A new technique for sizing of atrial septal defects

Accuracy of Transthoracic Echocardiography in Assessing Retro-aortic Rim prior to Device Closure of Atrial Septal Defects

OBJECTIVE

Deficient retro-aortic rim has been identified as a risk factor for device erosion following trans-catheter closure of atrial septal defects (ASDs). Transthoracic echocardiography (TTE) is the primary screening method for subjects for possible device closure of ASD, but its reliability in measuring retro-aortic rim size has not been assessed previously.

DESIGN

A single-institution cross-sectional analysis of children and adults referred for trans-catheter device closure of single ostium secundum ASD from January 1, 2005 to April 1, 2012 with reviewable TTE and trans-esophageal echocardiogram images was performed. Inter-rater reliability of measurements was tested in a 24% sample. Accuracy of TTE measurement of retro-aortic rim was assessed using a Bland-Altman plot with trans-esophageal echocardiogram measurement as the gold standard. Test characteristics of TTE detection of deficient retro-aortic rim were calculated. Risk factors for misclassification of deficient retro-aortic rim were assessed using receiver operator characteristic curves. Risk factors for measurement error were assessed through multivariate linear regression.

RESULTS

In total, 163 subjects of median age 5 years (range: 0.3-46 years) were included. Trans-thoracic echocardiography had 90% sensitivity, 84% specificity, 90% positive predictive value, and 83% negative predictive value to detect deficient retro-aortic rim. Bland-Altman plot demonstrated no fixed bias (P = .23), but errors in measurement increased on average as the aortic rim increased in size (P < .001). Prespecified patient level risk factors did not affect receiver operator characteristic curve area under the curve, nor were any patient-level risk factors independently associated with increased measurement error on TTE.

CONCLUSIONS

TTE is a sensitive and specific screening test for deficient retro-aortic rim across a range of patient ages and sizes.

The relation between atrial septal defect shape, diameter, and area using three-dimensional transoesophageal echocardiography and balloon sizing during percutaneous closure in children

BACKGROUND

A trans-catheter closure of an atrial septal defect (ASD) is efficient. Balloon sizing (BS) during the catheterization leads to an overestimation of ASD size. Three-dimensional transoesophageal echocardiography (3D-TEE) allows the ASD morphology to be assessed comprehensively. The aim of this study was to assess the relationships between the shape and the measurements of ASDs by 2D-, 3D-TEE, and BS in children.

METHODS AND RESULTS

Thirty children who underwent percutaneous closures of a single ASD were enrolled. ASD diameters were measured by 2D-transthoracic echocardiography (TTE), 2D-TEE, 3D-TEE and compared with BS. The ASD area was measured on 3D-TEE images after multi-planar reconstruction. ASD was estimated as round or oval on 3D-TEE 'en-face' view. 2D-TTE, 2D-TEE, and 3D-TEE(max) ASD diameters were well correlated with BS (r = 0.75; 0.80, and 0.85, respectively). Mean diameters were all significantly smaller than the mean BS. The mean difference between the balloon area and 3D-TEE area was 1.6 ± 1.4 cm(2) (P < 0.0001). The mean difference between BS and 3D-TEE(max) diameters was higher in round ASDs than in oval ASDs (4.0 ± 3.3 vs. 1.1 ± 3.3, P = 0.02). With multivariate linear regression analysis, two formulas were built to predict BS. The first model was BS = 1.07 × 3D-TEE(max)- 3.1 × ASDshape + 3. The ASD shape was 0 for round and 1 for oval ASDs. A second model was BS = 4.5 × ASDarea + 11.5.

CONCLUSION

The ASD shape is accurately estimated by 3D-TEE and influences the relationship between echocardiographic measurements and BS. The ASD shape, its maximal diameter and the area assessed by 3D-TEE may be sufficient to determine the device size without BS in children.

A comparison between size of the occluder device and two-dimensional transoesophageal echocardiographic sizing of the ostium secundum atrial septal defect

Objectives

Transcatheter closure of a secundum atrial septal defect (ASD II) has become an effective alternative for surgical treatment. In this study we evaluated the correlation between the two-dimensional transoesophageal echocardiographic (2D TEE) sizing of ASDs and the actual diameter of occluders in patients undergoing device closure.

