Ann Thorac Surg 2000;70:289-291
© 2000 The Society of Thoracic Surgeons
Case report
Intraoperative balloon angioplasty for aortic coarctation after Norwood operation
Isao Shiraishi, MDa,
Masaaki Yamagishi, MDa,
Tatsujiro Oka, MDa,
Ayumi Kawakita, MDa,
Kenji Hamaoka, MDa
a Divisions of Pediatrics and Pediatric Cardiovascular Surgery, Children’s Research Hospital, Kyoto Prefectural University of Medicine, Kyoto, Japan
Address reprint requests to Dr Shiraishi, Division of Pediatrics, Children’s Research Hospital, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamikyo-ku, Kyoto, Japan 602-8566
e-mail: isao{at}koto.kpu-m.ac.jp
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Abstract
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We report intraoperative balloon angioplasty for recurrent aortic coarctation in hypoplastic left heart syndrome. After bidirectional Glenn anastomosis, balloon angioplasty was performed via ascending aorta. Pressure gradient across the coarctation decreased from 45 to 8 mm Hg. Intravascular ultrasound revealed successful splits of thickened intima without any extensive dissection. Intraoperative balloon angioplasty is a safe and favorable procedure for hypoplastic left heart syndrome because balloon inflation before bidirectional Glenn anastomosis could induce serious ventricular collapse or arrhythmias.
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Introduction
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Despite modifications in surgical reconstruction of the aortic arch, recurrent aortic coarctation remains a significant problem in patients with hypoplastic left heart syndrome after Norwood operation [1, 2]. Unlike isolated aortic coarctations, balloon angioplasty of these patients is very risky because the neoaortic coarctation is a potent cause of ventricular dysfunction [3–5]. We introduced intraoperative balloon angioplasty during bidirectional Glenn procedure to avoid serious complications.
A boy was born at 38 weeks of gestation with a body weight of 2,958 g. Two days after birth, he was found to have systolic heart murmur and mild cyanosis. Echocardiography was performed and hypoplastic left heart syndrome was suspected. He was transferred to our University Hospital 5 days after birth. Echocardiography examination revealed mitral atresia, aortic atresia, hypoplastic left ventricle and left atrium, ventricular septal defect (5 mm in diameter), atrial septal defect (3 mm in diameter), hypoplastic ascending aorta, and patent ductus arteriosus. Color Doppler examination demonstrated mild tricuspid regurgitation and right-to-left shunt via ductus. Retrograde radial artery angiography showed hypoplastic ascending aorta, aortic coarctation, and normal coronary arteries. At 13 days after birth, modified Norwood operation was performed. Ductal tissue was excised from the aorta. A piece of pulmonary homograft was used to supplement the aortic arch repair. His postoperative course was uneventful for 3 months.
Three and a half months after Norwood operation, he began to show tachypnea and failure to thrive. Chest roentgenogram demonstrated cardiac enlargement (cardiothoracic ratio = 72%) and increased pulmonary blood flow. Two-dimensional echocardiography and Doppler echocardiography revealed severe tricuspid regurgitation, deteriorated right ventricular contraction (fraction shortening = 25%), thickened ventricular free wall (left ventricular free wall = 6.3 mm), and aortic coarctation (flow velocity = 3.6 m/s). Cardiac catheterization and angiography demonstrated ejection fraction of the right ventricle 46.8%, pulmonary mean pressure 13 mm Hg, pulmonary resistance 1.5 U.m2, no distortion of pulmonary arteries, severe tricuspid regurgitation, right ventricular end-diastolic pressure 7 mm Hg, and aortic coarctation (Fig 1A, 2.9 mm in diameter, pressure gradient = 35 mm Hg). Because the hemodynamic data satisfied the criteria for a bidirectional cavopulmonary connection, the second operation was performed at the age of 4 months. Instead of surgical reconstruction, intraoperative balloon angioplasty for aortic coarctation was designed because of his deteriorated ventricular function.
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Fig 1. (A) Retrograde ascending aortogram of the patient before balloon angioplasty. Neoaortic coarctation is noted at the isthmus (2.9 mm in diameter, arrowhead). (B) Roentgenogram image of the intraoperative balloon angioplasty. (C) Intravascular ultrasound after the balloon angioplasty. Small splits are found at the thickened intima (arrowheads). Bar, 2 mm. (D) Retrograde ascending aortogram of the patient after the balloon angioplasty. The coarctation is successfully dilated (6.2 mm in diameter, arrowhead).
