Balloon dilation of severe aortic stenosis in the neonate: comparison of anterograde and retrograde catheter approaches

Balloon Valvuloplasty in Congenital Critical Aortic Valve Stenosis in Neonates and Infants: A Rescue Procedure for the Left Ventricle

Congenital critical aortic valve stenosis (CAVS) is a life-threatening disease requiring urgent treatment. First-line therapy is still controversial. The aim of our study was (1) to analyze retrospectively the patients of our institution who underwent balloon aortic valvuloplasty (BAV) due to CAVS and (2) describe the techniques for improved feasibility of intervention using microcatheters and retrieval loops. Twelve patients underwent 23 BAVs: 1 BAV was performed in 3 patients, 2 BAVs were performed in 7 patients, and 3 BAVs were performed in 2 patients. The peak trans-valvular pressure gradient (Δp) and left ventricular shortening fraction (LVSF) improved significantly in the first two interventions. In the first BAV, Δp decreased from 73.7 ± 34.5 mmHg to 39.8 ± 11.9 mmHg (p = 0.003), and the LVSF improved from 22.3 ± 13.5% to 31.6 ± 10.2% (p = 0.001). In the second BAV, Δp decreased from 73.2 ± 33.3 mmHg to 35.0 ± 20.2 mmHg (p < 0.001), and the LVSF increased from 26.7 ± 9.6% to 33.3 ± 7.4% (p = 0.004). Cardiac surgery during the neonatal period was avoided for all children. The median time to valve surgery was 5.75 years. Few complications occurred, namely mild-to-moderate aortic regurgitation, one remediable air embolism, and one intimal injury to the ascending aorta. We conclude that BAV is a successful emergency treatment for CAVS, resulting in left ventricular relief, clinical stabilization, and a time gain until cardiac surgery.

Balloon Valvuloplasty for Congenital Aortic Stenosis: Experience at a Tertiary Center in a Developing Country

Background

Aortic valve stenosis accounts for 3–6% of congenital heart disease. Balloon aortic valvuloplasty (BAV) is the preferred therapeutic intervention in many centers. However, most of the reported data are from developed countries.

Materials and Methods

We performed a retrospective single-center study involving consecutive eligible neonates and infants with congenital aortic stenosis admitted for percutaneous BAV between January 2005 and January 2016 to our tertiary center. We evaluated the short- and mid-term outcomes associated with the use of BAV as a treatment for congenital aortic stenosis (CAS) at a tertiary center in a developing country. Similarly, we compared these outcomes to those reported in developed countries.

Results

During the study period, a total of thirty patients, newborns (n = 15) and infants/children (n = 15), underwent BAV. Left ventricular systolic dysfunction was present in 56% of the patients. Isolated AS was present in 19 patients (63%). Associated anomalies were present in 11 patients (37%): seven (21%) had coarctation of the aorta, two (6%) had restrictive ventricular septal defects, one had mild Ebstein anomaly, one had Shone's syndrome, and one had cleft mitral valve. BAV was not associated with perioperative or immediate postoperative mortality. Immediately following the valvuloplasty, a more than mild aortic regurgitation was noted only in two patients (7%). A none-to-mild aortic regurgitation was noted in the remaining 93%. One patient died three months after the procedure. At a mean follow-up of 7 years, twenty patients (69%) had more than mild aortic regurgitation, and four patients (13%) required surgical intervention. Kaplan–Meier freedom from aortic valve reintervention was 97% at 1 year and 87% at 10 years of follow-up.

Conclusion

Based on outcomes encountered at a tertiary center in a developing country, BAV is an effective and safe modality associated with low complication rates comparable to those reported in developed countries.

Decision-Making in the Catheter Laboratory: The Most Important Variable in Successful Outcomes

Increasingly the importance of how and why we make decisions in the medical arena has been questioned. Traditionally the aeronautical and business worlds have shed a light on this complex area of human decision-making. In this review we reflect on what we already know about the complexity of decision-making in addition to directing particular focus on the challenges to decision-making in the high-intensity environment of the pediatric cardiac catheterization laboratory. We propose that the most critical factor in outcomes for children in the catheterization lab may not be technical failures but rather human factors and the lack of preparation and robust shared decision-making process between the catheterization team. Key technical factors involved in the decision-making process include understanding the anatomy, the indications and objective to be achieved, equipment availability, procedural flow, having a back-up plan and post-procedural care plan. Increased awareness, pre-catheterization planning, use of standardized clinical assessment and management plans and artificial intelligence may provide solutions to pitfalls in decision-making. Further research and efforts should be directed towards studying the impact of human factors in the cardiac catheterization laboratory as well as the broader medical environment.

