The snare-assisted technique for transcatheter coil occlusion of moderate to large patent ductus arteriosus: immediate and intermediate results

Delivery systems for transcatheter therapies of congenital heart disease

INTRODUCTION

Delivery systems are crucially important for the implantation of medical devices in patients with congenital heart disease. However, very little data is available comparing the advantages and disadvantages of the various delivery systems.

AREAS COVERED

This article describes the delivery systems and methods used for delivery of atrial septal occluder devices, ventricular septal occluder devices, devices to occlude patent arterial ducts, and transcatheter pulmonary valves. Delivery systems are compared relating to prepping and loading, positioning of the delivery sheath/catheter, deployment, ability to recapture and reposition, as well as device release.

EXPERT OPINION

For most ASD/VSD/PDA occluder devices, the basic delivery mechanism has changed very little over the preceding 20 years. Future modifications may focus on meaningful modifications to the cable systems that reduce stiffness and improve angulation at the connection to the device. Over the next 5-10 years, it is expected to see significant changes to delivery systems used for transcatheter pulmonary valve implantation, that result in improvements in the ability to recapture and reposition self-expandable transcatheter valves during the deployment process, combined with kink resistant sheaths that facilitate easy tracking across often complex right ventricular outflow tracts.

Comparison of transcatheter patent ductus arteriosus closure between children and adults

The data comparing the characteristics and effect of transcatheter patent ductus arteriosus (PDA) closure between children and adults is scarce. We analyzed 54 consecutive patients who underwent transcatheter PDA closures. We divided the patients into 2 groups of < 18 years and ≥ 18 years and compared the hemodynamic changes before and after the PDA closure. Adults had a higher incidence of heart failure on admission, diagnoses by heart failure and incidental echocardiography, PDA calcifications, and procedural complications than children (all P < 0.05). The left ventricular end-diastolic volume index (LVEDVI), left atrial diameter index (LADI), and LV mass index (LVMI) decreased after the PDA closure in children but not in adults. The LV ejection fraction (LVEF) significantly decreased 1 day after the PDA closure in both groups but remained low at 6 months after the procedure in only adults. The percent change in the LVEDVI, LADI, LVMI, and LVEF from baseline to 6 months after the procedure was significantly lesser in adults than children (LVEDVI: - 5.2 ± 29.1% vs. - 34.9 ± 18.9%, LADI: - 7.0 ± 13.2% vs. - 22.1 ± 18.9%, LVMI: - 11.0 ± 16.5% vs. - 34.1 ± 15.7%, LVEF: - 5.9 ± 7.6% vs. 6.1 ± 9.1%, all P < 0.05). Transcatheter PDA closure was not associated with a reduction in the LV and LA volume as well as an improvement in the LV hypertrophy and LV function in adults as compared to children. We suggested that an early diagnosis and transcatheter PDA closure during childhood might provide clinical benefit before progressive LV remodeling and heart failure.

Long-Term Results of Transcatheter Closure of Large Patent Ductus Arteriosus with Severe Pulmonary Arterial Hypertension in Pediatric Patients

Aims:

Patent ductus arteriosus (PDA) is one of the most commonly seen congenital heart diseases prevalent today. The aim of this study is to evaluate the safety and efficacy of transcatheter closure of hypertensive ductus at long-term follow-up.

Materials and Methods:

Transcatheter closure was attempted in 52 patients with hypertensive ductus arteriosus. A lateral or right anterior oblique view aortogram was done to locate and delineate PDA. All the patients underwent clinical examination, electrocardiography, chest X-rays, and echocardiography before discharge and at 1, 6, and 12 months after the procedure and yearly thereafter.