Methods

The records of 54 patients who underwent transcatheter ASD closure were reviewed. ASD characteristics and maximum defect diameter were evaluated using preprocedure 2D TEE images. Appropriate device size was determined by the balloon sizing method, which measures the balloon occlusive diameter (BOD) via TEE and fluoroscopy. ASD closure was performed under continuous TEE monitoring using the Amplatzer occluder in all patients.

Results

The mean of the TEE-derived maximum defect diameter was significantly lower than the mean of the BOD (17.8 ± 4.5 vs 22.1 ± 5.1 mm; p < 0.001) and the mean size of the implanted occluder device (17.8 ± 4.5 vs 23.3 ± 5.1 mm; p < 0.001). However, a good correlation was found between the TEE-derived defect size and the BOD (BOD = 0.898 × TEE defect size + 6.212, R = 0.824; p < 0.001) and between the TEE measurement and the final size of the implanted Amplatzer (device size = 0.928 × TEE defect size + 6.853, R = 0.822; p < 0.001).

Conclusions

2D TEE may provide a good equation to predict the BOD or the size of the occluder device; however, further studies are needed to investigate whether it is feasible to perform transcatheter ASD occlusion without balloon sizing.

Trans-catheter closure of atrial septal defect: Balloon sizing or no Balloon sizing - single centre experience

BACKGROUND

Selecting the device size using a sizing balloon could oversize the ostium secundum atrial septal defect (OSASD) with floppy margins and at times may lead to complications. Identifying the firm margins using trans-esophageal echocardiography (TEE) and selecting appropriate-sized device optimizes ASD device closure. This retrospective study was undertaken to document the safety and feasibility of device closure without balloon sizing the defect.

METHODS

Sixty-one consecutive patients who underwent trans-catheter closure of OSASD guided by balloon sizing of the defect and intra procedural fluoroscopy (group I) and 67 consecutive patients in whom TEE was used for defect sizing and as intraprocedural imaging during device deployment (group II) were compared. The procedural success rate, device characteristics, and complications were compared between the two groups.

RESULTS

The procedure was successful in 79.7 % patients. The success rate in group II (60 of 67, 89.6%) was significantly higher than in group I (41 of 61, 67.2 %) (P = 0.002). Mean upsizing of ASD device was significantly lower in group II (P < 0.001). TEE also provided better success rate with smaller device in subjects with large ASD (>25 mm) and in those who were younger than 14 years of age. There were four cases of device embolization (two in each group); of which one died in group II despite successful surgical retrieval.

CONCLUSION

Balloon sizing may not be essential for successful ASD device closure. TEE-guided sizing of ASD and device deployment provides better success rate with relatively smaller sized device.

Assessment of atrial septal defect size with 3D-transesophageal echocardiography: comparison with balloon method

BACKGROUND

Transcatheter closure of atrial septal defect (ASD) is an alternative approach to surgery in selected patients. Balloon stretched diameter (BSD) is considered as the standard way of measuring ASD size. Three-dimensional transesophageal echocardiography (3D-TEE) provides views of the ASD allowing its measurement and identifying its spatial relation with neighboring structures. Our aim was to compare the BSD and 3D-TEE methods to measure the ASD size before transcatheter closure.

METHODS AND RESULTS

Seventy-six consecutive patients were enrolled for ASD device closure. Three-dimensional transesophageal echocardiography and balloon sizing were adequately performed in 70 patients before the defect closure. The mean maximal diameter measured by 3D-TEE was 20 +/- 15 mm (range 10-28) while the mean BSD was 22 +/- 4.8 mm (range 9-31). When comparing the 3D-TEE and transcatheter measurements, there was a good correlation between the two methods (y = 3.15 + 0.77x; r = 0.8). The defect as viewed by 3D-TEE was unique in 54 patients and multiple in 16 patients. In patients with a single defect, the correlation between the two methods was high (y = 1.74 + 0.84x; r = 0.85) while patients with multiple ASDs, the correlation was poor (y = 12.4 + 0.4x; r = 0.45). Transcatheter closure was performed successfully in 86%. The mean size of the Amplatzer device was 23 +/- 4.8 mm (range 4-32). The reference to choose the size of the device was the BSD in single defects and the 3D-TEE maximal diameter in multiple defects.

CONCLUSION

Three-dimensional transesophageal echocardiography and transcatheter methods are two complementary techniques for the success of transcatheter ASDs closure.

