Ann Thorac Surg 1999;67:841-843
© 1999 The Society of Thoracic Surgeons
Case Reports
Heart/single-lung transplant for a "failed Fontan" with pulmonary A-V malformation
Antonio R. Mott, MDa,d,
Thomas L. Spray, MDb,e,
Nancy D. Bridges, MDc,f
a Department of Anesthesiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
b Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
c Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
d Division of Anesthesiology and Critical Care Medicine, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
e Division of Cardiothoracic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
f Division of Cardiology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
Accepted for publication August 28, 1998.
Address reprint requests to Dr Bridges, Pediatric Cardiology, The Children’s Hospital of Philadelphia, 34th St and Civic Center Blvd, Philadelphia, PA 19104
e-mail: Bridges{at}email.chop.edu
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Abstract
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Pulmonary arteriovenous malformation can occur in patients with functional single ventricle after a cavopulmonary connection. There is no effective medical treatment for this complication. Pulmonary arteriovenous malformations may regress over time after heart transplantation, but may be a source of significant perioperative morbidity. We report the case of a woman with single ventricle, ventricular dysfunction, and bilateral pulmonary arteriovenous malformations who had successful treatment of both cardiac and pulmonary failure with en bloc heart and right lung transplantation.
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Introduction
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A 20-year-old woman with heterotaxia (polysplenia) and complex congenital heart disease consisting of dextrocardia, complete common atrioventricular canal severely malaligned to the right ventricle with segmental anatomy {A,D,L}, interrupted inferior vena cava with azygos continuation to a right superior vena cava, hepatic veins entering the left side of the common atrium, ipsilateral pulmonary venous connection, pulmonary atresia with stenotic but confluent pulmonary arteries, patent ductus arteriosus, and aorta arising from the right ventricle was referred for evaluation for thoracic organ transplantation. At 2 years of age, a right Blalock-Taussig shunt was performed, and at 5 years of age she underwent a modified Fontan procedure: right superior vena cava to right pulmonary artery anastomosis, and diversion of hepatic venous blood flow to the left pulmonary artery through a circumferential intracardiac baffle. Subsequently, atrial tachyarrhythmias, ventricular dysfunction, and bilateral pulmonary arteriovenous malformations (PAVMs) (right > left) with profound cyanosis developed (Fig 1). Her resting arterial oxygen saturation during spontaneous respiration in room air was 62%, and her hemoglobin was 16 g/dL. She had markedly diminished exercise capacity (New York Heart Association class IV).
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Fig 1. Pretransplant angiogram. Contrast injection showing the diffuse pulmonary arteriovenous malformations in the right lung.
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Coil embolization of several of the right lung PAVMs, performed at another institution, resulted in no improvement in systemic arterial oxygen saturation, exercise tolerance, or overall functional capacity. Holter monitoring revealed alternating junctional bradycardia and supraventricular tachyardia that was refractory to medical therapy. A cardiac catheterization performed under general anesthesia at the time of her pretransplant evaluation revealed a cardiac index of 3.3 L · min-1 · m-2 with a central venous pressure of 13 mm Hg and a pulmonary to systemic flow ratio of 0.46, with no intracardiac shunt. Temporary balloon occlusion of the right pulmonary artery, performed during administration of 100% oxygen, resulted in an increase in arterial oxygen saturation from 80% to 94%.
Progressive cyanosis led to hospitalization in the cardiac intensive care unit where treatment with continuous isoproteronol infusion resulted in improved oxygenation and exercise tolerance. After 32 months on the transplant list and 6 months of hospitalization, she underwent en bloc heart and right lung transplantation with a right bronchial anastomosis, anastomosis of the donor main pulmonary artery to the recipient left pulmonary artery, and implantation of the left pulmonary venous confluence into the left atrium. Except for postoperative bleeding from mediastinal bronchial arterial vessels that required reoperation on the evening of operation, her postoperative course was unremarkable. She was extubated on postoperative day 2 without incident and did not require significant inotropic support. Her arterial oxygen saturation in room air initially was 93% and subsequently ranged from 94% to 96%. She was discharged 2 weeks after thoracic organ transplantation with good graft function and no postoperative sequelae. At follow-up 9 months later, she has had no graft rejection and continues to have good cardiopulmonary function. Her exercise tolerance has dramatically improved (New York Heart Association class I), allowing her to complete a 20-km bicycle event.
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Comment
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The presence of PAVMs leads to progressive hypoxemia and disability in severely affected patients. Although there have been several theories as to the origin of PAVMs, their cause remains speculative. Patients with heterotaxia are known to be at increased risk for the development of PAVMs [1]. It has been proposed that hepatic venous blood contains a substance that prevents the development of PAVMs; thus patients who have had surgical procedures in which hepatic blood flow has been diverted from the pulmonary vasculature are at increased risk of developing PAVMs. This theory is supported by reports of regression of PAVMs after operative procedures that have allowed hepatic blood flow to traverse the pulmonary vascular bed [1–3]. Another theory implicates flow dynamics of the superior cavopulmonary connection in particular, and also the total cavopulmonary connection: it is hypothesized that these procedures submit the pulmonary vascular bed to a low-velocity, nonpulsatile flow and thereby promote the development of PAVMs [1].
