Evolution in the management of aorta to left ventricular tunnel in a national congenital cardiology centre.

An aorto-ventricular tunnel is a rare congenital cardiac defect, where a channel connects the lumen of the ascending aorta to the left or right ventricle. Four patients presented with an aorto-left ventricular tunnel over two decades at a median age of 8 months (range 0.1-10 months). Two patients (50%) had associated cardiac anomalies including hypoplastic left heart syndrome and left ventricular noncompaction/hypertrophic cardiomyopathy with aortic/pulmonary valve dysplasia in one patient each. Although traditionally surgical treatment has addressed this problem, management has evolved to transcatheter closure with excellent outcomes in appropriately selected patients at our national centre.

Leadless Micra Pacemaker Use in the Pediatric Population: Device Implantation and Short-Term Outcomes.

The development of Leadless cardiac pacemakers avoids the inherent complications that may occur secondary to lead insertion. A large number of devices have been inserted in adult patients although data in pediatric patients are lacking. We aimed to assess our experience with the Leadless device in the pediatric population. We performed a retrospective study on all pediatric patients who underwent insertion of a Leadless pacemaker in our center. Data were collected for demographic, procedural, and outcome variables. Nine patients with a median (IQR) age and weight of 13 (12-14) years and 37 (31-50) kg, respectively, were enrolled. The median (IQR) procedural time was 62 (60-65) min with insertion thresholds of 0.5 (0.35-1) Volts at 0.24 ms. All devices were successfully inserted without complication. One device was replaced with a single-lead endocardial pacemaker at 1 year for increased thresholds. Leadless pacemaker device insertion is feasible in pediatric patients. Further studies and long-term follow-up are needed to ascertain device longevity and complication rates.

Transcatheter Mitral Valve-in-Ring Implantation.

Failed surgical mitral valve repair using an annuloplasty ring has traditionally been treated with surgical valve replacement or repair1. For patients at high risk for repeat open heart surgery, placement of a trans-catheter aortic valve (i.e., TAVI valve) within the mitral ring (i.e., Mitral-Valve-in-Ring, MViR) has emerged as a novel alternative treatment strategy2-5 . We describe our experience of a failed mitral valve repair that was successfully treated with a TAVI valve delivered via the trans-septal approach, and summarise the data relating to this emerging treatment strategy.

Device closure of secundum atrial septal defect in a 4.5 kilogram infant: Novel use of the Amplatzer DuctOccluder II device.

Modest secundum atrial septal defects (2°ASD) may cause significant pulmonary over perfusion during infancy, particularly in conjunction with left heart obstructive lesions. Amplatzer Septal Occluders are not ideal in this setting especially given recent concerns regarding device erosion. We report the first use of the Amplatzer Duct Occluder II device (ADO2) to close a 2°ASD in a 4.5 kg infant.

First reported use of drug-eluting bioabsorbable vascular scaffold in congenital heart disease.

The aim of catheter intervention for vascular stenosis is the restoration of lumen area and optimization of distal blood flow. In pediatric practice, this has traditionally been a compromise between less effective balloon angioplasty and bare metal stent insertion with its attendant limitations of size. Bioabsorbable stents offer short-term relief of stenosis, radial support of the healing lesion, return of endothelial function and crucially, in children, the potential for long-term growth. Initial experience, in pediatric practice, with metal-based bioabsorbable stents was relatively disappointing with frequent restenosis secondary to early reabsorption. Design modifications resulting in polymer-based, drug eluting, bioabsorbable vascular scaffolds (BVS) have reportedly overcome some of these faults. We describe the first reported use of a drug eluting BVS in three patients with: (1) A newborn with severe right pulmonary artery (RPA) stensosis post repair of type two common arterial trunk. (2) A child with pulmonary atresia/ventricular septal defect (VSD) and major aorto-pulmonary collateral arteries (MAPCAs), and (3) An infant with severe left pulmonary artery (LPA) stenosis in the setting of an LPA sling.

