Catheter closure of atrial septal defect: successful use in a 3.6 kg infant

Outcomes of Device Closure of Atrial Septal Defects

Several devices have been designed and tried over the years to percutaneously close atrial septal defects (ASDs). Most of the devices were first experimented in animal models with subsequent clinical testing in human subjects. Some devices were discontinued or withdrawn from further clinical use for varied reasons and other devices received Food and Drug Administration (FDA) approval with consequent continued usage. The outcomes of both discontinued and currently used devices was presented in some detail. The results of device implantation are generally good when appropriate care and precautions are undertaken. At this time, Amplatzer Septal Occluder is most frequently utilized device for occlusion of secundum ASD around the world.

The Journey of an Indian Pediatric Cardiologist : Dr. K. C. Chaudhuri Lifetime Achievement Award/Oration at AIIMS, New Delhi, September 2017

The life journey of an Indian pediatric cardiologist, who bestowed considerable attention to the development of new knowledge and train/teach physicians around the world while providing care of patients with heart disease over a 45-y period, is reviewed. This appraisal focuses particular attention on the scientific contributions to the literature. These include spontaneous closure of physiologically advantageous ventricular septal defects, various issues related to a congenital heart defect namely, tricuspid atresia and transcatheter and, interventional pediatric cardiac procedures.

Centering-on-demand buttoned device: its role in transcatheter occlusion of atrial septal defects

Since the initial design and description of the buttoned device, it has undergone a number of design changes. Introduction of radiopacity in the knot (button) made it easier to visualize and document that buttoning has indeed occurred. Introduction of two buttons has markedly decreased the unbuttoning rate with potential for eliminating it. A centering mechanism was then incorporated into the device, which allowed closure of larger defects and use of smaller-sized devices. For some unknown reason, unbuttoning rate no longer occurs since the introduction of this device. The centering-on-demand (COD) device also appears to have increased the effective occlusion rates. At the present time, however, no long-term follow-up data are available to assess the long-term efficacy of the new device. Experience in a larger number of patients and evaluation of follow-up data are necessary to confirm the safety and efficacy observed in the small cohort reported in this review.

Intermediate-term results of Phase I Food and Drug Administration Trials of buttoned device occlusion of secundum atrial septal defects

OBJECTIVES

This study was conducted to evaluate the intermediate-term results of the multi-institutional U.S. trial of the buttoned device for transcatheter closure of atrial septal defects (ASDs).

BACKGROUND

The trial was conducted in three centers (University of Arizona, University of Michigan and University of Wisconsin) under a Food and Drug Administration (FDA)-approved clinical trial with investigational device exemption. Only short-term follow-up is known.

METHODS

All 46 patients who had successful implantation of the device were prospectively followed up. Patients were evaluated at 1, 6 and 12 months after device occlusion and yearly thereafter.

RESULTS

This cohort was followed up from 51 to 68 months (mean 60.8, median 62). Patient ages ranged from 1 to 62 years (median 4); weights ranged from 10 to 105 kg (median 18); and stretched ASD sizes were 14 +/- 4 mm (left to right shunts) and 10 +/- 3 mm (right to left shunts). Of the 46 patients, 45 (98%) had effective occlusion of their ASD, and 34 (74%) had complete ASD closure. The incidence of residual shunts decreased from 65% (30 of 46 patients) at 1 month after device placement to 27% (12 of 45 patients) at last follow-up. All residual shunts were quantitated as trivial. Only two patients (4%) required reintervention for significant residual defects. There were no cases of endocarditis or thromboembolism in 224 patient-years of follow-up.

CONCLUSIONS

In up to 5.5 years of follow-up, the buttoned device provided effective closure in 98% of patients in whom the device was successfully implanted. The incidence of residual shunts decreased during follow-up, and no instances of endocarditis or thromboembolism were observed.

