Current state of interventional cardiology in congenital heart disease.

Congenital interventional cardiology seeks to provide alternative percutaneous solutions to congenital cardiac problems in preference to more traditional surgical approaches. Simpler procedures have been refined and are now achievable in smaller children and infants. More complex procedures are increasingly recognised as superior to surgical alternatives, though most patients with complex disease inevitably undergo combinations of interventional, surgical and joint or hybrid procedures. This review seeks to highlight recent advances in these techniques of most interest to the readership of this journal.

Device closure of secundum atrial septal defect's and the risk of cardiac erosion.

Cardiac erosion related to transcatheter atrial septal defect closure devices is of increasing concern. Erosion is reported to have occurred with most of currently available occluder devices. Perhaps due to the very large number of implants worldwide, the Amplatzer (St Jude) occluder is associated with the majority of cardiac erosion events reported in the literature. Best current estimates of the incidence of erosion with the St Jude device are between one and three cases per 1000 implants. Most events occur early after implantation and it is rare, although not unheard of, for events to occur after a year following device insertion. It is important that those involved with closure programmes are vigilant for the problem, because device-related erosion is associated with a significant mortality risk. Despite considerable debate, the risk factors (either patient or device) for erosion remain unclear and require further investigation. Currently available data sets have focussed largely on erosion cohorts and are unable to place these cases in appropriate context with non-erosion closure cases. What is certain is that programmes implanting these devices must take care to implant appropriately sized devices and have in place plans to ensure that patients are both well informed and can access help and advice in the event of developing symptoms.

Transcatheter and endovascular stent graft management of coarctation-related pseudoaneurysms.

OBJECTIVE: Surgical correction of congenital aortic coarctation can lead to a number of important problems including late pseudoaneurysm formation. Redo surgery has a significant risk. Endovascular stent graft repair is increasingly used but there are limited data regarding this indication. We describe the experience of two UK congenital referral centres. DESIGN: Retrospective analysis of patients treated with endovascular aortic stent grafting for late pseudoaneurysms. SETTING: Two UK congenital heart centres, Bristol Heart Institute and Leeds General Infirmary. PATIENTS: 17 patients were treated 2006-2012. This represents all patients treated with this technique. MAIN OUTCOME MEASURES: Procedural and postprocedure success and complications. RESULTS: The average time from index repair to endovascular repair of pseudoaneurysm was 24.6 years. The majority (70.6%) had patch aortoplasty as the original surgical procedure and 41.2% were not under follow-up or discharged. Stent grafting procedural success rate was 100%. Median hospital stay postprocedure was 3 days. There was no procedural mortality or immediate complication. There were four minor early and three minor late complications. Imaging follow-up was available for an average of 31.6 months (range 6-65 months). All patients have demonstrated positive remodelling of the pseudoaneurysm with no incidence of continued expansion or stent graft failure up to 5 years following implant. CONCLUSIONS: Endovascular stent graft treatment of pseudoaneurysms show promising results in a population who have a high risk of surgical re-intervention. Complication rates appear to be low and recovery is quick. Longer-term data remain essential to scrutinise stent graft performance in this situation.

The early and mid-term fate of the axillary artery following axillary artery cut-down and cardiac catheterization in infants and young children.

OBJECTIVES: To study the early and mid-term vascular complications of axillary artery catheterization in children <2 years by clinical and ultrasound examination. BACKGROUND: Femoral arterial access for cardiac catheterization in young children is associated with significant morbidity. Early complications of axillary artery catheterization have been reported but no long-term vascular follow-up data are available. METHODS: Prospective case-control study using standard vascular ultrasound techniques to examine the upper limbs in study participants (n = 10). RESULTS: In total, 23% of axillary artery catheterizarions (56 procedures in 54 patients) resulted in acute arterial insufficiency requiring heparin. Of the survivors under follow-up (n = 33), none had symptoms of chronic arterial insufficiency. At a median follow-up of 8 years postprocedure, three out of the ten study participants had a weak brachial pulse in the test arm but no significant difference in arm measurements. Color Doppler revealed occlusion of the axillary artery in the test arm with collateralization in three patients. The brachial peak systolic velocity (V(max)) was significantly lower in the test arm than the control arm of all the patients with a mean difference of 30 cm/sec (P = 0.007). CONCLUSION: Our study is the first to examine the long-term vascular sequelae of axillary artery catheterization using ultrasound examination and highlights the importance of careful surveillance of vascular access sites. Although axillary artery cut-down for cardiac catheterization in infants and young children does not appear to result in clinical signs of chronic arterial insufficiency, we demonstrate clear evidence of flow abnormalities on vascular ultrasound which are of uncertain long-term significance.

