Hot topics in interventional cardiology: Proceedings from the society for cardiovascular angiography and interventions (SCAI) 2021 think tank

The Society for Cardiovascular Angiography and Interventions (SCAI) Think Tank is a collaborative venture that brings together interventional cardiologists, administrative partners, and select members of the cardiovascular industry community annually for high-level field-wide discussions. The 2021 Think Tank was organized into four parallel sessions reflective of the field of interventional cardiology: (a) coronary intervention, (b) endovascular medicine, (c) structural heart disease, and (d) congenital heart disease. Each session was moderated by a senior content expert and co-moderated by a member of SCAI's Emerging Leader Mentorship program. This document presents the proceedings to the wider cardiovascular community in order to enhance participation in this discussion, create additional dialog from a broader base, and thereby aid SCAI, the industry community and external stakeholders in developing specific action items to move these areas forward.

Critical Congenital Heart Disease Detection in the Screening Era: Do Not Neglect the Examination!

Pulse oximetry oxygen saturation (SpO ₂ )-based critical congenital heart disease (CCHD) screening is effective in detection of cyanotic heart lesions. We report a full-term male infant with normal perfusion who had passed the CCHD screening at approximately 24 hours after birth with preductal SpO ₂ of 99% and postductal SpO ₂ of 97%. Detection of a loud systolic cardiac murmur before discharge led to the diagnosis of pulmonary atresia (PA) with ventricular septal defect (PA-VSD) by echocardiogram. The infant was transferred to a tertiary care center after initiation of prostaglandin E1 (PGE1) therapy. Throughout the initial course, he was breathing comfortably without respiratory distress or desaturations on pulse oximetry. We believe that this is the first documented report of PA missed by CCHD screening. Thorough and serial clinical examinations of the newborn infant proved vital in the timely diagnosis of this critical disease. We review the hemodynamics and the recent literature evaluating utility of CCHD screening in the diagnosis of PA-VSD. Pulse oximetry-based CCHD screening should be considered a tool to enhance CCHD detection with an emphasis on detailed serial physical examinations in newborn infants.

Resource Allocation and Decision Making for Pediatric and Congenital Cardiac Catheterization During the Novel Coronavirus SARS-CoV-2 (COVID-19) Pandemic: A U.S. Multi-Institutional Perspective

BACKGROUND

The novel coronavirus (COVID-19) pandemic has placed severe stress on healthcare systems around the world. There is limited information on current practices in pediatric cardiac catheterization laboratories in the United States (US).

OBJECTIVES

To describe current practice patterns and make recommendations regarding potential resource allocation for congenital cardiac catheterization during the COVID-19 pandemic.

METHODS

A web-based survey was distributed regarding case candidacy and catheterization laboratory preparedness. Centers were categorized based on the current degree of disease burden in that community (as of April 1, 2020). Data and consensus opinion were utilized to develop recommendations.

RESULTS

Respondents belonged to 56 unique US centers, with 27 (48.2%) located in counties with a high number of COVID-19 cases. All centers have canceled elective procedures. There was relative uniformity (>88% agreement) among centers as to which procedures were considered elective. To date, only three centers have performed a catheterization on a confirmed COVID-19 positive patient. Centers located in areas with a higher number of COVID-9 cases have been more involved in a simulation of donning and doffing personal protective equipment (PPE) than low-prevalence centers (46.7% vs 10.3%, respectively; P<.001). Currently, only a small fraction of operators has been reassigned to provide clinical services outside their scope of practice.

CONCLUSIONS

At this stage in the COVID-19 pandemic, pediatric/congenital catheterization laboratories have dramatically reduced case volumes. This document serves to define current patterns and provides guidance and recommendations on the preservation and repurposing of resources to help pediatric cardiac programs develop strategies for patient care during this unprecedented crisis.

Procedural, pregnancy, and short-term outcomes after fetal aortic valvuloplasty

OBJECTIVES

We aimed to evaluate the effect of technical aspects of fetal aortic valvuloplasty (FAV) on procedural risks and pregnancy outcomes.

BACKGROUND

FAV is performed in cases of severe mid-gestation aortic stenosis with the goal of preventing hypoplastic left heart syndrome (HLHS).

METHODS

The International Fetal Cardiac Intervention Registry was queried for fetuses who underwent FAV from 2002 to 2018, excluding one high-volume center.

