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

Transcatheter Device Therapy and the Integration of Advanced Imaging in Congenital Heart Disease

Transcatheter device intervention is now offered as first line therapy for many congenital heart defects (CHD) which were traditionally treated with cardiac surgery. While off-label use of devices is common and appropriate, a growing number of devices are now specifically designed and approved for use in CHD. Advanced imaging is now an integral part of interventional procedures including pre-procedure planning, intra-procedural guidance, and post-procedure monitoring. There is robust societal and industrial support for research and development of CHD-specific devices, and the regulatory framework at the national and international level is patient friendly. It is against this backdrop that we review transcatheter implantable devices for CHD, the role and integration of advanced imaging, and explore the current regulatory framework for device approval.

Left ventricular size and function after percutaneous closure of patent ductus arteriosus in Chinese adults

BACKGROUND

Left ventricular (LV) systolic dysfunction can occur after patent ductus arteriosus (PDA) closure and data in adult Chinese patients are lacking.

METHODS

We examined adult Chinese patients who underwent successful transcatheter PDA closure at Zhongshan Hospital. Echocardiographic studies were performed before closure, before discharge, and at 1, 3, 6, and 12 months after closure. A total of 430 patients were included between January 2010 and December 2016. Patients were divided into two groups based on LV end-diastolic diameter (LVEDD): Dilated LV Group: >56 mm (n = 191) and Non-dilated LV Group: ≤56 mm (n = 239).

RESULTS

LVEDD and LV ejection fraction (LVEF) were significantly decreased immediately after closure. Reductions in LVEDD (-10.5% ± 7.1% vs. -4.6% ± 7.0%, P < 0.001) and LVEF (-8.9% ± 12.6% vs. -2.1% ± 8.6%, P < 0.001) were greater in the Dilated LV Group. LV end-systolic diameter (LVESD) remained unchanged compared to levels before closure (-4.0% ± 5.4%, P = 0.257; -2.6% ± 5.4%, P = 0.201). 48 patients in the Dilated LV Group (25.1%) and 7 patients in the Non-dilated LV Group (2.9%) developed late LV systolic dysfunction. In multivariable analysis, LVEF ≥60%, LVEDD <63 mm, and mean pulmonary arterial pressure (mPAP) <29 mmHg were predictive of normal LV function after closure.

CONCLUSION

Many adult Chinese patients developed early LV dysfunction after PDA closure and some patients developed late LV dysfunction. LVEF, LVEDD, and mPAP were identified as significant predictors of late LV systolic function.

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.

Patent ductus arteriosus closure using Occlutech® Duct Occluder, experience in Port Elizabeth, South Africa

Background:

Percutaneous closure of patent ductus arteriosus (PDA) has become standard therapy. Experience with the Occlutech® Duct Occluder is limited.

Methods:

Data regarding ductal closure using Occlutech® Duct Occluder were reviewed and prospectively collected. Demographics, hemodynamic and angiographic characteristics, complications, and outcomes were documented.

Results:

From March 2013 to June 2016, 65 patients (43 females and 22 males) underwent percutaneous closure of the PDA using Occlutech® Duct Occluder. The median age of the patients was 11 months (range, 1–454 months) and the median weight was 8.5 kg (range 2.5–78 kg). The mean pulmonary artery median pressure was 27 mmHg (range, 12–100 mmHg) and the QP: Qs ratio median was 1.8 (range, 1–7.5), with a pulmonary vascular resistance mean of 2.7 WU (standard deviation [SD] ±2.1). Thirty-two patients had Krichenko Type A duct (49%); 7, Type C (11%); 4, Type D (6%); and 22, Type E (34%). The ductal size (narrowest diameter at the pulmonic end) mean was 3.5 mm (SD ± 1.9 mm). The screening time mean was 17.3 min (SD ± 11.6). Out of 63 patients with successful closure of the PDA using Occlutech® Duct Occluder, there were 15 patients with small PDAs; 25 with moderate PDAs, and 23 with large PDAs. In one patient, the device dislodged to the descending aorta, and in two patients, to the right pulmonary artery immediately following deployment, with successful percutaneous (two) and surgical (one) retrieval. Complete ductal occlusion was achieved in all 63 patients on day one.

Conclusion:

The Occlutech® Duct Occluder is a safe and effective device for closure of ducts in appropriately selected patients.

Left Ventricular Dysfunction after Closure of Large Patent Ductus Arteriosus

Changes in left ventricular dimensions and performance were studied in 43 patients after transcatheter occlusion or surgical ligation of patent ductus arteriosus. The patients were assigned to 2 groups based on their ductal diameter: ≥ 3.1 mm to group A ( n = 27) and ≤ 3 mm to group B ( n = 16). The mean age and weight of the groups were comparable. Before intervention, group A had a significantly larger mean left ventricular end-diastolic diameter than group B, while all patients had normal shortening fraction and ejection fraction. Within 1 month after intervention, left ventricular end-diastolic diameter showed a trend towards regression while shortening fraction and ejection fraction decreased significantly in group A. There were no significant changes in these parameters in group B. Between 1 and 6 months after intervention, left ventricular performance improved in most of the group A patients who were followed up. We conclude that closure of large ductus arteriosus in children leads to significant immediate deterioration of left ventricular performance, which appears to recover within a few months. Echocardiographic study before hospital discharge is recommended in these patients. Serious deterioration of ventricular performance after closure may warrant the use of angiotensin converting enzyme inhibitors.

