Transcatheter Closure of a Large Aortopulmonary Window with Severe Pulmonary Arterial Hypertension Beyond Infancy

ABSTRACT: A patient presented with a large aortopulmonary window and significant pulmonary hypertension, and underwent successful closure with muscular ventricular septal occluder (ShenZhen Lifetech Scientific Inc.) without complications in short-term follow-up.

J INVASIVE CARDIOL 2012;24(2):E24-E26

Key words: percutaneous closure, aortopulmonary septal defect

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Aortopulmonary window (APW) is a rare congenital heart defect occurring in 0.1%-0.2% of patients with congenital heart disease. Large defects result in severe left-to-right shunt, present early with congestive heart failure, and need early treatment to avoid the risk of progressive pulmonary vascular disease. There have been reports of transcatheter closure of APWs but most have been in small defects. We present a case of large distal APW with severe pulmonary arterial hypertension, which was closed with a muscular ventricular septal occluder. It is probably one of the largest APWs closed by transcatheter technique.

Case Report

A 4-year-old girl weighing 12 kgs presented with history of recurrent chest infection. She had a large volume pulse with blood pressure of 100/50 mmHg. The precordium was hyperdynamic and she was saturating 90% in room air. The pulmonic component of second heart sound was loud and there was a grade 3/6 systolic murmur in the left second intercostal space. Chest x-ray showed pulmonary plethora and cardiomegaly. Echocardiography confirmed a large distal APW. There were no associated cardiac anomalies. A 64-slice CT angiogram with 3D reconstruction showed that the aortopulmonary window measured 16 x 14 mm and the lower margin of the defect was 6 mm away from the coronary ostium. It also clearly showed that the upper margin of the defect did not involve the ostium of the right pulmonary artery. This information gave us confidence to attempt a percutaneous device closure.

The child was taken up for assessment of PVR and device closure of the APW. The femoral artery and vein were percutaneously cannulated. Unfractionated heparin (100 units/kg) was administered after vascular access was obtained. There was a 20% increase in saturation at the left pulmonary arterial level compared to superior vena cava. She had high pulmonary artery pressures (76/44 mmHg, mean=55 mmHg, 2/3 of systemic pressures), Qp/Qs was 3.5:1 and PVRI was 6·1 Wood units·m2. Ascending aortography demonstrated a large distal APW measuring 14 mm. As the defect was about 6 mm away from coronary ostium, using an atrial septal occluder (which has a 7 mm rim) could have compromised the coronary opening so we decided to use a muscular VSD device. The defect was crossed antegradely from pulmonary artery and an extra stiff Amplatz (360 cm) wire (Cook Medical) was placed in the descending aorta. A 9 Fr long sheath (Cook) was tracked over the wire, across the APW, and was lodged into the descending aorta. An 18 mm muscular VSD device (ShenZhen) was introduced into the long sheath and the distal (left ventricular) disc was opened in the aorta. The device was then retracted towards the defect, and the proximal (right ventricular) disc was opened on the pulmonary arterial side of the defect. The mean PA pressure dropped to 36 mmHg. Appropriate device position was confirmed both by transthoracic echocardiography and angiograms in multiple views. There was no residual flow across and no obstruction to either aortic or pulmonary arterial flow. She was put on oral aspirin for 6 months and her 1-year follow-up showed improved physical growth, no obstruction to aortic or pulmonary arterial flow, and near normalization of PA pressures on 2D echocardiogram.

Discussion

The first report of an aortopulmonary window was that of Elliotson in 1830.¹ APW refers to a communication between the main pulmonary artery and the ascending aorta with separate semilunar valves and accounts for 0.1%-0.2% of all congenital heart defects. Mori et al² classified aortopulmonary connection into 3 types.

• Type 1 is the most common type and refers to a small defect midway between the semilunar valves and the pulmonary artery bifurcation.
• Type 2 is a more distal defect with the distal border formed by the pulmonary artery bifurcation.  
• Type 3 is a large confluent defect involving almost the entire aortopulmonary septum and is rare.  