Fontan fenestration closure with Amplatzer Duct Occluder II device.

OBJECTIVES: To evaluate Fontan fenestration closure using the Amplatzer Duct Occluder II device (ADO2). BACKGROUND: Fontan fenestration closure is a well established catheter intervention. A range of occlusion devices developed for other interventions have been utilized. Most of these devices, and especially the most commonly used Amplatzer Septal Occluder, are relatively bulky. The ADO2 is a low profile, flexible, and inexpensive device which seems well suited to the Fontan fenestration. METHODS: This study details retrospective review of patients undergoing Fontan fenestration closure with an ADO2 device. Outcome measures included procedural success, pre- and post-procedural differences in oxygen saturation and mean pulmonary artery pressure and complications. RESULTS: Thirteen patients were eligible for inclusion during the 34 month study period. All procedures were technically successful. There was a significant increase in oxygen saturations (Mean=+12%, P<0.01) after fenestration closure but no significant change in mean pulmonary artery pressure (Mean=+0.5 mm Hg, P=0.08). There were no procedural complications. CONCLUSION: Fontan fenestration closure with the ADO2 device is a simple, short, and cost-effective procedure. The ADO2 characteristics recommend it to occlusion of varying sizes and morphologies of Fontan fenestration.

Coronary stent insertion into a 20-year-old Blalock-Taussig Shunt.

A 21 year-old female with complex congenital heart disease presented with declining exercise tolerance, presyncope and increasing cyanosis despite regular venesection. Her double inlet left ventricle with rudimentary right ventricle, restrictive ventricular septal defect and pulmonary stenosis had been managed with a Classic Left Blalock-Taussig (B-T) Shunt aged 2 months and a Modified Right B-T Shunt at 4 years. Aortography revealed a patent but significantly narrowed Left B-T shunt with impaired blood flow and an aneurysmal pulmonary artery. Angioplasty and stenting of the shunt was undertaken and a 4.0 x 12mm coronary stent deployed. The patient's arterial oxygen saturation improved from 76% on pulse oximetry to 85% post procedure and she reported significantly improved exercise tolerance upon follow-up.

Catheter closure of moderate- to large-sized patent ductus arteriosus using the new Amplatzer duct occluder: immediate and short-term results.

OBJECTIVES: The aim of this study was to assess the immediate and short-term results of anterograde catheter closure of a moderate- to large-sized patent ductus arteriosus (PDA) using the new self-expandable, respositionable Amplatzer duct occluder (ADO) device. BACKGROUND: Transcatheter closure of a PDA using devices or coils is technically challenging and may be accompanied by a 38% incidence of residual shunts. METHODS: Twenty-four patients (6 male, 18 female) underwent attempted transcatheter closure of a PDA using the ADO at a median age of 3.8 years (range 0.4 to 48) and a median weight of 15.5 kg (range 6 to 70). The mean PDA diameter at its narrowest segment was 3.7+/-1.5 mm. A 6F long sheath was used for delivery of the ADO. Follow-up evaluation was performed with color flow mapping of the main pulmonary artery within 24 h and at 1 and 3 months after closure. RESULTS: Twenty three of the 24 patients had successful device placement. Angiography showed that 7 patients had complete immediate closure, 14 had a trace shunt (foaming through the device with no jet), and 2 had a small residual shunt (with a jet). Within 24 h, color Doppler revealed complete closure in all patients. The unsuccessful attempt was during an initial trial with a prototype that has been modified. The median fluoroscopy time was 13.5 min (range 6.3 to 47). All patients were discharged home the next day. There were no complications. Of the 23 patients, 21 completed the 1-month follow-up, all (95% confidence interval [CI] 86% to 100%) with complete closure, and 18 of 23 patients completed the 3-month follow-up, also all (95% CI 83% to 100%) with complete closure. CONCLUSIONS: Anterograde transcatheter closure using the new ADO is an effective therapy for patients with a PDA diameter up to 6 mm. Further clinical trials are underway.