Echocardiographic predictors of success of catheter closure of atrial septal defect with the buttoned device

Transcatheter occlusion of ostium secundum atrial septal defects (ASD) with the buttoned device has been shown to be feasible, effective, and safe. The final decision to implant the device is largely based on the balloon sizing of the ASD during cardiac catheterization. Only subjective criteria of ASD size and the septal rims on echocardiography have been used before catheterization, balloon sizing, and transcatheter occlusion. The purpose of this study was to determine whether objective echo criteria could be developed to predict successful occlusion of the ASD. During a 46-month period ending August 1992, 29 children with secundum ASD were evaluated for transcatheter occlusion. The device was successfully implanted in 15 (group A); in the remaining 14 children, this procedure could not be performed (group B). Preocclusion echos were analyzed by independent investigators who had no knowledge of outcome of the procedure. Echo parameters studied included size of ASD, length of atrial septum (LAS), and size of the superior and inferior rims in precordial and subcostal views and maximum jet width by color flow mapping. From these measurements several ratios were derived, and the data were compared. A smaller (p < 0.05) ASD was present in the group of patients with successful implantation of the device; LAS was similar (p > 0.1) in both groups. A lower (p < 0.05) ratio of ASD to LAS and a higher (p < 0.05) ratio of the superior and inferior septal rims to ASD were associated with the group of patients with successful implantation of the device.(ABSTRACT TRUNCATED AT 250 WORDS)

International experience with secundum atrial septal defect occlusion by the buttoned device

Several devices are available for transcatheter occlusion of atrial septal defect. This report describes the international experience with the buttoned device. During a 4.5-year period ending in February 1993, 180 transcatheter atrial septal defect occlusions were performed with the buttoned device. Patient age varied between 0.6 and 76 years and stretched atrial defect diameter between 5 and 25 mm. The defects were closed with 25 to 50 mm devices delivered through 8F (148 patients) or 9F (32 patients) sheaths. Twelve patients were adults whose defects were closed to prevent recurrence of cerebrovascular accidents caused by presumed paradoxic embolism. In the remaining patients the atrial defect was closed to treat the left-to-right shunt. The atrial septal defects were effectively occluded as demonstrated by (1) decrease in pulmonary-to-systemic flow ratio from 2.1 +/- 0.6 (mean +/- SD) to 1.05 +/- 0.1 (p < 0.01) by oximetry; (2) normalized S2 and disappearance of the diastolic murmur by auscultation; and (3) improvement in right ventricular volume overloading by echocardiogram. However, trivial to small shunts could be detected by color Doppler studies in 76 (45%) of 168 patients in whom such data are available. Complications included unbuttoning in 13 and whole-device embolization in 1. All patients remained stable, and retrieval of the device and surgical closure of the atrial septal defect were accomplished in 10 patients. Transcatheter retrieval was used in the remaining 4 patients. The incidence of unbuttoning, a major complication of the procedure, appeared to decrease with the increasing experience of the investigators and with device modification (third-generation). The follow-up duration varied between 1 month and 4 years. Six patients required surgery during the follow-up period. In the remaining patients (n = 160), clinical examination did not reveal signs of atrial shunts. Color Doppler studies revealed either complete disappearance of the previously demonstrated shunts or further diminution of their size. The results indicate that transcatheter occlusion of the atrial septal defects with buttoned devices is feasible, relatively safe, and effective, and it appears to be a viable alternative to surgery for some patients with secundum atrial septal defect. Complications are infrequent and should improve with experience.

Atrial septal defect occlusion with the buttoned device (a multi-institutional U.S. trial)

A clinical trial was conducted of the buttoned device for transcatheter closure of ostium secundum atrial septal defect. Occlusion was attempted in 57 patients aged 1 to 62 years (median 5). The procedure was abandoned in 7 patients after 1 or more unsuccessful attempts, and devices were released in 50 patients. Urgent surgical retrieval was necessary in 4 patients because of unstable device position: 3 devices "unbuttoned," with migration of the counteroccluder to the pulmonary artery or inferior vena cava, and 1 intact device embolized to the main pulmonary artery. All patients remained stable and underwent successful operation. Successful device implantation was therefore achieved in 46 patients, with immediate reduction in Qp/Qs from 1.8 +/- 0.6 to 1.1 +/- 0.2 (mean +/- SD, p < 0.0001). At most recent follow-up (1 to 20 months), 45 of 46 patients (98%) have no shunt or a trivial residual shunt. The prevalence of residual shunts declined from 65% at 1 month to 19% at 12 months after the occlusion procedure (p < 0.0001). Complications included unbuttoning of a fourth device, transient tricuspid regurgitation in 2 patients, and transient mitral regurgitation in 2 patients. An episode of asymptomatic atrial flutter was noted in a 46-year-old patient which may have been related to device implantation, but which has not recurred. There have been no cases of endocarditis or thromboembolism in 350 patient-months of follow-up. The buttoned device provided effective closure of the atrial septal defect in 45 of 57 patients (79%) in whom implantation was attempted and in 45 of 46 patients (98%) in whom device implantation was successfully accomplished.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental atrial septal defect closure with a new, transcatheter, self-centering device