Complex Decision Making in the Pediatric Catheterization Laboratory: Catheterizer, Know Thyself and the Data

Optimal outcomes are as much influenced by critical decision making pathways as by the technical skill of the operator. The complexity and potential cognitive traps underlying critical decision making has long been recognized in the aviation and business communities, however, remains a largely subconscious, unexamined discipline amongst congenital cardiac interventionalists. Challenges to making good decisions in the catheterization laboratory include heuristics, biases, and cognitive traps. In this paper we discuss some of the more common decision making challenges encountered and we address potential solutions to such decision making with particular focus towards standardization.

A Comparison of Anterograde Versus Retrograde Approaches for Neonatal Balloon Aortic Valvuloplasty

In neonates requiring balloon aortic valvuloplasty, both anterograde and retrograde approaches are feasible. A recent comparison of these two approaches is lacking. A retrospective cohort study of neonates at a single center undergoing BAV from 9/00 to 7/14 was performed. Records were reviewed including pre- and post-intervention echocardiograms and catheterization data. Comparisons of acute efficacy and procedural safety were made based on type of approach utilized. Forty-two neonates underwent BAV. Eleven cases utilized exclusively an anterograde approach, while 31 included a retrograde approach (including 4 with both approaches used). There were no significant differences between groups in baseline demographic and clinical characteristics. Additionally, by both pre-intervention echocardiogram and catheterization, there were no differences based on approach in aortic valve gradient, degree of aortic insufficiency (AI), or degree of mitral regurgitation (MR). Both approaches were equally efficacious in gradient reduction (45 ± 17 vs. 44 ± 21 mmHg, p = 0.97), and there was no difference in post-intervention AI as assessed by both catheterization and echocardiogram (52% vs. 64% none or trivial, p = 0.74). Additionally, there was no difference in the proportion of patients with an increased severity of MR after BAV (15% vs. 22%, p = 0.52). The retrograde approach required a larger arterial catheter and was associated with a higher rate of arterial thrombosis (61% vs. 18%, p = 0.014). Both anterograde and retrograde approaches to neonatal BAV appear to be equally efficacious in the short term. The anterograde approach avoids the need for a larger arterial catheter and may reduce the risk of arterial thrombosis.

Relation of Aortic Valve Morphologic Characteristics to Aortic Valve Insufficiency and Residual Stenosis in Children With Congenital Aortic Stenosis Undergoing Balloon Valvuloplasty

Aortic valve morphology has been invoked as intrinsic to outcomes of balloon aortic valvuloplasty (BAV) for congenital aortic valve stenosis. We sought to use aortic valve morphologic features to discriminate between valves that respond favorably or unfavorably to BAV, using aortic insufficiency (AI) as the primary outcome. All patients who underwent BAV at 2 large-volume pediatric centers from 2007 to 2014 were reviewed. Morphologic features assessed on pre-BAV echo included valve pattern (unicuspid, functional bicuspid, and true bicuspid), leaflet fusion length, leaflet excursion angle, and aortic valve opening area and on post-BAV echo included leaflet versus commissural tear. Primary end point was increase in AI (AI+) of ≥2°. Eighty-nine patients (median age 0.2 years) were included in the study (39 unicuspid, 41 functional bicuspid, and 9 true bicuspid valves). Unicuspid valves had a lower opening area (p <0.01) and greater fusion length (p = 0.01) compared with functional and true bicuspid valves. Valve gradient pre-BAV and post-BAV were not different among valve patterns. Of the 16 patients (18%) with AI+, 14 had leaflet tears (odds ratio 13.9, 3.8 to 50). True bicuspid valves had the highest rate (33%) of AI+. On multivariate analysis, leaflet tears were associated with AI+, with larger opening area pre-BAV and lower fusion length pre-BAV. AI+ was associated with larger pre-BAV opening area. Gradient relief was associated with reduced angle of excursion. Valve morphology influences outcomes after BAV. Valves with lesser fusion and larger valve openings have higher rates of leaflet tears which in turn are associated with AI.

Neonatal aortic stenosis

Neonatal aortic stenosis is a complex and heterogeneous condition, defined as left ventricular outflow tract obstruction at valvular level, presenting and often requiring treatment in the first month of life. Initial presentation may be catastrophic, necessitating hemodynamic, respiratory and metabolic resuscitation. Subsequent management is focused on maintaining systemic blood flow, either via a univentricular Norwood palliation or a biventricular route, in which the effective aortic valve area is increased by balloon dilation or surgical valvotomy. In infants with aortic annular hypoplasia but adequately sized left ventricle, the Ross-Konno procedure is also an attractive option. Outcomes after biventricular management have improved in recent years as a consequence of better patient selection, perioperative management and advances in catheter technology. Exciting new developments are likely to significantly modify the natural history of this disorder, including fetal intervention for the salvage of the hypoplastic left ventricle; 3D echocardiography providing better definition of valve morphology and aiding patient selection for a surgical or catheter-based intervention; and new transcutaneous approaches, such as duel beam echo, to perforate the valve.