RESULTS

The 108 fetuses had an attempted cardiac puncture (mean gestational age [GA] 26.1 ± 3.3 weeks). 83.3% of attempted interventions were technically successful (increased forward flow/new aortic insufficiency). The interventional cannula was larger than 19 g in 70.4%. More than one cardiac puncture was performed in 25.0%. Intraprocedural complications occurred in 48.1%, including bradycardia (34.1%), pericardial (22.2%) or pleural effusion (2.7%) requiring drainage, and balloon rupture (5.6%). Death within 48 hr occurred in 16.7% of fetuses. Of the 81 patients born alive, 59 were discharged home, 34 of whom had biventricular circulation. More than one cardiac puncture was associated with higher complication rates (p < .001). Larger cannula size was associated with higher pericardial effusion rates (p = .044). On multivariate analysis, technical success (odds ratio [OR] = 10.9, 95% confidence interval [CI] = 2.2-53.5, p = .003) and later GA at intervention (OR = 1.5, 95% CI = 1.2-1.9, p = .002) were associated with increased odds of live birth.

CONCLUSIONS

FAV is an often successful but high-risk procedure. Multiple cardiac punctures are associated with increased complication and fetal mortality rates. Later GA at intervention and technical success were independently associated with increased odds of live birth. However, performing the procedure later in gestation may miss the window to prevent progression to HLHS.

Hybrid approach to ventricular septal defect enlargement

The need for creation or enlargement of a ventricular septal defect (VSD) is a rare occurrence. It is most frequently required in patients with double-outlet right ventricle who develop restriction of a remote muscular VSD or obstruction of a perimembranous VSD secondary to atrioventricular (AV) valve attachments to the interventricular septum. Surgical and transcatheter options for VSD creation or enlargement are associated with several risks including heart block, AV valve injury, and perforation. We report the first description of a hybrid approach to VSD creation and enlargement in two patients.

Recanalization of Occluded Central Veins in a Parenteral Nutrition-Dependent Child With No Access

Central venous thromboses are common and pose challenges in the care of chronically ill pediatric patients. Among patients with intestinal failure (most commonly because of short bowel syndrome) who depend on parenteral nutrition, progressive loss of central venous access sites is a potentially fatal complication. We present the case of a 5-year-old girl with parenteral nutrition-dependent short bowel syndrome and no remaining standard central venous access sites despite medical anticoagulation, in whom angioplasty and stent implantations were used to reconstruct chronically occluded central veins. The patient presented with a bloodstream infection necessitating tunneled central venous line removal from the left internal jugular vein. All other standard access sites had known occlusions. The right iliofemoral vein (RIFV) and infrarenal inferior vena cava were recanalized and dilated with high-pressure balloons. The left internal jugular line was removed and a line was placed in the now-patent RIFV for antimicrobial therapy. After treatment, the RIFV line was removed and the vessels were stented open for future access. The occluded left innominate vein was recanalized and dilated to allow a new tunneled line to be placed. At 10 months, the line was functional and uninfected and the RIFV and inferior vena cava stents were patent without in-stent restenosis. We propose a new paradigm that uses these techniques to prevent access site exhaustion in patients who do not respond to anticoagulation therapy. This approach may reduce morbidity and mortality in patients with chronic access needs and the need for intestinal transplantation in patients with intestinal failure.

Outcomes of Transcatheter Tricuspid Valve-in-Valve Implantation in Patients With Ebstein Anomaly

We sought to describe the acute results and short- to medium-term durability of transcatheter tricuspid valve-in-valve (TVIV) implantation within surgical bioprostheses among patients with Ebstein anomaly (EA). Cases were identified from a voluntary, multicenter, international registry of 29 institutions that perform TVIV. Demographic, clinical, procedural, and follow-up data were analyzed. Eighty-one patients with EA underwent TVIV from 2008 to 2016. Thirty-four patients (42%) were New York Heart Association (NYHA) class 3/4 at time of TVIV. The most common indication for TVIV was the presence of moderate or severe tricuspid regurgitation (40%). Most patients received a Melody valve (64%). TVIV was ultimately successful in all patients, and there was no procedural mortality. Four patients (5%) developed acute valve thrombosis, 4 patients (5%) developed endocarditis, and 9 patients (11%) developed valve dysfunction not related to thrombosis or endocarditis. Eight patients (10%) underwent reintervention (2 transcatheter, 6 surgical) due to thrombosis (3), endocarditis (2), other valve dysfunction (2), and patient-prosthesis mismatch without valve dysfunction (1). Among 69 patients who were alive without reintervention at latest follow-up, 96% of those with NYHA status reported were class 1/2, a significant improvement from baseline (62% NYHA class 1/2, p <0.001). In conclusion, transcatheter TVIV offers a low-risk, minimally invasive alternative to surgical tricuspid valve re-replacement in patients with EA and a failing tricuspid valve bioprosthesis.