Division of labour within flowers: heteranthery, a floral strategy to reconcile contrasting pollen fates.

In many nectarless flowering plants, pollen serves as both the carrier of male gametes and as food for pollinators. This can generate an evolutionary conflict if the use of pollen as food by pollinators reduces the number of gametes available for cross-fertilization. Heteranthery, the production of two or more stamen types by individual flowers reduces this conflict by allowing different stamens to specialize in 'pollinating' and 'feeding' functions. We used experimental studies of Solanum rostratum (Solanaceae) and theoretical models to investigate this 'division of labour' hypothesis. Flight cage experiments with pollinating bumble bees (Bombus impatiens) demonstrated that although feeding anthers are preferentially manipulated by bees, pollinating anthers export more pollen to other flowers. Evolutionary stability analysis of a model of pollination by pollen consumers indicated that heteranthery evolves when bees consume more pollen than should optimally be exchanged for visitation services, particularly when pollinators adjust their visitation according to the amount of pollen collected.

Within-host dynamics of an intestinal pathogen of bumble bees.

The success of a pathogen depends not only on its transmission to new hosts, but also on its ability to colonize and persist within its current host. Studies of within-host dynamics have focused on only a few diseases of humans, whereas little is known about the factors that influence pathogen populations as they develop inside non-human hosts. Here, we investigate pathogen dynamics occurring within bumble bees (Bombus impatiens) infected by the gut trypanosome Crithidia bombi. Infection by C. bombi showed several features characteristic of vertebrate diseases, including a rapid initial increase in infection intensity, marked oscillations in parasitaemia, and the stimulation of a systemic immune response in infected bees. Within-host dynamics generated substantial variation in the infectiousness and flower-visiting behaviour of bumble bees. Changes in bee foraging that arise from infection may influence the probability of C. bombi transmission between bees at flowers.

Outcome after extended arch repair for aortic coarctation.

OBJECTIVES: To assess survival and long term arch patency rates in a consecutive group of children after extended arch repair for coarctation of the aorta. METHODS: Review of 191 consecutive children (154 (81%) under 1 year of age) operated on between 1990 and 2002 by a single surgeon using extended arch reconstructive techniques. For assessment of survival patients were divided into three groups: 1, coarctation alone, n = 104; 2, coarctation and ventricular septal defect, n = 38; and 3, coarctation in association with complex intracardiac anomalies, n = 49. A prospective and systematic clinical and echocardiographic evaluation of the aortic arch was undertaken. RESULTS: Median time to follow up was 4.2 years (range 1-10.6 years). Overall actuarial survival was 92%, 88%, and 88% at two, five, and 10 years. Mortality was significantly higher in those patients with complex intracardiac anatomy. Arch obstruction recurred in seven of 165 (4.2%) patients: four of 139 (2.9%) term and three of 10 (30%) premature infants (p < 0.001). CONCLUSIONS: Survival after extended arch reconstruction for coarctation is excellent. At long follow up recurrent arch obstruction is rare, with prematurity the only risk factor.

'Anti-bee' and 'pro-bird' changes during the evolution of hummingbird pollination in Penstemon flowers.

Floral phenotypes may be as much the result of selection for avoidance of some animal visitors as selection for improving the interaction with better pollinators. When specializing on hummingbird-pollination, Penstemon flowers may have evolved to improve the morphological fit between bird and flower, or to exclude less-efficient bees, or both. We hypothesized how such selection might work on four floral characters that affect the mechanics of pollen transfer: anther/stigma exsertion, presence of a lower corolla lip, width of the corolla tube, and angle of flower inclination. We surgically modified bee-pollinated P. strictus flowers changing one trait at a time to make them resemble hummingbird-pollinated P. barbatus flowers, and measured pollen transfer by bumblebees and hummingbirds. Results suggest that, apart from 'pro-bird' adaptations, specific 'anti-bee' adaptations have been important in shaping hummingbird-flowers. Moreover, some trait changes may have been selected for only if changing in concert with other traits.