Transcatheter trans-septal antegrade closure of muscular ventricular septal defects in young children

BACKGROUND

Surgical or transcatheter closure of muscular ventricular septal defects (mVSDs) in young children may be technically challenging and associated with significant complications.

OBJECTIVE

To assess the feasibility of trans-septal antegrade closure of mVSD in a selected subset of young children.

METHODS

This is a prospective study from a single centre from July 2011 to March 2013. Nine infants and children with single or multiple mVSDs were included in the study. The median age and weight were 6 months (range 4-18 months) and 4.5 kg (range 3.8-6.2 kg), respectively. Trans-femoral trans-septal antegrade technique was used in eight children. One child was excluded from the study because of abnormally tortuous anatomy of both the femoral veins and subsequently underwent VSD device closure by the trans-jugular approach. The follow-up evaluation included chest X-ray, ECG, and echocardiogram at 1 month, 3 months, 6 months, and 1 year.

RESULTS

The defects were closed successfully in all eight patients using Amplatzer mVSD device in 5 and Amplatzer Duct Occluder II in 3. Moderate mitral regurgitation due to entrapment of the anterior mitral leaflet occurred in one patient with a posteriorly located mVSD, necessitating removal of the device, and surgical closure of the mVSD. The small additional residual mVSD in one other patient closed spontaneously during the follow-up.

CONCLUSIONS

Transcatheter trans-septal antegrade closure of mVSD in young children is technically feasible and merits further consideration. Symptomatic relief in multiple mVSD can be achieved after closing larger defects.

Advances in interventional and hybrid therapy in neonatal congenital heart disease

In addition to the considerable surgical advances in treating congenital heart diseases, hybrid and transcatheter therapies have become a cornerstone of neonatal cardiology within the last decade. Approaches to the care of cyanotic newborns with congenital heart disease focused on manipulations of the inter-atrial septum, right ventricular outflow tract obstructions, and on the arterial duct as the source for pulmonary blood flow. Currently, fewer interventional procedures are used in newborns and small infants to treat excessive pulmonary blood flow caused by shunt lesions, but transcatheter techniques and hybrid strategies have been developed to treat newborns suffering from inadequate systemic perfusion. However, transcatheter techniques are still not available to treat failing systemic ventricles without obvious structural disorders of the myocardium or dilated cardiomyopathies in newborns and infancy, despite new surgical-interventional strategies are already developed to avoid or to delay early heart transplantation. In conclusion, material and technical improvements have enabled transcatheter techniques to replace medical-based therapies to solve structurally dependent cardiovascular diseases. However, evidence-based and long-term follow-up data are required.

Neonatal Interventions for Left-Sided Obstructive Lesions: Alternatives to Surgery

Percutaneous neonatal cardiac interventions are effective in management strategies. Aortic valve dilation has become a first line therapy with excellent outcomes and low morbidity equivalent to surgery. Percutaneous intervention for coarctation of the aorta can safely postpone surgical intervention in small unwell neonates, allowing stabilization and growth. Stent implantation can provide a stable and predictable relief of obstruction; however, care should be taken to implant stents so that they can be removed subsequently. As experience increases, the role of percutaneous techniques in the management of high-risk neonates with coarctation of the aorta will become better defined and improve the outcomes.

Percutaneous Balloon Valvuloplasty for Aortic Stenosis in Newborns and Children

In all cases of congenital valvar aortic stenosis (AS), reduced effective orifice area leads to obstruction to flow, usually resulting from thickening and reduced motion of the valve leaflets. The most severe cases of valvar AS present soon after birth, with low cardiac output secondary to left ventricular dysfunction. Interventional treatment options consist of open surgical valvotomy or balloon valvuloplasty, with both therapies providing excellent but usually only temporary relief of stenosis. This article focuses on balloon aortic valvuloplasty as a therapy for congenital valvar AS in infants and children, focusing on established techniques, outcomes, and future challenges.

Left ventricle pseudoaneurysm after aortic valvuloplasty

Acquired left ventricular aneurysm is extremely rare in children. This report describes an infant with acquired left ventricular aneurysm after percutaneous aortic balloon valvuloplasty for critical aortic stenosis. The potential risk factors for myocardial injury during cardiac catheterization and potential complications are discussed.

