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
aparnaprabh[email protected]
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 ×
AJTCCM VOL. 29 NO. 1 2023 26
CORRESPONDENCE: SCIENTIFIC LETTERS
anteroposterior × transverse) extending from
the anterior wall of the cervical oesophagus
to the posterior wall of the trachea on the le
side of midline at C6 - C7 at the level of the
3rd - 5th tracheal rings, ~44mm inferior to
the level of the glottis (Fig.2
- Supplementary
le: https://www.samedical.org/le/2021
). e
scan was followed by an oral contrast phase
(Fig. 3
- Supplementary file: https://www.
samedical.org/le/2022
).
No surgical emphysema was noted in the
adjoining so tissues and fat planes. Visualised
portions of the nasopharynx and oropharynx
appeared normal. e epiglottis, false cords
and true cords appeared normal. e parotid
and submandibular glands were bilaterally
normal and the thyroid gland showed normal
attenuation and enhancement. The neck
so tissues appeared normal. No signicant
cervical lymphadenopathy was seen. Based on
the CT ndings, a diagnosis of TO stula was
established. e patient underwent surgery
for repair of the fistula with end-to-end
anastomosis with the oesophageal repair.
Written informed consent was obtained from
the patient for publication of this case report
and the accompanying images.
Acquired non-malignant causes of TO
stula are rare and dicult to manage. Cough
while swallowing (Ono’s sign) is an important
clinical sign of TO fistula.[3] Paroxysms of
coughing occur on swallowing owing to an
increase in tracheal secretions and aspiration
while swallowing. Aspiration may result in
recurrent pneumonia. Expectorated material
may contain food particles. e incidence of
TO stula following endotracheal intubation
is <1%. It most oen develops aer prolonged
mechanical ventilation, with a mean period
of 42 days.[4]
Constant monitoring of endotracheal tube
cu volume and pressure is required to avoid
tracheal injury. Ischaemic damage to the
trachea with resultant necrosis occurs when
the cu pressure exceeds the tracheal mucosal
perfusion pressure. Cu pressure should not
exceed 20 cm H
2
O. Cu pressure of >30 cm
H
2
O compresses the mucosal capillaries, while
pressure of 50 cm H
2
O causes total occlusion of
the mucosal capillaries. Cu volume should not
exceed 6 - 8 mL.
[5]
However, tracheal damage can
even occur when the cu pressure is maintained
within the desired range. Traumatic intubation
attempts, a prolonged period of intubation (15
- 200 days, with a mean of 42 days), a wide-
bore gastric tube and excessive movement of
the tracheal tube during sterile swab dressing
are important predisposing factors. Dicult
tracheal intubation with the stylet inside the
tube can result in direct rupture. Anaemia,
diabetes, steroid therapy, shock, metabolic
acidosis and local infection can be predisposing
factors, owing to a decrease in mucosal blood
flow. The incidence of TO fistula is higher
in females than in males, implying that the
membranous trachea is less rm in women, and
in children.
[6]
e exact mechanism in our case
is uncertain. e stula was probably caused by
dicult/traumatic intubation, as it developed
~20 days aer the patient’s organophosphate
poisoning (relatively short duration). It may
have resulted from direct laceration by the
endotracheal tube tip caught in the posterior
tracheal flaccid membrane while advancing
the tube. Owing to its corrosive properties, the
organophosphate ingested by the patient could
have resulted in thinning of the oesophageal
lining, predisposing it to injury.
Before surgical repair of a TO fistula,
good supportive therapy such as measures
to prevent aspiration and pulmonary
infection, good nutrition and spontaneous
breathing are prerequisites for the success of
the operation. Use of a flexible nasogastric
tube, minimal endotracheal tube movement
while positioning/suctioning, a cu volume
<6 - 8 mL, keeping the cuff pressure <20
mm H2O, and selection of an endotracheal
tube of appropriate size can help avoid the
development of a TO stula.[6,7]
A high index of clinical suspicion is required
for early diagnosis and treatment of TO
fistula. Cuff pressure is risky when exerted
posteriorly against a rigid nasogastric tube in
the oesophagus.[7] TO stula can be diagnosed
by means of instillation of contrast medium
into the oesophagus, a CT scan, flexible
oesophagoscopy, or bronchoscopy (with direct
visualisation). CT helps to detect the level of
the fistula, providing sufficiently accurate
measurements of its width and length to assess
its severity. It also helps in terms of identifying
any associated comorbidities. Use of contrast
opacies the pathway of the connection. CT
will also reveal lung pathologies caused by the
stula.[7]
CT is important to establish the existence of
a TO stula, because spontaneous closure of
these stulas is exceptionally rare, and surgical
repair is required to close the connection.