BACKGROUND

Despite two decades of research, a transcatheter atrial septal defect closure device is not available for clinical use. We have designed a new superelastic Nitinol-Dacron, double-disk, self-centering, atrial septal defect closure device and studied its efficacy in a canine model of atrial septal defects.

METHODS AND RESULTS

Atrial septal defects were created surgically in 20 adult dogs using either a 7.5-mm or 10-mm punch. Percutaneous transcatheter closures were attempted using a new device. The device sizes used were 20 mm in 6 dogs, 22 mm in 9, and 25 mm in 5 (22.1 +/- 1.9 mm, mean +/- SD). The stretched atrial septal defect diameter was 10.5 +/- 1.3 mm, and the device to stretched atrial septal defect diameter ratio was 2.1 +/- 0.3. Closures were successful in 19 studies and unsuccessful in 1. Angiography showed a left-to-right shunt in all 20 dogs before closure. Immediately after closure (n = 19), there were no shunts in 17 and trivial shunts in 2. Six dogs were followed for a period of 4.7 +/- 3.0 months (range, 2 to 8 months). The trivial shunt present in 1 animal immediately after closure had closed by the time of the repeat study. Spontaneous embolization of the device was not seen during follow-up. A solitary wire fracture was found 8 months after closure in 1 device. Light microscopy at 8 weeks in 3 dogs showed the devices to be covered by smooth endocardium, enmeshed in mature collagen tissue, with a minimal mononuclear cell infiltration. Retrievability was assessed by deliberately embolizing 4 devices in 2 dogs into the right atrium (n = 1) and pulmonary artery (n = 3). All devices were successfully retrieved with a snare.

CONCLUSIONS

This feasibility study demonstrates that this new self-centering atrial septal defect closure device has a number of design features that permit effective and safe closures in a canine model. These results support the investigation of this device in human clinical trials.

Echocardiographic estimation of balloon-stretched diameter of secundum atrial septal defect for transcatheter occlusion

Stretched diameter of the atrial septal defect (ASD), determined by balloon sizing at cardiac catheterization, is commonly used to select the sizes of the devices used for transcatheter closure of the secundum ASD. We have previously evaluated the utility of pulmonary/systemic flow ratio and angiographic and echocardiographic (echo) sizes of the ASD in estimating stretched ASD diameter in a group of 16 patients and determined that echo diameter had the best correlation with stretched diameter (r = 0.82; p less than 0.001). The stretched diameter can be estimated: 1.05 x echo diameter in millimeters + 5.49. In this study we have prospectively evaluated this formula in estimating the stretched ASD diameter by two-dimensional echo measurements obtained in two (long and short-axis) subcostal views in another group of 21 patients aged 2.5 to 29 years (median 4.5 years). The echo size of the ASD was 9.7 +/- 3.0 mm, whereas the measured stretched diameter was 15.3 +/- 4.0 mm. The predicted stretched ASD diameter was calculated according to the above formula and was 15.7 +/- 3.1 mm, not significantly different (p greater than 0.1) from the measured stretched diameter. The correlation between predicted and measured stretched ASD sizes was excellent (r = 0.9; p less than 0.001). The mean squared error was 2.4. The differences between measured and predicted values were within 2 mm in all but three patients. It is concluded that stretched ASD diameter can be estimated accurately by two-dimensional subcostal echo measurements, which in turn could be used for selection of device size for occlusion of the ASD.