Rapid ventricular pacing for catheter interventions in congenital aortic stenosis and coarctation: effectiveness, safety, and rate titration for optimal results

INTRODUCTION

Infants and children with congenital aortic stenosis and coarctation of the aorta can be treated by catheter intervention. There are several pharmacological and mechanical techniques described to overcome the balloon movement; none, however, have proved entirely satisfactory. An alternative method to achieve balloon stability is the use of rapid ventricular pacing. We describe our experience with titrating the pacing rate and the use of this technique.

METHODS

A retrospective review of database was performed, to identify patients who underwent transcatheter intervention with rapid ventricular pacing. Invasive systemic pressures were documented with a catheter in the aorta. Rapid ventricular pacing was initiated at the rate of 180 per minute and increased by increments of 20 per minute to a rate required to achieve a drop in systemic pressure by 50% and a drop in pulse pressure by 25%. The balloon was inflated only after the desired pacing rate was reached. Pacing was continued until the balloon was completely deflated.

RESULTS

Thirty patients were identified, 29 of whom had interventions with rapid ventricular pacing. Balloon valvuloplasty of aortic valve was performed on 25 patients while 4 patients had stenting for coarctation by this technique. The rate of ventricular pacing required ranged from 200 to 260 per minute with a median rate of 240. Balloon stability at the time of intervention was achieved in 27 patients.

CONCLUSION

Rapid ventricular pacing is a safe and effective method to provide transient decrease in cardiac output at the time of transcatheter interventions to achieve balloon stability.

Balloon aortic valvuloplasty for congenital aortic stenosis using the femoral and the carotid artery approach: a 16-year experience from a single center

OBJECTIVES

The aim of this article is to report a 16-year experience with percutaneous balloon aortic valvuloplasty (BAVP) in newborns and young infants up to 3 months of age in a tertiary care cardiac reference center in a developing country and to determine its value in postponing open heart surgery.

BACKGROUND

Congenital aortic stenosis (AS) is a potentially life threatening disorder. BAVP and surgical procedures have similar short and medium-term efficacy.

METHODS

Thirty-one consecutive newborns and young infants with critical AS underwent BAVP in our department from 1991 to 2007. Mean patient age at time of the procedure was 22 days (range 2-92 days) and mean weight was 3,310 g (1,840-4,400 g).

RESULTS

There was a significant reduction in mean Doppler-derived peak gradient across the aortic valve immediately after the procedure (75.1 ± 22 versus 32.2 ± 13.02, P < 0.001), and this finding was maintained throughout follow-up. Since 2003, when the carotid approach became routine practice, no major vascular complications were observed. Mean time of follow-up was 81 months (5 days-196 months) with only two deaths (7.4%). Only 24% patients required surgical reintervention on the aortic valve during follow-up. Survival free from aortic valve surgery was 80% at 24 months, 66% at 63 months, and 50% at 80 months.

CONCLUSION

Percutaneous intervention for relief of critical aortic stenosis in newborns in a tertiary center of a developing country is safe and has excellent short and long-term results comparable to other centers throughout the world.

Balloon dilation of neonatal critical aortic valvar stenosis via the umbilical artery

OBJECTIVES

To report our experience with balloon dilation of critical aortic valvar stenosis in neonates via the umbilical artery using currently available catheters.

BACKGROUND

There is no agreement regarding the optimal vascular approach for balloon dilation of critical aortic valvar stenosis in neonates.

METHODS

Since June of 2005, we have attempted to obtain umbilical arterial access within the first week after birth in all neonates with critical aortic valvar stenosis. In patients in whom umbilical artery access was obtained, we proceeded with an attempt at balloon dilation.

RESULTS

We were presented with 5 patients with critical aortic valvar stenosis within the first week after birth, and the umbilical arterial approach was obtained in all, with effective relief of the stenosis achieved in 4.

CONCLUSIONS

The umbilical arterial approach should always be considered for balloon dilation of neonatal critical aortic valvar stenosis. Using currently available catheters, the procedure is safe, simple, and effective even in patients weighing less than 2.5 kilograms. Further experience using this approach is warranted.

Usefulness of Doppler echocardiography guidance during balloon aortic valvuloplasty for the treatment of congenital aortic stenosis

INTRODUCTION

Few data exist regarding the potential benefits of continuous echocardiographic guidance during balloon aortic valvuloplasty (BAV) for the treatment of congenital aortic stenosis (AS). The objectives of this study were 1) to prospectively evaluate, in a series of consecutive patients with severe AS, the efficacy of BAV guided by Doppler echocardiography (DE) in relieving AS while preventing the appearance of significant aortic regurgitation (AR), and 2) to compare the results obtained by BAV-DE with those obtained in a historical series of patients who underwent BAV without echocardiographic guidance (BAV guided by angiography, BAV-A).