Percutaneous Occlusion of Patent Ductus Arteriosus with Controlled-Release Coil

We evaluated the efficacy of the controlled-release Cook coil for percutaneous patent ductus arteriosus occlusion. Between October 1994 and December 1997, 45 consecutive patients with patent ductus arteriosus underwent cardiac catheterization and coil occlusion was attempted in 41, of whom 37 had Cook coils. A single coil was deployed in 34 of these patients and 2 or more coils were deployed in 3, with successful occlusion in 36 (97%). Immediate complete angiographic closure was achieved in 15 (41%), 18 (49%) had a trivial residual shunt, and 3 had a mild residual shunt on post-occlusion aortograms. Color Doppler echocardiography 24 hours after the procedure, revealed no detectable shunt in 33/36 (92%) and only a trivial residual shunt in 3 (8%) patients. Thus, 86% of patients with residual shunts immediately after occlusion had no evidence of residual shunts by 24 hours. No evidence of residual shunt or obstruction of the left pulmonary artery or the descending aorta was present at a mean follow-up of 26 months We concluded that Cook coils are a safe and cost-effective modality for percutaneous occlusion of patent ductus arteriosus with a high success rate and favorable intermediate-term follow-up.

A Retrospective Study of 1,526 Cases of Transcatheter Occlusion of Patent Ductus Arteriosus

Background:

Patent ductus arteriosus (PDA) is one of the most common congenital heart diseases and began to get treated by transcatheter occlusion since 1997 in China. Since then, several devices have been invented for occluding PDA. This study aimed to evaluate the technical feasibility, safety, and efficacy of transcatheter occlusion of PDA with different devices.

Methods:

One thousand five hundred and twenty-six patients (537 boys, 989 girls) with PDA from January 1997 to September 2014 underwent descending aortogram and transcatheter occlusion procedure. We retrospectively analyzed data of these patients, including gender, age, weight, size and morphology of PDA, and devices used in transcatheter occlusion, outcomes, and postoperational complications.

Results:

Median age and median weight were 4.0 years (range: 0.3–52.0 years old) and 15.3 kg (range: 4.5–91.0 kg), respectively. Mean ductal diameter, aortic ductal diameter, ductal length, and pulmonary artery pressure were 3.50 ± 2.15 mm, 10.08 ± 2.46 mm, 7.49 ± 3.02 mm, and 30.21 ± 17.28 mmHg, respectively. Morphology of PDA assessed by descending aortogram was of type A in 1428 patients, type B in 6 patients, type C in 79 patients, type D in 4 patients, and type E in 9 patients according to the classification of Krichenko. Of all the 1526 patients, 1497 patients underwent transcatheter PDA closure, among which 1492 were successful. Devices used were Amplatzer duct occluder I (ADO I, 1280, 85.8%), Cook detachable coils (116, 7.8%), ADO II (ADO II, 68, 4.6%), muscular VSD occluder (12, 0.8%), and Amplatzer vascular plug (16, 1.0%).

Conclusions:

Excellent occlusion rates with low complication rates were achieved with all devices regardless of PDA types. With transcatheter occlusion technique and devices developing, more patients with PDA can be treated with transcatheter closure both safely and efficiently.

Biomaterials and design in occlusion devices for cardiac defects: a review

This review examines the biomaterials used in occlusion devices for cardiac defects, and how the choice of these materials is dictated by design. Specifically, the devices used in three major applications, the atrial septal defect, the ventricular septal defect and the patent ductus arteriosus, are examined critically. A number of different devices are available, with varied performance in deployment and sealing. There is no device in any of the three categories that satisfies fully the range of requirements, and all have associated complications. The type and rate of complications are different among different devices. The short-term (immediate) complications are addressed by immediate retrieval. For longer-term complications, most of which can be fatal, currently only surgical retrieval and replacement are possible. Most of these longer-term complications can be alleviated by the use of fully degradable devices, which will eliminate concerns regarding the use of metals inside the heart, and if fully endothelialized, also minimize migration concerns. On the other hand, the lower moduli of currently available biodegradable materials need to be augmented. Improvements in the stiffness required for deployment can be accomplished with the use of fillers, nano- or micro-sized, and an example of this are radiopaque fillers.

Transcatheter closure of patent ductus arteriosus: past, present and future

This review aims to describe the past history, present techniques and future directions in transcatheter treatment of patent ductus arteriosus (PDA). Transcatheter PDA closure is the standard of care in most cases and PDA closure is indicated in any patient with signs of left ventricular volume overload due to a ductus. In cases of left-to-right PDA with severe pulmonary arterial hypertension, closure may be performed under specific conditions. The management of clinically silent or very tiny PDAs remains highly controversial. Techniques have evolved and the transcatheter approach to PDA closure is now feasible and safe with current devices. Coils and the Amplatzer Duct Occluder are used most frequently for PDA closure worldwide, with a high occlusion rate and few complications. Transcatheter PDA closure in preterm or low-bodyweight infants remains a highly challenging procedure and further device and catheter design development is indicated before transcatheter closure is the treatment of choice in this delicate patient population. The evolution of transcatheter PDA closure from just 40 years ago with 18F sheaths to device delivery via a 3F sheath is remarkable and it is anticipated that further improvements will result in better safety and efficacy of transcatheter PDA closure techniques.