Results:

The mean age of patients at procedure was 7.98 ± 4.79 (11 months–17 years), and the mean weight was 17.72 ± 10.81 (4–47) kg. Transcatheter closure of hypertensive ductus was successful in 50 (96.15%) patients. The mean preprocedural pulmonary artery pressure was 81.38 ± 17.31 (range: 55–113) mmHg which decreased to 29.65±8.63 (19-38) mmHg at follow up. The most commonly used device was Amplatzer duct occluder in 63% of the patients followed by Amplatzer muscular ventricular septal defect occluder in 37% of the patients. There were two procedural failures, namely aortic obstruction and left pulmonary artery stenosis, which were managed uneventfully. There were no procedural deaths or device embolization. At median follow-up of 86 months, all the patients are well with no complications.

Conclusion:

The long-term results suggested that transcatheter closure of PDA with severe pulmonary hypertension in pediatric patients is safe and effective with minimal complications.

Patent Ductus Arteriosus closure in preterms less than 2kg: Surgery versus transcatheter

BACKGROUND

As new devices come into the market, percutaneous techniques improve and interventionalists become more experienced; percutaneous closure gets more common in preterms. In this study we aimed to compare efficacy and safety of Patent Ductus Arteriosus closure surgically versus transcatheter method in preterms <2kg. Best of our knowledge this study is the first one that compares outcomes of surgery and percutaneous Patent Ductus Arteriosus closure in preterms.

METHODS & RESULTS

Between the dates July 1997 to October 2014 in our center Patent Ductus Arteriosus of 26 patients <2kg were closed percutaneously (Group A) and 31 less than 2kg operated (Group B). Weight of patients in percutaneous Patent Ductus Arteriosus closure group was significantly more than the surgery group. Mean gestational age of the patients in Group A was 30±1.8weeks, in group B was 28.6±3.5weeks. In group A; all cases were closed successfully except 4 cases: device embolization in 2, cardiac tamponade and iatrogenic aortic coarctation were seen. Pneumomediastinum and chylothorax were the major complications of the surgery group. There was no statistically significance between complication and success rates between two groups.

CONCLUSION

Percutaneous Patent Ductus Arteriosus closure is the candidate for taking the place of surgery in preterms. However, it is not applied routinely; can only be done in fully equipped large centers by experienced interventionalists.

Surgical Retrieval of Malpositioned Ductal Coil

A 3.5-year-old girl underwent transcatheter closure of a patent ductus arteriosus, which resulted in severe hemolysis. The malpositioned coil was surgically retrieved under cardiopulmonary bypass.

Transcatheter closure of patent ductus arteriosus

More than three decades have passed since the introduction of transcatheter devices for closure of patent ductus arteriosus, and many occluders have been made available since then. The ideal requirements of any procedure are a user-friendly technique, optimum success rate, no residual anomaly, minimal morbidity/mortality, and comparability or superiority to the existing conventional modality of treatment. With various advancements in device design, delivery and assisted systems, the tremendous procedural safety and effectiveness, along with low cost and widespread availability of these devices makes transcatheter closure of patent ductus arteriosus a preferred therapeutic modality in all age groups, with decreasing demographic trends of surgical management.

Transcatheter closure of moderate to large patent ductus arteriosus with the Amplatzer duct occluder

OBJECTIVES

To investigate the acute and follow-up results of transcatheter closure of moderate to large patent ductus arteriosus (PDA) with the Amplatzer duct occluder.

METHODS

Between April 2000 and June 2005, 237 patients underwent attempted transcatheter closure of PDA, of whom Amplatzer duct occluder was used in 68 patients with moderate-to-large-sized PDA (45 females, with ages ranging from 56 days to 75 years, median 3.3 years). Moderate to large PDA is defined as ductus diameter > or =2.5 mm (> or =3 mm in early phase of this study) in infants and young children, or > or =4 mm in adolescents and adults. The size of device selected was generally at least 1-2 mm larger than ductus diameter.

RESULTS

The ductus diameter ranged from 2.5 to 8.5 mm (4.1 +/- 1.3 mm). Amplatzer duct occluder was successfully deployed in 66 out of 68 patients. The size of device deployed ranged from 4 to 12 mm (6.3 +/- 1.6 mm). The causes of failure in the 2 patients included calcification of ductus resulting, in failure in advancing a sheath to descending aorta in 1 and kinking of a Cook sheath in the other. Distal embolization of the device occurred several hours later in one. After the device was retrieved percutaneously, the patient was sent to surgery. No other significant complications occurred. In the 3-month follow-up, complete occlusion was achieved in all patients. No patient had left pulmonary artery stenosis.