METHODS

From 1995 to 2006 a total of 36 consecutive patients with AS (median age 6 years, range, 1 day to 26 years) underwent BAV in our center, with systematic application of continuous DE guidance since 2003. BAV-DE consisted of measuring the aortic annulus, choosing balloon diameters and evaluating the results of each balloon dilation on the basis of DE.

RESULTS

Seventeen patients underwent BAV-DE (transthoracic and transesophageal DE in 3 and 14 patients, respectively) with successful transaortic gradient relief in 88% of them. None of the patients complicated with moderate or severe AR. At 17+/-13 months follow-up there had been 3 cardiac events (18%), all of them related to aortic restenosis. BAV-A was associated with longer fluoroscopic times (35 min vs 16 min, p=0.005 after adjusting for age and weight differences between groups) and a higher degree of AR following BAV (>or=2 degrees increase in AR, 32% vs 0%, p=0.045 after adjusting for age and weight). Angiographic measurements of the aortic annulus were higher than those obtained by DE (mean overestimation+2.5+/-1.8 mm, range 0 to +6 mm, p<0.0001).

CONCLUSION

BAV-DE provides successful gradient relief of severe AS with lower fluoroscopy time and a lower degree of AR compared to BAV-A. Overestimation of aortic annulus diameters by angiographic measurements might partially explain the high rate of significant AR associated with BAV in the absence of echocardiographic guidance.

Use of a 3 French system for balloon aortic valvuloplasty in infants

For infants with valvar aortic stenosis, balloon aortic valvuloplasty has supplanted surgical valvotomy as the initial treatment of choice at most institutions. Technological innovations have resulted in further miniaturization of balloon dilation catheters, allowing this procedure to be performed through smaller sheath sizes. Currently, the Tyshak-Mini balloon dilation catheter (B. Braun Medical) allows passage of up to an 8 mm dilation balloon catheter through a 3 Fr hemostatic sheath. The efficacy of this system for the treatment of valvar aortic stenosis in infants less than 6 months of age was evaluated in 20 patients undergoing 22 procedures. Mean age at the time of intervention was 26 +/- 46 days. Mean transvalvar gradient was 76 +/- 22 mm Hg prior to balloon dilation. Following balloon valvuloplasty, residual gradient was 26 +/- 12 mm Hg, reflecting a mean change in peak-to-peak gradient of 49 +/- 19 mm Hg. Postintervention increase in aortic insufficiency was one grade or less in 19/22 procedures, two grades in 2 procedures, and three grades in 1 procedure. There were no significant vascular complications reported immediately following the procedure. Repeat valvuloplasty was performed in three patients in which the 3 Fr system was used in two patients. The 3 Fr system for balloon aortic valvuloplasty in infants less than 6 months of age is effective and safe.

Catheter management of aortic valve stenosis in neonates and children

Therapy for severe aortic valve stenosis in infants and children has shifted from the operating suite to the catheterization laboratory and even to the bedside as a direct result of improved catheter technology, evolving techniques, and comparable results to conventional surgical intervention. This review summarizes the brief history pertaining to the various techniques and outcomes of transcatheter balloon valvuloplasty in infants and children with critical or severe aortic valve stenosis.

Axillary artery approach for balloon valvoplasty in young infants with severe aortic valve stenosis: Medium-term results

OBJECTIVES

To assess the feasibility and results of trans-axillary approach for balloon aortic valvoplasty (BAV) in early infancy.

BACKGROUND

Severe aortic valve stenosis (SAVS) is rare but serious condition in infancy, which may be promptly treated either by surgical aortic valvotomy or BAV. BAV is usually performed via the femoral artery route, which is associated with significant vascular complications and long procedure times.

METHODS

BAV via the trans-axillary approach was performed on twenty-seven sequential infants with SAVS presenting to a single tertiary referral center over an 11-year period. Maximum inflated balloon size was less than or equal to the aortic valve diameter.

RESULTS

Twenty-seven infants aged 1-77 days underwent BAV. Weight at time of procedure was 2.0-4.42 kgs. The median procedure and screening times were 82 and 7.9 minutes, respectively. Mean instantaneous Doppler gradient across the aortic valve reduced from 68 +/- 33 to 37 +/- 14 mmHg ( p < 0.0001). Three infants developed at least moderate aortic regurgitation. Right arm pulse volume was decreased in 12 infants; 5 received an intravenous heparin infusion. Longer-term follow-up demonstrated reduced or absent peripheral pulse in 5 infants. Transection of the axillary artery occurred in one infant requiring emergency microvascular repair. There was one post-procedural and one late death due to non-cardiac causes.

CONCLUSIONS

In early infancy balloon aortic valvoplasty via the axillary artery approach for severe aortic stenosis is an acceptable and safe alternative to the femoral arterial approach and results in short procedure and screening times. Longer-term vascular follow-up is required. (c) 2006 Wiley-Liss, Inc.

