Mazeni Alwi

The Amplatzer duct occluder: experience in 209 patients

OBJECTIVES The aim of the study was to assess the safety and efficacy of the Amplatzer ductal occluder (ADO) in transcatheter occlusion of patent ductus arteriosus (PDA). BACKGROUND Transcatheter closure of small to moderate sized PDAs is an established procedure. The ADO is a self-expandable device with a number of salutary features, notably its retrievability, ease of delivery via small 5F to 7F catheters and a range of sizes suitable even for the larger PDAs. METHODS Between November 1997 and August 1999, the ADO was successfully implanted in 205 of 209 patients with PDA. The inclusion criteria for this device occlusion method were patients with clinical and echocardiographic features of moderate to large PDA, weighing > or =3.5 kg as well as asymptomatic adolescents and adults with PDA measuring > or =5.0 mm on two-dimensional (2D) echocardiogram. Occlusion was achieved via the antegrade venous approach. Follow-up evaluations were performed with 2D echocardiogram, color-flow mapping and Doppler measurement of the descending aorta and left pulmonary artery velocity at 24 h and 1, 3, 6 and 12 months after implantation. RESULTS Two hundred and five patients had successful PDA occlusion using this device. The patients were between two months and 50 years (median 1.9) and weighed between 3.4 kg and 63.2 (median 8.4). Infants made up 26% of the total patients. The PDA measured from 1.8 to 12.5 mm (mean 4.9) at the narrowest diameter. Forty-four percent of patients achieved immediate complete occlusion. On color Doppler the closure rates at 24 h and 1 month after implant were 66% and 97%, respectively. At 6 and 12 months all except one patient attained complete occlusion. Device embolization occurred in three patients; in two this was spontaneous, and in the other it was due to catheter manipulation during postimplant hemodynamic measurement. Mild aortic narrowing was seen in an infant. CONCLUSIONS Patent ductus arteriosus occlusion using ADO is safe and efficacious. It is particularly useful in symptomatic infants and small children with relatively large PDA. Embolization can be minimized by selection of appropriate sized devices, and caution should be exercised in infants <5 kg.

Pulmonary atresia with intact ventricular septum percutaneous radiofrequency-assisted valvotomy and balloon dilation versus surgical valvotomy and Blalock Taussig shunt

OBJECTIVE We compared the result of radiofrequency (RF)-assisted valvotomy and balloon dilation with closed surgical valvotomy and Blalock Taussig (BT) shunt as primary treatment in selected patients with pulmonary atresia and intact ventricular septum (PA-IVS). BACKGROUND Patients with PA-IVS who have mild to moderate hypoplasia of the right ventricle (RV) and patent infundibulum have the greatest potential for complete biventricular circulation. The use of RF or laser wires to perforate the atretic valve followed by balloon dilation provides an alternative to surgery. METHODS Between May 1990 and March 1998, 33 selected patients underwent either percutaneous RF valvotomy and balloon dilation (group 1, n = 21; two crossed over to group 2) or surgical valvotomy with concomitant BT shunt (group 2, n = 14). Second RV decompression by balloon dilation or right ventricular outflow tract (RVOT) reconstruction were performed if necessary. Patients who remained cyanosed were subjected to transcatheter trial closure of the interatrial communication. Partial biventricular repair was offered to those with inadequate growth of the RV. RESULTS The primary procedure was successful in 19 patients in group 1. There was one in-hospital death and two late deaths. Of the remaining 16 survivors, 12 achieved complete biventricular circulation, 7 of whom required no further interventions. Two patients required repeat balloon dilation, 1 RVOT reconstruction and 2 transcatheter closure of interatrial communication. Two patients underwent partial biventricular repair. In group 2, there were 3 in-hospital deaths after the primary procedure and 1 patient died four months later. All survivors (n = 10) required a second RV decompression, 8 by balloon dilation and 2 by RVOT reconstruction, after which, two patients died. Of the final 8 survivors, 7 achieved complete biventricular circulation, 5 after coil occlusion of the BT shunt and 2 after closure of interatrial communication. CONCLUSIONS Radiofrequency valvotomy and balloon dilation is more efficacious and safe compared with closed pulmonary valvotomy and BT shunt in selected patients with PA-IVS.

