AJTCCM VOL. 29 NO. 1 2023 24
CORRESPONDENCE: SCIENTIFIC LETTERS
TO THE EDITOR: Anomalies of coronary arteries (CAs) are an
uncommon cause of chest pain and can lead to sudden death.[1] In
aorta-right atrial tunnel (ARAT), an abnormal extracardiac tubular
communication exists between the ascending aorta and the right
atrium (RA).[2] e embryological pathogenesis of ARAT is not certain,
but congenital deciency of aortic medial elastic lamina is a possible
cause. Patients can be asymptomatic, have precordial murmurs, or even
develop congestive heart failure.[3]For decades, premorbid diagnosis
of CA anomalies has been made with conventional angiography, but
retrospectively gated coronary computed tomography angiography
(CTA) is an accurate, quick and non-invasive alternative for diagnosis
and treatment planning.[4]
A 4-year-old boy presented with retrosternal chest pain and paroxysmal
breathlessness for 2 years, which had become worse over the past week.
ere was no history of cyanotic spells, failure to thrive, fever, cough,
haemoptysis, syncopal attacks, pedal oedema or easy fatigability. On
two-dimensional echocardiography (2D echo), an abnormal channel was
noted behind the aorta arising from the non-coronary sinus, showing
an arterial waveform on colour Doppler ultrasound associated with
continuous restrictive ow in the RA (Fig. 1 and Fig. 2 (Supplementary
file: https://www.samedical.org/file/2017)). The interatrial and
interventricular septa were intact. These findings prompted three
dierential diagnoses: aneurysmal dilatation of the le coronary artery
(LCA) arising from the non-coronary cusp with a retro-aortic course, an
LCA-RA stula, and ARAT.
For conclusive diagnosis, the child underwent CTA using a
128-section multidetector CT scanner (Philips Medical Systems, India).
A dilated vessel was seen arising just above the le coronary sinus (Fig.3
- Supplementary le: https://www.samedical.org/le/2016), coursing
posteriorly in the aorta-le atrial groove (Fig.4 - Supplementary le:
https://www.samedical.org/le/2018) and interatrial groove, measuring
12 mm at the ostium and 7 mm in the mid-portion. It bifurcated 1.3 cm
proximal to termination, with the larger channel opening into the RA,
6 mm below the superior cavoatrial junction (Fig.5 - Supplementary
file: https://www.samedical.org/file/2019), and the smaller channel
terminating at the superior cavoatrial junction.The left anterior
descending artery and LCA appeared to originate ~1.1 cm distal to its
origin. A diagnosis of ARAT was considered more likely than coronary-
cameral stula (CCF).
Mild cardiomegaly with normal situs, and atrioventricular concordance
with normal tricuspid and mitral valves and venous connections were
noted. Features of pulmonary hypertension in the form of dilation of
the main pulmonary artery and its visualised branches and mosaic
attenuation in the lungs were seen. Digital subtraction angiography
(DSA) confirmed ARAT (Fig.6 - Supplementary file: https://www.
samedical.org/le/2020).
e patient was prescribed oral diuretics for 5 months preoperatively
and underwent intracardiac repair. Intraoperatively ARAT was
conrmed, the RA was opened and the stula opening was closed. e
stula track was traced from aorta to pulmonary artery and ligated. A
postoperative 2D echo showed no ow across the previous tract. e
patient was stable postoperatively and was discharged on oral diuretics.
Written informed consent was obtained from the patient’s guardian for
publication of this case report and the accompanying images, which have
been anonymised.
ARAT is thought to be caused by a congenital aortic medial elastic
deciency and weakness which, combined with high aortic pressure,
leads to tunnel formation, draining proximally into the low-pressure
RA.[2,5] A posterior course in the le sinus tunnel and an anterior
course in the right sinus tunnel are seen. However, this theory does
not explain tunnels arising from the non-coronary sinus.[2] ARAT
causes a le-to-right shunt that over time leads to volume overload,
pulmonary hypertension, congestive cardiac failure, a tunnel or
sinus aneurysms, and rupture. Delayed diagnosis is associated with
increased age-related surgical mortality.[2]
Clinically, patients can be asymptomatic or present with
breathlessness on exertion, fatigue, chest pain, and recurrent
respiratory tract infections. On examination, a continuous murmur at
the right parasternal border is noted. Findings on chest radiography
are nonspecific, relating to chamber enlargement, pulmonary
hypertension and cardiac failure.
[2]
On CTA, ARAT is seen as a dilated vessel arising from the aorta or CA,
draining into one of the heart chambers.
[2]
Origin above the sinotubular
ridge dierentiates ARAT from aneurysm of the sinus of Valsalva, and
absence of myocardial branches dierentiates it from a CCF.
ARAT can be diagnosed using 2D echo, coronary angiography or
cardiac CTA. While high spatial and temporal resolution makes DSA
the gold standard in imaging CA anomalies, CTA is easily available,
cost-eective and non-invasive. It can also depict cardiac morphology,
vessel abnormalities and their relationships. Simultaneously, cardiac CT
can pick up pulmonary abnormalities. Perfusion CT data can deliver
quantitative haemodynamic information, such as blood volume, blood
ow, permeability surface-area product and mean transit time.
[6]
While
A rare case of aorta-right atrial tunnel demonstrated on coronary
computed tomography angiography
Fig.1. Two-dimensional echocardiography, showing a channel (blue
arrow) arising from the le coronary sinus of the aorta (blue star).
AJTCCM VOL. 29 NO. 1 2023 25
CORRESPONDENCE: SCIENTIFIC LETTERS
2D echo can depict such ndings, it is user dependent with a limited
acoustic window for imaging all parts of the heart. Cardiac CTA is
therefore an ideal imaging modality for CA abnormalities.
