Atrial and Ventricular Shunt Closure

Atrial Septal Defects
Atrial septal defects account for about one-third of all congenital heart abnormalities detected in adults.¹ A large defect in adult patients results in symptoms and complications such as arrhythmias, cardiac failure and pulmonary hypertension.^1,2 The first transcatheter device closure of an atrial septal defect was described in 1976.³ Today, percutaneous closure of this defect is widely practiced using different types of devices and has replaced surgical closure of a simple secundum atrial septal defect in most centers.^4–13
Worldwide data and experiences. Although many devices have been developed for catheter closure of secundum-type defects, three devices are used in the majority of centers: the CardioSEAL^®/STARFlex^®(NMT Medical, Inc, Boston, Massachusetts), the Amplatzer^® Septal Occluder (AGA Medical Corp., Golden Valley, Minnesota), and the Helex septal occluder (Gore Medical [WL Gore & Associates, Inc.], Flagstaff, Arizona). The Amplatzer septal occluder is currently the most widely used device because it is easy to implant and it allows closure of large orifices with excellent success rates in most patients. It was first used in a human in 1995. Device closure is currently not amenable to ostium primum and sinus venosus defects.
Several nonrandomized studies have compared transcatheter closure to surgery.^14–16 In these studies, shunt closure was achieved in 92–99% after interventional closure and in 98–100% after surgery. In a worldwide survey published by Omeish et al (mean age 12 years; 3,460 patients with a secundum atrial septal defect and a defect diameter of < 35 mm; treated with an Amplatzer septal occluder), the immediate sealing rate was 97%, at 6-month follow up it was 98%, at 1-year follow up it was 99%, and after 2 years, the rate was 100%.¹⁷
Carminati et al showed in a multicenter trial that 99% (310/314) of the patients treated with the CardioSEAL or STARFlex devices had no residual shunt immediately after the procedure.18 After 1 year, complete closure of the defect was achieved in 93% of the patients. Jones et al published the results of the U.S. multicenter pivotal study of the HELEX septal occluder for percutaneous closure of secundum atrial septal defects. Closure with the Gore HELEX^® septal occluder device (W.L. Gore & Associates), compared to surgical closure, showed a similar complete closure rate in both groups. The Helex device was safe and effective when compared with surgical repair and resulted in reduced anesthesia time and hospital stay.¹⁹ The complication rates in all studies were consistently low.^17–25 Severe complications like malpositioning and subsequent surgery occurred in 1–5%, embolization of the device in 0.4–4%, stroke in 0.1–0.3%, cardiac tamponade in 0.1%, cardiac perforation in 0.03% and endocarditis in 0.03% of patients.

Personal data and experiences. Since August 1992, percutaneous atrial septal defect closure was attempted in 819 adult patients (619 females and 200 males, mean age 47.2 ± 17). Table 1 shows the occluders that were implanted. The defects measured by balloon sizing ranged from 3.1 to 43 mm (mean 19.8 ± 6.7). One hundred five patients (13%) showed multiple defects. The mean quotient between pulmonary blood circulation and systemic circulation (Qp:Qs) was 1.9 ± 0.7, and the mean systolic pulmonary artery pressure was 33.3 ± 10.6 mmHg. Device implantation was eventually successful in 99%; in 44 patients, more than 1 device was implanted either during the same procedure or in a second procedure. The mean fluoroscopy time, including diagnostics, was 8.8 ± 9 minutes. Complications during hospital stay were death (0.1%; sudden death 3 days after procedure), need for surgical intervention (0.5%; 2 perforations of the aortic root, 1 device embolization, 1 thrombus), embolization (0.5%) and pericardial effusion (0.5%).
After discharge and during follow up (in total, 1,723 patient years), no device-related deaths occurred; 5.9% of the patients had minor complications such as cardiac arrhythmias, asymptomatic thrombi (0.9%; all resolved under medical therapy) and pericardial effusion (0.9%; no sequelae); and 0.9% of the patients sustained a transient ischemic attack or minor stroke. During follow up, complete closure was achieved in 92% of the patients. The Qp:Qs ratio was reduced to mean levels of 1.0 ± 0.3, and the mean systolic pressure dropped to 28.3 ± 10.1 mmHg.