Left heart growth, function, and reintervention after balloon aortic valvuloplasty for neonatal aortic stenosis

BACKGROUND

Transcatheter balloon aortic valvuloplasty (BAVP) has become the first-line treatment for critical aortic stenosis (AS) in neonates. However, little is known about the growth and function of left heart structures or about patterns of reintervention on the left heart after neonatal BAVP.

METHODS AND RESULTS

Between 1985 and 2002, 113 patients underwent neonatal BAVP at < or =60 days of age. There were 16 early deaths (14%), with a significant decrease from 1985 to 1993 (22%) to 1994 to 2002 (4%), and 6 patients had successful early conversion to a univentricular circulation. In the short term, the mean relative gradient reduction was 54+/-26%, and significant aortic regurgitation (AR) developed in 15% of patients. The 91 early survivors with a biventricular circulation were followed up for 6.3+/-5.3 years, during which time there was a steady increase in the frequency of significant AR. Freedom from moderate or severe AR was 65% at 5 years. In almost all patients with a baseline aortic annulus z score less than -1, the annulus diameter increased to within the normal range within 1 to 2 years. Similarly, left ventricular (LV) end-diastolic dimension z scores, which ranged from -5 to 7.5 before BAVP, normalized within 1 to 2 years in nearly all patients with a predilation z score less than -1. Among early survivors with a biventricular circulation, reintervention-free survival on the LV outflow tract was 65% at 1 year and 48% at 5 years, with younger age, higher pre- and post-BAVP gradients, and a larger balloon-annulus diameter ratio associated with decreased reintervention-free survival (P<0.01). Seventeen surgical interventions were performed on the aortic valve in 15 patients, including replacement in 7. Survival free from aortic valve replacement was 84% at 5 years.

CONCLUSIONS

BAVP for AS during the first 60 days of life results in short-term relief of AS in the majority of patients. Among early survivors, initially small left heart structures may be associated with worse subacute outcomes but typically normalize within 1 year. Reintervention for residual/recurrent AS or iatrogenic AR is relatively common, particularly during the first year after BAVP, but aortic valve replacement during early childhood is seldom necessary.

Outcomes of uncomplicated aortic valve stenosis presenting in infants

BACKGROUND

The management of uncomplicated aortic valve stenosis presenting with critical obstruction in infants continues to be associated with significant morbidity and mortality. However, not all infants have critical obstruction, and outcomes spanning the broader spectrum of disease severity are less well defined.

METHODS

In a 12-year period, 55 infants (<3 months of age) were seen with aortic valve stenosis and with anatomy suitable for biventricular repair. Clinical, echocardiographic, angiographic, management, and outcome data were reviewed.

RESULTS

Status at presentation (median age 6 days) included signs of congestive heart failure in 20 patients, cardiovascular collapse in 5 patients, and an asymptomatic heart murmur in 30 patients. The initial echocardiogram showed reduced left ventricular function in 26% of patients, with a mean peak instantaneous gradient of 69 +/- 30 mm Hg in patients with normal function. There were 5 deaths (9%), all in patients with poor ventricular function. The initial intervention was balloon valvotomy in 24 patients and surgical valvotomy in 20 patients, with 11 patients having no intervention to date. The freedom-from-intervention rate was 69% at age 1 week, 58% at 1 month, 36% at 3 months, and 28% at 1 year. Patients without cardiovascular collapse, normal left ventricular function, and gradients <60 mm Hg at presentation (n =1 9) had better survival and longer freedom from intervention than patients with poor ventricular function or gradients >or=60 mm Hg (n = 36, P =.0001).

CONCLUSION

Most infants with aortic valve stenosis receive intervention, although this may be safely delayed in selected patients with lower initial gradients and good left ventricular function.

Cardiac catheterisation in infants weighing less than 2500 grams

OBJECTIVES

To investigate the indications for, and outcome of, cardiac catheterisation in infants weighing less than 2500 g at a single institution over an 8-year period.

PATIENTS AND METHODS

We assessed all infants who were less than 2500 g at the time of cardiac catheterisation at Texas Children's Hospital from January 1993 to January 2001. Comparisons of morbidity and mortality were drawn with an equivalent number of infants of similar age weighing greater than 2500 g seen over the same period of time.