Management algorithm in pulmonary atresia with intact ventricular septum

Pulmonary atresia with intact ventricular septum (PAIVS) is a disease with remarkable morphologic variability, affecting not only the pulmonary valve but also the tricuspid valve, the RV cavity and coronary arteries. With advances in interventional techniques and congenital heart surgery, the management of PAIVS continues to evolve. This review is an attempt at providing a practical approach to the management of this disease. The basis of our approach is morphologic classification as derived from echocardiography and angiography. Group A, patients with good sized RV and membranous atresia, the primary procedure at presentation is radiofrequency (RF) valvotomy. Often it is the only procedure required in this group with the most favourable outcome. Patients with severely hypoplastic RV (Group C) are managed along the lines of hearts with single ventricle physiology. The treatment at presentation is patent ductus arteriosus (PDA) stenting with balloon atrial septostomy or conventional modified Blalock Taussig (BT) shunt. Bidirectional Glenn shunt may be done 6–12 months later followed by Fontan completion after a suitable interval. Patients in Group B, the intermediate group, are those with borderline RV size, usually with attenuated trabecular component but well developed infundibulum. The treatment at presentation is RF valvotomy and PDA stenting ± balloon atrial septostomy. Surgical re‐interventions are not uncommonly required viz. bidirectional Glenn shunt when the RV fails to grow adequately (1½ – ventricle repair) and right ventricular outflow tract (RVOT) reconstruction for subvalvar obstruction or small pulmonary annulus. Catheter based interventions viz. repeat balloon dilatation or device closure of patent foramen ovale (PFO) may also be required in some patients.

Transcatheter closure of multiple muscular ventricular septal defects using Gianturco coils

A 10-month-old boy underwent operation to close a large secundum atrial septal defect and multiple muscular ventricular septal defects. Closure of the ventricular septal defects was unsuccessful and led to worsening cardiac failure and inability to wean the patient from mechanical ventilation. Transcatheter closure of the ventricular septal defects using Gianturco coils was undertaken. This technique is an effective alternative for closure of multiple muscular ventricular septal defects in infants and small children.

Transcatheter occlusion of native persistent ductus arteriosus using conventional Gianturco coils

Two hundred eleven patients with small- to moderate-sized native patent ductus arteriosus underwent closure using Gianturco coils, employing the transvenous multiple catheter approach. Short-term results showed a high rate of complete occlusion and a potential long-term complication of mild left pulmonary artery stenosis in a small number of patients.

Stenting the ductus arteriosus: Case selection, technique and possible complications.

Ductal stenting is an attractive alternative to conventional shunt surgery in duct dependent congenital heart disease as it avoids thoracotomy and its related problems. With todays generation of coronary stents which have better profile, flexibility and trackability, ductal stenting may be achieved safely and with considerably less difficulty than previously described. As in Blalock-Taussig (BT) shunt, ductal stenting is indicated mainly in duct-dependent cyanotic lesions chiefly in the neonatal period. Unlike the Patent ductus arteriosus (PDA) as an isolated lesion, the ductus in cyanotic heart disease has a remarkable morphologic variability. The ductus tends to arise more proximally under the aortic arch, giving rise to a vertical ductus or occasionally it may arise from the subclavian artery. It also tends to be long and sometimes very tortuous, rendering stent implantation technically impossible. The ductus in these patients may also insert onto one of the branch pulmonary arteries with some stenosis at the site of insertion. The ductus in Tetralogy of Fallot with pulmonary atresia (TOF-PA) tend to exhibit these morphologic features and to a lesser degree in transposition of great arteries with ventricular septal defect and pulmonary atresia (TGA-VSD-PA) and the more complex forms of univentricular hearts. In the preliminary angiographic evaluation, it is important to delineate these morphologic features as the basis for case selection. Ductal stenting may be done by the retrograde femoral artery route or the antegrade transvenous route depending on the ductus morphology and the underlying cardiac lesion. The detailed techniques and essential hardware are described. Finally, major potential complications of the procedure are described. Acute stent thrombosis is the most serious and potentially catastrophic. Emergent treatment with thrombolytic therapy and mechanical disruption of thrombus are required. With proper case selection, appropriate technique and the right hardware ductal stenting provides reasonable short-medium term palliation in duct-dependent cyanotic heart disease.

Concomitant stenting of the patent ductus arteriosus and radiofrequency valvotomy in pulmonary atresia with intact ventricular septum and intermediate right ventricle: Early in-hospital and medium-term outcomes

OBJECTIVES Our objective was to determine the feasibility and early to medium-term outcome of stenting the patent ductus arteriosus at the time of radiofrequency valvotomy in the subgroup of patients with pulmonary atresia with intact ventricular septum and intermediate right ventricle. BACKGROUND Stenting of the patent ductus arteriosus and radiofrequency valvotomy have been proposed as the initial intervention for patients with intermediate right ventricle inasmuch as the sustainability for biventricular circulation or 1½-ventricle repair is unclear in the early period. METHODS Between January 2001 and April 2009, of 143 patients with pulmonary atresia and intact ventricular septum, 37 who had bipartite right ventricle underwent radiofrequency valvotomy and stenting of the patent ductus arteriosus as the initial procedure. The mean tricuspid valve z-score was -3.8 ± 2.2 and the mean tricuspid valve/mitral valve ratio was 0.62 ± 0.16. RESULTS Median age was 10 days (3-65 days) and median weight 3.1 kg (2.4-4.9 kg). There was no procedural mortality. Acute stent thrombosis developed in 1 patient and necessitated emergency systemic-pulmonary shunt. There were 2 early in-hospital deaths owing to low cardiac output syndrome. One late death occurred owing to right ventricular failure after the operation. Survival after the initial procedure was 94% at 6 months and 91% at 5 years. At a median follow-up of 4 years (6 months to 8 years), 17 (48%) attained biventricular circulation with or without other interventions and 9 (26%) achieved 1½-ventricle repair. The freedom from reintervention was 80%, 68%, 58%, and 40% at 1, 2, 3, and 4 years, respectively. CONCLUSIONS Concomitant stenting of the patent ductus arteriosus at the time of radiofrequency valvotomy in patients with pulmonary atresia with intact ventricular septum and intermediate right ventricle is feasible and safe with encouraging medium-term outcome.