Reduction in Radiation Dose in a Pediatric Cardiac Catheterization Lab Using the Philips AlluraClarity X-ray System

The objective of this study was to compare radiation doses and imaging quality using Philips AlluraClarity (Philips Healthcare, Best, The Netherlands) X-ray system and an older generation reference system. AlluraClarity is a new generation fluoroscopy system designed to reduce radiation without compromising image quality, but reports of its use in pediatric patients are limited. Dose area products (DAP, mGy cm²) and DAP/kg were compared in patients catheterized using Allura Xper and AlluraClarity systems over a year of use for each. Randomly selected studies from each system were assessed for image quality. The 430 patients imaged with Clarity were larger than the 332 imaged with Xper (median BSA: 0.74 vs. 0.64 m², p = 0.06), and median total fluoroscopic times (TFT) were similar (15.8 vs. 16.1 min, p = 0.37). Median DAPs were 8661 mGy cm² (IQR: 18,300 mGy cm²) and 4523 mGy cm² (IQR: 11,596 mGy cm²) with Xper and Clarity, respectively (p < 0.001). There was a reduction in median DAP in all procedure categories. After adjustment for BSA, TFT, and procedure type, using Clarity was associated with a 57.5% (95% CI 51.5-62.8%, p < 0.001) reduction in DAP for all procedures. Reductions did not significantly differ by weight (<10 kg, 10-40 kg, ≥ 40 kg). There was an adjusted percent reduction in DAP for each procedure category ranging from 39.0% (95% CI 25.6-50.1%, p < 0.001) for cardiac biopsies with or without coronary angiography to 67.6% (95% CI 61.2-72.8%, p < 0.001) for device occlusions. Mean overall imaging quality scores (4.3 ± 0.8 with Clarity vs. 4.4 ± 0.6 with Xper, p = 0.62) and scores based on specific quality parameters were similar in the two groups. Use of AlluraClarity substantially reduced radiation doses compared to the older generation reference system without compromising imaging quality in a pediatric cardiac catheterization lab.

Simultaneous transcatheter implantation of systemic and pulmonary venous baffle stents after mustard operation for d-transposition of the great arteries

We report a case of simultaneous transcatheter systemic and pulmonary venous baffle obstruction stenting in a post operative Mustard patient with d-transposition of the great arteries.

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.

Unmasking of an isolated right subclavian artery from the pulmonary artery after device occlusion of a patent arterial duct

Isolation of the right subclavian artery (RSCA) from the pulmonary artery is a rare anomaly of the aortic arch. We report a case of an isolated RSCA from the right pulmonary artery that was discovered at the time of device occlusion of a patent arterial duct. We review the literature and discuss management options.

Repeat balloon aortic valvuloplasty effectively delays surgical intervention in children with recurrent aortic stenosis

OBJECTIVE

Balloon aortic valvuloplasty (BAV) is the primary therapy for congenital aortic stenosis (AS). Recurrent AS following initial BAV or initial surgical valvotomy (SV) may require a second BAV (BAV2). We sought to determine the longterm outcomes of BAV2.

DESIGN

We reviewed all cases of BAV2, defined as BAV following primary BAV or SV between 1988 and 2009. Cases were reviewed for pre- and post-BAV2 echocardiographic and procedural details.

SETTING

Tertiary care dedicated children's hospital.

PATIENTS

Between 1985 and 2009, 43 patients underwent BAV2 (23 primary SV, 20 primary BAV) at median age 1.9 years (1 month-21 years) and median weight 15 (3.3-55) kg.

INTERVENTIONS

BAV2 performed following primary SV or primary BAV.

MAIN OUTCOME MEASURES

We evaluated the following endpoints: ≥ moderate AI post-BAV2, aortic valve replacement (AVR), additional BAV or SV post-BAV2, death and heart transplantation.