Results of transvenous occlusion of secundum atrial septal defects with the fourth generation buttoned device: comparison with first, second and third generation devices. International Buttoned Device Trial Group.

OBJECTIVES: The purpose of this study was to assess safety and effectiveness of the fourth generation buttoned device in dosing atrial septal defects (ASDs) and to test the hypothesis that introduction of double button reduces unbuttoning rate without reducing effectiveness. BACKGROUND: Because of the high unbuttoning rate (7.2%) with first, second and third generation buttoned devices, the device was modified (fourth generation) so that there were two radiopaque spring buttons 4 mm apart on the button loop attached to the occluder. METHODS: During a four-year period ending in September 1997, 423 patients, ages 1.5 to 80 years (median 16 years), underwent closure of ASD at 40 medical centers around the world. RESULTS: The ASD size varied between 5 and 30 mm (median 17 mm). The device size varied between 25 and 60 mm. Unbuttoning occurred in 4 (0.9%) of 423 patients. Effective occlusion, defined as no (n = 343) or trivial (n = 34) residual shunt on echo-Doppler studies performed within 24 h of the procedure, was demonstrated in 377 patients (90%). Thus, the unbuttoning rate (0.9 vs. 7.2%) decreased (p<0.01) while effective occlusion rate (90 vs. 92%) remained unchanged (p>0.1) with this device, compared with earlier generation devices. During follow-up from one month to five years (23+/-15 months), 21 (5%) of 417 patients required surgical (n = 12) or transcatheter (n = 9) reintervention, mostly to treat significant residual shunt. In the remaining patients there was gradual reduction and disappearance of the residual shunt. No wire integrity problems were observed. CONCLUSIONS: These data suggest that the fourth generation buttoned device is as effective as earlier generation devices, but without significant unbuttoning. Follow-up results remained good, with a reintervention-free rate of 89% at five years.

Dermatomyositis and Whipple's disease.

A 14-year-old boy presented with a 3-year history of a skin rash typical of juvenile dermatomyositis, and a 2-month history of mild proximal weakness, myalgia, and weight loss. A quadriceps biopsy showed perifascicular fibre atrophy, focal necrosis and regeneration, immunohistochemical labelling for HLA-1 on the surface of the fibres, and focal C5-9 deposition in capillaries. Macrophages with diastase-resistant, PAS-positive cytoplasm were present. Ultrastructural studies showed electron dense and membranous debris. The patient's symptoms responded to intravenous immunoglobulin and oral prednisolone. Four months after discontinuing prednisolone, the patient developed cardiac failure, ventricular tachycardia, and a recurrence of his rash. The 16S ribosomal RNA specific for Tropheryma whippelii was identified by polymerase chain reaction (PCR) analysis in skeletal and cardiac muscle. The myalgia and skin rash responded to prednisolone and oral co-trimoxazole, and the tachycardia is controlled by oral verapamil. This patient appears to have a novel association of juvenile dermatomyositis and Whipple's disease.

Comparison of the Sideris and Amplatzer septal occlusion devices.

The results of transcatheter atrial septal defect (ASD) occlusion with 2 different devices (Sideris adjustable buttoned device vs Amplatzer Septal Occluder) were compared in 2 consecutive series of patients. Comparative outcomes were assessed by whether a device was implanted or not, by complications and fluoroscopy time of implantation, and by the incidence of residual shunting on transthoracic echocardiography at follow-up. The patient and defect characteristics were similar in both groups. Twenty-eight of 33 Sideris devices and 37 of 39 Amplatzer devices were implanted. The fluoroscopy time for the Amplatzer implants was 13.4 minutes (range 8 to 41) compared with 23.7 minutes (range 11 to 60.6) for the Sideris implants (p <0.001). The complete occlusion rate for the Amplatzer device was 93% compared with 44% for the Sideris device at 1 year (p <0.001). In conclusion, the Amplatzer device produces higher occlusion rates of ASDs with shorter fluoroscopy times.

