Three-dimensional computed tomography showing partial anomalous pulmonary venous connection complicated by the scimitar syndrome

Atypical presentation of scimitar syndrome with severe hepatomegaly: a case report

Background 

Scimitar syndrome is a rare congenital disease characterized by partial or total anomalous pulmonary venous return from the right lung into the systemic venous system, and accounts for 0.5-2% of all congenital heart disease. Severe forms of the disease are diagnosed in childhood. However, because of the benign form of the syndrome in adults, many are asymptomatic, or present only mild symptoms including exertional dyspnoea, arrhythmias, and respiratory infections. We report an atypical presentation with hepatomegaly.

Case summary 

A 24-year-old woman was evaluated for abdominal discomfort. Physical examination revealed a remarkable hepatomegaly. Chest X-ray revealed dextroversion, enlargement of the right cavities, and a curvilinear opacity known as 'scimitar sign'. A transthoracic echocardiography demonstrated right ventricular dilation and a venous collector draining into right suprahepatic vein, which was severely dilated, with large hepatomegaly. Scimitar syndrome was confirmed by magnetic resonance imaging (MRI). Therefore, the patient underwent surgery, redirecting the pulmonary venous return to left atrium. Three months later, the patient remained asymptomatic and both the hepatomegaly and the right chamber volumes normalized.

Discussion 

Abdominal discomfort, as in our clinical case, is a highly atypical presentation of scimitar syndrome. It is important for physicians to be aware that diagnostic suspicion can be established from a chest X-ray, on which the scimitar sign can be distinguished in many cases. The diagnosis must be confirmed with other imaging modalities, such as echocardiography, MRI, or computed tomography. Corrective surgery may relieve the symptoms related to liver congestion at follow-up.

Not all right-sided hearts are the same-the importance of identifying the correct diagnosis

Scimitar syndrome is characterized by an anomalous venous return with the characteristic chest roentgenogram (CxR) appearance of the anomalous vein draining into the inferior vena cava (IVC). This appears as a curvilinear opacity paralleling the right border of the heart resembling a curved sword or Scimitar. A 27-year-old white woman with a reported history of dextrocardia was admitted after a drug overdose. Examination demonstrated an obtunded woman with tachycardia and right sided heart sounds. Her CxR revealed a right sided heart image with two curvilinear opacities in the retrocardiac area. Chest computed tomography (CT) demonstrated that these opacities join to represent an anomalous vein draining into IVC. Furthermore, an anomalous systemic artery arising from the abdominal aorta was seen to supply the right lower lobe. The patient was eventually diagnosed with Scimitar syndrome. This syndrome affects 1-3 in 100,000 live births while nearly half of the patients remain asymptomatic with some initially being misdiagnosed as dextrocardia, such as in our case. Correctly diagnosing these patients is of paramount importance as some can develop severe pulmonary hypertension and right ventricular failure. In turn, close ongoing echocardiographic monitoring can help identify those that may benefit from surgical interventions to prevent them from developing these complications.

Scimitar syndrome: A novel management approach for palliation in a sick infant

Scimitar syndrome is a rare congenital anomaly essentially requiring surgical management. Nonsurgical interventional treatments are rarely possible and are associated with poor outcome. We report a case of Scimitar syndrome with obstructed partial pulmonary venous confluence, large patent ductus arteriosus, and severe pulmonary artery hypertension, where a significant decrease in the pulmonary artery pressure was achieved by pulmonary venous stenting in combination with coiling of aberrant vascular supply to the sequestered lung segment. However, the child succumbed to lower respiratory tract infection. To the best of our knowledge, no such procedure in combination has been reported in the literature. <Learning Objective: The percutaneous approach to deal with pulmonary hypertension in a case of Scimitar syndrome is discussed. The outcome of this case suggests that interventional procedures such as pulmonary venous stenting could be done as an emergent palliative treatment to relieve pulmonary hypertension.>.

Scimitar syndrome in an asymptomatic adult: fortuitous diagnosis by imaging technique

Congenital cardiopathies in adults are a rare clinical entity in the cardiology consultations. Advances in imaging techniques allow the fortuitous diagnosis of mild forms of these congenital abnormalities. We describe a case of an asymptomatic 41-year-old man, with a medical history of recurrent pneumonia during childhood and an established diagnosis of scimitar syndrome by computed tomography.

