Ann Thorac Surg 1997;64:1174-1177
© 1997 The Society of Thoracic Surgeons
Case Report
Unusual Cause of Pulmonary Hypertension and Congestive Heart Failure in a Newborn
Eric N. Mendeloff, MD,
Charles B. Huddleston, MD,
Mark Payne, MD
Department of Cardiothoracic Surgery and Division of Pediatric Cardiology, St. Louis Children's Hospital, St. Louis, Missouri
Accepted for publication May 9, 1997.
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Abstract
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Anomalous systemic arterial supply to a lobe of the lung is a rare cause of pulmonary hypertension and congestive heart failure in the newborn period. We report the presentation and successful treatment of a neonate with this unusual anatomy. Proper diagnosis required both echocardiography and aortography, and surgical resection of the involved lobe was curative.
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Introduction
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Anomalous arterial connection between the aorta and lung tissue was first described by Huber in 1777. Such aberrant systemic arterial supply to a segment of lung represents a spectrum of lesions from sequestration (no bronchial or pulmonary arterial connections) to cases in which there are normal bronchial connections with dual arterial supply (pulmonary and systemic) to a portion of the lung. Anomalous systemic arterial supply to the lung may result in high-output congestive heart failure if the aberrant flow traverses the pulmonary capillary bed rapidly or directly connects to the pulmonary veins creating the physiologic equivalent of an arteriovenous fistula. The purpose of this article is to document our treatment of a newborn who presented with the relatively rare entity of pulmonary hypertension and congestive heart failure secondary to systemic arterial supply to a nonsequestered right lower lobe.
The patient was a 4-day-old, 3-kg female infant born after a term gestation who was discharged home from the nursery on day 1 of life in good condition. Over the next 3 days her oral intake decreased markedly in association with increasing respiratory distress. While en route to the physician's office for evaluation, the infant had a 1-minute episode of cyanosis and apnea and her mother performed rescue breathing. In the pediatrician's office the infant was poorly perfused with pallor and hypotonia and was admitted emergently to St. Louis Children's Hospital. Her physical examination revealed a lethargic infant with a pulse of 155 beats/min, respiratory rate of 60/min, and blood pressure of 68/45 mm Hg in all extremities. The anterior fontanel was soft and flat and her lungs were clear on auscultation, with rapid, shallow breathing. Cardiovascular examination revealed weak brachial and femoral pulses with decreased skin perfusion, a regular cardiac rhythm, a soft 2/6 systolic ejection murmur, and a gallop. The abdomen was soft, and the liver was mildly enlarged. Her neurologic examination was non-focal with generalized hypotonia. Initial laboratory data included the following arterial blood gas values: a pH of 7.16, oxygen tension of 53 mm Hg, carbon dioxide tension of 36 mm Hg, and HCO3 of 19, along with a white blood cell count of 8,000/µL with a hematocrit of 40%, blood urea nitrogen level of 6 mg/dL, and a creatinine level of 0.8 mg/dL. Radiography of the chest demonstrated marked cardiomegaly and increased pulmonary vascular markings consistent with congestive heart failure (Fig 1
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Fig 1. . Anteroposterior radiograph obtained on admission. Note the significantly increased cardiac silhouette and prominent pulmonary vascular markings.
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The general differential of cardiogenic versus septic shock was entertained and the patient was intubated, cultures were taken, and the patient was started on prostaglandin E1 and dobutamine infusions and treated with broad-spectrum antibiotics. Echocardiograms demonstrated a dilated right atrium and right ventricle with a right ventricular pressure estimate of 65 mm Hg, good biventricular function, two small mid-muscular ventricular septal defects, bilateral superior venae cavae, all pulmonary veins draining into the left atrium with significant left-to-right shunting across an atrial septal defect, and a small patent ductus arteriosus with bidirectional shunting (Fig 2). The prostaglandin E1 infusion was discontinued and cardiac catheterization was undertaken because of the unclear cause of the elevated right heart pressure and cardiomegaly. Results of this study revealed pulmonary hypertension with suprasystemic right ventricular and pulmonary artery pressures, a large left-to-right shunt at the atrial level, two small mid-muscular ventricular septal defects with bidirectional shunting and a pulmonary-to-systemic shunt ratio of 3.4:1. Importantly, there were multiple aortic collaterals directly into the lower lobe of the right lung with rapid opacification of the pulmonary veins, left atrium, and then across the atrial septal defect into the right atrium (Fig 3). Pulmonary artery injection revealed that the right pulmonary artery was smaller than the left pulmonary artery and only gave off branches feeding the right upper and right middle lobes. There was also a mild aortic coarctation with a gradient of 10 mm Hg.
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Fig 2. . Two-dimensional echocardiogram showing the preoperative appearance from the four-chamber view. Note the dilated right atrium (RA) and right ventricle (RV). The arrow denotes the secundum atrial septal defect. (LA = left atrium; LV = left ventricle.)