Poor sensitivity of routine fetal anomaly ultrasound screening for antenatal detection of atrioventricular septal defect.

OBJECTIVE: To report the antenatal detection rate in a consecutive series of liveborn infants with atrioventricular septal defect (AVSD). DESIGN: Review and analysis of referrals for detailed fetal echocardiography and postnatal diagnosis of AVSD. SETTING: Tertiary referral centre for congenital heart disease centre with data prospectively collected between 1996 to 2001. RESULTS: 92 consecutively liveborn infants with AVSDs were identified of which 27 (29%) were detected by routine obstetric antenatal ultrasound. The antenatal diagnosis rate was worse for liveborn infants with trisomy 21 (12 of 49 (25%) v 15 of 43 (35%) chromosomally normal children) and for infants with AVSD without other structural heart disease (18 of 74 (24%) v 9 of 18 (50%) infants with associated structural heart disease). CONCLUSION: Despite the potential ability of fetal ultrasound to detect AVSDs, the antenatal diagnosis rate is poor. This is particularly true for infants with trisomy 21 and is of importance when counselling parents with an apparently normal fetal ultrasound scan.

Successful treatment of left atrial disk thrombus on an Amplatzer atrial septal defect occluder with abciximab and heparin.

Acute device thrombosis is a rare but important complication after transcatheter atrial septal defect closure. In this case a mobile thrombus was noted on the left side of an Amplatzer atrial septal occluder after device release in a 12 year old boy with an uncomplicated atrial septal defect. The thrombus was successfully treated with an infusion of heparin and the glycoprotein IIa/IIIb receptor antagonist abciximab. Transoesophageal ultrasound performed the following day showed complete resolution of the clot. There are no reports to guide treatment of acute thrombosis in this setting. This combination of treatments was effective without complication in this case.

Management of valvar aortic stenosis in children.

What is the best treatment for the child with valvar aortic stenosis-balloon or surgical valvotomy?

Troponin for acute coronary syndromes: has NICE got it right?

The guidelines on the use of glycoprotein IIb/IIIa inhibitors for acute coronary syndromes issued by the National Institute for Clinical Excellence (NICE) recommend that blood troponin is used to identify patients who might benefit from therapy. There are, however, a number of circumstances in which troponin results may be misleading. Firstly, the trials which comprise the evidence base for the therapeutic effect were only based on patients with documented coronary artery disease. Secondly, troponin is elevated in patients with heart failure and concentrations fall with appropriate treatment. Thirdly, there is no internationally accepted standard for troponin, and there are therefore important differences at the 'cut-off' values between the methods of different manufacturers. Fourthly, immunoassays suffer from interfering antibodies and at least 17 case reports have been published outlining false positive tests. It is important that the shortfalls of troponin tests in the diagnosis of acute coronary syndromes are widely recognized.

Surgical and transcatheter (Amplatzer) closure of atrial septal defects: a prospective comparison of results and cost.

OBJECTIVE: To compare effectiveness, complications, and cost of Amplatzer with surgical atrial septal defect (ASD) closure. DESIGN: Prospective study. SETTING: Tertiary cardiac referral centre. PATIENTS: 43 consecutive patients (excluding non-UK residents) aged between 2.1 and 56.8 years (median 7) undergoing ASD closure. MAIN OUTCOME MEASURES: Procedural success, complications, regression of right ventricular dilatation (up to one year postprocedure), cost, inpatient stay, and home convalescent time. RESULTS: Amplatzer ASD closure was successful in 24 of 27 (89%) patients. Surgical closure was successful in all 19 cases. Cardiac complications affecting management occurred in three (11%) of the Amplatzer group (two procedural failures, one device embolisation) and 4 of 19 (21%) surgical patients (one pericardial pain, one global pericardial effusion requiring drainage, and one patient with anaemia requiring haematinics in addition to an incidental pericardial effusion and one further incidental pericardial effusion) (p = NS). There were complications that did not affect management in a further 5 of 19 surgical patients. There was no significant difference in regression of right ventricular dilatation by six months postprocedure (median right ventricular end diastolic diameter decrease: Amplatzer group 17.5%, surgical group 15.1%; median cardiothoracic ratio decrease: Amplatzer 7.9%, surgical 7.5%). Both hospital stay and home convalescent times were significantly shorter after Amplatzer closure (median hospital stay: Amplatzer one day, surgery six days; median convalescent time: Amplatzer two weeks, surgery 5.5 weeks). Median cost was similar for both groups (Amplatzer pound5375, surgical pound5412). CONCLUSIONS: Amplatzer ASD closure has a lower chance of success with a single procedure than surgery. Overall, there were more complications in the surgical group but the majority of these were minor and did not require any change in management. Resolution of right ventricular dilatation over the study period was similar for both techniques. Time spent in hospital and away from work or school was shorter for the Amplatzer group. The cost of both techniques was similar.

