angioplasty, 8 vessels had additional high-pressure balloon angioplasty and stent placement, and 7 vessels underwent CB dilation alone. The diameter of these vessels increased from 1.3 +/- 0.7 to 2.8 +/- 0.9 mm (p <0.001). Six of the 38 vessels were treated with a CB catheter augmenting technique; these vessels were larger with an initial diameter of 2.6 +/- 0.8 mm and increased to 4.4 +/- 1.7 mm (p <0.001). Of the 38 vessels, 35 increased by >50%, for a procedural success rate of 92%. Intimal damage was angiographically evident in 17 of 38 vessels (45%) after CB angioplasty; 1 procedure was complicated by an unconfined tear requiring coil occlusion of the distal vessel and another resulted in a confined tear, successfully managed with stent implantation. This study supports prior reports of successful angioplasty with CB therapy for resistant PA stenosis, identifies potential complications, and expands the experience to infants, larger vessels, and sublobar locations.

Balloon dilatation and stent implantation for vascular stenosis

BACKGROUND

Previous results show that the success rate of balloon angioplasty for pulmonary artery stenosis is low. Mortality and morbidity are significant in balloon angioplasty for coarctation of the aorta.

METHODS

A review of the experience of balloon angioplasty for pulmonary artery stenosis and coarctation of the aorta at our institution was performed. A review of scientific reports of balloon angioplasty for these lesions was investigated.

RESULTS

Review of our results indicates that balloon angioplasty for pulmonary artery stenosis can be performed with a high success rate (80-90%), (i) by performing it at an appropriate time, (ii) by using high-pressure balloons, (iii) by using stents, and (iv) by using intravascular ultrasound (IVUS). Major complications occurred in 3% at our institution in balloon angioplasty for pulmonary artery stenosis. Incomplete dilation has been noted in 10-25% of patients of coarctation of the aorta. Aortic aneurysm has been reported in 2-7% of patients. Re-stenosis and/or hypertension also occur. The re-stenosis rate may be decreased if the aorta is dilated until signs of intimal tear are observed. Systemic hypertension may be noted in the long term after balloon angioplasty of coarctation of the aorta, even in patients with fairly good anatomical repair. The mechanisms for hypertension are not clear, but residual stenosis, even mild, may result in upper body hypertension.

CONCLUSIONS

Although there are significant limitations in the procedures, balloon angioplasty is effective in the management of pulmonary artery stenosis and coarctation of the aorta.