Scimitar syndrome
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《美国医学杂志》
Department of Radiology, Topiwala National Medical College and B.Y.L. Nair Charitable Hospital, Dr. A.L. Nair Road, Mumbai, India
Abstract
Scimitar syndrome, a rare anomaly of partial pulmonary venous drainage into the hepatic portion of the inferior vena cava, detected in a ten-day-old neonate who presented clinically with respiratory distress and diagnosed on ultrasound of the thorax is being reported here.
Keywords: Scimitar syndrome; Anomalous pulmonary venous drainage; Pulmonary venolobar syndrome
Scimitar syndrome, also known as congenital pulmonary venolobar syndrome, is a rare congenital anomaly most commonly consisting of partial anomalous pulmonary venous connection of the right lung to the inferior vena cava, right lung hypoplasia, dextroposition of the heart, and anomalous systemic arterial supply from aorta or one of its branches to the right lung.
There is a variable presentation of this syndrome, ranging from infants who are asymptomatic to those with heart failure and severe pulmonary hypertension. The triad of respiratory distress, right lung hypoplasia, and dextroposition of the heart should alert the clinician to the possibility of this syndrome.[1] Very few cases are mentioned in the literature.
We report a case of scimitar syndrome in a ten-day-old neonate who presented clinically with respiratory distress and was diagnosed on ultrasound.
Case report
A 10-day-old male baby was admitted to intensive care unit with respiratory distress. He was a full term baby born at home to a primi mother. Immediate postnatal period was uneventful. On fifth day of life he developed respiratory distress and was admitted to the hospital. The baby was cyanotic, had severe tachypnea with the respiratory rate of 110-120/minute and chest retractions. He had tachycardia with heart rate of 160 -180/minute, and the heart sounds were audible on the right side of the chest. There was no evidence of any external congenital anomaly. Crackles on left side of chest were present on systemic examination. Investigations revealed normal haemogram, the X-ray chest showed increased density in the right hemi thorax, absent cardio- mediastinal structures on the left side and hyperinflation of the left lung Figure1. The ultrasound of the thorax revealed dextroposition of heart and a large atrial secundum defect Figure2. A large anomalous pulmonary vein crossing the diaphragm and joining the hepatic inferior vena cava Figure3a, b was noted. Thus the diagnosis of "Scimitar syndrome" was considered in view of partial anomalous pulmonary venous drainage, hypoplastic right lung and dextroposition of the heart. The baby was managed with decongestive measures, antibiotics and ventilator support. X-ray chest done on seventh day of admission revealed the classic "Scimitar sign" as a result of clearing of right lung of fluid Figure4. The baby died on tenth day because of worsening of hypoxia and sepsis.
Discussion
Scimitar syndrome, also known as 'congenital pulmonary venolobar syndrome', is a rare congenital anomaly most commonly consisting of partial anomalous pulmonary venous connection of the right lung to the inferior vena cava, right lung hypoplasia, (these two are the most constantly occurring components), dextroposition of the heart, and anomalous systemic arterial supply from aorta or one of its branches to the right lung.
Additional anomalies that occur with this syndrome include: hypoplastic or absent pulmonary artery, anomalous systemic arterial supply to the right lung from aorta or one of its branches, and bronchopulmonary sequestration, absence of the inferior vena cava, and accessory diaphragm.[2] The incidence of the associated congenital cardiovascular abnormalities not usually regarded as part of the scimitar syndrome is 36% in the pediatric age group and is highest (75%) among the neonates. These include atrial septal defect, ventricular septal defect, coarctation of the aorta, abnormalities of the aortic arch, and abnormal relationship of the pulmonary arteries and bronchi.[3]
The defining characteristic of 'Scimitar syndrome' is the partial anomalous pulmonary venous return. Usually this anomalous venous return is to the hepatic portion of the inferior vena cava, but it may also be to the portal vein, a hepatic vein, or the right atrium. The name comes from this anomalous pulmonary vein, which may be visible on chest radiograph as a curvilinear shadow just above the right diaphragm said to resemble a "Scimitar" or Turkish sword. This finding may not be evident in all the cases; however it was visible in our case after clearing of the lung fluid. The diagnosis is usually established on chest roentgenogram that shows "dextrocardia" and "hypoplasia of the right lung".[4] But in our case the diagnosis was established on ultrasound much before it became evident on chest X-ray.
Scimitar syndrome has a variable presentation based on the age at which the diagnosis is made. Infants typically present with the main symptoms of severe respiratory insufficiency and cardiac failure.[1], [5], [6] Pulmonary hypertension is commonly associated in them.
In older children and adults the diagnosis of scimitar syndrome is often made incidentally who undergo chest radiography for diverse reasons.[7] Recurrent respiratory infections and a heart murmur may be the mode of presentation in them. Children who are diagnosed with scimitar syndrome after infancy have fewer associated defects and less pulmonary hypertension than their infant counterparts do.