Results of Charleston bracing in skeletally immature patients with idiopathic scoliosis.

Previous studies have reported varying success rates with the use of the Charleston brace in idiopathic scoliosis. However, these studies have included patients from multiple centers, those with double curves, and those still undergoing treatment. This article presents the results of Charleston bracing in 42 skeletally immature patients (Risser 0/1) treated at one institution and followed up for a mean of 3.3 years after brace discontinuation. Selection criteria included a diagnosis of idiopathic scoliosis, Risser stage 0 or 1, at least 10 years of age at the time of bracing, female gender, a single curve between 25 degrees and 40 degrees, and no prior treatment. The average age at the time of bracing was 12.5 years (range 10-15) and the average curve was 30.3 degrees (range 25 degrees -40 degrees ). Outcome was considered a failure if the curve had increased more than 5 degrees at last follow-up, if surgical intervention was required, or if there was a change of orthosis during treatment (e.g., Charleston to Boston). In 25 of the 42 patients (60%), the brace was successful in preventing progression of the curve (mean follow-up 3.4 years; range 1.1-11.7). Thoracic curves had the same success as thoracolumbar and lumbar curves. Based on these results, the authors conclude that the Charleston brace is effective in preventing progression of curve. Proper patient selection is important.

Mitral regurgitation after anthracycline treatment for childhood malignancy.

OBJECTIVE: To investigate the new onset of mitral regurgitation in patients with otherwise normal echocardiograms after anthracycline treatment and to assess its relation to other selected indicators of myocardial damage. DESIGN: Prospective echocardiographic and electrocardiographic study. SETTING: Tertiary paediatric cardiac referral centre. PATIENTS: 305 patients, aged 2-33 years (median 14 years), treated with cumulative anthracycline doses of between 150-450 mg/m(2) (median 180 mg/m(2)) for childhood malignancy. MAIN OUTCOME MEASURES: Colour flow Doppler detection of mitral regurgitation and its relation to changes in echocardiographic indices of left ventricular function (systolic and diastolic dimensions, fractional shortening) and to changes in the 12 lead ECG; and the prevalence of mitral regurgitation in the anthracycline treated patients in comparison with previously studied normal volunteers of similar age. RESULTS: 34 patients (11.6%) developed ultrasound detectable mitral regurgitation, which was not apparent clinically, during or after anthracycline treatment, compared with only 1.8% of a normal population of similar age (p < 0.0001). Nine of the 34 also developed non-specific T wave abnormalities. All 34 patients had normal systolic function at the time of initial detection of mitral regurgitation, but four later developed impaired left ventricular function (5, 11, 20, and 27 months after the first detection of mitral regurgitation). CONCLUSIONS: Mitral regurgitation occurs much more often in patients treated with anthracyclines than in the normal population. Echocardiographic detection of new mitral regurgitation with or without ECG abnormalities may be an early predictor of anthracycline cardiomyopathy.

Comparison of the posterior approach versus the dorsal approach in the treatment of congenital vertical talus.

The purpose of this study was to compare retrospectively the results of a single-stage dorsal approach versus the posterior approach for the surgical treatment of congenital vertical talus (CVT) at a single institution. Twenty-four patients (33 feet) with CVT were treated surgically between 1960 and 1998. Eighteen patients (25 feet) underwent a posterior release (group 1), and six patients (eight feet) underwent surgery via the dorsal approach (group 2). All patients were evaluated at a minimal follow-up of 3 years. Preoperative and follow-up radiographs were evaluated, and a modified version of the clinical score by Adalaar was used. Group 1 had 45 procedures on 25 feet, whereas group 2 had no repeated or revision operations. The clinical score was 6.75 for group 1 and 8.0 for group 2. Tourniquet time was 123 minutes and 87 minutes for groups 1 and 2, respectively. Twelve group 1 patients (48%) had avascular necrosis (AVN) versus none of the group 2 patients. Both groups had similar preoperative and postoperative radiographic measurements. Both approaches were able to reduce successfully the talonavicular joint; however, the single-stage dorsal incision group required significantly less operative time, had better clinical scores, and had fewer complications 3 years after surgery.