Transcatheter closure of atrial septal defect by "buttoned" devices

During a 21-month period ending in August 1991, 12 patients underwent transcatheter closure of atrial septal defect (ASD) with a "buttoned" device through an 8Fr sheath, using an institutional review board-approved, custom-made device protocol initially, and Food and Drug Administration-approved clinical trials subsequently. Ten children had left-to-right shunts across the ASD and 2 adults had their patent foramen ovale closed to prevent recurrent paradoxical embolism (including cerebrovascular accidents). The device dislodged in 1 of the 4 patients in whom a first-generation device was used, and retrieval of the device, and surgical closure of the ASD were performed without incident. In the remaining 11 patients (age range 7 months to 45 years, weight 3.6 to 64 kg), the device remained intact, and pulmonary-to-systemic flow ratio decreased from 2.1 +/- 0.3 to 1.04 +/- 0.06. Follow-up chest x-ray and echo-Doppler studies were available in all patients 0.5 to 18 months after the procedure. The device was intact in all patients. Small residual shunt detected by color Doppler was seen in 2 children. Right ventricular size decreased (23 +/- 6 to 17 +/- 3 mm; p less than 0.01), and paradoxical septal motion disappeared in all patients. There was no recurrence of paradoxical embolism in the 2 adults. No complications occurred during follow-up. It is concluded that transcatheter closure of ASD with the buttoned device is feasible, effective and safe, and can be accomplished with small, 8Fr sheaths (even in infants weighing 3.6 kg), follow-up results are excellent, and clinical trials on a larger number of patients are needed.

Corrective surgery for tricuspid atresia: which modification of Fontan-Kreutzer procedure should be used? A review

Various modifications of Fontan-Kreutzer procedure have evolved over the years. The available literature was reviewed in an attempt to evaluate whether one of these operations is preferable to others. Although there is no complete agreement, direct atriopulmonary anastomosis in the absence of a subpulmonary ventricular chamber, and atrioventricular connection via a homograft conduit in patients with a good-sized (greater than 30% of normal), well-formed (with both trabecular and outlet portions) right ventricle appear to be reasonable choices. In patients with more than the usual risk or at low risk for the Fontan-Kreutzer procedure, other alternatives (namely, total cavopulmonary connection for patients with asplenia/polysplenia syndrome and systemic venous anomalies and bidirectional cavopulmonary anastomosis or Fontan-Kreutzer with a small temporary atrial septal defect) could be considered. The role of experimental skeletal muscle augmentation or replacement of right heart chambers and cardiac transplantation in the corrective treatment of tricuspid atresia needs to be defined as more data become available.

Relationship of echocardiographic, shunt flow, and angiographic size to the stretched diameter of the atrial septal defect

Stretched diameter of the atrial septal defect (ASD), measured by balloon sizing, is generally used as a guide to the selection of the size of the device utilized for transcatheter closure of the ASD. Balloon sizing is a cumbersome procedure and sometimes requires the use of very large size balloon catheters. Several methods of assessment of ASD size, namely, echographic, pulmonary-to-systemic flow ratio (Qp:Qs), and angiographic measures, were undertaken in a group of 16 patients, aged 7 months to 45 years (median, 4.5 years), who were being evaluated for transcatheter closure of ASD; the results were compared with the stretched diameter. Although the echographic size of the ASD (9.9 +/- 4.1 mm, mean +/- SD) is similar (p greater than 0.1) to the angiographic size (7.9 +/- 2.5 mm), it is much smaller (p less than 0.01) than the stretched diameter (16.1 +/- 5.3 mm). When the relationship between various measures of ASD was examined, although the Qp:Qs ratio and angiographic size have a significant (p less than 0.05) correlation with the stretched diameter (r = 0.55 and 0.54, respectively), the echo diameter has the best correlation coefficient, r = 0.82, p less than 0.001. The stretched diameter can be estimated by the equation: 1.05 x echo + 5.49 mm. It is concluded that the echographic diameter is a useful adjunct in the estimation of the stretch ASD diameter, which in turn can be used in the selection of the size of the device for transcatheter occlusion of the ASD.

Transcatheter closure of patent ductus arteriosus with buttoned device: first successful clinical application in a child

Several devices are available for transcatheter closure of PDA. Most of the available devices either require complicated intracardiac maneuvering or need a large-sized sheath for implantation of the device. A recently described "buttoned" device developed by Sideris et al. that can be delivered across the ductus via a 7F sheath had undergone successful trials in animal models. Because of the ease of device implantation and the requirement for a smaller-sized sheath for delivery than that used with other devices, we have used this custom-made double-disc device in a 5-year-old child and have shown successful closure of the ductus by angiography and by color Doppler studies. Further clinical trials with this device seem warranted.