RESULTS

The gradient decreased from 61.4 ± 16.0 mm Hg to 26.0 ± 13.6 post-BAV2 (P < 0.01). Gradient prior to BAV2 was higher in primary SV patients (66 ± 13 mm Hg) than in primary BAV patients (56 ± 18 mm Hg, P = 0.04). 24 patients had no further events after BAV2, while 19 patients (44%) experienced 23 events including: AVR (n = 8), SV (n = 6), BAV3 (n = 2), death (n = 5), and transplant (n = 1). Regression demonstrated that adverse events were associated with higher post-BAV2 gradient (P < 0.01). Repeat intervention on the aortic valve and AVR were associated with higher post BAV2 gradient (P = 0.04, P = 0.01). Prior to BAV2, 7 patients (17%) had AI > mild, compared to 21 (51%) patients after BAV2. Cox regression revealed that primary BAV was associated with development of AI > mild after BAV2 (P < 0.01).

CONCLUSION

BAV2 is associated with decreased valve gradient, though with an increase in AI. However, residual AS, not AI, is associated with poor outcomes following BAV2. BAV2 effectively treats recurrent AS and postpones need for surgical intervention.

Melody valve implantation in the pulmonary and tricuspid position

Percutaneous implantation of valved stents is now routinely performed to treat pulmonary valve regurgitation and stenosis. In addition, there are isolated reports of implantation of valved stents in the tricuspid position to treat prosthetic tricuspid stenosis or regurgitation when a prosthetic valve ring exists. We present a case in which a patient with combined severe tricuspid valve and pulmonary valve disease was successfully treated with sequential implantation of percutaneous valved stents in a single procedure. The procedure was straightforward, of short duration, and dramatically improved the patient's functional status.

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.

Twenty-five year experience with balloon aortic valvuloplasty for congenital aortic stenosis

Balloon aortic valvuloplasty (BAV) is the primary therapy for congenital aortic stenosis (AS). Few reports describe long-term outcomes. In this study, a retrospective single-institution review was performed of patients who underwent BAV for congenital AS. The following end points were evaluated: moderate or severe aortic insufficiency (AI) by echocardiography, aortic valve replacement, repeat BAV, surgical aortic valvotomy, and transplantation or death. From 1985 to 2009, 272 patients who underwent BAV at ages 1 day to 30.5 years were followed for 5.8 ± 6.7 years. Transplantation or death occurred in 24 patients (9%) and was associated with depressed baseline left ventricular shortening fraction (LVSF) (p = 0.04). Aortic valve replacement occurred in 42 patients (15%) at a median of 3.5 years (interquartile range 75 days to 5.9 years) after BAV and was associated with post-BAV gradient ≥25 mm Hg (p = 0.02), the presence of post-BAV AI (p = 0.03), and below-average baseline LVSF (p = 0.04). AI was found in 83 patients (31%) at a median of 4.8 years (interquartile range 1.4 to 8.7) and was inversely related to post-BAV gradient ≥25 mm Hg (p <0.04). AI was associated with depressed baseline LVSF (p = 0.02). Repeat valvuloplasty (balloon or surgical) occurred in 37 patients (15%) at a median of 0.51 years (interquartile range 0.10 to 5.15) and was associated with neonatal BAV (p <0.01), post-BAV gradient ≥25 mm Hg (p = 0.03), and depressed baseline LVSF (p = 0.05). In conclusion, BAV confers long-term benefits to most patients with congenital AS. Neonates, patients with post-BAV gradients ≥25 mm Hg, and patients with lower baseline LVSF experienced worse outcomes.

Outcomes of transcatheter occlusion of patent ductus arteriosus in infants weighing ≤ 6 kg

OBJECTIVES

We sought to analyze the outcomes of transcatheter patent ductus arteriosus (PDA) occlusion using a variety of devices in infants weighing ≤6 kg.

BACKGROUND

Indications for transcatheter closure of a PDA in infancy include congestive heart failure and/or failure to thrive. Devices available for small infants may be problematic for various reasons, including sheath size, stiffness of delivery system, and anchoring and retrievability characteristics of the device. The Amplatzer Ductal Occluder is approved by U.S. Food and Drug Administration for children weighing >6 kg and older than 6 months of age.

METHODS

We performed a multicenter, retrospective analysis of children weighing ≤6 kg in whom transcatheter PDA occlusion was attempted between January 1995 and November 2005 at Texas Children's Hospital and January 2001 to November 2005 at Children's Hospital of San Diego.

RESULTS

A total of 62 patients underwent attempted closure. The mean age at catheterization was 4.7 ± 2.8 months with a mean weight at catheterization of 4.6 ± 0.9 kg. Successful device placement was achieved in 58 of 62 patients (94%). Among those receiving a device, complete occlusion was noted in all 58 patients at either catheterization or last available follow-up.

CONCLUSIONS

Percutaneous closure of PDA should be considered even in infants ≤6 kg.