Transcatheter device closure of patent ductus arteriosus without arterial access--single institution experience

OBJECTIVE

Retrospective analysis of feasibility, safety and advantages of device closure of patent ductus arteriosus (PDA) using only venous access.

BACKGROUND

Arterial access for transcatheter device closure of PDA has been a standard practice, but has inherent complications, especially in infants.

METHOD

Records of patients who underwent PDA device closure from 2004 to 2012 were reviewed. Echocardiography was used for patient selection and for assessment of procedural outcome.

RESULT

151 out of 179 patients underwent PDA device closure with venous access alone, weighing 2.2-58 kg with half <10 kg and follow up of 6 months-8 years. Fluoroscopic time ranged from 2.2 to 16 min. Immediate closure was achieved in 146 patients. Two patients had new-onset left pulmonary artery turbulence and one had residual flow.

CONCLUSION

PDA device closure without arterial access can be accomplished safely and effectively in vast majority of patients including infants.

Ductal closure using the Amplatzer duct occluder type two: experience in Port Elizabeth hospital complex, South Africa: cardiovascular topic

OBJECTIVE

To report outcomes in percutaneous ductal closure using the Amplatzer duct occluder type two (ADO II).

METHODS

Records of patients admitted for percutaneous closure of patent ductus arteriosus (PDA) were reviewed.

RESULTS

From May 2009 to July 2012, 36 patients were assigned to closure using the ADO II. There were 21 females and 15 males. The median age was 16.5 (2-233) months; median weight, 8 (3.94-39.2) kg; and median height, 75 (55-166) cm. The mean pulmonary artery pressure was 24.4 (± 10.4) mmHg, the pulmonary blood flow:systemic blood flow (Qp:Qs) ratio was 2.25 (± 1.97), and mean pulmonary resistance (Rp) was 1.87 (± 1.28) Wood units. The mean ductal size was 2.74 (± 1.3) mm. In 30 patients the device was delivered through the pulmonary artery. Thirty-three patients achieved complete closure by discharge (day one).

CONCLUSION

The ADO II is capable of closing a wide range of ducts in carefully selected patients. Our findings are comparable with other studies regarding ductal closure rates.

Comparison of the efficacy of different-sized Amplatzer duct occluders (I, II, and II AS) in children weighing less than 10 kg

The transcatheter closure of patent ductus arteriosus (PDA) may cause more complications in small children. Amplatzer (St. Jude Medical, Plymouth, MN) has produces three types of devices for ductal occlusion: the Amplatzer duct occluder I (ADO I) and II (ADO II) and the recently introduced ADO II additional sizes (ADO II AS). We performed this study to determine the efficacy and complication rates in children who weigh <10 kg for the three types of devices used in our clinic. Between February 2007 and March 2012, 77 patients weighing <10 kg had their PDAs occluded with ADOs. The mean age of the patients was 0.76 ± 0.44 years (range 17 days-2 years), and their mean weight was 6.73 ± 2.05 (range 1.2-9.9) kg. In total, 54 girls (70.1 %) and 23 boys (29.9 %) with a mean pulmonary ductus diameter of 2.55 ± 1.0 (1.08-5.94) mm were included in the study. The ADO I was used in 26 patients (33.8 %); the ADO II was used in 43 patients (55.8 %); and the ADO II AS was used in 8 patients (10.4 %). The mean ages of patients with the ADO I, ADO II, and ADO II AS were 1.07 ± 0.48, 0.66 ± 0.31, and 0.28 ± 0.17 years (p < 0.05), respectively. Their mean weights were 7.86 ± 1.45, 6.50 ± 1.85, and 4.36 ± 2.49 kg (p < 0.05), respectively. Their mean narrowest ductal diameters were 3.11 ± 0.96, 2.25 ± 1.06, and 2.33 ± 1.01 mm (p < 0.05), respectively. The use of the ADO II and ADO II AS was found to be more common in type C defects. One patient with the ADO I and 5 patients with the ADO II (7.8 %) developed varying degrees of left pulmonary artery stenosis or iatrogenic aortic coarctation. In 1 patient, the ADO II AS was replaced with the ADO II due to a significant residual shunt observed during the procedure. Each of the ADOs has its own advantages and disadvantages. Although the ADO I is convenient for medium- and large-sized defects, the ADO II and ADO II AS can be used both anterogradely and retrogradely. The ADO II AS is safe and efficient to use in small infants.

Transcatheter closure of patent ductus arteriosus using ado device: retrospective study of 149 patients

Background:

Patent ductus arteriosus (PDA) is a common form of congenital heart disease and forms about 5-10% of congenital heart diseases. Surgical closure is safe and effective; however, certain patients may experience some morbidity. Recently, transcatheter closure of PDA using the Amplatzer duct occluder has been shown to be safe and efficacious.

Objectives:

To evaluate whether transcatheter closure with this device offers an alternative to surgical closure of PDA.

Patients and Methods:

Between July 2006 to July 2008, 149 patients (98 females and 51 males) with PDA underwent cardiac catheterization in an attempt to close their PDA by transcatheter approach using Amplatzer duct occluder device.

Results:

The patient's age ranged from 4 months to 45 years (median 5 years). Successful PDA closure was achieved in 136 patients (91.2%) with 100% complete closure rate within 24 hours after the procedure. Thirteen patients (8.7%) had unsuccessful attempts, 11 (7.3%) of them had failure of deployment of the device, while embolization of the device occurred in two of the patients (1.3%).