RESULTS

We performed interventional procedures in 22, and diagnostic catheterisations in 12 infants weighing less than 2500 g. Interventions included pulmonary valvoplasty in six patients, balloon angioplasty of critical coarctation in one, aortic valvoplasty in two, septostomy in ten, and coil occlusion of an arteriovenous malformation, redirection of a subclavian venous line, and coil occlusion of a patent arterial duct in one patient each. The median age at catheterisation was 5 days for children less than 2500 g, and 10 days for those above 2500 g. The median weights were 2.3 kg and 3.3 kg, and the median gestational ages were 35 weeks and 38 weeks, for the two respective groups. Of those weighing less than 2500 g, two died (6%), with no deaths occurring in those weighing more than 2500 g. In 3 patients weighing less than 2500 g (9%), there was vascular compromise, one child with bilateral femoral venous obstruction requiring fasciotomy compared, to one in the group weighing greater than 2500 g (2%).

CONCLUSION

There is a significantly increased risk of mortality and vascular compromise in infants weighing less than 2500 g. Interventional catheterisation in these infants may be lifesaving, but given the aforementioned risks, diagnostic catheterisation should be deferred if possible in favor of noninvasive modalities.

Anterograde balloon valvuloplasty for the treatment of neonatal critical valvar aortic stenosis

We report our experience with anterograde balloon valvuloplasty in 17 neonates treated between November 1996 and June 2001 for critical aortic stenosis. Patients with hypoplastic left heart syndrome were excluded. Anterograde balloon valvoplasty of the aortic valve was possible in all 17 patients. The mean peak systolic gradient prior to cardiac catheterization was 73 mm Hg (range, 30-117 mm Hg) and decreased to 37 mm Hg (range, 21-60 mm Hg) after the dilation. Aortic regurgitation after balloon valvoplasty was absent or mild in 14/17 patients, moderate in 2 patients, and severe in 1 patient. There was no mortality or echocardiographic evidence for aortic cusp perforation or mitral regurgitation associated with the procedure. Redilation was necessary in 3/17 patients. Two patients are awaiting elective Ross operation. One patient with endocardial fibroelastosis died at 11 months of age. Anterograde balloon valvoplasty can be safely and effectively performed to palliate neonates with critical aortic valve stenosis.

Issues in transcatheter treatment of critical aortic stenosis in the newborn infant

Critical aortic valve stenosis is not a frequently seen disease. In most cases, these patients are in critical condition. Transcatheter dilatation is one of the therapeutic options for treatment. This article addresses important issues in transcatheter dilatation in the newborn infant.

Transcatheter intervention in the neonate with congenital heart disease

Over the past 30 years, interventional cardiology has developed as a distinct subspecialty, playing a major role in the management of infants with CHD. In the neonatal period, a wide variety of transcatheter interventions are performed routinely, either as palliation or therapy, as adjunct to surgery, or in place of surgical intervention. Among these are creation or enlargement of ASDs to allow atrial mixing; balloon valvotomy to treat congenital valvar stenoses; balloon angioplasty or stenting of stenotic vessels (pulmonary arteries, coarctation of aorta, or systemic or pulmonary veins) or postoperative anastomoses; closure of [figure: see text] unwanted vessels (congenital fistulae or collaterals); and other miscellaneous interventions. A wide variety of patients are candidates for these procedures, including those with transposition of the great arteries or other defects with transposition physiology, left atrial outlet obstruction and hypertension, severe valvar pulmonary or aortic stenosis, hypoplastic stenotic pulmonary arteries with severe symptomatology, severe coarctation of aorta and high surgical risks, large aortopulmonary collaterals or other hemodynamically significant unwanted vessels, acute thrombosis of certain surgical anastomoses, and many more. In experienced hands, these procedures are highly successful and safe, with a low morbidity and mortality (less than 1%).

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.

Anterograde double-balloon valvoplasty for treatment of severe valvar aortic stenosis in a preterm baby weighing 1400 grams

We describe our treatment of a premature baby born weighing 1400 g with severe aortic stenosis, with a gradient of 80 mmHg across the valve. Efforts to advance a 6 mm angioplasty catheter into the stenotic aortic valve via the left ventricle failed. Anterograde angioplasty, instead, was performed using two 4 mm coronary angioplasty catheters. Six months subsequent to the intervention, the pressure gradient measured 25 mmHg, and there was no hemodynamically significant aortic insufficiency.

Transseptal approach in children after patch occlusion of atrial septal defect: first experience with the cutting balloon

Two children required a transseptal approach to the left heart for endovascular stent redilation late after pericardial patch closure of atrial septal defects performed at the time of their initial surgical intervention. Following perforation of thickened interatrial patches in both patients, cutting balloons were used to create adequate interatrial communications. Cathet. Cardiovasc. Intervent. 48:378-381, 1999.

