ABSTRACT: Objective. We devised a new technique for interventional closure of atrial septal defect (ASD) using the Amplatzer Septal Occluder (ASO), and validated this by comparing it with a cohort using the conventional method. Background. Transcatheter closure of ASD is a widely accepted modality of treatment. Although the outcome is good, there are occasional technical difficulties encountered. Method. In this three-step technique, the device is protruded to form a “tulip bud.” This “tulip bud” is then aligned adjacent to and along the plane of the ASD. The second step involves withdrawing the sheath in quick succession to deploy atrial discs over the septal defect. Finally, good placement of the occluder is checked before release. Results. Twenty-seven consecutive patients (1.4–77.2 years of age, median = 15) underwent device closure by this method. Nineteen (70.4%) had a deficient aortic rim ( 0.05). The percentage of patients with aortic root deficiency was slightly higher in “tulip-bud” group compared to the conventional group (63.2% vs. 58.4%; p = 0.039). No complications were observed in either series. Conclusion. This is a promising new method to circumvent some of the difficulties associated with closure of large ASDs and deficient aortic rim.
J INVASIVE CARDIOL 2009;21:623–626
Key words: ASD, interventional cardiology, transcatheter, device occlusion, Amplatzer septal occluder
ABBREVIATIONS LIST
ASD = atrial septal defect
ASO = Amplatzer Septal Occluder
LAD = left atrial disc
RAD = right atrial disc
SD = standard deviation
TEE = transesophageal echocardiography
TTE = transthoracic echocardiography
Transcatheter device closure of atrial septal defects (ASD) has evolved significantly over the past decade with improvements made to design and profile. Indeed, device closure is now widely accepted as the modality of choice for the treatment of significant ASDs. The different models have ranged from the CardioSEAL® (NMT Medical, Inc., Boston, Massachusetts) and STARFlex (NMT Medical),1,2 AngelWings (Microvena Corp., White Bear Lake, Minnesota),3 Amplatzer (AGA Medical Corp., Golden Valley, Minnesota),4–8 and Gore Helex Septal Occluder Gore Helex Septal Occluder (W.L. Gore and Associates, Inc., Flagstaff, Arizona),9 to the more recently available bioabsorbable devices.10,11 Of these, the Amplatzer Septal Occluder (ASO) is well accepted, widely used and arguably one of the easier devices to deploy. The outcomes associated with the use of this device have also been validated.6–7,12
Despite this, deployment of the ASO can occasionally pose a technical challenge. This is especially true in large secundum ASDs and ASDs with a deficient aortic rim. It is not infrequent that the device is deployed inadvertently either completely in the left atrium, or in the right atrium due to the large size of some defects. In many cases, while one end of the device holds on well to the septal rim, both discs of the other end may not catch on the other septal rim. The difficulty in obtaining a well-placed device is experienced especially by the novice, and not infrequently by expert operators. This can be frustrating, as it prolongs procedural and fluoroscopy times. In fact, in some instances, the interventional therapeutic approach has sometimes been abandoned in favor of surgical correction.
As our experience in transcatheter ASD closure increases, we may be able to overcome some of the challenges. This paper describes a novel method of ASO deployment that our group devised through a detailed analysis of the results and difficulties encountered in our series. We worked through from first principles, bearing in mind the anatomy of the ASD, design of the ASO and the usual deployment technique. The results of our initial experience and comparison to a control group using the conventional method are discussed.