Conclusions:

Amplatzer duct occluder device is safe and effective for closure of different types and sizes of PDA with low rate of complication.

The results of transcatheter occlusion of patent ductus arteriosus: success rate and complications over 12 years in a single center

Background and Objectives

Percutaneous occlusion of patent ductus arteriosus (PDA) has become increasingly attractive with the evolution of devices and techniques. We reviewed results for percutaneous occlusion of PDA using various devices in a single center.

Subjects and Methods

A retrospective review was done for 118 consecutive procedures performed in 111 patients with PDA between January 1996 and December 2007.

Results

The median age of the patients was 4.5 years (0.9 to 60.3 years); body weight was 16.9 kg (6.8 to 74.7 kg). The median PDA diameter at the pulmonic end was 3.8 mm (0.7 to 10 mm); mean pulmonary artery pressure was 21.0 mmHg (7 to 60 mmHg). Complete occlusion occurred in 76/111 (68.4%) immediately after implantation and in 100/111 (90.0%) at one year of follow-up. Second procedures for residual shunts were done in 7 patients. After the year 2001, the complete closure rate was 95.2% compared to 71.4% before 2001. Complications associated with the procedure were left pulmonary artery narrowing (all <20 mmHg) in 14, arrhythmia in 2, and death in 1.

Conclusion

Evolution of devices, cumulative experience, and health insurance covering the cost of devices have contributed to good outcomes in our center for percutaneous occlusion of PDA. Our results have improved over the years, particularly with the use of the Amplatzer duct occluder.

Complications after transcatheter closure of patent ductus arteriosus

To evaluate the short- and mid-term results and complications ensuing the transcatheter closure of patent ductus arteriosus (PDA). Between October 1999 and December 2005, 117 patients (34 males and 83 females) underwent attempted percutaneous closure of PDA with a minimum diameter of more than 3 mm. Follow-up evaluations were conducted at 1 day and 1, 3, 6, 12 months after the performance of the transcatheter closure. The median age of patients at catheterization was 11 yr (range, 0.6 to 68 yr), median weight was 30 kg (range, 6 to 74 kg), and the median diameter of PDA was 4 mm (range, 3 to 8 mm). This procedure was conducted successfully in 114 patients (97.4%), using different devices. Major complications were detected in 4 patients (3.4%); significant hemolysis (2), infective endocarditis (1), failed procedure due to embolization (1). Minor complications occurred in 6 patients (5.1%); mild narrowing of the descending aorta (2) and mild encroachment on the origin of the left pulmonary artery (4). Although the transcatheter closure of PDA may be considered to be effective, several complications, including hemolysis, embolization, infective endocarditis, and the narrowing of adjacent vessels may occur in certain cases.

Transcatheter closure of a large patent ductus arteriosus in a young child using the Amplatzer duct occluder

The Amplatzer duct occluder (ADO) provides a safe and effective therapy for patients with moderate- to large-sized patent ductus arteriosus (PDA), but there have been few reports of transcatheter closure of very large PDAs in young children and infants. We report a successful transcatheter closure of a very large PDA, 10.5 mm in diameter at the narrowest point, with a 14/12-mm ADO. To our knowledge, this is the largest PDA ever closed by an interventional method in such a young child.

Transcatheter closure of persistent ductus arteriosus with the Amplatzer duct occluder in very young symptomatic children

OBJECTIVES

To analyse safety, efficacy, and follow up results of percutaneous closure of persistent ductus arteriosus (PDA) in very young symptomatic children.

PATIENTS AND DESIGN

Between March 2000 and March 2003, of 197 patients treated at the authors' institution 18 were symptomatic children aged < or = 3 years old. Seven of these children were < or = 1 year old. Indications for closure were failure to thrive (12 patients) and frequent respiratory infections (six patients). The procedure was carried out under heavy sedation with fluoroscopic control. The Amplatzer duct occluder device was used. Basal physical examinations and echocardiograms were performed before the procedure and at follow up (three, six, and 12 months and yearly thereafter).

RESULTS

Mean (SD) age was 18.3 (10) months and mean (SD) weight at closure was 9.1 (2.2) kg. Neither death nor any major complications occurred. Complications occurred in three patients aged < or = 1 year. Two patients had a mild inguinal haematoma. One patient had femoral artery thrombosis that was successfully treated by intravenous urokinase. The mean (SD) follow up was 12.8 (8.5) months. No problems occurred. Patients with recurrent respiratory infections had no significant recurrences and children who had failed to thrive had significantly increased growth.

CONCLUSIONS

In experienced hands, percutaneous closure of moderate to large PDA in very young symptomatic children is safe, effectively closes the PDA, and solves clinical problems.

Obstruction of the Aorta and Left Pulmonary Artery After Gianturco Coil Occlusion of Patent Ductus Arteriosus

We report an unusual case of simultaneous obstruction of the left pulmonary artery and descending thoracic aorta after Gianturco coil occlusion in a 15-month-old boy. The diagnosis was made by echocardiography and cardiac angiography. At surgery, thrombi coating on the protruded parts of the Gianturco coil in the pulmonary artery and aorta were found.

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.