The triad of respiratory distress, right lung hypoplasia, and dextroposition of the heart should alert the clinician to the possibility of this syndrome.[1] The age at detection of scimitar syndrome and the presence of associated anomalies is important in predicting the outcome. In general, infants presenting in heart failure have a greater number of associated anomalies and their prognosis is much worse.[4] Treatment for symptomatic scimitar syndrome consists of surgical repair. Repair of the anomalous venous return and ligation of collaterals is generally recommended, although right pneumonectomy (either as primary therapy or if repair failed) also provides similar early and late results.[4] Postoperative pulmonary venous obstruction usually develops in the infants.[8]
The prognosis for older children is benign, either with or without surgery. Therefore the therapeutic approach for patients with scimitar syndrome, respiratory manifestations and onset beyond the neonatal period, should be conservative.[5]
References
1. Mordue BC. A case series of five infants with scimitar syndrome. Adv Neonatal Care 2003; 3 : 121-132.
2. Frederic N Silverman. The Heart. In John Caffey, eds. Pediatric X-Ray Diagnosis. 6th edn. Volume 1. Chicago, Year Book Medical Publishers. 1973: 506-507.
3. Gikonyo DK, Tandon R, Lucas RV Jr, Edwards JE .Scimitar syndrome in neonates: report of four cases and review of the literature. Pediatr Cardiol 1986; 6 : 193-197.
4. Huddleston CB, Exil V, Canter CE, MendeloffEN. Scimitar syndrome presenting in infancy. Ann Thorac Surg 1999; 67 : 154-159.
5. Lluna Gonzalez J, Barrios Fontoba JE, Cavalle Garrido T, Gutierrez San Roman C, Malo Concepcion P, Carrasco Moreno JI et al. Scimitar syndrome: series of 12 cases. Cir Pediatr 1995; 8 : 2-6.
6. Dupuis C, Charaf LA, Breviere GM, Abou P. Infantile form of the scimitar syndrome with pulmonary hypertension. Am J Cardiol 1993; 71 : 1326-1330.
7. Gao YA, Burrows PE, Benson LN, Rabinovitch M, Freedom RM. Scimitar syndrome in infancy. J Am Coll Cardiol 1993; 22 : 873-882.
8. Najm HK, Williams WG, Coles JG, Rebeyka IM, Freedom RM. Scimitar syndrome: twenty years' experience and results of repair. J Thorac Cardiovasc Surg 1996; 112 : 1161-1168.(Rokade Muktachand L, Rana)
Abstract
Scimitar syndrome, a rare anomaly of partial pulmonary venous drainage into the hepatic portion of the inferior vena cava, detected in a ten-day-old neonate who presented clinically with respiratory distress and diagnosed on ultrasound of the thorax is being reported here.
Keywords: Scimitar syndrome; Anomalous pulmonary venous drainage; Pulmonary venolobar syndrome
Scimitar syndrome, also known as congenital pulmonary venolobar syndrome, is a rare congenital anomaly most commonly consisting of partial anomalous pulmonary venous connection of the right lung to the inferior vena cava, right lung hypoplasia, dextroposition of the heart, and anomalous systemic arterial supply from aorta or one of its branches to the right lung.
There is a variable presentation of this syndrome, ranging from infants who are asymptomatic to those with heart failure and severe pulmonary hypertension. The triad of respiratory distress, right lung hypoplasia, and dextroposition of the heart should alert the clinician to the possibility of this syndrome.[1] Very few cases are mentioned in the literature.
We report a case of scimitar syndrome in a ten-day-old neonate who presented clinically with respiratory distress and was diagnosed on ultrasound.
Case report
A 10-day-old male baby was admitted to intensive care unit with respiratory distress. He was a full term baby born at home to a primi mother. Immediate postnatal period was uneventful. On fifth day of life he developed respiratory distress and was admitted to the hospital. The baby was cyanotic, had severe tachypnea with the respiratory rate of 110-120/minute and chest retractions. He had tachycardia with heart rate of 160 -180/minute, and the heart sounds were audible on the right side of the chest. There was no evidence of any external congenital anomaly. Crackles on left side of chest were present on systemic examination. Investigations revealed normal haemogram, the X-ray chest showed increased density in the right hemi thorax, absent cardio- mediastinal structures on the left side and hyperinflation of the left lung Figure1. The ultrasound of the thorax revealed dextroposition of heart and a large atrial secundum defect Figure2. A large anomalous pulmonary vein crossing the diaphragm and joining the hepatic inferior vena cava Figure3a, b was noted. Thus the diagnosis of "Scimitar syndrome" was considered in view of partial anomalous pulmonary venous drainage, hypoplastic right lung and dextroposition of the heart. The baby was managed with decongestive measures, antibiotics and ventilator support. X-ray chest done on seventh day of admission revealed the classic "Scimitar sign" as a result of clearing of right lung of fluid Figure4. The baby died on tenth day because of worsening of hypoxia and sepsis.
