Eleftherios B. Sideris

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.

Transvenous atrial septal defect occlusion in piglets with a "buttoned" double-disk device.

The feasibility and safety of transvenous closure of atrial septal defects by a new device was tested in 20 piglets, in which atrial septal defects were created by foramen ovale dilatation with angioplasty balloons. The device was small enough to be introduced in a 7F or 8F sheath, and it measured 20-25 mm. It has no hooks and consists of a foam occluder from the left atrium and a counter-occluder from the right atrium, buttoned independently. The animals were observed by angiography and color flow mapping, and they were electively killed at various intervals up to 2 months after occlusion. The device was not thrombogenic and had endothelialized by 2-3 weeks. All atrial defects were found to be completely occluded. Complications occurred only with the first three prototype devices, including counter-occluder detachment, right atrial perforation, and need for double occlusion and pulmonary artery embolization. No such complications occurred in the last 17 experiments because of modifications of the device and operator experience. These observations showed the feasibility of occlusion of moderate-size atrial septal defects in piglets by a new device introduced through a small sheath. The method appears promising for potential human application.

Transcatheter occlusion of patent ductus arteriosus with adjustable buttoned device. Initial clinical experience.

BACKGROUND Several devices are available for transcatheter occlusion of patent ductus arteriosus. Most of these devices either require complicated intracardiac maneuvering, have not been tried in humans, or need a large-sized sheath for implantation of the device. METHODS AND RESULTS During a 26-month period ending November 1992, 14 patients underwent transcatheter closure of patent ductus arteriosus with an adjustable buttoned device delivered via a 7F sheath under an institutional review board-approved custom-made device protocol. The children were 15 months to 8 years of age with weight range of 7.2 to 19 kg. The patent ductus arteriosus measured from 2 to 7.5 mm (median, 3 mm) at the narrowest diameter and was conical, short, or tubular. They were occluded with devices measuring 15 to 20 mm. The ratio of pulmonary to systemic flow decreased (P < .01) from 1.9 +/- 0.6 (mean +/- SD; range, 1.3 to 3.2) to 1.05 +/- 0.1 (1 to 1.3). Continuous murmur of patent ductus arteriosus disappeared in all except 1 patient. Small residual shunts were detected by color Doppler studies in 4 of 14 patients (29%). All patients were followed for 1 to 24 months (mean, 6 +/- 7 months). The device was intact in all patients, and no breakage of the wires was noted. No shunts were seen in 12 of 14 patients (86%), and minute residual shunts were seen in 2 children. No major complications were encountered. CONCLUSIONS It is concluded that transcatheter closure of patent ductus arteriosus with the adjustable buttoned device is feasible and effective and can be accomplished via small 7F sheaths; a 7F sheath is adequate for all ductal sizes; and the adjustable length of the loop accommodated all types of patent ductus arteriosus. Clinical trials on a larger number of patients are warranted.

Results of transvenous occlusion of secundum atrial septal defects with the fourth generation buttoned device: comparison with first, second and third generation devices☆

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.

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.

Follow-up results of transvenous occlusion of patent ductus arteriosus with the buttoned device.

OBJECTIVES The purpose of this presentation is to document results of buttoned device (BD) occlusion of patent ductus arteriosus (PDA) in a large number of patients with particular emphasis on long-term follow-up in an attempt to provide evidence for feasibility, safety and effectiveness of this method of PDA closure. BACKGROUND Immediate and short-term results of BD occlusion of PDA have been documented in a limited number of children. METHODS During a six-year period ending August 1996, transcatheter BD closure of PDA was attempted in 284 patients, ages 0.3 to 92 years (median 7) under a protocol approved by the local institutional review boards and FDA with an investigational device exemption in U.S. cases. RESULTS The PDAs measured 1 to 15 mm (median 4) at the narrowest diameter; 20 were larger than 8 mm and 10 larger than 10 mm. They were occluded with devices measuring from 15 to 35 mm delivered via 7F (N = 140) or 8F (N = 144) sheaths. Successful implantation of the device was accomplished in 278 (98%) of 284 patients. The Qp:Qs decreased from 1.8+/-0.6 (mean+/-SD) to 1.09+/-0.19 (p < 0.001). Effective occlusion defined as no (N = 167 [60%]) or trivial (N = 79 [28%]) residual shunt was achieved in 246 (88%) patients. All types of PDAs, irrespective of the shape (conical, tubular or short), size (small or large) or length (short or long) of the PDA and previously implanted Rashkind devices, could be occluded. Follow-up data, 1 to 60 months (median 24) after device implantation, were available in 234 (84%) patients. Seven (3%) patients required reintervention to treat residual shunt with (N = 2) or without (N = 5) hemolysis. Actuarial reintervention-free rates were 95% at 1 and 5 years. There was gradual reduction of actuarial residual shunts and were 40%, 28%, 21%, 14%, 11%, 10%, 6% and 0% respectively at 1 day, 1, 6, 12, 24, 36, 48 and 60 months after device implantation. Incorporation of folding plug over the button loop in 10 additional patients produced immediate and complete occlusion of PDA. CONCLUSIONS This large multiinstitutional experience confirms the feasibility, safety and effectiveness of buttoned device closure of PDAs. All types of PDAs irrespective of the shape, length and diameter can be effectively occluded. Incorporation of folding plug over the button loop produces complete PDA occlusion at the time of device implantation.