CONCLUSIONS

Transcatheter closure of moderate-to-large-sized ductus with Amplatzer ductus occluder is effective and safe.

Comparison of Two Foreign Body Retrieval Devices with Adjustable Loops in a Swine Model

The purpose of the study was to compare two similar foreign body retrieval devices, the Texan (TX) and the Texan LONGhorn (TX-LG), in a swine model. Both devices feature a < or = 30-mm adjustable loop. Capture times and total procedure times for retrieving foreign bodies from the infrarenal aorta, inferior vena cava, and stomach were compared. All attempts with both devices (TX, n = 15; TX-LG, n = 14) were successful. Foreign bodies in the vasculature were captured quickly using both devices (mean +/- SD, 88 +/- 106 sec for TX vs 67 +/- 42 sec for TX-LG) with no significant difference between them. The TX-LG, however, allowed significantly better capture times than the TX in the stomach (p = 0.022), Overall, capture times for the TX-LG were significantly better than for the TX (p = 0.029). There was no significant difference between the total procedure times in any anatomic region. TX-LG performed significantly better than the TX in the stomach and therefore overall. The better torque control and maneuverability of TX-LG resulted in better performance in large anatomic spaces.

Comparison of the Texan Foreign Body Retrieval Device and the Amplatz Goose Neck Snare in Vivo and in Vitro

PURPOSE

To compare the capturing ability of the Texan foreign body retrieval device with that of the Amplatz gooseneck snare in a swine model and to analyze their capturing mechanisms.

MATERIALS AND METHODS

The Texan device with a < or = 30-mm adjustable loop was compared with the 5-mm, 15-mm, and 35-mm Amplatz snares for retrieval of foreign bodies from the iliac vein, infrarenal aorta, inferior vena cava, and stomach. Capture times by two investigators were compared.

RESULTS

All 24 attempts with the Texan device were successful, as were 21 of 23 attempts with the Amplatz snare; two attempts with the 5-mm Amplatz snare were abandoned, and the failures were attributed to the suboptimal size of the snare. Other than the two abandoned attempts, there was no difference between the capturing performances of the Texan device and the 5-mm, 15-mm, and 35-mm Amplatz snares when they were compared side by side. In all vascular interventions, however, the Texan device performed significantly better in capture times than did the 5-mm and 15-mm Amplatz snare (P = .015). In all interventions, the Texan device performed significantly better in capture times than did all three sizes of the Amplatz snare (P= .012).

CONCLUSION

The overall performance of the Texan device based on its capturing ability was significantly better than that of the Amplatz snares. The adjustability of the loop and the more versatile capturing technique made capture and retrieval of foreign bodies easier.

A strategic approach to transcatheter closure of patent ductus: Gianturco coils for small-to-moderate ductus and Amplatzer duct occluder for large ductus

OBJECTIVE

To investigate the effectiveness of the strategy of transcatheter occlusion with the Gianturco coil for small-to-moderate sized ductus and with Amplatzer duct occluder (ADO) for large ductus.

PATIENT AND METHODS

For ductus closure, the following strategy was applied: ADO was used in large ductus: infants and young children weighing < 15 kg with a ductus diameter > or = 3 mm and in older children or adults with a ductus diameter > or = 4 mm and coils were employed in patients with small-to-moderate sized ductus. During a 3-year period, this strategy was applied in 136 patients. The results were compared between 214 patients (group I) undergoing ductus closure using only coil before application of this strategy and strategic closure in 136 patients (group II). Each group was divided into 2 subgroups: subgroup A with large ductus and subgroup B with small-to-moderate ductus. There were 54 patients in subgroup IA, 160 in subgroup IB, 33 in subgroup IIA and 103 in subgroup IIB, respectively.

