Clinical evaluation of the new Amplatzer duct occluder II for patent arterial duct occlusion.

BACKGROUND: Several devices such as coils and Amplatzer duct occluder (ADO) are used for catheter closure of patent arterial ducts (PDA). These carry a high success rate but residual shunts, suboptimal device orientation, and technical problems are encountered. The Amplatzer duct occluder II (ADO II) is designed to address these limitations. OBJECTIVES: To evaluate the technical features of the new ADO II device for PDA closure and document the immediate/early closure rate, complications and device behavior during implantation. METHODS: Prospective, two center study from February 2008 to January 2009. Twenty-seven patients (18 females) received the ADO II. The median age was 22 months (range: 7 months-68 years) and the median weight was 11.7 kg (range: 6.9-108). The median PDA diameter was 2.6 mm (range: 1-4.4). The approach was arterial in 13 and venous in 14 patients. Follow-up included echocardiography at 1 day and 1 month postimplantation. RESULTS: All implantations were technically successful with immediate complete angiographic closure in 21 and trivial contrast flow in six patients. The median procedure time was 43 min (range: 15-82) and the fluoroscopy time was 6 min (range: 2.2-26.5). Echocardiography confirmed no residual shunts on the following day. There were no complications. CONCLUSION: The new ADO II is a versatile and very effective device for closure of PDAs of various shapes, lengths, and up to diameters of 5.5 mm. The disc articulations, high early closure rate, arterial or venous approach options, and small diameter delivery catheter are all beneficial features.

Percutaneous transcatheter communication between the pulmonary artery and atrium following an extra-cardiac Fontan: an alternative approach to fenestration avoiding conduit perforation.

In a nonfenestrated modified Fontan, transcatheter creation of a fenestration presents technical difficulties, especially with the extra-cardiac modification where a Gore-Tex tube is placed between the inferior caval vein and the pulmonary arteries. The authors describe an alternative approach to perforating the Gore-Tex tube to create a fenestration by making a communication between the pulmonary artery and the atrial chamber, thus bridging the two circulations through native tissue.

Management of end-stage central venous access in children referred for possible small bowel transplantation.

UNLABELLED: The 3-year survival after small bowel transplantation (SBTx) has improved to between 73% and 88%. Impaired venous access for parenteral nutrition can be an indication for SBTx in children with chronic intestinal failure. AIM: To report our experience in management of children with extreme end-stage venous access. SUBJECTS: The study consisted of 6 children (all boys), median age of assessment 27 months (range, 13-52 months), diagnosed with total intestinal aganglionosis (1), protracted diarrhea (1), and short bowel syndrome (4), of which gastroschisis (2) and malrotation with midgut volvulus (2) were the causes. All had a documented history of more than 10 central venous catheter insertions previously. All had venograms, and 1 child additionally had a magnetic resonance angiogram to evaluate venous access. Five of 6 presented with thrombosis of the superior vena cava (SVC) and/or inferior vena cava. METHODS: Venous access was reestablished as follows: transhepatic venous catheters (5), direct intra-atrial catheter via midline sternotomy (4), azygous venous catheters (2), dilatation of left subclavian vein after passage of a guide wire and then placing a catheter to reach the right atrium (1), radiological recanalization of the SVC and placement of a central venous catheter in situ (1), and direct puncture of SVC stump(1). Complications included serous pleural effusion after direct intra-atrial line insertion, which resolved after chest drain insertion (1), displacement of transhepatic catheter needing repositioning (2), and SVC stent narrowing requiring repeated balloon dilatation. OUTCOME: Four children with permanent intestinal failure on assessment were offered SBTx, 3 of which were transplanted and were established on full enteral nutrition; the family of 1 child declined the procedure. In the remaining 2 children in whom bowel adaptation was still a possibility, attempts were made to provide adequate central venous access as feeds and drug manipulations were undertaken. One of them received liver and SBTx nearly 3 years after presenting with end-stage central venous access, because attempts to achieve independence from parenteral nutrition had failed. The other child died immediately after a transhepatic venous catheter placement, possibly from a nutritional depletion syndrome as no physical cause of death was found. Direct intra-atrial catheters in transplanted children proved to be adequate for the management of uncomplicated transplantation, although the usual infusion protocol had to be modified considerably, and the lack of access would have been critical if massive blood transfusion had been required during the transplant procedure. CONCLUSION: It was possible to reestablish central venous access in all cases. However, this was time consuming and difficult to assemble a skilled team consisting of one of more: surgeon, cardiologist, interventional radiologist, and transplant anesthetist. Small bowel transplantation is easier and safer with adequate central venous access, and we advocate liaison with an SBTx center at an early stage.