Transcatheter Patch Occlusion of the Left Atrial Appendage Using Surgical Adhesives in High-Risk Patients With Atrial Fibrillation

OBJECTIVES The efficacy of left atrial appendage (LAA) occlusion using the Transcatheter Patch (TP) (Custom Medical Devices, Athens, Greece) in conjunction with surgical adhesives was assessed. BACKGROUND The TP is a bioabsorbable device that can be adjusted for the shape and size of the LAA without the risk of perforation. It is attached by a surgical adhesive and is released in 45 min. METHODS Occlusion of the LAA was performed in 20 high-risk patients, 59 to 89 years of age, with atrial fibrillation. A 2-stage polyethylene glycol surgical adhesive was applied to the distal half of the device. Activation of the adhesive was achieved by direct injection of alkaline solution. Fluoroscopy and transesophageal echocardiography only were used for device placement in 17 patients. In 3 patients, angiography was used as well. Follow-up transesophageal echocardiography was performed upon discharge. RESULTS The procedure was successful in 17 cases. In the 3 patients in whom angiography was performed, the patch did not attach and was retrieved. In 1 case, the patch was placed beyond the mouth of the appendage, resulting in a residual opening. There was further improvement of the occlusion rate on the follow-up transesophageal echocardiography. There was 1 complication related to the procedure, namely, thrombus was released from the long sheath in the left atrium upon withdrawal and required treatment to be dissolved. No recurrent strokes were reported. CONCLUSIONS Occlusion of the LAA by the TP is feasible and effective in most patients with atrial fibrillation at high risk for embolic stroke. Angiography before placement probably affects patch adhesion and is contraindicated.

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.

Results of transvenous buttoned device occlusion of patent ductus arteriosus in adults

Examination of the immediate and follow-up results of transvenous buttoned device occlusion of patent ductus arteriosus suggests that the method is feasible, safe, and effective irrespective of the size and shape of the ductus. Although residual shunts are present, they tend to disappear during follow-up, and complete occlusion at the time of implantation may be achieved by incorporation of a folding plug over the button loop of the device.

The immediate release patch in the correction of experimental atrial septal defects

Objectives: The purpose of this study was to evaluate the safety and efficacy of the Immediate Release Patch (IRP) in the occlusion of experimental Atrial Septal Defects (ASDs). Background: The IRP consists of a polyurethane foam patch, supported by a balloon catheter which incorporates a detaching mechanism. This mechanism allows for withdrawal of the catheter from the balloon/patch complex. After release, the device is held in position using a bioabsorbable safety thread, which is sutured subcutaneously at the groin. Methods: Experimental ASDs, 10–14 mm in diameter, were created in ten piglets. The ASDs were then corrected using IRPs 12–16 mm in diameter, under fluoroscopy and echocardiography. The animals were followed for one to four months, and were then euthanized and autopsied. A RAST test, which detects the presence of IgE antibodies for latex, was performed in seven animals. Results: All procedures, except for one, resulted in full occlusion of the defects, without serious complications. No devices embolized, and in less than two months, the balloons had deflated and the area of the device had decreased significantly. The autopsies revealed complete endothelialization as well as no thrombus formation on the device or the thread. The thread was absorbed after one month. In a single case, infection was detected on the right side of the device. Latex antibodies were not detected. Conclusion: The IRP was effective and safe in the animal model of an ASD. There was evidence of bio‐absorption of the complete device over time, without adverse reaction to latex. Clinical application is justified.