RESULTS

In group I, PDA occlusion was successful in 207 (96.7%) and failed in 7 (6 of group IA and 1 of group IB). In group II, ductus closure was successful in 134 patients (98.5%) (32/33 with ADO and 102/103 with coils). There was no significant difference in success rate between group I and II. Distal embolization occurred in 19 patients of group I and in 2 of group II, respectively (19/214 vs. 2/136, P < 0.01). There was no significant difference in success rate between group IA and IIA but the distal embolization rate was higher in group IA than IIA (13/54 vs. 1/33, P=0.014). Left pulmonary artery stenosis was found exclusively in 9 patients of group I at the 6-month follow-up (P < 0.05). Nine patients in group I required second intervention to achieve complete occlusion.

CONCLUSIONS

The strategy of ductus closure worked well by reducing embolization rate, incidence of left pulmonary artery stenosis and the need of second intervention.

New retrievable coil anchors: preliminary in vivo experiences in swine

PURPOSE

To design and test retrievable coil anchors to improve the safety and efficacy of coil embolization.

METHODS

Fifty-two 0.038-inch homemade retrievable stainless steel coils were equipped with one of four different pre-shaped nitinol anchors and tested in 38 pigs. All coils with the anchor were completely retrieved and redeployed 3-18 times (median 7 times) prior to release. Types 1 and 2 anchored coils were acutely deployed in the external iliac arteries (n = 10 each), and chronically tested (1 week) in the common carotid arteries (n = 6 each). Larger type 1 (n = 4), type 3 (n = 6), and type 4 (n = 4) anchored coils were acutely deployed in the abdominal aorta. The largest type 1 anchors (n = 6) were acutely tested in the inferior vena cava.

RESULTS

All anchored coils were successfully retrieved and repositioned several times. All but two coils formed a compact plug and there was no coil migration except with two mechanically defective type 3 anchors.

CONCLUSION

The use of retrievable anchors allowed the coils to be retrieved and repositioned, prevented coil migration, and enabled compact coil configuration.

Comparison of percutaneous closure of large patent ductus arteriosus by multiple coils versus the Amplatzer duct occluder device

This study compared the efficacy and costs of the most used approaches for percutaneous closure of large patent ductus arteriosus, that is, multiple coils and the Amplatzer duct occluder (ADO) device. From April 2000 to September 2003, 47 patients underwent closure of large, symptomatic patent ductus arteriosus (diameter 4.6 +/- 3.0 mm/m(2); QP/QS 2.1 +/- 1.9) with multiple Cook detachable coils (n = 19) or the ADO device (n = 28). The multiple coil approach was significantly cheaper (1,389 +/- 168 vs 3,811 +/- 38, p <0.0001) but as effective as the ADO device over a mid-term follow-up (occlusion rate 89.5% vs 96.4%, p = NS).

Interventional treatment of patent ductus arteriosus in 2004

In 2004, the interventional treatment of patent ductus arteriosus (PDA) is definitive and curative. In current practice, coils are used for smaller PDA, and devices are employed for larger PDA. Developing technologies offer small improvements in control and results, but do not appear to promise major changes in practice. This review summarizes the current and emerging interventional technologies directed at PDA closures.

Bioptome-assisted coil occlusion of moderate-large patent ductus arteriosus in infants and small children