The patient described in this report had undergone a modified Fontan procedure that resulted in the diversion of nearly all hepatic venous blood to the left lung, in which the development of PAVM was minimal, whereas blood flow to the severely affected right lung originated almost exclusively from the superior vena cava. This finding lends concern to the practice of offsetting the superior and inferior venae cava anastomosis in a total cavopulmonary connection–modified Fontan operation to improve flow dynamics. It may in fact predispose the patient to the development of PAVM in the lung supplied predominantly by the superior vena cava.
Regression of PAVMs after orthotopic heart transplantation alone has been reported [4, 5], and this is probably the operation of choice for patients with minimal or moderate intrapulmonary shunting caused by PAVMs. However, these patients will have persistent hypoxemia in the immediate perioperative period. If the volume of right to left shunting is large, the patient will be at risk for graft dysfunction secondary to hypoxemia, and for paradoxical emboli.
The patient reported here had severe cardiopulmonary dysfunction attributable to intractable dysrhythmias, cardiac diastolic dysfunction, and a large intrapulmonary right to left shunt occurring primarily in the right lung; these problems were addressed with en bloc heart and right lung transplantation. This management strategy has several noteworthy benefits. Postoperative cyanosis is diminished by the presence of the nonshunting transplanted lung. In the event of graft dysfunction or rejection in the transplanted lung, the presence of the unaffected native lung will reduce the risk of respiratory failure. The technical aspects of performing en bloc heart and right lung transplantation are somewhat greater than either orthotopic heart transplantation alone or of en bloc heart/lung transplantation. This is an important consideration in planning an operation for a patient who is already at greatly increased risk of bleeding because of chronic cyanosis and prior chest operation. The disadvantage of increased technical difficulty may be balanced in some cases by the advantage of limiting entry into one thorax.
The approach to thoracic organ transplantation—who should be listed, when, and for what specific operation—must be individualized for patients with complex congenital heart disease and pulmonary dysfunction, and must be based on an evaluation that includes a complete surgical history and complete hemodynamic and pulmonary evaluation. Patients with mild to moderate hypoxia secondary to PAVMs will probably be well-served by orthotopic heart transplantation alone. When the primary indication for transplantation is lung dysfunction—as for example in the case of irreversible pulmonary hypertension—serious consideration should be given to lung transplantation alone, as long as a durable two-ventricle repair of the heart can be achieved. We have taken this approach in patients with transposition of the great arteries and tetralogy of Fallot [6]. However, we have been reluctant to take this approach with functional single ventricle. Thus, when PAVMs appear to be the major contributor to disability in a patient with single ventricle, and particularly if one lung is more seriously affected than the other, we recommend the approach described in this report.
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References
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Srivastava D., Preminger T., Lock J., et al. Hepatic venous blood and the development of pulmonary arteriovenous malformations in congenital heart disease. Circulation 1995;92:1217-1222.[Abstract/Free Full Text]
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Knight W., Mee R. A cure for pulmonary arteriovenous fistulas?. Ann Thorac Surg 1995;59:999-1001.[Abstract/Free Full Text]
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Shah M., Rychik J., Fogel M., Murphy J., Jacobs M. Pulmonary AV malformation after superior cavopulmonary connection: resolution after inclusion of hepatic veins in the pulmonary circulation. Ann Thorac Surg 1997;63:960-963.[Abstract/Free Full Text]
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Graham K., Sondheimer H., Schaffer M. Resolution of cavopulmonary shunt associated pulmonary arteriovenous malformation after heart transplant. J Heart Lung Transplant 1997;16:1271-1274.[Medline]
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Lamour J., Hsu D., Kichuk M., et al. Regression of pulmonary arteriovenous malformation following heart transplantation. J Heart Lung Transplant 1997;16:71.
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Bridges N.D., Mallory G.B., Huddleston C.B., Canter C.E., Sweet S.C., Spray T.L. Lung transplantation in children and young adults with cardiovascular disease. Ann Thorac Surg 1995;59:813-821.[Abstract/Free Full Text]
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E. A. Bacha, R. A. Jonas, J. E. Mayer Jr, S. Perry, and P. J. del Nido
MANAGEMENT OF PULMONARY ARTERIOVENOUS MALFORMATIONS AFTER SURGERY FOR COMPLEX CONGENITAL HEART DISEASE
J. Thorac. Cardiovasc. Surg.,
January 1, 2000;
119(1):
175 - 176.
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Abstract
Introduction