Staged surgical management of hypoplastic left heart syndrome: a single institution 12 year experience.

OBJECTIVE: To describe a 12 year experience with staged surgical management of the hypoplastic left heart syndrome (HLHS) and to identify the factors that influenced outcome. METHODS: Between December 1992 and June 2004, 333 patients with HLHS underwent a Norwood procedure (median age 4 days, range 0-217 days). Subsequently 203 patients underwent a bidirectional Glenn procedure (stage II) and 81 patients underwent a modified Fontan procedure (stage III). Follow up was complete (median interval 3.7 years, range 32 days to 11.3 years). RESULTS: Early mortality after the Norwood procedure was 29% (n = 95); this decreased from 46% (first year) to 16% (last year; p < 0.05). Between stages, 49 patients died, 27 before stage II and 22 between stages II and III. There were one early and three late deaths after stage III. Actuarial survival (SEM) was 58% (3%) at one year and 50% (3%) at five and 10 years. On multivariable analysis, five factors influenced early mortality after the Norwood procedure (p < 0.05). Pulmonary blood flow supplied by a right ventricle to pulmonary artery (RV-PA) conduit, arch reconstruction with pulmonary homograft patch, and increased operative weight improved early mortality. Increased periods of cardiopulmonary bypass and deep hypothermic circulatory arrest increased early mortality. Similar factors also influenced actuarial survival after the Norwood procedure. CONCLUSION: This study identified an improvement in outcome after staged surgical management of HLHS, which was primarily attributable to changes in surgical technique. The RV-PA conduit, in particular, was associated with a notable and independent improvement in early and actuarial survival.

Management of cor triatriatum dexter by balloon dilatation in three dogs.

Two dogs, one immature and one adult, were presented with a history of progressive ascites. In a third, immature dog, increasing exercise intolerance had been noted. Echocardiography demonstrated a partition in the right atrium (cor triatriatum dexter) and echocontrast studies documented normal flow from the cranial vena cava into the right atrium and ventricle. A saphenous vein contrast study demonstrated flow from the caudal vena cava into an accessory right atrial chamber (sinus venarum). The sinus venarum communicated with the true right atrium via a small defect in the atrial membrane in one dog, and additionally with the left atrium via a right-to-left shunting foramen ovale in the other dogs. All defects were visualised on angiographic studies by selective catheterisation of the caudal vena cava via the femoral vein. Balloon dilatation of the defect was then performed using a small followed by a larger balloon angioplasty catheter to enlarge the defect in the atrial membrane. Clinical signs improved within days and were sustained in the long-term in all cases.

Early results of right ventricular-pulmonary artery conduits in patients under 1 year of age.

OBJECTIVES: Management strategies for the repair of many complex heart defects require the implantation of a valved conduit between the right ventricle (RV) and the pulmonary artery (PA), often using aortic or pulmonary homograft valves. Their limited availability, however, has led to the development and use of new conduits. We retrospectively compared our experience with small homografts in patients of less than 1 year of age with the TissueMed bioprosthetic valved conduit. METHODS: From March 1994 to November 1997 29 patients in their first year of life underwent conduit implantation for complex heart defects. These were retrospectively reviewed in order to determine the incidence of death or conduit stenosis. Seventeen patients received homografts and 12 TissueMed conduits. RESULTS: Diagnoses and operative details including conduit size were similar in the two groups and in all cases complete repair of the underlying defect was carried out. Early post-operative mortality was 4/17 (23.5%) in the homograft group and 3/12 (25%) in the TissueMed group. Echo Doppler evaluation within 1 month of operation showed no right ventricular outflow tract (RVOT) obstruction in any of the survivors. In the TissueMed group 8/9 (77%) survivors have gone on to develop significant RVOT obstruction within 12 months of operation. There have been three late deaths in this group all related to severe RVOT obstruction. Two patients died during an attempt at balloon dilatation and one patient died of progressive right heart failure. Five patients had successful replacement of the TissueMed conduit. One child remains well with no evidence of RVOT obstruction. At operation to replace conduit, or at autopsy, the stenoses were related to the deposition of fibrous tissue at the anastomotic suture lines. In the homograft group none of the survivors developed RVOT obstruction during the first 12 months post-operatively. There was one late death (non-cardiac in origin) and one child is awaiting conduit replacement 40 months after initial implantation for obstruction. CONCLUSIONS: The homograft is a satisfactory conduit for re-establishment of RV-PA continuity in infancy. Further work needs to be undertaken in order to elucidate the mechanisms of early graft failure in bioprosthetic conduits if these are to be a suitable alternative for RV outflow reconstruction in infants.