Coil occlusion of patent ductus arteriosus (PDA), although inexpensive, is technically challenging for the moderate-large ducts in small children. Bioptome assistance allows better control and precision. We describe case selection strategies, technique, immediate and short-term results of bioptome-assisted closure of moderate-large (>/= 3 mm) PDA in 86 infants and children </= 10 kg (age, 18 days to 3 years; median, 8 months; weight, 6.6 +/- 1.9 kg; duct size, 3.6 +/- 0.8 mm; pulmonary artery mean pressures, 33 +/- 12 mm Hg). Patients with PDA > 6 mm (> 4 mm for children under 5 kg) and/or shallow ampullae (by echocardiography) underwent operation (n = 41). Specific technical modifications included use of long sheaths (5.5-8 Fr) for duct delineation and coil delivery, cutting of coils turns (51 patients) to accommodate the coils in the ampulla, and simultaneous delivery of multiple coils (n = 43). As far as possible, coils were deployed entirely in the ampulla. Median fluoroscopy time was 7.3 min (1.2-42 min). Successful deployment was feasible in all (final pulmonary artery mean pressures, 20 +/- 4.6 mm Hg). Coils embolized in 14 (16%) patients (all retrieved). Complete occlusion occurred immediately in 63 patients (73%) and in 77 patients (89%) at 24 hr. Three patients had new gradients in the left pulmonary artery. Follow-up (62 patients; median duration, 13 months) revealed small residual Doppler flows in 11 patients (18%) at the most recent visit. Bioptome-assisted coil occlusion of moderate-large PDA in selected infants and small children is feasible with encouraging results.

Echocardiographic predictors of failure in patients undergoing coil occlusion of patent ductus arteriosus

In this study, we sought to determine whether the risk of failure of coil occlusion of patent ductus arteriosus (PDA) could be predicted on the basis of echocardiographic variables. The echocardiographic characteristics of patients in whom PDA coil occlusion failed were compared with those in whom the procedure was successful. A total of 5 variables were evaluated: PDA diameter (PDAd); indexed PDAd; PDA shape; left ventricular end-diastolic diameter; and the presence of flow reversal in the descending aorta. We found that 2 variables related to the size of the duct (PDAd and PDAd/body surface area), and 2 related to the magnitude of the shunt (left ventricular end-diastolic diameter and flow reversal) were positively associated with failure (P <.05). PDAd and flow reversal had the greater effect in each group and remained significant when they were put into a logistic regression model to predict failure (P =.004 and.053, respectively). In conclusion, echocardiographic variables can predict risk of failure in patients undergoing PDA coil occlusion.

Comprehensive assessment of patent ductus arteriosus by echocardiography before transcatheter closure

BACKGROUND

Anatomic type and angiographic measurements of patent ductus arteriosus (PDA) are used to determine the suitability of transcatheter closure (TCC). The purpose of this study is to evaluate whether these PDA features can be obtained by 2-dimensional echocardiography (2DE).

METHODS

We retrospectively compared PDA measurements and type from 36 patients submitted to TCC between November 1995 and October 2000.

RESULTS

The patient age ranged between 2 months to 10.5 years (median = 1.2 years). A significant correlation was found between measurements of PDA minimal diameter (R(2) = 0.88) and diameter at aortic ostium (R(2) = 0.72); whereas a poor correlation existed between measurements of the ampulla length. The 2DE and angiographic PDA classification were concordant in 31 of 36 (86%) patients.

CONCLUSION

Our data support the use of 2DE measurements of PDA minimal diameter and PDA diameter at the aortic end to assess suitability for TCC. In the majority of cases, PDA type can be diagnosed by 2DE.

[Transcatheter closure of patent ductus arteriosus using the Amplatzer duct occluder: initial results and mid-term follow-up]

INTRODUCTION AND OBJECTIVES

Transcatheter closure of patent ductus arteriosus is a well-established procedure. The aim of this study was to assess the initial and mid-term results of the treatment of PDA with the Amplatzer duct occluder.

PATIENTS AND METHODS

From October 1999 to December 2001, 30 children underwent transcatheter closure of persistent ductus arteriosus at a mean SD age of 5 4.02 years (range: 3 months to 14 years) and weight of 20.3 10.3 kg (range: 4.5-45 kg). Infants under 10 kg weight made up 46% of total patients. A lateral view aortogram was made to determine the morphology of the ductus and select the size of the device. Occlusion was achieved using the anterograde venous approach. Follow-up evaluations were made with chest X-ray and echocardiogram at 24 hours and 1, 4 and 12 months after implantation.

RESULTS

Twenty-eight patients (93.3%) immediately achieved complete occlusion, and on color Doppler examination the closure rate was 100% within 24 hours of implantation. There was no device embolization. In the follow-up, a 19-month-old patient developed a 20 mmHg gradient across the aortic arch.

