| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J Thorac Cardiovasc Surg 2006;131:471-473
© 2006 The American Association for Thoracic Surgery
Brief Communication |
Department of Paediatric Cardiac Surgery, Diana, Princess of Wales Children's Hospital, Birmingham, United Kingdom.
Received for publication June 20, 2005; revisions received September 19, 2005; accepted for publication September 27, 2005. * Address for reprints: W. J. Brawn, FRCS, FRACS, Department of Paediatric Cardiac Surgery, Diana, Princess of Wales Children's Hospital, Steelhouse Lane, Birmingham, B4 6NH, UK (Email: william.brawn{at}bch.nhs.uk).
After relief of obstructive lesions in Shone syndrome, left ventricular dysfunction might persist, with high left ventricular end-diastolic pressure (LVEDP) and pulmonary hypertension (PHT).
1
We reasoned that the right ventricle (RV), having been trained by means of PHT, could support the systemic circulation. The left ventricle (LV), although dysfunctional in the systemic circulation, would be adequate to support the pulmonary circulation. With this arrangement, PHT might resolve. This was achieved in 2 patients with the combined atrial and arterial switch procedure (double-switch procedure), which is usually used in congenitally corrected transposition.
2
Clinical Summary
Patient 1
An 18-month-old boy (7.5 kg) with Shone syndrome and previous coarctation and parachute mitral valve repair presented with failure to thrive and PHT. His aortic valve was bicuspid. Preoperative evaluation showed severe mitral regurgitation and a non–apex-forming LV with endomyocardial fibroelastosis, although its end-diastolic diameter was normal (25 mm; predicted range, 21-31 mm). LVEDP was 17 mm Hg. Pulmonary artery (PA) pressures were 120/70 mm Hg (mean, 85 mm Hg), decreasing to 65/50 mm Hg (mean, 45 mm Hg) with increased inspired oxygen. Systemic pressures were 95/60 mm Hg.
A double-switch procedure was performed. A supravalve ring was excised from the mitral valve, and its anterior commissure was partially closed. A 13-mm pulmonary homograft was placed in the native aortic root (neopulmonary outflow tract) because coronary artery mobilization necessitated partial excision of the bicuspid aortic valve. Postoperative course was uneventful without pulmonary vasodilators (eg, nitric oxide), with extubation on the second day.
Patient 2
A 34-month-old girl (10.9 kg) with Shone syndrome and previous balloon valvuloplasty for aortic stenosis presented with failure to thrive and PHT. Preoperative evaluation showed severe tricuspid regurgitation, dysplastic mitral valve, a non–apex-forming LV with endomyocardial fibroelastosis, and an LVEDP of 28 mm Hg, although end-diastolic diameter was normal (32 mm; predicted range, 23-35 mm). PA pressures were 82/35 mm Hg (mean, 52 mm Hg), with a wedge pressure of 24 mm Hg. Systemic pressures were 78/39 mm Hg. The reversibility of PHT was not tested because transpulmonary gradient was low.
A double-switch procedure was performed with tricuspid valve repair with De Vega annuloplasty.
3
The mitral valve was not repaired. The postoperative course was complicated by high temperatures and an inflammatory response. The patient was extubated 8 days later. No pulmonary vasodilators were used.
Comments on Surgical Technique
In healthy hearts the PA is anterior to the aorta. Accordingly, the newly neo-PA remained posterior to the reconstructed aorta (Figure 1). The coronary arteries required more mobilization than usual to relocate them to medially hinged flaps on the neoaorta.
4
Routine cardiopulmonary bypass at 18°C, periods of circulatory arrest, and crystalloid cardioplegia (repeated every 30 minutes) were used. Bypass, crossclamp, and total circulatory arrest times were 172, 150, and 56 minutes, respectively, in the first patient, and 174, 131, and 11 minutes, respectively, in the second. Postoperatively, adrenaline, dobutamine, and milrinone infusions were instituted.
|
In both patients there was laminar flow in both outflow tracts and in the systemic and pulmonary venous pathways. PA pressures decreased immediately and continued to decrease over the follow-up periods (Figure 2). Right ventricular dysfunction persisted in the first patient who underwent heart transplantation 2 years later, when the mean PA pressure was 20 mm Hg. This was complicated by bleeding and cerebral injury. He died 3 months later. The second patient is progressing well and thriving 3 months after the operation. She has mild-to-moderate right ventricular dysfunction.
|
Failure to thrive, PHT, and increased LVEDP might complicate relief of obstructive lesions in Shone syndrome. This was seen in our 2 patients and also reported in isolated aortic stenosis.
5
Because of high LVEDP, small LV, and PHT, we believed that further surgical intervention to the left heart lesions, in particular the mitral valve, would not be successful. Cardiac transplantation was contraindicated because of PHT. Heart-lung transplantation was not considered because of its poor results.
We reasoned that if pulmonary venous pressures could be reduced, PHT should resolve. In both patients the RV was trained by using PHT at systemic pressures. We believed that the RV in the systemic circulation would be more efficient than the impaired LV and that its lower end-diastolic pressures would resolve the PHT. This was observed in the first patient, who later underwent transplantation for persisting right ventricular dysfunction. The second patient is markedly improved and thriving, with decreasing PA pressures.
The double-switch procedure is an extreme form of palliation for Shone syndrome but might allow resolution of PHT. The RV might support the systemic circulation for many years. If it fails, in the setting of low PA pressures, cardiac transplantation would be an option.
References
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