The IMPACT registry: IMproving Pediatric and Adult Congenital Treatments

Tremendous advances have occurred in catheter-based interventions for congenital heart disease. Multicenter trials of these advances are either out of date or have been limited in scope. As such little is known on the application of these techniques in the current era. The IMPACT Registry (IMproving Pediatric and Adult Congenital Treatments) will allow us to measure variability in the performance and outcomes of both diagnostic and interventional cardiac catheterization procedures in all children and adults with congenital heart disease. The IMPACT Registry will be harmonized with the Society of Thoracic Surgeons Congenital Heart Disease Database, thereby allowing us to compare catheter-based interventions with surgical interventions when appropriate. The initial release of the registry will only include hospital-based outcomes, but ultimately it will transition to a longitudinal registry. The IMPACT Registry will provide the necessary benchmark tools for quality improvement activities for cardiac catheterization procedures in congenital heart disease.

Successful use of bivalirudin for superior vena cava recanalization and stent placement in a child with heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a potentially life-threatening, adverse effect of heparin therapy. Patients with this complication require an alternative approach to anticoagulation. Bivalirudin is a direct thrombin inhibitor with an efficacy comparable to that of heparin, a short half-life, and reduced bleeding complications in adults. We present the case of a 2-year-old boy with HIT Type II who underwent recanalization of an occluded superior vena cava and stent placement, utilizing bivalirudin as anticoagulant.

Late Left Pulmonary Artery Stenosis After the Norwood Procedure is Prevented by a Modification in Shunt Construction

BACKGROUND

Late left pulmonary artery (LPA) stenosis occurs commonly after the Norwood procedure, and complicates subsequent stages. Compression by the neoaorta and ductal stump may favor flow into the right pulmonary artery, resulting in LPA hypoplasia. We hypothesize that an early compromise of LPA flow contributes to late LPA stenosis, and have modified our shunt to compensate.

METHODS

We reviewed 34 consecutive neonates undergoing the Norwood procedure between 1999 and 2002, and morphometric data from angiograms obtained before the bidirectional cavopulmonary anastomosis (BDCPA). The Norwood technique included an autologous arch reconstruction with or without augmentation, and a polytetrafluoroethylene Blalock-Taussig shunt (BTS). Starting February 2001, the distal shunt was modified from an end-to-side construction to an oblique anastomosis directed into the retroaortic LPA.

RESULTS

Norwood survival was 82%. LPA stenosis required plasty in 10 of 13 (77%) premodification survivors, and in 2 of 9 (22%) postmodification (p = 0.027). Bypass time was 151 +/- 65 minutes with LPA plasty versus 95 +/- 50 minutes without. Mortality (15% vs 0%), hospital stay (25 +/- 35 vs 9 +/- 6 days), and incidence of subsequent interventions were correspondingly higher with LPA stenosis. Ten of 13 patients (77%) with a BTS insertion point outside the central region of the pulmonary artery required LPA plasty, versus 2 of 9 (22%) with an insertion nearer to the center (p = 0.027).

CONCLUSIONS

An oblique distal BTS anastomosis directed leftward onto the retroaortic pulmonary artery at the time of the Norwood procedure may prevent late LPA stenosis and its attendant morbidity.

Delivery of stents to target lesions: techniques of intraoperative stent implantation and intraoperative angiograms

Mullins et al. [6] reported the first use of stent implantation to treat stenotic branch pulmonary arteries in 1988. In the early to mid-1990s, numerous reports confirmed its safety and efficacy, but there were limited stent and balloon designs and stent implantations were performed using relatively large delivery systems (10- to 12-Fr sheaths) [7, 8]. The general accepted patient size was limited to those weighing 12 kg or greater. Intraoperative stent implantation for branch pulmonary artery stenosis was reported in the early to mid-1990s [1-3, 5, 9]. Indications in these early reports included small patient size or difficult anatomy or patients who had additional cardiac lesions and needed surgery independent of the branch stenosis. The idea was to take advantage of the open-heart exposure provided in the operating room to permit direct access to the stenotic segment. Hence, all intraoperative stent implants were performed under direct visualization on bypass. There were no discussions on advantages over the routine percutaneous approach. Currently, with advances in stent and balloon technology as well as increased operator experience, many of those reported cases probably would have undergone cardiac catheterization for a percutaneous stent implant rather than open-heart surgery. The purpose of this report is to review the current indications, advantages, and disadvantages of intraoperative stent implantation as well as to discuss the techniques that are helpful to optimize intraoperative stent positioning. The role and advantages of intraoperative angiography will also be presented.