CONCLUSIONS

Patent ductus arteriosus can be easily occluded with the Amplatz Duct Occluder, which is effective and particularly useful in infants and children with relatively large PDA. Further experience and long-term follow-up are still needed to assess the safety of this device in smaller children.

Transcatheter occlusion of the patent ductus arteriosus: a comparison of two devices

BACKGROUND

Transcatheter occlusion of the arterial duct is a safe and effective alternative to surgical closure. The Rashkind umbrella occluder and the Cook coil are two established devices, although the former is no longer manufactured.

AIMS

To assess any difference in outcomes between the use of the Cook detachable coil and the Rashkind double umbrella in patent ductus arteriosus (PDA) occlusion.

METHODS

A retrospective study of 77 patients in whom PDA occlusion was attempted using the Cook detachable PDA coil from March 1996 to March 2000. A comparison was carried out with patients in whom occlusion was attempted using the Rashkind double umbrella between 1989 and 1996.

RESULTS

The rate of immediate complete occlusion was 24% compared with 29.9% for the Rashkind device. The figure for complete occlusion after 24 hours with the PDA coil was 63% compared with 61.5% in the Rashkind group (p > 0.1). The overall closure rate in the coil group was 72% versus 74.6% for umbrellas.

CONCLUSION

The outcome in terms of complete duct closure using the Cook coil is comparable with figures obtained using the Rashkind umbrella. Both devices have a good safety profile in the short and medium-terms.

Transcatheter closure of patent ductus arteriosus using Gianturco coils in adolescents and adults

We present the short- and intermediate-term results of transcatheter closure of patent ductus arteriosus with Gianturco coils in adolescents and adults. During a 5-year period, 55 patients (44 females, 11 males) with ages ranging from 14 to 72 years (median, 23) underwent attempted transcatheter closure of patent ductus with the Gianturco coils. The diameter of the narrowest segment of the ductus ranged from 0.8 to 7.6 mm (3.9 +/- 1.3 mm). The 55 patients were divided into three groups. Group I consisted of nine patients with a ductal diameter < or = 3 mm, group II consisted of 27 patients with a ductal diameter > 3 mm but < or = 4 mm, and group III consisted of 19 patients with a ductal diameter > 4 mm. Four- to five-loop Gianturco coils were used, which were deployed via retrograde aortic route. Multiple-coil technique was generally applied in group II patients. Balloon occlusion technique in combination with multiple-coil technique was generally used in group III patients. Deployment of coil was successful in 51 patients (93%) but failed in 4. The success rate of coil deployment in group I, II, and III were 100% (9/9), 96% (26/27), and 84% (16/19), respectively. A mean of 1.9 +/- 0.7 coils was deployed per patient. Of the four patients with unsuccessful coil deployment, three underwent surgery and one received implantation with Amplatzer duct occluder. Distal embolization of 21 coils occurred in 10 patients (3 in group II and 7 in group III), from whom 20 coils were retrieved with a gooseneck snare and 1 coil was removed during surgery. The mean diameter of ductus in the 10 patients with distal embolization was significantly larger than that in those without (5.2 +/- 1.4 vs. 3.7 +/- 1.1 mm; P < 0.01). Among the 51 patients with successful coil deployment, immediate complete closure was achieved in 20 (39%), while trivial to mild leak was present in 31 (61%). No significant complications were encountered. After a follow-up period ranging from 5 to 42 months, four patients had a small residual shunt and three underwent a second intervention with complete occlusion. None had left pulmonary artery stenosis documented with Doppler echocardiography. Transcatheter closure of ductus with the Gianturco coils is safe and feasible in the majority of adolescents and adults. Taking high embolization rate in patients with a ductus diameter > 4 mm into consideration, controlled-release coils, Buttoned device, or Amplatzer duct occluder can be a better choice.