Eponym. Scimitar syndrome

Scimitar syndrome is a rare congenital anomaly, characterized by partial or complete anomalous pulmonary venous drainage of the right or left lung into the inferior vena cava. The syndrome is commonly associated with hypoplasia of the right lung, pulmonary sequestration, persisting left superior vena cava, and dextroposition of the heart. The pathogenesis of the syndrome is unclear, but it seems to originate from a basic developmental disorder of the entire lung bud early in embryogenesis. Two main forms of scimitar syndrome have been described. Signs and symptoms can start during infancy (infantile form) or beyond (childhood/adult form). The infantile form generally presents within the first 2 months of life with tachypnea, recurrent pneumonia, failure to thrive, and signs of heart failure. The diagnosis of scimitar syndrome is usually made based on the characteristic chest X-ray films and can be confirmed by angiography; however, it is now done mostly by transthoracic or transesophageal echocardiography, noninvasive computed tomography, or magnetic resonance angiography. Fetal echocardiography using three-dimensional power Doppler imaging permits prenatal diagnosis. Most frequently, patients are asymptomatic in the absence of associated abnormalities and can be followed conservatively. For patients with congestive heart failure, repeated pneumonia, or pulmonary-to-systemic blood flow ratios greater than 1.5 and pulmonary hypertension, it is important to reroute the anomalous right pulmonary veins and repair the associated cardiac defects in order to avoid progression to right ventricular failure. The triad of respiratory distress, right lung hypoplasia, and dextroposition of the heart should alert the clinician to think of scimitar syndrome.

Magnetic resonance and computed tomographic evaluation of congenital heart disease

Magnetic resonance imaging (MRI) and contrast-enhanced computed tomography (CT) provide noninvasive visualization of morphologic changes in pediatric and adult patients with congenital heart disease, as well as the functional changes caused by the underlying morphologic abnormalities. Clinical experience with MRI is richer than that with fast CT, but CT appears to provide accurate and high-quality imagery for diagnosis. The two modalities may be complementary. That is, intracardiac anatomy is so well depicted by MRI, and CT provides exquisite images of the great vessels. Furthermore, in adult patients, MR and CT are helpful in demonstrating and quantitating physiologic changes superimposed by acquired cardiovascular disease on the underlying congenital malformations. Using MRI, spin echo acquisitions provide the image data for evaluation of morphologic changes, and gradient reversal techniques add functional and flow data to complement morphologic changes. Contrast-enhanced electrocardiographic (ECG)-gated multidetector and electron beam CT examination provide morphologic information and may be used as a data set for off-line functional quantitation.

CT of congenital heart disease: normal anatomy and typical pathologic conditions

Computed tomography (CT) plays an important supplementary role in the evaluation of patients with congenital heart disease (CHD). Fast multisection spiral CT can be used to obtain isotropic volume data, and high-quality two- and three-dimensional multiplanar reformatted images can be created to accurately and systematically delineate the normal and pathologic morphologic features of the cardiovascular system. CT may be technically challenging and demanding in uncooperative young children. However, it can be used to systematically evaluate the aorta, pulmonary artery, pulmonary vein, cardiac chambers and ventriculoarterial connection, relationship between the upper lobe bronchi and pulmonary arteries, coronary artery, valves, systemic veins (superior vena cava, inferior vena cava, hepatic veins), and visceral situs with a step-by-step approach. This approach may be helpful in understanding the anatomy of the cardiovascular system in CHD patients. CT has both advantages and disadvantages in evaluating patients with CHD. Nevertheless, it is useful in this setting, and radiologists who perform CT in young children with CHD should be familiar with the advantages and disadvantages of CT and with the normal anatomy and typical pathologic conditions in affected patients.

A case series of five infants with scimitar syndrome

Scimitar syndrome is a rare association of congenital cardiopulmonary anomalies consisting of a 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 to the right lung. To date, this syndrome has not been reported or discussed in the nursing literature. In this article, 5 patients are presented to illustrate the variable presentation of this syndrome, ranging from infants who are asymptomatic to those with heart failure and severe pulmonary hypertension. The clinical signs and symptoms, diagnostic dilemmas, and medical and surgical management are discussed. The triad of respiratory distress, right lung hypoplasia, and dextroposition of the heart should alert the clinician to the possibility of this syndrome.

Thoracic venous anatomy multidetector row CT evaluation

Two-dimensional CT angiography provides much information of the systemic and pulmonary thoracic veins. The combination of MDCT and volume-rendering techniques postprocessing provides higher-quality data sets and a method fully to harness the potential for image display and interpretation. Although this may not radically alter sensitivity for detection of systemic or pulmonary venous pathology it does provide a more comprehensive and sophisticated evaluation through volume acquisition and interpretation.