Transcatheter occlusion of a post-Fontan residual hepatic vein to pulmonary venous atrium communication using the Amplatzer septal occluder.

A residual hepatic vein to left atrial communication may result in progressive cyanosis after the Fontan procedure. This problem has usually been treated surgically by ligation or re-inclusion of the residual hepatic vein in the Fontan circulation. Previous attempts at transcatheter closure of such veins have been unsuccessful. An Amplatzer septal occluder was successfully used for transcatheter closure of a post-Fontan hepatic vein to pulmonary venous atrium fistula in an 8 year old boy.

Transcatheter closure of a mid-muscular ventricular septal defect with an amplatzer VSD occluder device.

A 5 year old girl with a haemodynamically significant mid-muscular ventricular septal defect (VSD) had successful transcatheter closure using the Amplatzer VSD occluder. This device passes through a small diameter sheath and can be easily retrieved or repositioned. These properties may make it a suitable device for closure of large mid-muscular defects in small children.

Importance of right ventricular outflow tract angiography in distinguishing critical pulmonary stenosis from pulmonary atresia.

OBJECTIVE: To investigate the spectrum of pulmonary atresia and critical pulmonary stenosis using right ventricular outflow tract angiography and explore its implications for catheter interventional treatment. DESIGN: Prospective clinical study. SETTING: Two paediatric cardiology centres. SUBJECTS: 11 neonates or infants (aged 1 day to 8 months; weighing 2.3 to 7.8 kg) with pulmonary atresia or where the differentiation of pulmonary atresia from critical pulmonary stenosis was unclear on either echocardiography or angiography. METHODS: Right ventricular outflow tract angiography was performed on all patients to distinguish pulmonary atresia from critical pulmonary stenosis before opening the right ventricular outflow tract. RESULTS: Right ventricular outflow tract angiography showed that three of seven patients diagnosed as pulmonary atresia by echocardiography had pin hole jets across the pulmonary valve; another had a probe patent valve that appeared imperforate on both echocardiography and right ventricular outflow tract angiography. Three of the four patients diagnosed by echocardiography as critical pulmonary stenosis were found on right ventricular outflow tract angiography to have pulmonary atresia. The remaining patient had such a tiny orifice that a second orifice had to be created with a radiofrequency catheter. The right ventricular outflow tract was opened successfully in 10 of the 11 patients, six of whom required application of radiofrequency energy. The right ventricular to aortic systolic pressure ratio fell from 1.4 (0.9 to 1.9) to 0.6 (0.2 to 1.1) (P < 0.05). All 11 patients were alive and well with transcutaneous oxygen saturations ranging from 84% to 95% at a median follow up duration of nine months. CONCLUSIONS: Critical pulmonary stenosis and pulmonary atresia cannot always be accurately distinguished by echocardiography. Right ventricular outflow tract angiography helps to distinguish the two groups. In most cases the right ventricular outflow tract can be opened without mortality and with short to medium term survival.

Transcatheter closure of patent foramen ovale using the Amplatzer septal occluder to prevent recurrence of neurological decompression illness in divers.