Transcatheter closure of persistent ductus arteriosus in infants using the Amplatzer duct occluder

AIM

To evaluate whether transcatheter closure with the Amplatzer duct occluder offers an alternative to surgical treatment in infants with a persistent ductus arteriosus.

METHODS

12 patients under 1 year of age (age 1-11 months, body weight 2.6-8.7 kg) with clinical and echocardiographic findings of a significant duct were considered for transcatheter closure with the Amplatzer occluder. The device is made of a Nitinol and polyester fabric mesh and provides occlusion by stenting the duct. Measured angiographically, the narrowest diameter of the ducts ranged from 1.5-5 mm; in six patients pulmonary hypertension was also present.

RESULTS

The devices were implanted and complete duct occlusion was demonstrated during follow up in 10 patients. Procedure related difficulties occurred in nine of the 12 cases and led to relatively long procedure and fluoroscopy times (procedure time 50-180 minutes, median 80 minutes; fluoroscopy time 4.9-49 minutes, median 16 minutes). In two infants transcatheter closure could not be achieved and surgical duct ligation had to be carried out.

CONCLUSIONS

In small infants with a persistent ductus arteriosus the Amplatzer duct occluder offers an alternative to surgical treatment, but further improvement of the implantation system is necessary before the procedure can be recommended as the treatment of choice.

Experimental evaluation of a modified Amplatzer duct occluder

The purpose of this study was to evaluate a new device specifically designed for patent ductus arteriosus (PDA) occlusion based on PDA anatomy. Percutaneous closure of aortopulmonary shunts was attempted in 10 dogs. Shunts were surgically created in the location and orientation of PDA. The occlusion prosthesis consisted of a cylindrical frame filled with polyester and a 32 degree angled retention disk. The delivery system of the device included a 6 Fr thin-walled Teflon introducing sheath, an antirotating delivery catheter, and cable. Complete occlusion of the shunt was obtained in nine animals. One animal died before device placement. Temporary hemolysis occurred in one dog after device placement. The disk of device was completely covered by smooth glistening neoendothelium at 1-3 months postmortem examination. None of the devices protruded into the lumen of the aorta. The device is an improvement over the standard Amplatzer duct occluder. The angled retention disk lies flatly against the aortic wall, avoiding turbulence or an aortic pressure gradient.

New embolization coil containing a nitinol wire core: preliminary in vitro and in vivo experiences

PURPOSE

To improve the stability of the standard stainless steel embolization coil by adding a nitinol wire core.

MATERIALS AND METHODS

With use of one coil with a nitinol wire core and one without one, stability and resistance to elongation were measured in vitro. Thirty-one factory-made stainless-steel macrocoils equipped with preshaped nitinol wire cores were acutely deployed into branches of the superior mesenteric artery (SMA) in five pigs (part I of the study). Fifteen homemade retrievable coils with thermal shape memory (TSM) nitinol wire cores were acutely deployed in the abdominal aortae or inferior venae cavae of four pigs (part II). Coils with a superelastic (SE) nitinol wire core (n = 9), a TSM nitinel wire core (n = 5), and without a core (n = 5) were compared in carotid embolization (part III).

RESULTS

In vitro, the expansile strength of the reinforced coils was significantly greater and elongation was significantly less than the standard coils (P <.01). In part I, coils were easily deployed via diagnostic catheters. In part II, ability to reposition the coils facilitated optimal coil configuration, which resulted in effective self-anchoring and occlusion. In part III, no coils with a SE core migrated, whereas one of five with a TSM core and three of five without reinforcement migrated immediately. The core significantly increased coil stability and postplacement configuration (P <.01).

CONCLUSIONS

Addition of a nitinol wire core increases the intravascular stability of the standard embolization coil by significantly enhancing expansile force and postplacement configuration. The wire core does not adversely affect the handling of the coil. The ability to reposition/retrieve the coil is a desirable feature.

Gianturco-Grifka vascular occlusion device for closure of patent ductus arteriosus

We retrospectively reviewed the results of catheter closure of patent ductus areteriosus using the Ginaturco-Grifka vascular occlusion device in our institution. All patients in whom it was attempted had successful implantation, complete closure on follow-up, and no complications.

