Scimitar syndrome: five cases examined with two-dimensional and Doppler echocardiography

Surgical management of the scimitar syndrome

BACKGROUND AND AIM

We sought to address the varied anatomical details, the diagnostic challenges, associated cardiopulmonary anomalies, the techniques, and outcomes of management, including re-interventions of scimitar syndrome.

METHODS

A total of 92 published investigations of scimitar syndrome were reviewed. Diagnostic information was provided by clinical presentations, radiographic findings, transthoracic and transesophageal echocardiography, computed-tomographic angiography, magnetic resonance imaging, angiocardiography, and ventilation/perfusion scans. These investigations served to elucidate the origin, course, and termination of the scimitar vein, the intracardiac anatomy, the presence of associated defects, and the patterns of any accompanying pulmonary lesions prior to surgical intervention.

RESULTS

Of the patients described, up to four-fifths presented during infancy, with cardiac failure, increased pulmonary flow, and pulmonary hypertension. Associated cardiac and extracardiac defects, particularly hypoplasia of the right lung, are present in up to three-quarters of cases. Overall operative mortality has been cited between 4.8% and 5.9%. Mortality was highest in patients with preoperative pulmonary hypertension, and those undergoing surgery in infancy. Despite timely surgical intervention, post-repair obstruction of the scimitar vein, intra-atrial baffle obstruction, or stenosis of the inferior caval vein were reported in up to two-thirds of cases. The venous obstruction could not be related to any particular surgical technique. On long term follow-up, one sixth of patients reported persistent dyspnoea and recurrent respiratory infections.

CONCLUSIONS

Any infants presenting with heart failure, right-sided heart, and hypoplastic right lung should be evaluated to exclude the syndrome. An increased appreciation of variables will contribute to improved surgical management.

Multimodality imaging in an adult patient with scimitar syndrome

The “Scimitar syndrome” is a rare congenital anomaly characterized by combination of partial or complete pulmonary venous return from the right lung to the inferior vena cava either above or below the diaphragm together with hypoplasia of the right lung and sometimes systemic arterial supply to the right lung. In this case, multimodality imaging findings such as the vein draining into the inferior vena cava, the presence of hypertrophied and dilated right ventricle, the absence of other cardiac abnormalities, displacement of the heart without malrotation and the mediastinum to the right, normal bronchial and vascular continuity in the whole lung, absence of pulmonary sequestration and systemic collaterals, normal perfusion and systolic functions of the left ventricle were reported.

Transcatheter occlusion of the isolated scimitar vein anomaly camouflaged under dual pulmonary venous drainage of the right lung by the Amplatzer Ductal Occluder

A 3.5-year-old girl, who presented recurrent pneumonia without discernible cyanosis or desaturation due to isolated scimitar vein anomaly camouflaged by dual pulmonary venous drainage of the right lung, underwent anterograde transvenous occlusion for this abnormal vessel successfully by the Amplatzer Ductal Occluder at 4 years old.

Retrospective prenatal diagnosis of scimitar syndrome aided by three-dimensional power Doppler imaging

Scimitar syndrome is a rare malformation of the arterial supply and venous drainage of the lung. We report the case of a fetus that presented with cardiac asymmetry and malposition of the fetal heart. Postnatally, scimitar syndrome was confirmed at cardiac catheterization. Retrospective reconstruction of three-dimensional power Doppler volumes, obtained during fetal life, allowed direct visualization of the abnormal aortopulmonary collateral vessel. This had not been seen on conventional scans. This case demonstrates many of the strengths of three-dimensional sonographic techniques for the delineation of complex vascular anatomy. It confirms that a prospective diagnosis of scimitar syndrome should be possible during fetal life.