Risk factors for augmentation of the flow of blood to the lungs in pulmonary atresia with intact ventricular septum after radiofrequency valvotomy

Some patients with pulmonary atresia with an intact ventricular septum, mild to moderate right ventricular hypoplasia, and a patent infundibulum remain duct dependent on the flow of blood through the arterial duct despite adequate relief of the obstruction within the right ventricular outflow tract. The objective of our study was to review the risk factors for stenting of the patent arterial duct, or construction of a Blalock-Taussig shunt, in the patients with pulmonary atresia and an intact ventricular septum who remain duct-dependent following radiofrequency valvotomy and dilation of the imperforate pulmonary valve. We reviewed the data from 53 patients seen between November 1995 and December 2001. Of the 47 patients who survived, 6 required stenting of the patent arterial duct, while 4 needed construction of a modified Blalock-Taussig shunt to augment the flow of blood to the lungs at a mean of 7 plus or minus 5.7 days following the initial intervention. The remaining 37 patients required no additional procedures. We compared the findings in these two groups. The mean diameter of the tricuspid valve in the patients requiring early reintervention was 8.5 plus or minus 3.7 millimetres, giving a Z-score of -1.1 plus or minus 1.47, whilst those in the group without early reintervention had values of 10.7 plus or minus 2.2 millimetres, giving a Z-score of -0.58 plus or minus 1.18 (p equal to 0.003). No statistically significant differences were found in right ventricular morphology, McGoon ratio, or residual obstruction across the right ventricular outflow tract after decompression of the right ventricle. The diameter of the tricuspid valve, therefore, appears to be the only factor predicting the need for augmentation of flow of blood to the lungs. As just over one-fifth of our survivors required such augmentation, we hypothesize that stenting of the patent arterial duct may be performed as an integral part of primary transcatheter therapy in patients with pulmonary atresia and intact ventricular septum who have moderate right ventricular hypoplasia and a small tricuspid valve.

The value of transesophageal echocardiography in transcatheter closure of atrial septal defects in the oval fossa using the Amplatzer septal occluder

BACKGROUND From January, 1997, as part of an international multicentric trial, we have been closing small-to-moderate atrial septal defects within the oval fossa using the Amplatzer Septal Occluder (ASO, AGA Medical). METHODS All patients with defects within the oval fossa deemed potentially suitable for transcatheter closure were investigated by transesophageal echocardiography with the aim of gaining extra information that might alter the decision to use the device to close the defect. Views were obtained in transverse and longitudinal planes, permitting measurements of the diameter of the defect, and its distance from the atrioventricular valves, coronary sinus, and pulmonary veins. Additionally, we sought to identify multiple defects, and to exclude sinus venosus defects. RESULTS Of 56 patients with left-to-right shunts, 41 (73.2%) were deemed suitable for closure with the Amplatzer Septal Occluder. All underwent the procedure successfully, with no complications. This includes 5 patients with multiple small defects that were sufficiently close to the main defect to be closed with a single device. Only two of these had been detected on the transthoracic study. In the remaining 15 of 56 patients, transcatheter closure was deemed unsuitable. In 9 patients, this was due to the limitation of the size of the device available during the period of study, this representing a relative contraindication. In the remaining 6 (10.7%), transcatheter closure was not performed because multiple defects were too far apart to be closed with a single device in 3 patients, two patients were noted to have a sinus venosus defect, and another was noted to have anomalous connection of the right upper pulmonary vein to the right atrium. Excluding patients contraindicated due to the size of the defect alone, transesophageal echocardiography provided extra information in one-tenth of our patients, which altered the decision regarding management. CONCLUSION Transesophageal echocardiography is indispensable in the evaluation of patients undergoing transcatheter closure of atrial septal defect.

The new Occlutech® PDA occluder: Initial human experience

To evaluate the feasibility, safety, and efficacy of the Occlutech® PDA occluder for closure of patent ductus arteriosus (PDA).