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After median sternotomy, a temporary venous bypass was made between the innominate vein and right atrial appendage, and Blalock-Taussig shunt was dissected. End-to-side anastomosis of superior vena cava and right pulmonary artery was accomplished without cardiopulmonary bypass. To decrease ventricular afterload during balloon inflation, a temporal arterial shunt was established between peripheral end of Blalock-Taussig shunt and the femoral artery. Then, a 6F catheter introducer was inserted into the ascending aorta and tightly fixed. Intravascular ultrasound before angioplasty revealed extremely thickened intima at the aortic coarctation. The pressure gradient between the ascending and descending aorta was 45 mm Hg. Balloon angioplasty was performed using 6 and 8 mm PowerFlex (Johnson and Johnson Medical, Arlington, TX) catheters at 6 atm, maintained for 5 to 10 seconds, repeatedly (Fig 1B). After the sixth inflation, the pressure gradient between the ascending and descending aorta decreased to 8 mm Hg. The intravascular ultrasound after balloon dilatation demonstrated small splits at intima without any extensive dissection of aorta (6.2 mm in diameter, Fig 1C). The temporal arterial shunt was then removed and the operation was completed.
Three months after the second operation, cardiac catheterization and angiography was performed. The data demonstrated that the diameter of the coarctation was 7.4 mm (Fig 1D), peak-to-peak systolic pressure gradient was 13 mm Hg, ejection fraction of the right ventricle was 59.6%, ventricular end-diastolic pressure was 8 mm Hg, and there was mild tricuspid regurgitation and no evidence of pulmonary artery stenosis or hypoplasia. Ten months after the bidirectional Glenn procedure, the postoperative course was uneventful. The latest cardiac catheterization showed that the peak-to-peak systolic pressure gradient across the coarctation was 5 mm Hg. The patient is now waiting for Fontan procedure.
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Comment
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Postoperative neoaortic coarctation is a critical problem in patients with hypoplastic left heart syndrome after the Norwood operation [1, 2]. Unlike isolated aortic coarctation, ductal tissue in patients with hypoplastic left heart syndrome usually forms a sling completely encircling the lumen at the site of junction [6]. It sometimes extends to the aortic isthmus and the descending aorta both proximally and distally. This extension of residual ductal tissue is believed to be responsible for a high incidence of recurrent aortic coarctation.
Intraoperative balloon angioplasty has several advantages for patients with hypoplastic left heart syndrome after Norwood operation. First, sufficient surgical reconstruction for the recurrent coarctation is technically difficult because of severe adhesion around the distal aortic arch. Second, the balloon dilatation before the bidirectional Glenn procedure has relatively high morbidity and mortality in patients with hypoplastic left heart syndrome [3, 4]. It appears that neoaortic coarctation after the Norwood operation tends to increase pulmonary blood flow via Blalock-Taussig shunt, right ventricular enlargement, impaired tricuspid regurgitation, and right ventricular dysfunction. The combination of shunt dependent circulation, ventricular dysfunction, and acute ventricular afterload during balloon inflation may cause cardiovascular collapse. Recurrent ventricular fibrillation during percutaneous balloon angioplasty has been also reported in patients with hypoplastic left heart syndrome after the Norwood operation [5]. In these cases, any ventricular arrhythmias have not been recorded before the angioplasty. The complex hemodynamics is thought to result in conditions that induce ventricular tachycardia and fibrillation. To avoid the ventricular collapse and arrhythmias, balloon angioplasty should be followed by the bidirectional Glenn anastomosis because the volume reduction in the right ventricle after the bidirectional Glenn anastomosis decreases the risk of these complications. In our case, a temporal bypass between the stump of the Blalock-Taussig shunt and the femoral artery was also established to avoid the ventricular afterload during balloon inflation. Third, intraoperative balloon angioplasty for aortic coarctation also has technical advantages. In our case, 6F or larger-sized catheter introducers could be inserted via the ascending aorta for the patient with 3.4 kg body weight. This allowed us to use larger balloon catheters for dilatation compared with a femoral arterial approach. In conjunction with intravascular ultrasound after each balloon inflation, intraoperative balloon angioplasty for aortic coarctation during bidirectional Glenn procedure is a safe and favorable intervention in patients with hypoplastic left heart syndrome after the Norwood operation.
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References
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Accepted for publication November 24, 1999.
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Abstract
Introduction