Amplatzer Device closure of Atrial Septal Defects and Patent Ductus Arteriosus: Initial Experience

Surgical closure of Atrial Septal Defects (ASD) and Patent Ductus Arteriosus (PDA) can be performed successfully with low mortality. However, the morbidity associated with general anaesthesia, thoracotomy, cardiopulmonary bypass, postoperative monitoring in the intensive care unit, several days of hospital stay and the requirement of blood products is considerable. The expense associated with this morbidity, operative scar and the psychologic trauma to the patient and parents are additional disadvantages of surgery. Hence, the closure of these defects by transcatheter methods with various devices has been evaluated worldwide. We report the initial experience at our centre with closure of secundum ASDs and large PDAs with the Amplatzer Septal Occluder and Amplatzer Duct Occluder.

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.

Experimental evaluation of a new transcatheter vascular embolization device in the swine model

PURPOSE

To evaluate a new transcatheter device suitable for arterial embolization in an animal model.

MATERIALS AND METHODS

A new prototype self-expanding braided embolic device (Embolizor), consisting of nitinol wire strands fixed at either end with platinum-iridium bands and covered with a film of polyethylene, was deployed through 5-F diagnostic catheters into renal artery branches in five swine. Standard stainless-steel spring coils were deployed in other renal branches and served as controls. The animals underwent follow-up selective renal arteriography to determine presence or absence of vessel recanalization or device migration 15-23 days after device deployment. Histopathologic evaluation of target vessels and peripheral renal parenchyma was also performed.

RESULTS

Ten Embolizors and 10 stainless-steel coils were deployed in arteries ranging in size from 1.8 to 3.0 mm in diameter. The Embolizor was easily and precisely deployed. Angiographic evidence of vascular occlusion in the Embolizor group was noted within 30 seconds in eight device deployments and within 5 minutes in two. No early or delayed device migration was noted on follow-up arteriography. In the control group, seven of 10 previously occluded arteries were recanalized. No recanalization was noted in the Embolizor group. Light microscopy revealed evidence of infarction in all specimens examined. Whereas three specimens in the Embolizor group contained occasional giant cells, there were numerous multinucleated giant cells present within the interstices of all control spring coils.

CONCLUSION

The Embolizor was easily, precisely, and successfully deployed through standard selective diagnostic angiographic catheters. Short-term follow-up demonstrated no recanalization or migration of the device. The Embolizor was shown on histopathologic analysis to have no significant foreign body reaction.

Patent ductus arteriosus equipment and technique. Amplatzer duct occluder: intermediate-term follow-up and technical considerations

Between May 1997 and June 2000, 69 patients, ages 0.1 to 34 years, underwent attempted anterograde transcatheter closure of a patent ductus arteriosus (PDA) using the Amplatzer Duct Occluder (ADO). The ADO is a cone-shaped, self-centering, and repositionable occluder made of nitinol wire mesh. A 5Fr to 7Fr sheath was used for the delivery of the device. The mean PDA diameter (at the pulmonary end) was 4.6 +/- 1.9 mm (range 1 mm-8.5 mm). Sixty-seven of the 69 patients had successful device placement. The mean ADO smallest diameter was 6.9 +/- 1.8 mm (range 4 mm-12 mm). Complete angiographic closure occurred in 62 (92.5%) of 67 patients (95% confidence interval, 88.22%-98.77%). In five patients, there was a trivial residual shunt immediately after the procedure. At 24 hours, color Doppler flow imaging revealed complete closure in all 67 (100%) patients. The unsuccessful attempts occurred in two patients with a small, 1-mm diameter native PDA and residual PDA after surgical occlusion. Fluoroscopy time was 7.6 +/- 1.8 minutes (4 min-18 min). No complications were observed. At a median follow-up of 1.5 years (range 0.25 to 3.2 years), all patients had complete closure without complications. We conclude that transcatheter closure using the ADO is a highly effective and safe treatment for most patients with PDA.

The duct-occlud device: design, clinical results, and future directions

The successful employment of embolization coils for transcatheter occlusion of the patent ductus arteriosus (PDA) has resulted in acceptance of transcatheter occlusion as the treatment of choice for small to medium-sized PDAs. The Duct-Occlud device was developed to further improve the technique by utilizing a controlled release mechanism and coil shape specifically designed for the geometry of the ductus arteriosus. Clinical studies have demonstrated excellent efficacy with low embolization rates and low incidences of complications. Newer modifications have been designed for occlusion of larger PDAs and subaortic ventricular septal defects, and preliminary clinical results have been promising.

The Sideris buttoned devices for transcatheter closure of patent ductus arteriosus

This article reviews the experience in the last decade with Sideris buttoned devices for occlusion of patent ductus arteriosus (PDA). The devices used were the regular buttoned device, the infant buttoned device, the device with the folding plug, and the wireless device. The buttoned devices were implanted transvenously and introduced through 7Fr-8Fr long sheaths for PDAs up to 12 mm; wireless devices required 9Fr-11Fr sheaths for PDAs up to 22 mm. All different shapes of ductus were occluded. The records of 356 patients in the international and Food and Drug Administration (FDA) supervised United States (US) clinical trials were reviewed. Despite excellent long-term full occlusion rates and the absence of significant complications with the regular buttoned device, modifications were necessary to improve the full occlusion rates in 24 hours. The 24-hour rates improved from 60% with the regular device to 85% with the folding plug device. Most residual shunts disappeared on long-term follow-up without significant complications. Wireless devices were developed for very large PDAs and have excellent occlusion rates. The buttoned device with the incorporated folding plug and the wireless devices are currently under clinical trial. The safety record of the new devices needs to be established with larger clinical trials.