"Transseptal" technique through atrial baffles for 3-dimensional mapping and ablation of atrial tachycardia in patients with d-transposition of the great arteries

Access to targets for radiofrequency ablation in patients with congenital heart disease may be limited by anatomy and by surgically placed obstacles. In patients with atrial switch anatomy for d-transposition of the great arteries, the critical isthmus for maintenance of intraatrial macroreentry circuits is found often on the pulmonary venous side of the atrial baffle. A retrograde approach is extremely difficult for these arrhythmias. Use of transseptal techniques for diagnostic catheterization in these patients has been reported. We report the use of a transseptal technique in two cases in conjunction with 3-dimensional electroanatomic mapping for the successful ablation of atrial reentry tachycardias in patients with Mustard and Senning anatomy.

Absent posteroinferior and anterosuperior atrial septal defect rims: factors affecting nonsurgical closure of large secundum defects using the amplatzer occluder

Using transesophageal echocardiography, we sought to determine the anatomic characteristics of the secundum atrial septal defects (ASDs) that extend into the inferior sinus venosus and have no posteroinferior (PI) rim, to determine the factors related to potential closure with an Amplatzer occluder. We also sought to understand why large secundum ASDs with a PI but without an anterosuperior (AS) rim may require special techniques to reorient the left atrial disk before deployment of the waist and right atrial disk. We measured the lengths of 5 separate rims of the circumferences of 76 secundum ASDs, including anteroinferior, AS, superior, posterosuperior, and PI rims. We also measured anteroposterior and superoinferior defect diameters, total septal lengths, and the ratios of defect diameter to total septal length. The atrial depth was measured at the axial angle of the delivery sheath in 5 defects with no AS rim for which special techniques were required to achieve successful closure. Of 76 secundum ASDs, 13 (17%) had no PI rim. Each defect extended from the fossa ovalis into the inferior sinus venosus. Compared with defects with a PI rim, the factors related to potential closure included 100% larger defect diameters, shorter posterosuperior rim lengths, larger defect to total septal length ratios, and completely flat posterior atrial walls. When the AS rim was absent the factors related to the need for special techniques included diameters >/= 22 mm, atrial depth < the calculated Amplatzer occluder left atrial disk diameter, rigid wire/disk interface, and obligatory left atrial disk orientation more or less perpendicular to the atrial septal plane.

Refinements in the implantation of pulmonary arterial stents: impact on morbidity and mortality of the procedure over the last two decades

INTRODUCTION

There is limited data on medium to long-term outcome, and the morbidity and mortality associated with the implantation, of pulmonary arterial stents.

PURPOSE

To assess changes in morbidity and mortality over the last two decades.

METHODS

Retrospective analysis of all patients stented between September, 1989 and July, 2001.

RESULTS

We implanted 664 Palmaz stents in 338 patients. The overall number included 229 patients who had undergone repair of tetralogy of Fallot, in whom 468 stents were implanted, 61 patients with congenital stenosis of the branches of the pulmonary trunk, in whom we placed 115 stents, 16 patients after an arterial switch operation who had 38 stents, and 32 patients after the Fontan operation who had 43 stents implanted. The mean age was 12.2 years, and the mean weight was 38 kg. The mean systolic pressure gradient decreased from 41 to 8.7 mmHg, the mean diameter of the stented vessel increased from 5.4 to 11.2 mm, and the ratio of right ventricular to femoral arterial pressure decreased from 0.66 to 0.45, each of these being significant at the level of p being less than 0.01. At a mean follow-up of 5.6 years, the mean gradient was 20 mmHg, the mean ratio of pressure between right ventricle and femoral artery was 0.5, and mean luminal diameter was 9.3 mm. Complications included migration of the stent in 8 patients, and pulmonary edema, hemoptysis and death in 5 patients each. There has been no mortality or morbidity since July of 1997. Technical changes include conservative serial dilations in congenital pulmonary arterial stenosis, avoidance of over-dilation, and simultaneous implantation of stents in the right and left pulmonary arteries in those with systemic pulmonary arterial pressure. Technological advances included shorter stents, improved balloon profiles, and central inflation of the stents.

CONCLUSIONS

Modification of stenting practices, and increased experience of the operators over the last two decades, has virtually abolished any morbidity or mortality associated with the implantation of stents for congenital or postoperative pulmonary arterial stenoses.