Percutaneous transluminal angioplasty for the treatment of complete arterial occlusion after retrograde cardiac catheterization in infancy

Nine patients with arterial thrombosis were treated with transcatheter recanalization and subsequent balloon dilation of the occluded vessel. Repeat angiography or duplex sonography 3 to 14 months after intervention showed completely patent arteries without restenosis in 7 patients; there was residual narrowing of the vessel in the remaining 2 patients.

Left ventricular outflow obstruction

Patients with LVOT obstruction require lifelong follow-up because the obstruction may be progressive or recurrent. Several procedures are usually required, either by surgery or by interventional cardiac catheterization, to repair or palliate the obstructive lesion. The treatment of these patients continues to evolve, and, despite the complexity of these patients' lesions, the morbidity and mortality rates have decreased and are expected to decrease further in the future.

Interventional cardiac catheterization

Over the past decade, transcatheter interventions have become increasingly important in the treatment of patients with congenital heart lesions. These procedures may be broadly grouped as dilations (e.g., septostomy, valvuloplasty, angioplasty, and endovascular stenting) or as closures (e.g., vascular embolization and device closure of defects). Balloon valvuloplasty has become the treatment of choice for patients in all age groups with simple valvar pulmonic stenosis and, although not curative, seems at least comparable to surgery for congenital aortic stenosis in newborns to young adults. Balloon angioplasty is successfully applied to a wide range of aortic, pulmonary artery, and venous stenoses. Stents are useful in dilating lesions of which the intrinsic elasticity results in vessel recoil after balloon dilation alone. Catheter-delivered coils are used to embolize a wide range of arterial, venous, and prosthetic vascular connections. Although some devices remain investigational, they have been successfully used for closure of many arterial ducts and atrial and ventricular septal defects. In the therapy for patients with complex CHD, best results may be achieved by combining cardiac surgery with interventional catheterization. The cooperation among interventional cardiologists and cardiac surgeons was highlighted in a report of an algorithm to manage patients with tetralogy of Fallot or pulmonary atresia with diminutive pulmonary arteries, involving balloon dilation, coil embolization of collaterals, and intraoperative stent placement. In this setting, well-planned catheterization procedures have an important role in reducing the overall number of procedures that patients may require over a lifetime, with improved outcomes.

Recent advances in interventional pediatric cardiovascular disease

Transcatheter therapy in children with congenital or acquired heart disease is a challenging, innovative, and constantly evolving field. In this article we review the various "nonsurgical" techniques that are currently available, with a discussion of their applications and an update on the recent advances in the field of interventional cardiology.

Transumbilical venous, anterograde, snare-assisted balloon aortic valvuloplasty in a neonate with critical aortic stenosis

Balloon aortic valvuloplasty is an acceptable alternative to surgery in the treatment of critical aortic stenosis in the neonate. In this report, we describe a 1-day-old infant with critical aortic stenosis who was successfully treated with an anterograde, transumbilical venous, snare-assisted balloon aortic valvuloplasty. Based on this experience, it is suggested that the anterograde transumbilical venous approach is a feasible and effective alternative to retrograde femoral, carotid, or umbilical arterial and transfemoral venous anterograde routes for performing balloon aortic valvuloplasty in the neonate.

Adenosine induced transient cardiac standstill in catheter interventional procedures for congenital heart disease

OBJECTIVE

To describe the use of intravenous adenosine to create transient cardiac standstill during balloon dilatation procedures for congenital heart defects.

SETTING

A tertiary paediatric cardiac centre.

DESIGN AND PATIENTS

This was a prospective pilot study. Thirteen patients born with congenital heart disease and who had stenotic lesions requiring relief were considered for the technique. All were suitable for balloon dilatation. Their ages ranged from 2 months to 30 years, mean (SD) 9.9 (9.8) years. The dose of adenosine varied from 0.125 mg/kg to 0.555 mg/kg, mean 0.33 (0.127).

RESULTS

Two patients only developed sinus bradycardia in response to adenosine, which may have been related to the technique of administration. The other 11 experienced a period of asystole, which ranged from 2.4 to 10.8 seconds, mean 4.99 (2.27), and a total atrioventricular block period of 5.0 to 21.2 seconds, mean 9.47 (4.64). The interval between adenosine injection and the onset of asystole varied from 2.4 to 15.8 seconds, mean 8.05 (3.6), depending on cannula size, site of administration, and cardiac output. The peak gradient across the stenotic lesions fell from 52.3 (23.7) to 17.8 (11.9) mm Hg (p < 0.001). Apart from one short episode of atrial fibrillation there were no complications.

CONCLUSIONS

Intravenous adenosine is a safe and effective agent for creating transient cardiac standstill during balloon dilatation procedures for congenital heart disease. This achieves stability which is likely to improve results and reduce complications. It may have applications in other fields of cardiac intervention where an immobile heart is desirable during the critical phase of a procedure.