Ventricular Septal Defects
Over the last few years, percutaneous closure of ventricular septal defects has become an alternative to surgical repair.26 Several devices have been used for this purpose: the Sideris buttoned device, the Rashkind device, Gianturci coils, the Clamshell device, the CardioSEAL^® and CardioSEAL/ STARFlex device, the Amplatzer occluder family and the Nit-Occlud^® coils (Pfm AG, Cologne, Germany). Technically, ventricular septal defect closure is a more difficult procedure when compared to transcatheter atrial septal defect or patent foramen ovale closure. Its success necessitates precise anatomic definition of the defect and its relation to other cardiac structures. Depending on their location within the septum, defects can be classified as muscular or perimembranous. The most common defects are the perimembranous ventricular septal defect (approximately 70%), while muscular defects may occur in around 15% of patients. Indications for ventricular septal defect closure are symptoms of heart failure, signs of right-heart chamber overload and a history of endocarditis. In patients with an overload of right-heart chambers, closure is necessary in order to prevent pulmonary arterial hypertension, ventricular dysfunction, arrhythmias and aortic regurgitation. Ventricular septal rupture is a severe complication of myocardial infarction.²⁷ Device closure is feasible, but even more difficult than in congenital ventricular septal defects.
Worldwide data and experiences. Percutaneous closure of a ventricular septal defect remains one of the most challenging procedures in interventional cardiology. Chordae tendinae, aortic and tricuspid valves, high pressure in the left ventricle and disparity of the interventricular tissue represent tricky obstacles for final device attachment (further complicated by ventricular septal aneurysms and a multiperforated septum). Compared to percutaneous atrial septal defect closure, ventricular septal defect closure requires venous and arterial access to establish an arteriovenous wire loop. Muscular defects have been closed with transcatheter devices for the past 15 years. Although perimembranous defects are more common than muscular defects, they have become more amenable to closure since the introduction of the Amplatzer^® Membranous Ventricular Septal Defect Occluder. Of all ventricular septal defect occluding systems, the Amplatzer products (atrial septal defect device, membranous and muscular ventricular septal defect occluder, eccentric and concentric ventricular septal defect occluders, persistent ductus arteriosus device), the Nit-Occlud coils and the STARflex device have been the most effective in providing stable results. Surgical closure of ventricular septal defects is generally safe, but death may occur in 0.6–5% of patients.^28–32 Additionally, the procedure is associated with significant morbidity including complete atrioventricular block in 1–5% of cases,^28,29,33,34 and significant residual shunting in 1–10% of patients.^28,30,31,35 Percutaneous ventricular septal defect closure has been reported in the literature (Table 2). While ventricular septal defect closure in the 1980s and early 1990s was rather risky, results have improved with the new generation of ventricular septal defect coils and occluders.

Personal data and experiences. Ventricular septal defect closure was attempted in 56 patients (23 females and 33 males, mean age 45 ± 21.6 years). Devices were implanted as follows: 16 Nit-Occlud coils, 8 muscular and 17 membranous Amplatzer devices, 12 atrial septal defect Amplatzer devices, 1 patent foramen ovale Amplatzer and 3 patent ductus arteriosus Amplatzer devices. In 5 patients, a second device was implanted during a second procedure due to residual shunting. In 12 patients, the ventricular septal defect was located at the muscular part of the septum, and at the perimembranous part in 33 patients. All perimembranous ventricular septal defect patients were either treated with a membranous Amplatzer device or a Nit-Occlud coil. The mean ventricular septal defect diameter measured invasively was 7.2 ± 4.2 mm. Altogether, myocardial infarction was the origin of a ventricular septal defect in 9 patients, and 1 patient suffered from traumatic rupture of the septum.
Transcatheter occlusion was successful in 93% (57/61) of the procedures. Five patients underwent a repeat transcatheter device implantation due to residual leakage. One patient with a post myocardial infarction ventricular septal defect died within 12 hours of the implantation. Another patient with a ventricular septal defect after myocardial infarction was sent to surgery after the successful implantation of an Amplatzer atrial septal defect occluder due to recurrent ventricular tachycardia. In 1 patient with a congenital perimembranous ventricular septal defect, 2 Amplatzer devices embolized into the right chamber. Both occluders were successfully rescued by catheter techniques in the same procedure, and the third implant was released in an optimal position. After a mean follow up of 18.2 ± 18.6 months, only 8 patients (14%) showed residual shunting, which was minor in all of them.