Real-time evaluation of the hemodynamic effects of atrial septal defect closure in adults with left ventricular dysfunction

Transcatheter closure of atrial septal defects with left-to-right shunt induces an abrupt overload of the left ventricle that may cause acute heart failure in patients with left ventricular dysfunction. We report two cases of ostium secundum atrial septal defects associated with left ventricular dysfunction of different etiology. The hemodynamic evaluation of left ventricular function during transient abolition of the shunt with the sizing balloon of the Amplatzer system helped to establish the most correct therapeutic strategy.

Left ventricular decompression through a patent foramen ovale in a patient with hypertrophic cardiomyopathy: a case report

The foramen ovale is considered an unidirectional flap-like valvular structure. Yet, it may increase in size and allow a continuous left-to-right shunt in order to reduce left ventricular filling pressures.

We report the case of a 63-year-old woman with hypertrophic cardiomyopathy, referred for percutaneous closure of a coexisting secundum atrial septal defect. Before catheterization, however, transesophageal echocardiography revealed a continuous left-to-right shunt within the atrial septum, thus suggesting the diagnosis of patent foramen ovale with stable left-to-right shunt. At catheterization, performed under general anesthesia and transesophageal echocardiographic monitoring, left ventricular early- and end-diastolic pressures were 2 and 12 mmHg and pulmonary-to-systemic flow ratio was 1.4. Provocative maneuvers were not able to reverse the shunt. In order to assess the effect of the increased left ventricular preload due to the abolition of the shunt, an Amplatzer sizing balloon was inflated for 5 minutes across the patent foramen ovale. Diastolic pressures rose up to 5 and 18 mmHg, respectively. Such a worsening of left ventricular function suggested us not to perform the closure procedure.

Transcatheter closure of any interatrial communication with stable left-to-right shunt induces an abrupt overload of the left ventricle that may cause acute heart failure in patients with coexisting left ventricular dysfunction. The hemodynamic evaluation of left ventricular function during transient abolition of the shunt is an useful tool in order to establish the most correct therapeutic strategy. The closure procedure should not be performed if a worsening of left ventricular function occurs.

Catheter Closure of Atrial Septal and Ventricular Septal defects Using The Amplatzer Devices

The Amplatzer Septal Occluder (ASO) is a device that combines the advantages of being a double-disc with a self-centering mechanism. It is the first and only device to ever receive full approval for clinical use in children and adults with secundum atrial septal defects (AD) from the United States Food and Drug Administration. It has been used successfully to close secundum ASDs, patent foramen avale and Fontan fenestrations. The first patient to undergo closure with the ASO was approximately 6 years ago. So far the mid-term results are very encouraging with no long-term complications for the presence of the device. Complications encountered with the use of the Amplatzer septal occluder are rare and most may be managed in the catheter laboratory. Most of the complications occur in the immediate period post-implantation. The Amplatzer muscular and membranous ventricular septal defect devices are still undergoing clinical trials in the United States; however, they are fully approved in many countries. Long-term results about safety and efficacy, as well as results involving larger defects are being collected.

Transthoracic three-dimensional echocardiography prior to closure of atrial septal defects in children

AIMS

Our aims were to use transthoracic three-dimensional echocardiography to assess the morphology of atrial septal defects in children prior to closure, and to compare the three-dimensional echocardiographic data with transcatheter and surgical findings.

METHODS AND RESULTS

We used transthoracic three-dimensional echocardiography in 62 consecutive patients, aged from 2 to 18 years, with atrial septal defects, measuring the maximal diameter and the extent of the rims. Subsequent to the study, we referred 42 patients for transcatheter closure, the rims being measured at greater than 4 mm. We found a good correlation between the maximal diameter of the defect as measured at transthoracic three-dimensional echocardiography and using a balloon (y = 3.45 - 0.73x; r = 0.78; p < 0.0001), the mean difference between the measurements being 2.4 +/- 2.8 mm. Successful closure with the Amplatzer septal occluder, having a mean size of 22 +/- 4 mm, was achieved in 95% of the patients. Of the original cohort, 20 patients were referred for surgical closure. In these patients, the inferior rim had been deemed insufficient in 5, the postero-superior rim in 6, and the postero-inferior rim in 9. Complete agreement was found when the deficiency of the rim as judged using transthoracic three-dimensional echocardiography was compared with intraoperative findings. The correlation between measurements of the deficiency of the rim achieved by transthoracic three-dimensional echocardiography and at surgery was excellent (y = 0.2 + 0.98x; r = 0.93; p < 0.0001), the mean difference between the measurements being no more than 0.6 +/- 0.4 mm.

