Further experience with transcatheter closure of the patent ductus arteriosus using the Amplatzer duct occluder.

OBJECTIVE: The aim of this study was to report further experience with transcatheter closure of the patent ductus arteriosus (PDA) using the Amplatzer duct occluder (ADO). BACKGROUND: The design of previously used devices is not ideal for this purpose, and their use has been associated with several drawbacks, especially in large PDAs. METHODS: Forty-three patients, aged 0.3 to 33 years (mean 6.4+/-6.7 years), with a moderate to large, type A to E PDA, underwent attempted transcatheter closure using the ADO. The device is a plug-shaped repositionable occluder made of 0.004-in. nitinol wire mesh. It is delivered through a 5F to 6F long sheath. The mean PDA diameter (at the pulmonary end) was 3.9+/-1.2 mm (range 2.2 to 8 mm). All patients had color flow echocardiographic follow-up (6 to 24 months) at 24 h, 1 and 3 months after closure, and at 6-month intervals thereafter. RESULTS: The mean ADO diameter was 6.1+/-1.4 mm (range 4 to 10 mm). Complete angiographic closure was seen in 40 of 43 patients (93%; 95% confidence interval [CI] 85.4% to 100%). The remaining three patients had a trivial angiographic shunt through the ADO. At 24 h, color flow mapping revealed no shunt in all patients. A 9F long sheath was required for repositioning of a misplaced 8-mm device into the pulmonary artery. The mean fluoroscopy time was 7.9+/-1.6 min (range 4.6 to 12 min). There were no complications. No obstruction of the descending aorta or the pulmonary artery branches was noted on Doppler follow-up studies. Neither thromboembolization nor hemolysis or device failure was encountered. CONCLUSIONS: Transcatheter closure using the ADO is an effective and safe therapy for the majority of patients with patency of the arterial duct. Further studies are required to establish long-term results in a larger patient population.

Transcatheter closure of muscular ventricular septal defects with the amplatzer ventricular septal defect occluder: initial clinical applications in children.

OBJECTIVES: The aim of this study was to close muscular ventricular septal defects (MVSDs) in children, with a new device, the Amplatzer ventricular septal defect occluder (AVSDO). BACKGROUND: The design of previously used devices for transcatheter closure of MVSDs is not ideal for this purpose and their use has been limited by several drawbacks. METHODS: Six patients, aged 3 to 10 years, with MVSDs underwent transcatheter closure using the AVSDO. The device is a modified self-centering and repositionable Amplatzer device that consists of two low profile disks made of Nitinol wire mesh with a 7-mm connecting waist. The prosthesis size (connecting waist diameter) was chosen according to the measured balloon stretched VSD diameters. A 6-F or 7-F sheath was used for the delivery of the AVSDO. Fluoroscopy and transesophageal echocardiography were utilized for optimal guidance. RESULTS: The location of the defect was midmuscular in five patients and beneath the pulmonary valve in one. The balloon stretched MVSD diameter ranged from 6 to 11 mm. Device placement was successful in all patients, and complete occlusion occurred in all six patients (95% confidence interval 54.06% to 100%). Two patients developed transient complete left bundle branch block. No other complications were observed. CONCLUSIONS: This encouraging initial clinical success indicates that the AVSDO is a promising device for transcatheter closure of MVSDs in children. Further clinical trials and longer follow-up are needed before the widespread use of this technique can be recommended.

Closure of atrial septal defects with the Amplatzer occlusion device: preliminary results.

OBJECTIVES: This study reports our clinical experience with transcatheter closure of secundum atrial septal defects (ASDs) in children, using the Amplatzer, a new occlusion device. BACKGROUND: None of the devices previously used for transcatheter closure of interatrial communications has gained wide acceptance. METHODS: We examined the efficacy and safety of the Amplatzer, a new self-centering septal occluder that consists of two round disks made of Nitinol wire mesh and linked together by a short connecting waist. Sixteen patients with secundum ASD met established two- and three-dimensional echocardiographic and cardiac catheterization criteria for transcatheter closure. The Amplatzer's size was chosen to be equal to or 1 mm less than the stretched diameter. The device was advanced transvenously into a 7F long guiding sheath and deployed under fluoroscopic and ultrasound guidance. Once its position was optimal, it was released. RESULTS: The mean ASD diameter by transesophageal echocardiography was 14.1+/-2.3 mm and was significantly smaller (p < 0.001) than the stretched diameter of the ASD (16.8+/-2.4 mm). The mean device diameter was 16.6+/-2.3 mm. No complications were observed. After deployment of the prosthesis, there was no residual shunt in 13 (81.3%) of 16 patients. In three patients there was trivial residual shunt immediately after the procedure that had disappeared in two of them at the 3-month follow-up. CONCLUSIONS: The Amplatzer is an efficient prosthesis that can be safely applied in children with secundum ASD. However, a study including a large number of patients and a longer follow-up period are required before this technique can be widely used.