Conclusion
It is now well accepted that transcatheter closure is the standard technique for atrial septal defect closure. It is as effective as surgery, but with less morbidity. Long-term follow-up data on ventricular septal defect occlusion are still lacking. Furthermore, closure of ventricular septal defects is a more complex and challenging procedure that requires technical expertise and precise delineation of the defect and its relation to other cardiac structures. A broad repertoire of devices is necessary, since ventricular septal defect position, form and complications are quite variable. Nevertheless, transcatheter closure is a safe and effective procedure in selected patients and a good alternative given the high morbidity and mortality rates associated with surgical closure of ventricular septal defects.

References

1. Campbell M. Natural history of atrial septal defect. Br Heart J 1970;32:820–826.
2. Craig RJ, Selzer A. Natural history and prognosis of atrial septal defect. Circulation 1968;37:805–815.
3. King TD, Thompson SL, Steiner C, Mills NL. Secundum atrial septal defect: Nonoperative closure during cardiac catheterization. JAMA 1976;235:2506–2509.
4. Mills NL, King TD. Late follow-up of nonoperative closure of secundum atrial septal defects using the King-Mills double-umbrella device. Am J Cardiol 2003;92:353–355.
5. Rome JJ, Keane JF, Perry SB, et al. Double-umbrella closure of atrial septal defects: Initial clinical applications. Circulation 1990;82:751–758.
6. Das GS, Voss G, Jarvis G, et al. Experimental atrial septal defect closure with a new, trans-catheter, self-centering device. Circulation 1993;88:1754–1764.
7. Latson LA. The CardioSEAL device: History, techniques, results. J Intervent Cardio 1998;11:501–505.
8. Prieto LR, Foreman CK, Cheatham JP, Latson LA. Intermediate term outcome of trans-catheter secundum atrial septal defect closure using the Bard Clamshell Septal Umbrella. Am J Cardiol 1996;78:1310–1312.
9. Justo RN, Nykanen DG, Boutin C, et al. Clinical impact of transcatheter closure of secundum atrial septal defects with the double umbrella device. Am J Cardiol 1996;77:889–892.
10. Pedra CA, Pihkala J, Lee KJ, et al. Trans-catheter closure of atrial septal defects using the CardioSEAL implant. Heart 2000;84:320–326.
11. Rao PS, Berger F, Rey C, et al. Results of trans-venous occlusion of secundum atrial septal defects with the 4th generation buttoned device: Comparison with 1st, 2nd, and 3rd generation devices. International Buttoned Device Trial Group. J Am Coll Cardiol 2000;36:583–592.
12. Masura J, Gavora P, Formanek A, Hijazi ZM. Trans-catheter closure of secundum atrial septal defects using the new self-centering Amplatzer septal occluder: Initial human experience. Cathet Cardiovasc Diagn 1997;42:388–393.
13. Sievert H, Babic UU, Hausdorf G, et al. Transcatheter closure of atrial septal defect and patent foramen ovale with the ASDOS device (a multi-institutional European trial). Am J Cardiol 1998;82:1405–1413.
14. Berger F, Vogel M, Alexi-Meskishvili V, et al. Comparison of results and complications of surgical and Amplatzer device closure of atrial septal defects. J Thorac Cardiovasc Surg 1999;118:674–680.
15. Du ZD, Hijazi ZM, Kleinman CS, et al. Comparison between transcatheter and surgical closure of secundum atrial septal defect in children and adults. Results of a multicenter nonrandomized trial. J Am Coll Cardiol 2002;39:1836–1844.
16. Butera G, Carminati M, Chessa M, et al. Percutaneous versus surgical closure of secundum atrial septal defect: Comparison of early results and complications. Am Heart J 2006;151:228–234.
17. Omeish A, Hijazi ZM. Transcatheter closure of atrial septal defects in children and adults using the Amplatzer Septal Occluder. J Intervent Cardiol 2001;14:37–44.
18. Carminati M, Giusti S, Hausdorf GA, et al. European multicentric experience using the CardioSEAL and STARFlex double umbrella devices to close interatrial communications holes within the oval fossa. Cardiol Young 2000;10:519–526.
19. Jones TK, Latson LA, Zahn E, et al for the 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.