Reconstruction of stenotic or occluded iliofemoral veins and inferior vena cava using intravascular stents: re-establishing access for future cardiac catheterization and cardiac surgery

OBJECTIVES

The study evaluated the safety and efficacy of stent reconstruction of stenotic/occluded iliofemoral veins (IFV) and inferior vena cava (IVC).

BACKGROUND

Patients with congenital heart defects and stenotic or occluded IFV/IVC may encounter femoral venous access problems during future cardiac surgeries or catheterizations.

METHODS

Twenty-four patients (median age 4.9 years) underwent implantation of 85 stents in 22 IFV and 6 IVC. Fifteen vessels were severely stenotic and 13 were completely occluded. Although guide wires were easily passed across the stenotic vessels, occluded vessels required puncture through the thrombosed sites using a stiff wire or transseptal needle. Once traversed, the occluded site was dilated serially prior to stent implantation.

RESULTS

Following stent placement, the mean vessel diameter increased from 0.9 +/- 1.6 to 7.4 +/- 2.6 mm (p < 0.05). Twenty-one of 28 vessels had long segment stenosis/occlusion requiring two to seven overlapping stents. Repeat catheterizations were performed in seven patients (9 stented vessels) at mean follow-up of 1.6 years. Seven vessels remained patent with mean diameter of 6.4 +/- 2.0 mm. Two vessels were occluded, but they were easily recanalized and redilated. Echocardiographic follow-up in two patients with IVC stents demonstrated wide patency. In four additional patients, a stented vessel was utilized for vascular access during subsequent cardiac surgery (n = 3) and endomyocardial biopsy (n = 1). Therefore, 13 of 15 stented vessels (87%) remained patent at follow-up thus far.

CONCLUSIONS

Stenotic/obstructed IFV and IVC may be reconstructed using stents to re-establish venous access to the heart for future cardiac catheterization and/or surgeries.

18-year experience with transseptal procedures through baffles, conduits, and other intra-atrial patches

The presence of an intra-atrial patch (IAP) has been considered a relative contraindication to transseptal puncture (TSP). The purpose of this study is to determine the efficacy and safety of the TSP through baffles, conduits, pericardial patches and other prosthetic materials in the intra-atrial septum. We reviewed the records of all pediatric patients with IAP who underwent TSP at Texas Children's Hospital from November 1979 through February 1998. The review included the cardiac diagnoses, indications for TSP, technical difficulties and follow up echocardiograms specifically addressing residual atrial shunts A total of 1958 TSP were performed. Thirty-nine patients had IAP. Cardiac diagnoses in those 39 patients included D-transposition of the great arteries after Mustard (10) or Senning procedure (6), single ventricle variant post-Fontan operation (4), total anomalous venous return repair (4), atrioventricular canal repair (9) and atrial septal defect with patch repair (6). Patients' age ranged from 1-31 years (median 7 years). The duration from the time of surgical repair to TSP ranged from 0.1-21 years (median 5 years). Indications for TSP included diagnostic and therapeutic intervention for pulmonary venous obstruction (12), creation of a baffle fenestration (2), prosthetic mitral valve evaluation (1), left ventricular outflow tract evaluation (1), access the left heart for hemodynamic evaluation (23). The IAP was traversed in 38/39 patients (97.5%), followed by diagnostic or therapeutic prograde left-heart catheterization. No complications were encountered. Follow up echocardiography in 30/38 PTS demonstrated no residual shunting across the atrial septum except for two cases in which the atrial baffle had been intentionally fenestrated. Transseptal puncture through an intra-atrial patch is a safe procedure. This technique is effective in permitting diagnostic and therapeutic left heart catheterization and does not result in residual shunting through the patch.

Balloon aortic valvuloplasty in a 1,600-gram infant

We present a 1,600 g infant who underwent successful balloon aortic valvuloplasty from the right carotid artery approach. A simple technique to facilitate access to the left ventricle and expedite the procedure is described. Issues unique to performing balloon aortic valvuloplasty on such a small child are discussed.