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Fig 3. . Cineangiogram of the descending aorta in the anteroposterior view. The tip of the venous catheter is positioned in the right atrium, and the pigtail catheter is positioned at approximately T3. Note the multiple collateral vessels to the right lower lung arising from the descending aorta.
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The patient was taken to the operating room for planned right lower lobectomy. Flexible fiberoptic bronchoscopy revealed normal airway anatomy with presence of all segmental bronchi to both lungs. A right lower lobectomy was performed via right thoracotomy. The right lung appeared grossly normal without any evidence of a sequestrum. As delineated by the catheterization, the entire blood supply to the right lower lobe came from eight to ten collateral vessels of varying size, which came directly off of the descending thoracic aorta while the venous drainage was normal (see Fig 2
). She tolerated the procedure well and was discharged home on postoperative day 12. After going home she maintained a steady growth curve, and follow-up echocardiograms revealed that the atrial septal defect closed spontaneously and that right ventricular and pulmonary artery pressures normalized.
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Comment
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Litwin and associates [1] were the first to report surgical intervention (lobectomy) for treatment of unrelenting congestive heart failure in a newborn with anomalous systemic arterial supply to a portion of the lung parenchyma. Unlike our patient, who had multiple aortopulmonary collaterals supplying the right lower lobe, the patient in that report had a solitary large branch off of the descending thoracic aorta into the right lower lobe. The few other case reports of similar entities that have appeared in the literature reveal a predilection for the lower lobes much like in a true sequestration [2, 3]. In addition, there have been reports in which there is dual blood supply to the involved lung in which case a pulmonary resection can be avoided and the only necessary treatment may be ligation or transcatheter coil ablation of the systemic collaterals [3]. In the case presented in this article the right heart was predominantly affected by virtue of the multilevel left-to-right shunt at the level of the atrial septum, the patent ductus arteriosus, and the aortic collaterals. Although the final pathology report stated that the right lower lobe parenchyma and capillary vascular bed were normal without evidence of atrioventricular fistulas, the overall pathophysiologic effect was similar to what would be expected with a large systemic arterial-to-pulmonary venous fistula combined with an atrial septal defect. Our patient was not symptomatic immediately after birth, likely because of elevated pulmonary vascular resistance acting to limit left-to-right shunting. Once the resistance began to drop the shunt became more significant, resulting in congestive heart failure. That the abnormal arterial supply to the right lower lobe was the major underlying factor in this patient is confirmed by the fact that after resection of the right lower lobe, the right heart and pulmonary hypertension resolved and the atrial septal defect spontaneously closed. Also of note is that although echocardiography is the only diagnostic tool needed for most infant cardiovascular diseases, the diagnosis in this case was not at all clear until a pulmonary angiogram and descending thoracic aortogram were obtained at catheterization.
Cairns and colleagues [4] described a patient with a diaphragmatic hernia, right lung malformation, anomalous pulmonary venous drainage, systemic arterial supply to the lung, and abnormalities of the pulmonary artery. They classified this patient as having a variant of hypogenetic lung syndrome, which is a term describing a spectrum of abnormalities of lung size, lobation, and bronchial stenosis, which may be associated with congenital heart defects in up to 25% of cases (most commonly atrial septal defect). Although our patient does have an atrial septal defect and systemic arterial supply to the right lower lobe, the lung size, lobar formation, and bronchial distribution were all normal. Also absent in our patient is an abnormally draining pulmonary vein seen on plain chest radiographs (such as also seen in the scimitar syndrome), a trait that Cairns and colleagues point out is distinctive of hypogenetic lung syndrome. Nonetheless, the constellation of findings in the patient in this report bears some resemblance and may represent a less extreme variant of this hypogenetic lung syndrome.
In summary, we have presented a patient born with aberrant systemic arterial blood flow to the right lower lobe and an atrial septal defect. Together, these lesions resulted in a large left-to-right shunt with resultant pulmonary hypertension and congestive heart failure in the newborn period. Physical examination and noninvasive tests did not clarify the diagnosis, and only with cardiac catheterization could the correct diagnosis and appropriate treatment plan be achieved.
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Footnotes
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Address reprint requests to Dr Mendeloff, St. Louis Children's Hospital, One Children's Place, Suite 5W24, St. Louis, MO 63110 (e-mail: mendeloff_e{at}a1kids.wustl.edu).
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References
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- Litwin BS, Plauth WH, Nadas AS. Anomalous systemic arterial supply to the lung causing pulmonary artery hypertension. N Engl J Med 1967;283:1098–9.
- Yabek SM, Burstein J, Berman W, Dillon T. Aberrant systemic arterial supply to the left lung with congestive heart failure. Chest 1981;80:636–7.[Abstract/Free Full Text]
- Ernst S, Bruschke A. An aberrant systemic artery to the right lung with normal pulmonary tissue. Chest 1971;60:606–8.[Abstract/Free Full Text]
- Cairns RA, Culbam JAD, Stringer DA, Murphy JJ. Pediatric case of the day. Radiographics 1995;15:496–9.[Medline]
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Abstract
Introduction