CONCLUSIONS

Transthoracic three-dimensional echocardiography proved accurate in measuring the maximal diameter and rims of atrial septal defects within the oval fossa. This non-invasive method will be valuable in selecting children for transcatheter or surgical closure of such defects.

Magnetic resonance image-guided transcatheter closure of atrial septal defects

BACKGROUND

Recent developments in cardiac MRI have extended the potential spectrum of diagnostic and interventional applications. The purpose of this study was to test the ability of MRI to perform transcatheter closures of secundum type atrial septal defects (ASD) and to assess ASD size and changes in right cardiac chamber volumes in the same investigation.

METHODS AND RESULTS

In 7 domestic swine (body weight, 38+/-13 kg), an ASD (Q(p):Q(s)=1.7+/-0.2) was created percutaneously by balloon dilation of the fossa ovalis. The ASD was imaged and sized by both conventional radiography and MRI. High-resolution MRI of the ASD diameters correlated well with postmortem examination (r=0.97). Under real-time MR fluoroscopy, the introducer sheath was tracked toward the left atrium with the use of novel miniature MR guide wires. The defect was then closed with an Amplatzer Septal Occluder. In all animals, it was possible to track and interactively control the position of the guide wire within the vessels and the heart, including the successful deployment of the Amplatzer Septal Occluder. Right atrial and ventricular volumes were calculated before and after the intervention by using cine-MRI. Both volumes were found to be significantly reduced after ASD closure (P<0.005).

CONCLUSIONS

These in vivo studies demonstrate that catheter tracking and ASD device closure can be performed under real-time MRI guidance with the use of intravascular antenna guide wires. High-resolution imaging allows accurate determination of ASD size before the intervention, and immediate treatment effects such as changes in right cardiac volumes can also be measured.

Closure of secundum atrial septal defects with the Amplatzer septal occluder device: techniques and problems

Percutaneous transvenous closure of atrial septal defects (ASDs) has become feasible in recent years, as later-generation devices have largely overcome initial difficulties in device deployment and complication rates. The Amplatzer septal occluder (ASO) is one such device that we have used extensively and is, in our opinion, the most versatile and practical to use. It is capable of closing defects up to 40 mm in diameter via a relatively low-profile delivery sheath. More importantly, the ASO may be easily withdrawn into the sheath after deployment but prior to release, which is essential in safely closing difficult defects where successful positioning on the initial deployment is not guaranteed. In this article based on our experience, review of the literature, and communications with other operators, we describe the various problems encountered in closing atrial septal defects and make suggestions as to the best way of overcoming these difficulties.

The Amplatzer septal occluder

The Amplatzer Septal Occluder is made from a Nitinol wire mesh shaped into 2 disks with a connecting waist, which serves to center the device in the defect while occluding it. The Amplatzer device is also available in a configuration with no central waist for use in patients with patent oval foramen, or multi-perforated aneurysm of the interatrial septum. For the purposes of this review, we analysed our experience using the Amplatzer device in 150 patients with interatrial communications. Of these, 104 had a defect within the oval fossa, 33 a patent oval foramen, and 13 had undergone fenestration of a Fontan procedure. Of those with defects within the oval fossa, a device was implanted in 100 patients, and 2 of these patients subsequently required surgical intervention, 1 because of migration and the other because of malformation of the device. Of the remaining 98 patients, complete occlusion has been achieved in 90% at 1 year. Any residual leaks are either trivial or small. In those with a patent oval foramen, the septal occluder was used to close 20, whilst the device designed specifically for this purpose was used in 13. On follow-up contrast echocardiography, only 2 patients have a small residual right-to-left shunt. Complete occlusion was achieved for all the Fontan fenestrations, although 1 patient later underwent surgery for baffle dehiscence. Other significant complications occurred in 2 patients who developed deep vein thrombosis, and 3 patients who suffered transient supraventicular arrhythmias. Although the Amplatzer device has been in clinical use for only 3 years, its unique design, and ease of use, has resulted in its widespread adoption by many centres. The results to date are very encouraging, but it must be remembered that there is, as yet, no long-term follow-up data available for this life-long implant.