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.

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.

Recommendations of the British Paediatric Cardiac Association for therapeutic cardiac catheterisation in congenital cardiac disease

The aims of these recommendations are to improve the outcome for patients after, and to provide acceptable standards of practice of therapeutic cardiac catheterisation performed to treat congenital cardiac disease. The scope of the recommendations includes all interventional procedures, recognising that for some congenital malformations, surgical treatment is equally as effective as, or occasionally preferable to, interventional treatment. The limitations of the recommendations are that, at present, no data are available which compare the results of interventional treatment with surgery, and certainly none which evaluate the numbers and types of procedures that need to be performed for the maintenance of skills. Thus, there is a recognised need to collect comprehensive data with which these recommendations could be reviewed in the future, and re-written as evidence-based guidelines. Such a review will have to take into account the methods of collection of data, their effectiveness, and the latest developments in technology. The present recommendations should, therefore, be considered as consensus statements, and as describing accepted practice, which could be used as a basis for ensuring and improving the quality of future care.

Comparison of the one-and-a-half-year results of closure of patent ductus arteriosus by transcatheter coils placement with surgical ligation

Patent ductus arteriosus (PDA) is a common type of congenital cardiovascular lesion. It usually needs surgical ligation in a full-term baby after 1 year of age. Transcatheter implantation of coils was introduced for the closure of small- to moderate-sized PDA in 1992. From November 1995 to November 1998, the authors closed the PDA in 153 patients by transcatheter implantation of coils and by surgical ligation in 10 patients. One hundred fourteen of them were studied for more than 1(1/2) years. The regular follow-up studies, including physical examination; electrocardiography; and pulsed, continuous-wave, and color Doppler flow mapping, were performed on day one and day 2, and 1 week, 1 month, 3 months, 6 months, and 1 year after the procedure. The results of the closure of PDA by surgical ligation or coil placement were compared and analyzed in all the patients.

Closure of the patent ductus arteriosus with the amplatzer PDA device: immediate results of the international clinical trial

The purpose of this article is to present the immediate and short-term results of the international registry of transcatheter closure of patent ductus arteriosus (PDA) using the Amplatzer duct occluder (ADO). Three hundred sixteen patients (221 females) in various centers with clinical and/or echocardiographic evidence of PDA underwent an attempt of catheter closure at a median age of 2.1 years and median weight of 10.7 kg. The median Qp/Qs ratio was 2.3, the median length of the PDA was 6.7 mm and the median diameter of the PDA at its narrowest point (usually the pulmonic end) was 3.8 mm. Immediately after closure and by angiography, the PDA was completely closed in 177/311 patients (56%) and within 24 hr the complete closure rate increased to 76% (235/308). Complications were encountered in 15 patients, including 1 major complication due to device embolization and subsequent death, 6 moderate complications, and 8 minor complications. The median fluoroscopy time was 12 min and the median total procedure time was 70 min. One hundred fourteen patients reached the 6-month follow-up. Color Doppler echocardiography demonstrated complete closure in 109 patients (94.6%). Thirty-eight patients reached the 1-year follow-up mark. There was complete closure in 100% of the patients as documented by color Doppler echocardiography. So far there has been no episodes of delayed device migration, endocarditis, thromboembolism, and wire fracture or device disruption. We conclude that the ADO is safe and effective in most patients with PDA up to a diameter of 10.6 mm. Further clinical trials are underway to assess its long-term safety and efficacy.

Immediate and early results of closure of moderate to large patent arterial ducts using the new Amplatzer device

OBJECTIVES

Our aim was to assess the immediate and short term results of closure of moderate and large patent arterial ducts using the self-expanding and repositionable Amplatzer device.

METHOD

We attempted closure in 25 patients (10 Females and 15 males) using the Amplatzer occluder. Their median age was 48 months with a range from 8 months to 26 years and median weight of 14 kg with a range from 4.5 kg to 48 kg. The mean ductal diameter was 4.1 mm (S.D 1.51 mm). A 6F/7F long sheath was used to deliver the device. Follow up was performed with colour- flow mapping of the pulmonary trunk within 24 hours, at 3 months, and 6 months of closure.

RESULTS

Of the 25 patients, the device was placed successfully in 23. Concurrent angiography showed immediate closure in 12 patients, while 8 had trivial shunting and 3 had mild shunting. Within 24 hours, Doppler examination revealed complete closure in all but three patients, who had a mild residual shunt. Two attempts were unsuccessful. Both these patients underwent successful surgical ligation. All except one patient were discharged on the next day. Of the 23 patients, 15 (65%) have been followed up for 3 months, while 8 (35%) have completed 6 months of follow-up. Of the three patients initially with mild residual flow, two had completely closed at 3 months The one remaining patient is yet to be seen at the 3 month follow-up. Thus, at 3 months, all patients studies had shown complete closure.

CONCLUSION

Antegrade transcatheter closure using the Amplatzer duct occluder is an efficacious treatment for bigger patent arterial ducts. Long-term follow-up is necessary to show sustained benefits and confirm the absence of side effects.

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.