Discussion
Scimitar syndrome, also known as 'congenital pulmonary venolobar syndrome', is a rare congenital anomaly most commonly consisting of partial anomalous pulmonary venous connection of the right lung to the inferior vena cava, right lung hypoplasia, (these two are the most constantly occurring components), dextroposition of the heart, and anomalous systemic arterial supply from aorta or one of its branches to the right lung.
Additional anomalies that occur with this syndrome include: hypoplastic or absent pulmonary artery, anomalous systemic arterial supply to the right lung from aorta or one of its branches, and bronchopulmonary sequestration, absence of the inferior vena cava, and accessory diaphragm.[2] The incidence of the associated congenital cardiovascular abnormalities not usually regarded as part of the scimitar syndrome is 36% in the pediatric age group and is highest (75%) among the neonates. These include atrial septal defect, ventricular septal defect, coarctation of the aorta, abnormalities of the aortic arch, and abnormal relationship of the pulmonary arteries and bronchi.[3]
The defining characteristic of 'Scimitar syndrome' is the partial anomalous pulmonary venous return. Usually this anomalous venous return is to the hepatic portion of the inferior vena cava, but it may also be to the portal vein, a hepatic vein, or the right atrium. The name comes from this anomalous pulmonary vein, which may be visible on chest radiograph as a curvilinear shadow just above the right diaphragm said to resemble a "Scimitar" or Turkish sword. This finding may not be evident in all the cases; however it was visible in our case after clearing of the lung fluid. The diagnosis is usually established on chest roentgenogram that shows "dextrocardia" and "hypoplasia of the right lung".[4] But in our case the diagnosis was established on ultrasound much before it became evident on chest X-ray.
Scimitar syndrome has a variable presentation based on the age at which the diagnosis is made. Infants typically present with the main symptoms of severe respiratory insufficiency and cardiac failure.[1], [5], [6] Pulmonary hypertension is commonly associated in them.
In older children and adults the diagnosis of scimitar syndrome is often made incidentally who undergo chest radiography for diverse reasons.[7] Recurrent respiratory infections and a heart murmur may be the mode of presentation in them. Children who are diagnosed with scimitar syndrome after infancy have fewer associated defects and less pulmonary hypertension than their infant counterparts do.
The triad of respiratory distress, right lung hypoplasia, and dextroposition of the heart should alert the clinician to the possibility of this syndrome.[1] The age at detection of scimitar syndrome and the presence of associated anomalies is important in predicting the outcome. In general, infants presenting in heart failure have a greater number of associated anomalies and their prognosis is much worse.[4] Treatment for symptomatic scimitar syndrome consists of surgical repair. Repair of the anomalous venous return and ligation of collaterals is generally recommended, although right pneumonectomy (either as primary therapy or if repair failed) also provides similar early and late results.[4] Postoperative pulmonary venous obstruction usually develops in the infants.[8]
The prognosis for older children is benign, either with or without surgery. Therefore the therapeutic approach for patients with scimitar syndrome, respiratory manifestations and onset beyond the neonatal period, should be conservative.[5]
References
1. Mordue BC. A case series of five infants with scimitar syndrome. Adv Neonatal Care 2003; 3 : 121-132.
2. Frederic N Silverman. The Heart. In John Caffey, eds. Pediatric X-Ray Diagnosis. 6th edn. Volume 1. Chicago, Year Book Medical Publishers. 1973: 506-507.
3. Gikonyo DK, Tandon R, Lucas RV Jr, Edwards JE .Scimitar syndrome in neonates: report of four cases and review of the literature. Pediatr Cardiol 1986; 6 : 193-197.
4. Huddleston CB, Exil V, Canter CE, MendeloffEN. Scimitar syndrome presenting in infancy. Ann Thorac Surg 1999; 67 : 154-159.
5. Lluna Gonzalez J, Barrios Fontoba JE, Cavalle Garrido T, Gutierrez San Roman C, Malo Concepcion P, Carrasco Moreno JI et al. Scimitar syndrome: series of 12 cases. Cir Pediatr 1995; 8 : 2-6.
6. Dupuis C, Charaf LA, Breviere GM, Abou P. Infantile form of the scimitar syndrome with pulmonary hypertension. Am J Cardiol 1993; 71 : 1326-1330.
7. Gao YA, Burrows PE, Benson LN, Rabinovitch M, Freedom RM. Scimitar syndrome in infancy. J Am Coll Cardiol 1993; 22 : 873-882.
8. Najm HK, Williams WG, Coles JG, Rebeyka IM, Freedom RM. Scimitar syndrome: twenty years' experience and results of repair. J Thorac Cardiovasc Surg 1996; 112 : 1161-1168.(Rokade Muktachand L, Rana)