Scimitar syndrome: A new multipatch technique and incidence of postoperative pulmonary vein obstruction

Clinical characteristics, imaging findings, management, and outcomes of patients with scimitar syndrome at a tertiary referral healthcare center in Colombia

Scimitar Syndrome is part of a complex spectrum of congenital cardiovascular anomalies related to anomalous pulmonary venous return. Depending on the extent of involvement, treatment can be either expectant or surgical. Prognosis and survival have been controversial, with some results supporting early surgical management. This research aims to disclose the outcomes and describe the management, clinical and imaging characteristics of patients diagnosed with Scimitar Syndrome treated in a tertiary referral healthcare center. Longitudinal descriptive observational study. The study included all patients diagnosed with scimitar syndrome in our institution between January/2011 and December/2022. A description of the sociodemographic and clinical characteristics, diagnostic tools used, treatment features, and patient outcomes is provided. Eleven patients were included, with a mean age at diagnosis of five years (CI 0-17), six of which were female (54.55%). Nine (81.82%) patients had evidence of a scimitar vein on the chest radiograph, six (54.55%) cardiac dextroposition, six (54.55%) pulmonary hypoplasia, five (45.45%) right pulmonary artery hypoplasia, and three (27.27%) had aortopulmonary collaterals. Four (36.36%) patients had horseshoe lungs, and four (36.36%) had bronchopulmonary sequestration. In the associations, two (18.18%) patients were found to have an atrial septal defect, three (27.27%) ventricular septal defect, and one (9%) had Tetralogy of Fallot. Pulmonary hypertension was demonstrated in two (18.18%) patients. Seven (63.64%) required surgical management to correct the scimitar vein, and two patients died due to unrelated complications. Scimitar syndrome presents diagnostic and treatment challenges, necessitating a multidisciplinary approach for timely care. Chest radiography and CT scans are primary diagnostic tools, with surgical intervention often warranted alongside other heart defects or significant hemodynamic repercussions. Medical management is effective for mild to moderate cases. Long-term patient outcomes remain uncertain due to study limitations, but improved life expectancy is anticipated with ongoing care.

Fetal Diagnosis of Scimitar Syndrome in the Presence of Complex Congenital Heart Disease

Fetal diagnosis of scimitar syndrome requires a high index of suspicion. We present two fetal cases of complex congenital heart disease associated with scimitar syndrome, one of them is diagnosed with scimitar syndrome in utero. We emphasize prenatal echocardiographic findings that may assist with arriving at the correct prenatal diagnosis. We also discuss potential challenges in suspecting the presence of scimitar syndrome in utero. The postnatal echocardiographic findings and course are described for both patients. We reviewed the available literature on prenatal diagnosis of scimitar syndrome in the presence of complex congenital heart disease. We describe a new association of VACTERL, imperforate anus, scimitar syndrome, and double-outlet right ventricle all on the same patient, as well as the first prenatal diagnosis of scimitar syndrome associated with hypoplastic left heart syndrome with restrictive atrial septum. Advanced imaging modalities such as a fetal lung Magnetic Resonance Imaging is suggested as a confirmatory test when scimitar syndrome is suspected in utero in the presence of complex congenital heart disease.

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.