Subclinical aortic perforation with the infant double-button patent ductus arteriosus occluder

Modification of the double-button (Sideris) patent ductus arteriosus (PDA) occluder has resulted in a single-strut aortic component rather than the conventional cross-strut design. We report the use of this infant PDA occluder for transcatheter closure in three patients with PDA measuring 2 mm, 3.7 mm, and 4 mm. Subclinical aortic perforation with a small aortic aneurysm developed in two patients 1 year after occluder implantation. The third patient had developed a small aortic aneurysm without perforation at 3-month follow-up. All three patients had a residual shunt and underwent successful PDA surgical closure with aortic aneurysmal repair. Single-strut umbrella designs are not recommended for PDA transcatheter closure.

Long-term outcome of transcatheter coil closure of small to large patent ductus arteriosus

Coil closure of patent ductus arteriosus (PDA) has become an accepted alternative to surgical closure in most pediatric cardiac centers. However, little is known about the mid-to long-term outcome of this procedure. Therefore, we evaluated the immediate, short-, and long-term outcome of transcatheter coil closure (TCC) of PDA using single or multiple Gianturco coils or the Gianturco-Grifka Vascular Occlusive Device (GGVOD). One hundred forty-nine patients underwent an attempt at TCC of their PDAs at a median age of 2.4 years (2 weeks to 55 years) and median weight of 13.5 kg (2.3-87 kg). There were 33 patients < 1 year of age. The median PDA minimal diameter was 2 mm (0.4-7 mm) with 26 patients whose PDA minimal diameter was > 4 mm. A 4 Fr catheter was used for coil deployment in 136 patients, a 3 Fr in 4, and an 8 Fr in 4 patients who received the GGVOD. A single coil was used in 77 patients and multiple coils (2-6) were used in 66 patients. One hundred forty-six patients had successful closure (142 had immediate complete closure and 4 had residual shunt), 3 patients failed the initial attempt (2 underwent surgical ligation and 1 had a successful second attempt a year later). Of the four patients with residual shunt, three underwent a second procedure with implantation of 1-3 coils resulting in complete closure in all and one patient had spontaneous resolution of the residual shunt. Complications were encountered in nine patients: six had coil migration with successful retrieval in four; two had left pulmonary artery stenosis (2.4 kg and 6.3 kg infants), and one patient had loss of femoral arterial pulse. The median fluoroscopy time was 16 min (2-152 min). One hundred forty-two patients had the procedure as an outpatient, five patients stayed greater than 24 hr, and two of these patients were in hospital for 1 month for noncardiac reasons. At a median follow-up interval of 3.0 years (1 month to 5.1 years), there were no episodes of delayed coil migration, delayed recanalization, thromboembolic episodes, or bacterial endocarditis. Lung perfusion scans performed at a median follow-up interval of 1.6 years in 31 patients who received multiple coils revealed 45% +/- 5% blood flow to the left lung. Long-term follow-up of coil closure of PDA indicates that the technique is safe and effective for most patients with PDA up to a diameter of 7 mm.

[Interventions in congenital heart disease and their sequelae in adults]

The advancements of cardiac surgery over the last decades led to larger numbers of patients with operated congenital heart diseases surviving into adulthood. In Germany it is estimated that over 120,000 adults have operated congenital heart diseases. Five to 7% of them will need yearly hospital admissions. Interventional procedures are additional tools used to treat these patients with various sequelae or residua (Table 1). In the following review we concentrate on 2 different interventional procedures: dilatation and stent implantations for treatment of stenosis and the different devices used for the closure of shunt lesions. For congenital valvular pulmonary stenosis, balloon dilatation is the therapy of choice regardless the age of the patient. Stent implantation for the treatment of peripheral pulmonary stenosis (e.g., after previous systemic pulmonary shunts) can decrease the need for redo surgery, which is accompanied with increased risk. Stent implantations proved also to be useful to treat stenoses after Mustard patch in patients with transposition of the great arteries, after Fontan procedures or dealing with the rare pulmonary venous stenosis. In contrast, dilatation of bioprosthesis and conduit stenosis are not promising. Balloon dilatation of valvular aortic stenosis is an accepted therapy in childhood up to adolescents. Table 2 compares a surgical series including many infants with critical aortic stenosis with a series of balloon dilatation in children and another one in adults regarding lethality, complications, and results. Table 3 illustrates the immediate and late results of balloon dilatation of aortic coarctation in 3 different studies. The high recurrence rate in infants made clinicians refrain from taking this age group for balloon dilatation. In children and adult patients, good results are reported (75% reduction of gradients). The complication rate is low (2.3 to 3.3%) and aneurysm formation rate seldom (1 to 7%). Stenosed aorto-pulmonary collaterals will rarely need balloon dilatation. Surgical closure of atrial septal defect is a low risk procedure with a very low rate of residual shunts (2%). Of the 5 available devices for transcatheter closure of atrial septal defect Type II, only 2 occluders are in use in Germany, the Clamshell and the Amplatzer device. The largest clinical studies of the different systems, their efficacy, complications and residual shunt rate are presented in Table 4. For the deployment of these occluders a TEE is always needed. There are many more systems in clinical use to close the patent arterial duct (PDA) (Table 5). The Ivalon plug as well as the Rashkind device have probably only historical value. Different types of coils (Gianturco, Cook detachable, PFM) are now in use worldwide. The reason for their widespread use, besides their easy application, is the fact that most coils are relatively cheap and need only small sheaths for deployment. Their further evaluation identified a residual shunt rate of 5% as well as a number of complications (embolization, hemolysis, stenosis of the left pulmonary artery) in 0 to 6%. For the large PDA the Amplatzer device has recently been introduced. An additional indication for the use of the different occluding devices are aorto-pulmonary collaterals, venovenous fistulae, pulmonary or coronary artery fistulae. Aorto-pulmonary collaterals are often associated with complex cardiac lesions and occasionally appear after palliative procedures. An excellent cooperation between adult and pediatric cardiologists is needed in order to offer the group of adults with congenital heart diseases an adequate and comprehensive management.