Transcatheter coil closure of muscular ventricular septal defects.

We report two patients with small, muscular ventricular septal defects, both of whom had a potential risk of infective endocarditis and underwent transcatheter closure using a detachable Cook coil. We suggest that in selected patients this technique offers a simple and cost-effective alternative to surgery or double-disc device procedures.

Covered stents in the treatment of aortic coarctation.

Coarctation of the aorta can be managed in different ways depending upon the age of presentation, anatomical details of the coarctation, the aortic arch anatomy, and whether the coarctation is native or a recurrence following surgery. In infants, surgery is the preferred treatment of choice, whereas in older children and adults, percutaneous procedures, such as balloon angioplasty or stent implantation, are becoming increasingly popular methods for treating coarctation. Various types of stents have been used and this paper specifically addresses the use of covered or graft Jomed stents in a small group of patients with coarctation.

The use of Amplatzer devices to occlude vascular fistulae.

The Amplatzer occluders are Nitinol-based devices that are preshaped for specific indications, primarily to close atrial septal defects, patent foramen ovale/fenestrations, or to occlude patent arterial ducts or one designed specifically for closure of ventricular septal defects. The flexible quality of the Nitinol together with the different designs of Amplatzer occluders make it possible for these plug devices to be used for conditions other than what they are designed for. This is particularly the case for fistulae where no specific devices are available and hence improvisation may be required. The established use of the Amplatzer occluder devices primarily for atrial septal defects and for patent arterial ducts provide the confidence to use them for alternative conditions where few or no alternatives are available or if surgery is the only option. This article describes the use of Amplatzer occluder devices for two unusual conditions, namely to occlude a pulmonary arteriovenous malformation and to close an aorto-left ventricular tunnel.

Total anomalous pulmonary venous connection: outcome of surgical correction and management of recurrent venous obstruction.

OBJECTIVE: Total anomalous pulmonary venous connection (TAPVC) can be corrected with low mortality and good outcome. If complicated by pulmonary vein stenosis (PVS), either at presentation or secondary to the repair, the long-term outcome is compromised. We have evaluated an institutional experience with TAPVC, with particular regard to the evolving management of PVS. METHODS: Retrospective analysis of 85 consecutive patients with non-isomeric TAPVC undergoing surgical correction over a 10-year period (1988-1997). In addition, three patients were referred to us with secondary PVS, having had their primary procedure elsewhere. Attention was focused on incidence of PVS, and strategies for management. RESULTS: Median age at first operation was 33 days (range 1-533). Site of drainage was supracardiac (43/88), infracardiac (20/88), cardiac (17/88), and mixed (8/88). On presentation, 35% of patients were ventilated. Early mortality was 7% (6/85), with one late non-cardiac death. 82% of the original patients (70/85) are currently well at a median follow-up of 64 months (range 6-119). The incidence of PVS requiring intervention was 11% (9/85). Median time to PVS was 41 days. In these patients, 18 balloon angioplasties, four endovascular stent placements (in two patients), and a further 23 surgical procedures were performed. Of the nine patients undergoing re-intervention after initial surgery at our institution, five (56%) survived. Two of these have no residual obstruction and right ventricular pressure (RVP) < 50% systemic, two have unilateral obstruction and RVP < 50% systemic, and one has bilateral obstruction and RVP 80% systemic. Of the three patients referred to us with secondary PVS, two are alive and well, and one died early after the first re-operation. CONCLUSIONS: Intrinsic obstruction (endocardial sclerosis or thickening) is associated with worse prognosis and earlier re-intervention than extrinsic (anatomical) obstruction. We advocate an early, aggressive approach to the management of patients with TAPVC, especially in the presence of PVS. This complication is most appropriately managed by a combination of re-operation and repeated balloon dilation.