Patients and Method
The in-situ “tulip-bud” method was used by the leading operators in a consecutive series of patients from July 2007 to January 2009 at two tertiary cardiac centers in Singapore. It was a retrospective evaluation of data on 48 patients compared with a prospective study of 27 patients. The latter group comprised 27 patients (males = 8, females = 19), with an age range of 1.4–77.2 years (median = 15). As per our protocol, right-heart catheterization together with oximetry were performed. The ASD size, location and its rims were studied in detail with transesophageal echocardiography (TEE).13 The ASD size was measured by TEE on three planes employing four-chamber (0°), short-axis (40–60º) and long-axis views (90–110°). An appropriate-sized ASO of up to 120% of the average size was chosen without balloon sizing. Right upper-lobe pulmonary vein angiography was performed at 30° left anterior oblique and 30° cranial projections. Our new technique consisted of three important steps. First, we started by positioning the delivery sheath (with the device inside the sheath) in the direction of the right upper pulmonary vein. This was to ensure good position in aligning the left atrial disc (LAD) to the plane of the atrial septum when opened. The device was then partially deployed to form the “tulip-bud” configuration (Figure 1A), and was kept like so until the next step. It was important to gauge from the angiogram and TEE (which indicates the ASD site) that this tulip bud was carefully placed just adjacent to the ASD in the left atrium (Figure 1B). In this manner, further deployment of the device will allow the ASO to straddle the defect and occlude it in good position. This led to the second step, where we fully deployed the rest of the LAD, waist and right atrial disc (RAD) in rapid succession by withdrawing the sheath backward while holding the delivery cable firmly to maintain position (Figures 1C, D and E). Once this was completed, the third and final step involved careful assessment of the TEE results, followed by release when good placement was confirmed. The duration of deployment of both discs, the duration from deployment to release of the device and the number of attempts of deployment per patient were recorded.
We also compared the demographic characteristics (age and weight), ASD morphology (ASD size, percentage with aortic rim deficiency), shunt size (Qp/Qs), choice of ASO (ASO size and degree of oversizing) and performance indices (procedure and fluoroscopy times) between these groups of patients using the novel in-situ tulip-bud deployment method of closure and the previous group of 48 consecutive patients using the conventional method (Table 1). This served to assess whether there was any bias in favor of the novel-method patient group.
Results
Twenty-seven consecutive patients underwent device closure using this novel method between July 18, 2007 and February 1, 2009. Nineteen out of 27 (70.4%) had a deficient aortic rim ( 0.05) between the conventional and tulip-bud method groups. The percentage of patients with aortic root deficiency was slightly higher in the “in-situ tulip-bud” group compared to that of the conventional group (63.2% vs. 58.4%; p = 0.039) (Table 1). There were no complications observed in the series, and all patients had complete closure of their ASD.
Discussion
While the technique for transcatheter closure of ASDs using an ASO is relatively straightforward, difficulties14 may be encountered in patients with a short aortic rim and the larger ASDs.15–18 Often, in these situations, many attempts may be required during the procedure before achieving successful deployment. We sought to condense the technique into three steps to improve outcomes in the more challenging ASD patients.
One of the difficulties encountered has been that the LAD is not aligned with the plane of the atrial septum. The conventional ASO deployment method involves full LAD deployment in the left atrium, with the ASO then being pulled back towards the atrial septum. During this passage, the LAD frequently slips through the defect, especially in patients with an aortic rim deficiency. Some interventionalists have resorted to the left or right upper pulmonary vein technique or using the Hausdorf sheath19 (Cook, Inc., Bloomington, Indiana) to overcome this problem. Dalvi20 and Wahab21 and colleagues have also reported the use of balloon-assisted and dilator-assisted methods, respectively, to overcome the difficulties faced with large ASDs. Our novel technique helps to address this in a different fashion. While the technique is similar in concept to the “left atrial roof technique,”22 the actual deployment differs. In the left atrial roof technique, the left disc is fully deployed in the left atrium before withdrawing the sheath. In our method, we find that rotating the sheath in the right upper pulmonary vein direction aligns and maintains the device’s disc on the plane of the atrial septum. Allowing the LAD to protrude in the shape of a “tulip bud” allows for a favorable position in preparation for full deployment.
The second step addresses the “tulip bud” and device position in relation to the defect. This estimation is very important and must be aided by angiography and TEE, which enable preparation for accurate device deployment. By keeping the LAD only partially deployed in the shape of a “tulip-bud” just distal to the ASD, it eliminates or significantly lessens the chance of the LAD slipping through the ASD. When this is accurately assessed, withdrawal of the sheath, while keeping the device in the desired position, effectively allows the ASO to assume the proper shape and formation over the defect. Good coordination of both hands is imperative at this stage so that the device is not inadvertently moved out of position when the sheath is being withdrawn.