Successful transcatheter closure of a patent ductus arteriosus: using two Gianturco coils in a 41-year-old woman. A case report

Patent ductus arteriosus (PDA) is a form of congenital heart disease uncommonly diagnosed in adult patients. Transcatheter closure of PDA has been widely used in children. However, the experience is limited in adults especially with use of Gianturco coils. The authors describe a case of successful transcatheter closure of a PDA, incidentally diagnosed in a 41-year-old woman, by successively deploying two coils by a transarterial approach. No residual shunting was seen angiographically after the procedure. A literature review of similar procedures in adult patients is discussed.

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.

[Ductus closure in adults with the Rashkind device: comparative results]

INTRODUCTION

Catheter occlusion of the persistent ductus arteriosus with Rashkind device is an alternative to the surgical closure demonstrated in children, however a few results have been reported of occlusion in adults.

METHOD

From 1990 to 1996 in 127 patients with persistent ductus arteriosus undergoing occlusion by Raskind device. Two groups according age: 105 children (< 14 years) and 22 adults (> 14 years), were studied retrospectively. The results were analysed by immediate aortogram and follow-up at 24 hours, 6 and 12 months by color-Doppler echocardiograms.

RESULTS

The adults were frequently asymptomatic (86%) and with high incidence (59%) of silent ductus. Similar QP/QS (1.61 +/- 0.47 in adults vs 1.49 +/- 0.51) was calculated although pulmonary pressure was superior in children (12.50 +/- 2.97 vs 16.84 +/- 5.88 mmHg; p = 0.003). In group > 14 years the ductal anatomy favorable (Krichenko type A or B) was more frequent (91% vs 73%; p = 0.06) and ductal diameter significantly higher (3.03 +/- 1.50 vs 2.41 +/- 0.96 mm; p = 0.009). In adults 17 mm umbrella were used more frequently (91 vs 61%; p = 0.02). Absence complications (embolization, bacteremia, haemolysis, proximal stenosis of the left pulmonary artery) were found in adults against 4.72% in children. The occlusion were more effective in adults specially in early controls: 55% vs 34% (p = 0.09), 82% vs 69%, 91% vs 77% and 95% vs 83% (p > 0.10). Multivariate analysis identified age as an independent predictor of complete occlusion.

CONCLUSION

Our experience in transcatheter occlusion of persistent ductus arteriosus with Rashkind device in adults support the efficacy, safety and excellent early results despite higher incidence of silent asymptomatic ductus.

Interventional procedures for congenital heart disease

Interventional techniques available for use in treating congenital heart disease include balloon dilation of valves and vessels, stent placement and coil embolization of collaterals, patent ducts and other arterial fistulae. In addition, a variety of devices for closure of atrial and ventricular septal defects and patent ducts currently are under investigation. Radiofrequency ablation of arrhythmias also is applicable to the pediatric population.

Mild or subclinical intravascular haemolysis subsequent to transcatheter occlusion of the patent arterial duct

One of the important complications of transcatheter occlusion of the patent duct by insertion of either the Rashkind double umbrella or coil devices is intravascular haemolysis, particularly the severe form which occurs in 0.5-0.6% of cases. The incidence of subclinical or mild intravascular haemolysis including morphologic changes in the red cells, however, is not known, especially in the group of patients with residual shunt. We studied laboratory and haematologic changes in 37 patients subsequent to transcatheter occlusion. Their ages ranged from 2 years 2 months to 11 years 8 months (6.2 + 2.7 years), and the duration of occlusion had ranged from 1 month to 2 years 11 months (1.24 + 0.89 years). In 30 cases we had used the Rashkind double umbrella device, and nine of these patients (30%) had a residual shunt. The other seven ducts were closed with detachable coils, and five of these cases (71%) had residual shunting. There was evidence of mild or subclinical intravascular haemolysis in almost half the cases, although no patient developed acute intravascular haemolysis. Fragmented red cells, blur cells and spherocytes from blood smears were found in up to one-third of the overall series, with no differences found according to persistence of shunting. Haemosiderin was found in the urine of the group with residual shunting and in 13-23% of those with complete occlusion. Serum hypohaptoglobin was found in 9-13% of the patients with a residual shunt, and in 9-23% of those with complete occlusion. Four of the patients had haptoglobin levels < 50 mg/dl. There were no patients with reticulocytes counts > 2% in the blood smears. We conclude that subclinical or mild intravascular haemolysis, along with morphologic changes in the red blood cells, are significant findings subsequent to occlusion of the patent arterial duct with either the Rashkind double umbrella or detachable coils.

Recent advances in interventional pediatric cardiovascular disease

Transcatheter therapy in children with congenital or acquired heart disease is a challenging, innovative, and constantly evolving field. In this article we review the various "nonsurgical" techniques that are currently available, with a discussion of their applications and an update on the recent advances in the field of interventional cardiology.