OBJECTIVE: Large flap valve patent foramens may cause paradoxical thromboembolism and neurological decompression illness in divers. The ability of a self expanding Nitinol wire mesh device (Amplatzer septal occluder) to produce complete closure of the patent foramen ovale was assessed. PATIENTS: Seven adults, aged 18-60 years, who had experienced neurological decompression illness related to diving. Six appeared to have a normal atrial septum on transthoracic echocardiography, while one was found to have an aneurysm of the interatrial septum. METHODS: Right atrial angiography was performed to delineate the morphology of the right to left shunt. The defects were sized bidirectionally with a precalibrated balloon filled with dilute contrast. The largest balloon diameter that could be repeatedly passed across the septum was used to select the occlusion device diameter. Devices were introduced through 7 F long sheaths. All patients underwent transthoracic contrast echocardiography one month after the implant. RESULTS: Device placement was successful in all patients. Device sizes ranged from 9-14 mm. The patient with an aneurysm of the interatrial septum had three defects, which were closed with two devices. Right atrial angiography showed complete immediate closure in all patients. Median (range) fluoroscopy time was 13.7 (6-35) minutes. Follow up contrast echocardiography showed no right to left shunting in six of seven patients and the passage of a few bubbles in one patient. All patients have been allowed to return to diving. CONCLUSION: The Amplatzer septal occluder can close the large flap valve patent foramen ovale in divers who have experienced neurological decompression illness. Interatrial septal aneurysms with multiple defects may require more than one device.

Transcatheter closure of a residual postmyocardial infarction ventricular septal defect with the Amplatzer septal occluder.

Acute ventricular septal rupture following myocardial infarction carries a high mortality. Early surgery improves survival but long term outcome depends on residual shunting and left ventricular function. Residual shunting is common despite apparently successful closure and may require reoperation. Transcatheter closure is an established method of treating selected congenital defects but clinical experience of transcatheter closure in postinfarction ventricular septal rupture is minimal. Transcatheter closure of a residual ventricular septal defect was successfully done using a new device, the Amplatzer septal occluder, in a 50 year old Indian man who had previously undergone emergency surgical repair for postinfarction acute ventricular septal rupture. The technique is described and its potential as a treatment in postinfarction ventricular septal rupture, its possible complications, and the important aspects of case selection and device design are discussed.

Lung perfusion studies after detachable coil occlusion of persistent arterial duct.

OBJECTIVE: To evaluate relative lung perfusion following complete occlusion of persistent arterial duct with detachable Cook coils. METHODS: Ductal occlusion using detachable coils was performed in 35 patients (median age 3.9 years, range 0.5 to 16; 32 native ducts, three patients with previous devices). If the duct could be crossed with a 0.035 inch guidewire and a 4 F catheter after coil implantation, a further coil was implanted. Between one and seven coils were used (median two). RESULTS: Complete ductal occlusion was confirmed by echocardiography 24 hours after the procedure in all patients. Lung perfusion scans were performed three months after the procedure in 33 of 35 patients (two older patients with a single coil each did not attend). Decreased perfusion to the left lung (defined as < 40% of total lung flow) was observed in only one patient, who had previously had a 17 mm Rashkind umbrella implanted. There was no correlation between left lung perfusion and peak left pulmonary artery Doppler velocities (r = 0.27 and p = 0.125 for the entire group; r = 0.29 and p = 0.124 after excluding patients with previous devices). CONCLUSIONS: Coil occlusion is effective in achieving complete closure of the duct. An aggressive approach using multiple coils did not compromise perfusion to the left lung.

Occlusion of Fontan fenestrations using the Amplatzer septal occluder.

OBJECTIVE: To evaluate the efficacy and safety of the Amplatzer septal occluder device for occlusion of Fontan fenestrations. SUBJECTS: Five children aged 5-10 years who had undergone a fenestrated Fontan operation. SETTING: Tertiary paediatric cardiology centre. METHODS: Each patient had right and left heart catheterisation to assess haemodynamic suitability for fenestration closure. Sizing of the defect was achieved with a balloon wedge catheter and transoesphageal echocardiography. Transcatheter occlusion of the fenestration was accomplished using a 4 mm device in three patients, and 5 mm or 9 mm devices in the other two patients. Residual shunting following occlusion was assessed using angiography and echocardiography. RESULTS: 100% occlusion rate of the fenestration was achieved in all patients. No complications or device failures were seen during the three month follow up period. CONCLUSION: The Amplatzer septal occluder device is safe, and effectively occludes the Fontan fenestration.