While the first step of our technique takes care of the plane alignment issue, the second step concentrates on achieving good and accurate positioning. The third step, then, is the final confirmatory one to ensure that the device is in good position. This is of course vital before release of the ASO. We find that this technique leverages on the mid-septal edge of the ASD defect to anchor the device and hold it in place as the left and right discs are quickly deployed to close on the defect. This would also apply in the presence of an atrial septal aneurysm, as the swift motion of deployment of the device aligned with the atrial septum facilitates the process. A theoretical advantage exists in patients with a short aortic rim, as we have found the device to be more stable and secure, minimizing excessive movement against heart motion, and thereby reducing the possibility of erosion.
In the majority of patients (77.8%), this novel technique allowed complete occlusion requiring only one attempt at deployment. A reduction in the number of attempts at deployment will minimize procedural risks and decrease the likelihood of using increasingly larger devices, which may increase the risk of erosion.22 There have been a few patients where more than one attempt was necessary, but these were in the initial phase of perfecting the technique as would be expected in any learning curve. Many of these were due to judgemental error of placement of the tulip bud in relation to the position of the ASD, especially when the technique was taught to a first-time user. The only challenging situation would be attempting to close a large defect with an aortic rim deficiency using a relatively small device required due to inadequate atrial septal length. This happened in only 1 of our patients. In the majority of the patients, only one attempt was necessary before release of the ASO, and good results were achieved. We therefore consider this is a promising new method, and would like to share it with interventional cardiologists who perform transcatheter closure using ASOs. In fact, it is a good way to train the novice as well, as it offers a better understanding of the anatomy and angiography in relation to the device’s shape and function. Hopefully, other interventional cardiologists can confirm our good preliminary results.
Conclusion
Our study describes a novel in-situ “tulip-bud” technique for transcatheter closure of ASDs. We conceived this technique by analyzing some of our previous failures and difficulties in relation to ASD anatomy and ASO design. The results showed good outcomes, and this method appears promising, particularly for patients with a difficult ASD and deficient aortic rim who might otherwise be sent for surgery.
From the Division of Cardiology, Department of Paediatrics, National University of Singapore, Singapore and the Gleneagles Hospital, Singaore.
The authors report no conflicts of interest regarding the content herein.
Manuscript submitted June 19, 2009, provisional acceptance given July 6, 2009, final version accepted July 15, 2009.
Address for correspondence: Swee Chye Quek, MD, Head and Senior Consultant, Division of Cardiology, Department of Paediatrics, National University of Singapore 5 Lower Kent Ridge Road, Singapore 119074. E-mail: paeqsc@nus.edu.sg
1. Nugent AW, Britt A, Gauvreau K, et al. Device closure rates of simple atrial septal defects optimized by the STARFlex device. J Am Coll Cardiol 2006;48:538–544.
2. Butera G, Carminati M, Chessa M, et al. CardioSEAL/STARflex versus Amplatzer devices for percutaneous closure of small to moderate (up to 18 mm) atrial septal defects. Am Heart J 2004;148:507–510.
3. Kay JD, O’Laughlin MP, Ito K, et al. Five-year clinical and echocardiographic evaluation of the Das AngelWings atrial septal occluder. Am Heart J 2004;147:361–368.
4. Omeish A, Hijazi ZM. Transcatheter closure of atrial septal defects in children & adults using the Amplazter Septal Occluder. J Interven Cardiol 2001;14:37–44.
5. Fischer G, Stieh J, Uebing A, et al. Experience with transcatheter closure of secundum atrial septal defects using the Amplatzer septal occulder: A single centre study in 236 consecutive patients. Heart 2003;89:199–204.
