Cardiovascular Journal of Africa: Vol 27 No 1 (January/February 2016)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 1, January/February 2016 30 AFRICA
Vascular rings: a radiological review of anatomical
variations
Iqbal Siddi Ganie, Khatija Amod, Darshan Reddy
Abstract
Background: The imaging modalities used to diagnose vascu-
lar rings have evolved over time, from basic radiographic
studies to advanced cross-sectional imaging. The goal of pre-
operative imaging is to provide the surgeon with an accurate
representation of the ring configuration so that the surgical
approach may be planned.
Methods: We conducted a review of all patients with vascular
rings who underwent surgery at Inkosi Albert Luthuli Central
Hospital, Durban, South Africa from 1 July 2008 to 1 July
2013.
Results: Eight patients were diagnosed with vascular rings.
Seven patients had an abnormal plain chest radiograph (right
aortic arch, tracheal narrowing, or abnormal mediastinal
silhouette), while in six patients the contrast oesophagogram
demonstrated a fixed extrinsic oesophageal indentation.
Computed tomography angiography confirmed the pathol-
ogy in all cases, with six double aortic arches and two right
aortic arches with aberrant left subclavian artery and left
ligamentum arteriosum.
Conclusions: We advocate a diagnostic imaging algorithm
consisting of plain chest radiography, contrast oesoph-
agogram and computed tomography angiography prior to
surgery. Magnetic resonance imaging may provide an alter-
native axial imaging modality depending on institutional
preference.
Keywords: vascular rings, aortic arch anomalies, double arch,
aberrant subclavian artery, Kommerell diverticulum
Submitted 16/5/14, accepted 3/10/15
Published online 2/12/15
Cardiovasc J Afr 2016; 27: 30–36
DOI: 10.5830/CVJA-2015-076
Vascular rings generally present in infancy and early childhood,
with symptoms relating to tracheal compression (cough, stridor
or dyspnoea) or oesophageal compression (dysphagia, feeding
difficulties). While diagnostic imaging algorithms vary between
institutions, the main function of pre-operative imaging is
to confirm the diagnosis, provide detailed definition of the
ring configuration, and enable accurate surgical planning and
treatment.
Methods
We reviewed the electronic patient surgical records and archived
imaging data of all patients diagnosed with complete vascular
rings between July 2008 and July 2013 at Inkosi Albert Luthuli
Central Hospital, Durban, South Africa. All patients were under
the care of the cardiothoracic surgical service and underwent
in-patient imaging prior to surgery.
The imaging modalities available at our institution include
plain chest radiography, oesophageal contrast studies, computed
tomography angiography (CTA), magnetic resonance imaging
(MRI), echocardiography, bronchoscopy and conventional
catheter angiography. For the purpose of this study, all archived
imaging underwent secondary review by an independent
radiologist, as acknowledged.
A Siemens Somatom Definition AS 128 slice 64 detector
scanner was used for all our patients. Chloryl hydrate (10%)
was used for sedation in all the cases at a dose of 0.5 ml/kg.
Omnipaque 350 was used as iodinated contrast and the dose
utilised was 4 ml/kg. ECG gating and breath holding were not
applied. Axial, coronal and sagittal images were obtained and
3D reconstructions were employed for clear visualisation of the
vascular anatomy.
Results
Over the study period, eight patients were diagnosed with
complete vascular rings (detailed patient characteristics are
presented in Table 1). All patients presented between two and
24 months of age, with the commonest presenting symptoms
relating to the upper aerodigestive tract (stridor, wheeze or
dysphagia). In two patients the vascular ring was an incidental
finding; the first presented with congestive cardiac failure as a
result of a large ventricular septal defect (VSD); the second had
persistent stridor following the extraction of an impacted coin in
the oesophagus (Fig. 1).
A plain chest radiograph (CXR) was undertaken in all
patients, and was abnormal in seven of the eight patients (right
aortic arch, widened mediastinal silhouette, tracheal narrowing).
Contrast oesophagogram (CO) was undertaken in six patients.
In all cases this study demonstrated a fixed extrinsic oesophageal
indentation.
Computed tomography angiography (CTA) was used to
define the detailed anatomical configuration of the vascular
ring in all eight patients, and was our primary imaging tool used
to plan surgery. Six patients had double aortic arches, and two
patients had a right aortic arch with an aberrant left subclavian
artery and left ligamentum arteriosum.
Department of Radiology, University of KwaZulu Natal,
Durban, South Africa
Iqbal Siddi Ganie, MB ChB, FC Rad D
Khatija Amod, MB ChB, FC Rad D, MSc (Med) (SA)
Department of Cardiothoracic Surgery, University of
KwaZulu Natal, Durban, South Africa
Darshan Reddy, MB ChB, FC Cardio (SA), MMed (UKZN),