Scoliosis in cerebral palsy: an overview and recent results.

The natural history of scoliosis in cerebral palsy as well as the treatments that include observation, bracing, and surgery are reviewed. If surgery is indicated, a careful preoperative evaluation is essential, focusing especially on the patient's nutritional, gastrointestinal, neurologic, and orthopedic systems. Intraoperative and perioperative issues such as blood loss control are reviewed. The Luque-Galveston method of instrumentation for scoliosis secondary to cerebral palsy is our preferred method of treatment. Our recent results compare favorably with the literature with fewer complications.

Cardiac catheter guided surgical closure of an apical ventricular septal defect.

Surgical closure of muscular ventricular septal defects can be difficult. We report a technique in which a preoperatively placed cardiac catheter allowed accurate localization of a residual apical muscular defect at operation. The approach not only allowed improved visualization of the defect from the right side of the heart, but also helped to minimize the size of the left ventriculotomy required for satisfactory closure.

Effectiveness of the boston brace in treatment of large curves in adolescent idiopathic scoliosis.

STUDY DESIGN: This is a retrospective study of 50 patients with adolescent idiopathic scoliosis with curves measuring 35 degrees to 45 degrees who were treated with a Boston brace. OBJECTIVES: The purpose of this study was to determine whether the Boston brace could effectively halt long-term progression in skeletally immature adolescents with idiopathic scoliosis who had a curve between 35 degrees and 45 degrees. SUMMARY OF BACKGROUND DATA: The Boston brace has been shown to be effective in preventing curve progression in adolescent idiopathic scoliosis, but its efficacy in large curves has not been fully studied. METHODS: Fifty adolescents were treated with a Boston brace for idiopathic scoliosis curves of 35-45 degrees (mean, 38.55 degrees ). All were judged to be skeletally immature based on menarcheal status (mean, 2.6 months before menarche), Risser sign (mean, 0.90; range, 0-2), and chronologic age (mean, 13 +/- 1 years). Patients were recalled for long-term follow-up at a mean of 9.7 years (range, 6.23-13.22 years) after brace discontinuation. Three well-matched patient subsets were then identified based on compliance. Group 1 (n = 24) consisted of patients who were compliant with the brace program and wore the brace 18 or more hours per day, Group 2 (n = 14) contained patients who wore the brace 12-18 hours per day, and Group 3 (n = 12) contained patients who wore the brace 0-12 hours per day. RESULTS: There was a significant difference in the amount of initial correction seen in the brace between the groups: 49%, 45%, and 33% curve correction in the brace for Groups 1, 2, and 3, respectively (P < 0.05). At long-term follow-up there was a statistically significant difference between Groups 1, 2, and 3 in the percentage of patients in whom the curve had progressed to more than 45 degrees (P < 0.001), who had more than 5 degrees of curve progression (P < 0. 05), or who had undergone posterior spinal fusion (P < 0.001). CONCLUSIONS: These long-term data confirm that the Boston brace when used 18 or more hours per day is effective in preventing progression of large curves at a mean of 9.8 years after bracing is discontinued.

An examination of the knee function during gait in children with myelomeningocele.

In this retrospective study, 37 patients with myelomeningocele who had undergone gait analysis were examined. Patients were divided into groups based on the level of involvement (29 sides: L4; 26 sides: L5; 19 sides: S1-2). Results showed increased knee flexion and associated knee extensor moments with increasing level of neurologic involvement. The mean coronal plane knee position in stance was normal in all groups and not related to coronal plane knee moment. However, there was an increased incidence of a net knee adductor moment in stance with increasing involvement (mean, 0.02 +/-0.18 N.m/kg for the L4 group). The presence of a visual valgus thrust based on video records was not reliable in predicting an abnormal knee coronal plane moment. An abnormal knee adductor moment in stance was most highly related to coronal plane trunk motion (r = -0.62) and not tibial torsion (r = -0.340). Increased transverse plane range of motion of the knee was most highly related to transverse plane trunk motion (r = 0.67).