20. Chessa M, Carminati M, Butera G, et al. Early and late complications associated with transcatheter occlusion of secundum atrial septal defect. J Am Coll Cardiol 2002;39:1061–1065.
21. Vincent RN, Raviele AA, Diehl HJ. Single-center experience with the HELEX septal occluder for closure of atrial septal defects in children. J Intervent Cardiol 2003;16:79–82.
22. Purcell IF, Brecker SJ, Ward DE. Closure of defects of the atrial septum in adults using the Amplatzer device: 100 consecutive patients in a single center. Clin Cardiol 2004;27:509–513.
23. Krumsdorf U, Ostermayer S, Billinger K. Incidence and clinical course of thrombus formation on atrial septal defect and patient foramen ovale closure devices in 1,000 consecutive patients. J Am Coll Cardiol 2004;43:302–309.
24. Masura J, Gavora P, Podnar T. Long-term outcome of transcatheter secundumtype atrial septal defect closure using Amplatzer septal occluders. J Am Coll Cardiol 2005;45:505–507.
25. 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 vs. sufficient rims. Am J Cardiol 2002;90:865–869.
26. Hijazi ZM. Catheter closure of atrial septal and ventricular septal defects using the Amplatzer devices. Heart Lung Circ 2003;12:S63–S72.
27. Crenshaw BS, Granger CB, Birnbaum Y, et al; for the GUSTO-I Trial Investigators. Risk factors, angiographic patterns, and outcomes inpatients with ventricular septal defect complicating acute myocardial infarction. Circulation 2000;101:27–32.
28. Mavroudis C, Backer CL, Jacobs JP. Ventricular septal defect. In: Mavroudis C, Backer CL (eds). Pediatric Cardiac Surgery, 3rd Edition. St. Louis: Mosby, Inc.; 2003, pp.298–320.
29. Hobbins SM, Izukawa T, Radford DJ, et al. Conduction disturbances after surgical correction of ventricular septal defect by the atrial approach. Br Heart J 1979;41:289–293.
30. Wollenek G, Wyse R, Sullivan I, et al. Closure of muscular ventricular septal defects through a left ventriculotomy. Eur J Cardiothorac Surg 1996;10:595–598.
31. Serraf A, Lacour-Gayet F, Bruniaux J, et al. Surgical management of isolated multiple ventricular septal defects: Logical approach in 130 cases. J Thorac Cardiovasc Surg 1992;103:347–342.
32. Backer CL, Winters RC, Zales VR, et al. The restrictive muscular ventricular septal defect: How small is too small to close? Ann Thorac Surg 1993;56:1014.
33. Ross-Hesselink JW, Mejiboom FJ, Spitaels SEC, et al. Outcome of patients after surgical closure of ventricular septal defect at a young age: Longitudinal follow-up of 22–34 years. Eur Heart J 2004;25:1057–1062.
34. Bol-Raap G, Weerheim J, Kappetein AP, et al. Follow-up after surgical closure of congenital ventricular septal defect. Eur J Cardiothorac Surg 2003;24:511–515.
35. Kitagawa T, Durham LA, Mosca RS, Bove EL. Techniques and results in the management of multiple ventricular septal defects. J Thorac Cardiovasc Surg 1998;115:848–856.
36. Chessa M, Carminati M, Cao QL, et al. Transcatheter closure of congenital and acquired muscular ventricular septal defects using the Amplatzer device. J Invasive Cardiol 2002;14:322–327.
37. Knauth AL, Lock JE, Perry SB, et al. Transcatheter device closure of congenital and postoperative residual ventricular septal defects. Circulation 2004;110:501–507.
38. Holzer R, Balzer D, Cao QL, et al. Device closure of muscular ventricular septal defects using the Amplatzer muscular ventricular septal defect occluder: Immediate and mid-term results of a U.S. registry. J Am Coll Cardiol 2004;43:1257–1263.
39. Masura J, Gao W, Gavora P, et al. Percutaneous closure of perimembranous ventricular septal defects with the eccentric Amplatzer device: Multicenter follow-up study. Pediatr Cardiol 2005;26:216–219.
40. Carminati M, Butera G, Chessa M, et al. Transcatheter closure of congenital ventricular septal defects with Amplatzer occluders. Am J Cardiol 2005;96(Suppl):52L–58L.
41. Arora R, Trehan V, Thakur AK, et al. Transcatheter closure of congenital muscular ventricular septal defect. J Intervent Cardiol 2004;17:109–115.
42. Carminati M, Butera G, Chessa M, et al. Transcatheter closure of congenital ventricular septal defects: Results of the European Registry. Eur Heart J 2007;28:2361–2368.