Abstract
The morphology variations of the so-called scimitar vein are many and
varied. We present a synthesis of 92 published investigations of the
overall scimitar syndrome. We reviewed the clinical presentations,
diagnostic modalities, surgical approaches, and outcomes. 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. In short, they
defined the disease prior to surgical intervention. 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. 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.