Occlusion of congenital ventricular septal defects by the buttoned device. "Buttoned device" Clinical Trials International Register.

OBJECTIVES: To study the feasibility of congenital ventricular septal defect occlusion by the buttoned device and to establish guidelines for its safe and effective application. DESIGN: A descriptive study of all patients with a congenital ventricular septal defect undergoing transcatheter occlusion with the buttoned device, from March 1994 to May 1995. These patients were otherwise candidates for elective surgery at their institutions because they had persistence of a significant shunt (Qp:Qs = 1.5-2.1:1, median = 1.7), with left ventricular enlargement and/or symptoms, although their systolic pulmonary artery pressure was invariably normal (20-28 mm Hg, median = 25). The angiographic diameter of the defect ranged from 2.5 to 14 mm (median 6 mm). SETTING: A multi-institutional study. PATIENTS: Out of 25 cases attempted, 18 children and adults aged 4-35 years had devices implanted. Fifteen of these patients had membranous ventricular septal defects and three had muscular defects. All patients with a membranous ventricular septal defect had an associated aneurysm of the membranous septum. INTERVENTIONS: The buttoned device was introduced either directly or, in the last 12 cases, over a wire bridging the femoral artery and the femoral or jugular vein; the devices were delivered through 7-9 French (F) long sheaths. A membranous defect was regarded as suitable for device closure if the distance from the centre of the defect to the insertion of the right coronary aortic valve leaflet was more than 50% of the size of the required device. The device was guided by echocardiography and fluoroscopy. All muscular defects were corrected through the right jugular vein and all membranous ones through the femoral vein. RESULTS: All 18 patients underwent initial successful implantation of the device. In thirteen patients the shunts were completely occluded and in the remaining five there were trivial residual shunts. In two patients with membranous ventricular septal defects a change from the original position was noticed at two weeks; mild aortic regurgitation developed in one and the murmur recurred in the other; the devices had to be removed surgically. One patient developed transient third degree atrioventricular block during implantation; no tricuspid regurgitation was observed. CONCLUSION: Clinical occlusion of congenital ventricular septal defects was achieved in 16 out of the 18 attempted cases (13 full occlusions). Membranous ventricular septal defect occlusion can be effective and safe if patients and device sizes are carefully selected.

Balloon expandable stents for systemic venous pathway stenosis late after Mustard's operation.

OBJECTIVES: Description and evaluation of current experience with the use of balloon expandable stents for the relief of systemic venous pathway stenosis late after Mustard's operation. DESIGN: Retrospective observational study of technical procedures, angiographic, and haemodynamic findings. PATIENTS: Twenty long term survivors of Mustard's operation for transposition of the great arteries (TGA) with angiographic evidence of systemic venous pathway narrowing. INTERVENTION: Systemic venous pathway stenoses were stented using balloon expandable Palmaz stents. RESULTS: Twenty seven stents were deployed across 24 stenoses. Seventeen stents were placed in the inferior baffle (16 patients), with an increase in mean (range) minimum diameter from 9.6 (4.5-15.9) to 16.5 (11.9-22.2) mm (p = 0.007), and a reduction in mean pressure gradient from 3.1 (0-8) to 0.67 (0-3) mm Hg (p = 0.002). Eight stents were placed in the superior pathways of eight patients, with diameters widened from 9.1 (3.5-14.1) to 15.2 (8.7-19.2) mm (p = 0.018), and gradients reduced from 6.4 (2-11) to 0.9 (0-2) mm Hg (p = 0.02). Two badly deployed stents were safely withdrawn from their intracardiac positions and redeployed in the iliac vein. Transvenous pacemaker insertion was facilitated by prior stent insertion. CONCLUSIONS: The use of balloon expandable stents for late systemic pathway narrowing after Mustard's operation is safe and effective. The beneficial effects of stenting are likely to be more durable than those of balloon angioplasty alone, but longer term follow up is required.