6. Matsura J, Gavora P, Podnar T. Long-term outcome of transcatheter secundum-type atrial septal defect closure using Amplatzer septal occluders. J Am Coll Cardiol 2005;45:505–507.
7. Diab KA, Cao QL, Bacha EA, et al. Device closure of atrial septal defects with the Amplatzer septal occluder: Safety and outcome in infants. J Thorac Cardiovasc Surg 2007;134:960–966.
8. Butera G, Romagnoli E, Carminati M, et al. Treatment of isolated secundum atrial septal defects: Impact of age and defect morphology in 1,013 consecutive patients. Am Heart J 2008;156:706–712. Epub 2008 Jul 30.
9. Jones TK, Latson LA, Zahn E, et al. Multicenter Pivotal Study of the HELEX Septal Occluder Investigators. Results of the U.S. multicenter pivotal study of the HELEX septal occluder for percutaneous closure of secundum atrial septal defects. J Am Coll Cardiol 2007;49:2215–2221.
10. Jux C, Bertram H, Wohlsein P, et al. Interventional atrial septal defect closure using a totally bioresorbable occluder matrix: Development and preclinical evaluation of the BioSTAR device. J Am Coll Cardiol 2006;48:161–169.
11. Mullen MJ, Hildick-Smith D, De Giovanni JV, et al. BioSTAR Evaluation StTudy (BEST): A prospective, multicenter, phase I clinical trial to evaluate the feasibility, efficacy, and safety of the BioSTAR bioabsorbable septal repair implant for the closure of atrial-level shunts. Circulation 2006;114:1962–1967.
12. Wilson NJ, Smith J, Prommete B, et al. Transcatheter closure of secundum atrial septal defects with the Amplatzer septal occluder in adults and children-follow-up closure rates, degree of mitral regurgitation and evolution of arrhythmias. Heart Lung Circ 2008;17:318–324. Epub 2008 Apr 14.
13. Mazic U, Gavora P, Masura J. The role of transesophageal echocardiography in transcatheter closure of secundum atrial septal defects by the Amplatzer septal occluder. Am Heart J 2001;142:482–488.
14. Harper RW, Mottram PM, McGaw DJ. Closure of secundum atrial septal defects with Amplatzer septal occluder device: Techniques and problems. Catheter Cardiovasc Interv 2002;57:508–524.
15. Kannan BR, Francis E, Sivakumar K, et al. Transcatheter closure of very large (≥ 25 mm) atrial septal defects using the Amplatzer septal occluder. Catheter Cardiovasc Interv 2003;59:522–527.
16. Pedra CA, Pedra SR, Esteves CA, et al. Trascatheter closure of secundum atrial septal defects with complex anatomy. J Invasive Cardiol 2004;16:117–122.
17. Suárez De Lezo J, Medina A, Pan M, et al. Transcatheter occlusion of complex atrial septal defects. Catheter Cardiovasc Interv 2000;51:33–41.
18. Du ZD, Koenig P, Cao QL, et al. Comparison of transcatheter closure of secundum atrial septal defect using the Amplatzer septal occluder associated with deficient versus sufficient rims. Am J Cardiol 2002;90:865–869.
19. Varma C, Benson LN, Silverslides C, et al. Outcomes and alternative techniques for device closure of the large secundum atrial septal defect. Catheter Cardiovasc Interv 2004;61:1311–1319.
20. Dalvi BV, Pinto RJ, Gupta A. New technique for device closure of large atrial septal defects. Catheter Cardiovasc Interv 2005;64:102–107.
21. Wahab HA, Bairam AR, Cao QL, Hijazi ZM. Novel technique to prevent prolapse of the Amplatzer septal occluder through large atrial septal defect. Catheter Cardiovasc Interv 2003;60:543–545.
22. Amin Z, Hijazi ZM, Bass Jl, et al. Erosion of Amplatzer septal occluder device after closure of atrial septal defects: Review of registry of complications and recommendations to minimize future risk. Catheter Cardiovasc Interv 2004;63:496–502.