Divided left atrium in association with tricuspid atresia and discordant ventriculo-arterial connections.

Division of the morphologically left atrium is a rare abnormality, constituting around 0.1% of congenital heart disease. It may coexist with other cardiac abnormalities, and this association may obscure its recognition. We report an uncommon association with tricuspid atresia and discordant ventriculo-arterial connections, the latter dominating the clinical picture. Accurate diagnosis was made by transthoracic cross-sectional echocardiography, and the patient was referred to surgery without need for cardiac catheterisation.

Left ventricular diastolic function in congenital myotonic dystrophy.

OBJECTIVE: Examination of left ventricular function and conduction abnormalities in myotonic dystrophy. DESIGN: Twelve patients (median age, 13.7 years) with myotonic dystrophy had detailed electrocardiography and echocardiography performed. Echocardiographic parameters were compared with body surface area (BSA) matched median normal values. RESULTS: Fractional shortening was slightly reduced (by 28-29%) in three patients and three patients had mild mitral valve prolapse. Diastolic function was abnormal; isovolumic relaxation time (IVRT) and duration of early filling were prolonged compared with control values (median IVRT, 74 v 61 ms). Peak E velocity was increased (median, 0.82 v 0.78 m/s) but atrial phase filling was normal. Heart rate was reduced (median, 68 v 81 beats/min). Conduction abnormalities were common but showed no clear relations with diastolic abnormalities. CONCLUSIONS: Young patients with myotonic dystrophy have myocardial diastolic dysfunction as well as abnormal electrophysiology. The prognostic implications of such abnormalities require further study.

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.

Recovery pattern of left ventricular dysfunction following radiofrequency ablation of incessant supraventricular tachycardia in infants and children.

OBJECTIVE: To assess recovery pattern of left ventricular function secondary to incessant tachycardia after radiofrequency ablation in a group of infants and children. DESIGN AND SETTING: A combined prospective and retrospective echocardiographic study carried out in a tertiary paediatric cardiac centre. PATIENTS: Echocardiographic evaluation of left ventricular size and function in nine children with incessant tachycardia, before and after successful radiofrequency ablation. Age at ablation ranged from 2 months to 12.5 years (mean 4.1 years). Recovery of left ventricular function was analysed in relation to age at ablation (group I < 18 months, group II > 18 months). MAIN OUTCOME MEASURE: Ventricular recovery pattern. RESULTS: Seven of the nine children had left ventricular dysfunction; six of these also had left ventricular dilatation. All children with left ventricular dysfunction had normalisation of ejection fraction and fractional shortening; left ventricular dilatation also improved, but the improvement occurred after recovery of function. There was a shorter recovery time for left ventricular function in younger (group I) than in older children (group II) (mean (SD) 5.7 (7.2) months v 31.3 (5.2) (p < 0.002). CONCLUSIONS: Tachycardia induced cardiomyopathy is reversible following curative treatment with radiofrequency. Recovery of left ventricular systolic function precedes recovery of left ventricular dilatation. Time course to recovery is shorter in younger children.

Occlusion of persistent left superior vena cava to unroofed coronary sinus using vena cava filter and coils.

A 48 year old female with complex cyanotic heart disease and pulmonary hypertension was partly cyanosed because of a persistent left superior vena cava draining into an unroofed coronary sinus. The left superior vena cava, which measured 22 mm in diameter, was successfully occluded with a Günther Tulip Vena Cava Mreye Filter which acted as a barrier for embolisation coils.

Percutaneous transluminal balloon angioplasty of abdominal aortic coarctation in an infant.

Abdominal aortic coarctation is rare in children. We report successful percutaneous transluminal balloon angioplasty of an abdominal aortic coarctation in an infant who presented with heart failure.