Treatment should be initiated as soon as the diagnosis is conrmed,
to avoid complications. Asymptomatic ARAT can be supportively
managed by use of diuretics and other medications to reduce cardiac
aerload, with regular monitoring. However, symptoms inevitably
worsen, and stula closure is the denitive management.
[7]
Curative
options include simple ligation, or ligation with reimplantation of
coronary ostium or coil embolisation in selected cases. Direct closure
of the atrial opening is done with a patch of aortic origin or plication
of the tunnel. If the origin of the CA is deep in the tunnel, it should
be reimplanted with a part of the tunnel into the respective sinus of
Valsalva.
[2]
In conclusion, ARAT is a rare congenital heart disease that is
accurately diagnosed on CTA. CTA helps formulate management
guidelines, which are dependent on the size and location of the tunnel,
haemodynamic factors, and complications. It is ideal for follow-up of
conservatively managed cases. Early diagnosis of ARAT improves
prognosis and reduces postoperative morbidity.
T Kalekar, MBBS, MD (Radiodiagnosis)
Department of Radiodiagnosis, Dr D Y Patil Medical College, Hospital
and Research Centre, Pune, Maharashtra, India
A S Prabhu, MBBS
Department of Radiodiagnosis, Dr D Y Patil Medical College, Hospital
and Research Centre, Pune, Maharashtra, India
aparnaprabhu5@gmail.com
D Dilip, MBBS, MD (Radiodiagnosis)
Department of Radiodiagnosis, Dr D Y Patil Medical College, Hospital
and Research Centre, Pune, Maharashtra, India
A Dolas, MBBS, MS, MCh (CVTS)
Dr D Y Patil Medical College, Hospital and Research Centre, Pune,
Maharashtra, India
1. Huang Y-K, Lei M-H, Lu M-S, Tseng C-N, Chang J-P, Chu J-J. Bilateral coronary-
to-pulmonary artery stulas. Ann orac Surg 2006;82(5):1886-1888.https://doi.
org/10.1016/j.athoracsur.2006.02.040
2. Gajjar T, Voleti C, Matta R, Iyer R, Dash PK, Desai N. Aorta-right atrial tunnel:
Clinical presentation, diagnostic criteria, and surgical options. J orac Cardiovasc
Surg 2005;130(5):1287-1292. https://doi.org/10.1016/j.jtcvs.2005.07.021
3. Mahesh K, Francis E, Kumar RK. Aorta to right atrial tunnel: Prenatal diagnosis
and transcatheter management in a neonate. J Am Coll Cardiovasc Interv
2008;1(6):716-717.https://doi.org/10.1016/j.jcin.2008.05.011
4. Kim SY, Seo JB, Do KH, etal. Coronary artery anomalies: Classication and ECG-
gated multi-detector row CT ndings with angiographic correlation. Radiographics
2006;26(2):317-333. https://doi.org/10.1148/rg.262055068
5. Lee S, Kim SW, Im SI, etal. Aorta-right atrial tunnel: Is surgical correction
mandatory? Circulation 2016;133(13):e454-e457. https://doi.org/10.1161/
CIRCULATIONAHA.115.020161
6. Jennings D, Raghunand N, Gillies RJ. Imaging hemodynamics. Cancer Metastasis
Rev 2008;27(4):589-613. https://doi.org/10.1007/s10555-008-9157-4
7. Jainandunsing JS, Linnemann R, Maessen J, etal. Aorto-atrial stula formation
and therapy. J Thorac Dis 2019;11(3):1016-1021. https://doi.org/10.21037/
jtd.2019.02.63
Afr J Thoracic Crit Care Med 2023;29(1):e270. https://doi.
org/10.7196/AJTCCM.2023.v29i1.270
Tracheo-oesophageal stula in a case of organophosphate
poisoning
TO THE EDITOR: Tracheo-oesophageal (TO) stula is an abnormal
connection between the trachea and the oesophagus. e stula can
be congenital or acquired, developing as a result of malignant disease,
infection, trauma and ruptured diverticuli.[1]
Prolonged mechanical ventilation with an endotracheal or
tracheostomy tube can result in a TO stula.[2] Factors that can lead to
development of a stula include duration of intubation, cu pressure,
the type of tube used for the procedure, poor nutrition, infection and
extended use of steroids, while ingestion of a corrosive substance may
be a coexisting cause of necrosis of the region. Food particles and
uid from the oesophagus can enter the trachea through the stula,
leading to infection, pneumonia, congestion, bronchial obstruction
and respiratory distress. Before patients develop symptoms of
bronchial infection, a cough reex immediately aer ingestion of food
or water is commonly noted in the initial phase. e severity of the
symptoms depends on the width and length of the stulous connection.
Investigation with bronchoscopy and contrast-enhanced computed
tomography (CT) is required to exclude the possibility of a TO stula.[1]
A 55-year-old woman presented with complaints of coughing aer
ingestion of water and food for 2 months, together with diculty in
swallowing. She had ingested organophosphate 3 months previously,
aer which she was intubated for a prolonged period of 20 days –
12days in the intensive care unit and 8 days in the surgical ward (further
details of the intubation are not available, as it was done elsewhere). On
discharge, no abnormality was noted on clinical examination. She had
had no similar symptoms in the past. Upper gastrointestinal endoscopy
revealed a stulous opening of ~6 mm, ~18 cm from the incisors,
with the area epithelialised. No ulcer or malignant lesion was present
(Fig.1). e rest of the oesophagus and the stomach and duodenum
were normal. Results of all other routine examinations were normal.
Endoscopy was followed by a plain CT scan of the neck, which
showed a TO fistula measuring 6 × 4 × 6 mm (craniocaudal ×