Transcatheter closure of surgical shunts in patients with congenital heart disease

The aim of this study was to review contemporary techniques, devices, and results of transcatheter occlusion of surgical shunts in 2 pediatric cardiac programs. Closure of superfluous surgical shunts may reduce cardiac work and risk of endocarditis. Previous studies have shown that transcatheter closure of shunts is feasible, but have not demonstrated acceptable efficacy or safety. In addition, the performance of new techniques and devices has not been reviewed. Between 1993 and 1998, 18 patients with congenital heart disease underwent transcatheter closure of 19 Blalock-Taussig shunts. Detachable and standard Gianturco coils and Gianturco-Grifka vascular occlusion devices were employed. All 19 shunts had complete closure. Eight shunts had initial placement of detachable coils. Five shunts had stents placed that bridged the pulmonary end of the shunts. These 5 and 4 additional shunts had closure by standard coils. Two shunts were closed with Gianturco-Grifka devices. There were no complications, no embolizations, and no requirement for surgery precipitated by the procedures. This review of contemporary techniques, devices, and results suggests that transcatheter occlusion of surgical shunts is effective and safe.

A technique to prevent newly implanted stent displacement during subsequent catheter and sheath manipulation

We describe a novel technique to prevent the displacement or migration of a newly implanted stent as a consequence of any subsequent catheter and sheath manipulation during the same catheterization procedure. The technique involves reinflation of the dilation balloon within the stent immediately after implant followed by advancing the long delivery sheath carefully over the balloon as the balloon is slowly deflated within the stent. The technique was used successfully in 78 stents in 30 patients without stent dislodgment or migration.

The snare-assisted technique for transcatheter coil occlusion of moderate to large patent ductus arteriosus: immediate and intermediate results

OBJECTIVES

The purpose of this study was to evaluate the feasibility, safety and efficacy of using a snare-assisted technique to coil occlude the moderate to large size patent ductus arteriosus (PDA).

BACKGROUND

Transcatheter occlusion of small PDAs using Gianturco coils is safe and effective. However, in larger size PDAs and/or those with short PDA length, the procedure still carries risks of coil embolization, incomplete occlusion and failure to implant the coil.

METHODS

From January 1994 to June 1997, the records of 104 consecutive snare-assisted coil occlusions of moderate to large PDAs (minimum diameter >2.0 mm) were reviewed. Immediate and intermediate outcomes including complete and partial occlusion, failure to implant and complications were analyzed with respect to ductal type and size.

RESULTS

Patient age ranged from 0.1 to 70.1 years (median 3.3 years). Minimum PDA diameter ranged from 2.1 to 6.8 mm (mean 3.0 +/- 0.9 mm). Angiographic types were A-62, B-13, C-6, D-14 and E-9. Using the snare-assisted technique, coil placement was successful in 104/104 patients (100%), irrespective of size or angiographic type. Immediate complete closure was observed in 73/104 (70.2%) and was related to smaller PDA size, but not to angiographic type. Complete closure was documented in 102/104 (98.1%) at 2- to 16-month follow-up. Successful closure was unrelated to PDA size or type. Coil embolization to the pulmonary artery occurred in 3/104 (2.9%) patients and was not related to PDA size or type. The need for multiple coils was found in 28/104 patients (26.9%), and was related to larger PDA size, but not to angiographic type.

CONCLUSIONS

The snare-assisted delivery technique allows successful occlusion of moderate to large PDAs up to 6.8 mm, irrespective of angiographic type. This technique permits improved control and accuracy of coil placement, and facilitates delivery of multiple coils.

Does ductal occlusion with the gianturco coil cause left pulmonary artery and/or descending aorta obstruction?

Thirty-two patients (median age 4.5 years) underwent transcatheter Gianturco coil occlusion of a patent ductus arteriosus. Transthoracic echocardiography was performed the day after coil placement and at intermediate follow-up (median 8.6 months). Echocardiographic results were compared with angiographic and hemodynamic data obtained during catheterization. Two-dimensional (2D) echocardiography performed the day after ductal occlusion displayed evidence of coil protrusion into the left pulmonary artery in 28 of 31 patients (90%) and into the descending aorta in 17 of 29 (59%). However, pulsed Doppler analysis demonstrated normal left pulmonary arterial flow velocities in 28 of 29 patients (97%) and normal descending aortic flow velocities in 26 of 27 (96%). Pulse Doppler results were corroborated by angiographic and hemodynamic catheterization data, which showed no evidence of adjacent vessel obstruction. Peak Doppler velocities among patients with and without 2D echocardiographic left pulmonary artery or descending aorta coil impingement did not differ significantly. The discrepancy between 2D and pulse Doppler findings did not change significantly at intermediate follow-up. Thus, transcatheter occlusion of the patent ductus arteriosus with properly implanted Gianturco coils does not cause significant obstruction to flow in the left pulmonary artery or descending aorta despite frequently misleading 2D echocardiographic images of coil impingement on these vessels.