Closure of the defect is indicated in all patients with APW to abate the catabolic effects of congestive heart failure as well as to avoid the risks of progressive pulmonary vascular disease. The standard treatment is surgical closure, which most often involves a transaortic approach using median sternotomy and cardiopulmonary bypass. This also allows for correction of associated anomalies. Transcatheter closure of APW is not frequent in literature due to relative rarity of defects with good margins and the presence of associated anomalies. Most reports on transcatheter closure of APW have been in smaller defects. Stamato et al³ used a modified double umbrella occluder system to close APW in a 3-year-old while Tulloh and Rigby⁴ used a double umbrella system to close a 3 mm APW in a 9-week-old infant. There have been reports of closure of APW with buttoned device⁵ and a residual APW with Amplatzer device.⁶ In recent years, Amplatzer duct occluders have been used increasingly to close APWs of sizes ranging from 2 mm to 8.7 mm in patients age 6 months to 10 years.^7-10 Use of atrial septal occluder has been reported without complications in an infant with 5 mm APW¹¹ as well as a 16-year-old adolescent with 7 mm APW.⁸ Large APWs in symptomatic infants have also been closed with a Blockaid device, Muscular VSD device, and PMVSD device.¹² All the cases reported previously are either relatively large APWs in symptomatic infants or small APWs (which have a low propensity to cause progressive pulmonary vascular disease) in older age group.  This case is unique because the defect was large, distally located, associated with severe pulmonary arterial hypertension and elevated PVR, presented in an older age group, and was still amenable to percutaneous closure.

Conclusion

We conclude that transcatheter device closure of APW should be considered when the anatomy is favorable in terms of location, size, and margins of the defect as well as favorable physiology in terms of reversible PVR even in the setting of near systemic PA pressures. CT angiogram gives additional information in planning the feasibility of transcatheter closure in such large defects.

References

1. Elliotson J. Case of malformation of the pulmonary artery and aorta. Lancet. 1830;247-250.
2. Mori K, Ando M, Takao A, Ishikawa S, Imai Y. Distal type of aortopulmonary window: Report of 4 cases. Br Heart J. 1978;40(6):681-689.
3. Stamato T, Benson LN, Smallhorn JF, Freedom RM. Transcatheter closure of an aortopulmonary window with a modified double umbrella occluder system. Cathet Cardiovasc Diagn. 1995;35(2):165-167.
4. Tulloh RMR, Rigby ML. Transcatheter umbrella closure of aorto-pulmonary window. Heart. 1997;77(5):479-480.
5. Jureidini SB, Spadaro JJ, Rao PS. Successful transcatheter closure with the buttoned device of aortopulmonary window in an adult. Am J Cardiol. 1998;81(3):371-372.
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8. Naik GD, Chandra VS, Shenoy A, et al. transcatheter closure of aortopulmonary window using Amplatzer device. Catheter Cardiovasc Interv. 2003;59(3):402-405. 
9. Sivakumar K, Francis E. Transcatheter closure of distal aortopulmonary window using Amplatzer device. Congenit Heart Dis. 2006;1(6):321-323.
10. Viswanathan S, Vaidyanathan B, Krishna Kumar R. Transcatheter closure of the aortopulmonary window in a symptomatic infant using the Amplatzer ductal occluder. Heart. 2007;93(12):1519.
11. Pillekamp F, Hannes T, Koch D, Brockmeier K, Sreeram N. Transcatheter closure of symptomatic aortopulmonary window in an infant. Images Paediatr Cardiol. 2008;35:11-17.
12. Trehan V, Nigam A, Tyagi S. Percutaneous closure of nonrestrictive aortopulmonary window in three infants. Catheter Cardiovasc Interv. 2008;71(3):405-411.

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From the Department of Pediatric Cardiology, Apollo Health City, Jubilee Hills, Hyderabad, India.
Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.
Manuscript submitted July 2, 2011 and final version accepted August 10, 2011.
Address for correspondence: Dr. Anurakti Srivastava, Department of Pediatric Cardiology, Apollo Health City, Jubilee Hills, Hyderabad, India. Email: anurakti07@yahoo.co.in