Early experience with the Amplatzer ductal occluder for closure of the persistently patent ductus arteriosus

Using an Amplatzer duct occluder, 106 patients (weight 21 +/- 18 kg) underwent an attempt at catheter closure of a persistently patent ductus arteriosus (PDA). Their age ranged from 22 days to 48 years. The PDA measured between 1.2 to 8.1 mm at its narrowest diameter. The device was successfully implanted in 105 patients. The immediate closure rate was 70% and gradually increased to 100% at 1-month follow-up. There was no clinical evidence of hemolysis and no incidence of device embolization or bacterial arteritis. Doppler evaluation showed no evidence of aortic arch or pulmonary artery obstruction. The device, which is currently undergoing multicenter clinical trial in the United States, is proving to be a safe and effective device for closure of the persistently PDA.

Results of the phase I food and drug administration clinical trial of duct-occlud device occlusion of patent ductus arteriosus

The purpose of this study was to evaluate the safety and the efficacy of transcatheter patent ductus arteriosus (PDA) occlusion with the Duct-Occlud device. Six centers participated in this phase I U.S. Food and Drug Administration-approved clinical trial with investigational device exemption. Patients with restrictive PDA (less than 4-mm minimum diameter) were eligible for the study. Sixty-two patients were enrolled. Forty-eight patients had successful implantation of Duct-Occlud devices. Patient follow-up evaluations were conducted at hospital discharge and after 2 and 12 months. At discharge and after 1 year, all patients had clinical PDA closure. Closure assessed by color flow Doppler was 55% at discharge, 88% at 2 months, and 94% at 1 year. There were no complications related to implantation or noted in follow-up evaluations. The Duct-Occlud device is safe and efficacious for the closure of small- to moderate-size patent ductus arteriosus.

Interventional catheterization

Several investigations have been performed to evaluate the mid-term results of coil embolization for patent ductus arteriosus. Excellent results were obtained with coils if the minimum diameter of the ductus was less than 4 mm. Balloon dilation of native coarctation and recoarctation may be associated with complications such as aneurysm formation. Stent placement may solve some of the problems of balloon dilation, but the stents currently available are not perfect. Results of transcatheter closure of atrial septal defect using new devices have been were reported. The self-expanding nitinol double-disk device (Amplatzer septal occluder) (AGA Medical Corporation, Golden Valley, Minnesota) is becoming popular because it is easy to implant, is easy to retrieve before its release, can occlude a relatively large defect, and has a low rate of residual leak. Although the immediate results with this device were excellent, surgical closure is still the standard treatment and we need to see the long-term results of transcatheter closure.

Interventional pediatric cardiology: device closures

Surgical treatment of various septal defects has been long established. With the advances in transcatheter therapy dilatation techniques for valvular stenosis and vascular obstruction have become established procedures. Closure of septal defects in the catheterization laboratory has also been introduced; some of these have come into regular use in current practice. In 1967, Porstmann et al reported the use of Ivalon plug to close patent ductus arteriosus (PDA). Since then, several devices have been used including Rashkind PDA ocluder (not being used now), Gianturco coils, detachable coils (for small PDA), CardioSEAL and other umbrella devices and Amplatzer PDA occluder. Closure rates vary from 95-98% in most series, however, some of these devices are very expensive, more so, when compared to the cost of surgical ligation of PDA. Catheter closure of secundum atrial septal defect (ASD) has also been done by various devices like clamshell device, Sideris Buttoned device, ASDOS device, Amplatzer device and cardioSEAL. So far no device has been accepted as ideal for every case, however, Amplatzer device has been used most extensively. Issues such as completeness of endothelialisation, incidence of late arrhythmias, endocarditis remain uncertain. However, in select population of ASD cases with a central secundum defect, device closure is being used increasingly. Device closure of ventricular septal defect remains challenging and controversial and is probably available to a small group of children with defects that are difficult to close surgically and involve higher risk.