Surgical repair should be done when the
patient is stable, and critically ill patients
need to be conservatively managed until they
become suciently stable.[7]
In conclusion, endotracheal intubation aer
organophosphate poisoning is a rare cause of
TO stula. A high index of clinical suspicion
is needed for early diagnosis and treatment.
Coughing while swallowing (Ono’s sign) is
an important clinical indication of TO stula.
Appropriate cuff pressure and cuff volume
are of the utmost importance in preventing
TO stula. A CT scan of the neck and thorax
with instillation of oral contrast are important
non-invasive radiological investigations.
Bronchoscopy and exible oesophagoscopy
can directly diagnose the fistula. Surgical
repair is the denitive treatment, as TO stulas
very rarely close spontaneously.
S M Khaladkar, MBBS, MD
(Radiodiagnosis)
Department of Radiodiagnosis, Dr D Y Patil
Medical College, Hospital and Research
Centre, Dr DY Patil Vidyapeeth, Pune,
Maharashtra, India
S Goyal, MBBS, MD (Radiodiagnosis)
Department of Radiodiagnosis, Dr D Y Patil
Medical College, Hospital and Research
Centre, Dr DY Patil Vidyapeeth, Pune,
Maharashtra, India
S S Vinay Kumar Parripati, MBBS, MD
(Radiodiagnosis)
Department of Radiodiagnosis, Dr D Y Patil
Medical College, Hospital and Research Centre,
Dr DY Patil Vidyapeeth, Pune, Maharashtra,
India
Fig. 1. Upper gastrointestinal endoscopy
showing a fistulous opening ~6mm in size
and ~18 cm from the incisors, with the area
epithelialised (arrow). No ulcer or malignant
lesion is present.
AJTCCM VOL. 29 NO. 1 2023 27
CORRESPONDENCE: SCIENTIFIC LETTERS
V Gupta, MBBS, MD (Radiodiagnosis)
Department of Radiodiagnosis, Dr D Y Patil Medical College, Hospital
and Research Centre, Dr DY Patil Vidyapeeth, Pune, Maharashtra, India
S Goyal, MBBS, MD (O&G)
Government Medical College, Amritsar, Punjab, India
goyalshr[email protected]om
1. Diddee R, Shaw IH. Acquired tracheo-oesophageal stula in adults. Cont Educ
Anaesth Crit Care Pain 2006;6(3):105-108. https://doi.org/10.1093/bjaceaccp/mkl019
2. Swami GA, Punpale A, Samudre SS, Asawa GR. A rare case of acquired
tracheo-esophageal fistula in adult. Int Surg J 2021;8(9):2796-2798. https://doi.
org/10.18203/2349-2902.isj20213619
3. Rao SV, Boralkar AK, Jirvankar PS, Sonavani MV, Kaginalkar VR, Chinte C.
Tracheoesophageal stula following endotracheal intubation for organophosphorus
poisoning. J Assoc Physicians India 2016;64(12):84-85.
4. Epstein SK. Late complications of tracheostomy. Respir Care 2005;50(4):542-549.
5. Hameed AA, Mohamed H, Al-Mansoori M. Acquired tracheoesophageal stula due to
high intracu pressure. Ann orac Med 2008;3(1):23-25. https://doi.org/10.4103/1817-
1737.37950
6. Kaloud H, Smolle-Juettner FM, Prause G, List WF. Iatrogenic ruptures of the
tracheobronchial tree. Chest 1997;112(3):774-778. https://doi.org/10.1378/
chest.112.3.774
7. Babu MS, Suvarna D, Shetty C, Nadella A. Tracheo-esophageal stula. Br J Med Pract
2014;7(2):a717.
Afr J Thoracic Crit Care Med 2023;29(1):e267. https://doi.
org/10.7196/AJTCCM.2023.v29i1.267
Motor neuron disease presenting with acute hypercapnic
respiratory failure
TO THE EDITOR: Motor neuron disease (MND) is rare, and
respiratory failure at initial presentation is even rarer. Most patients
present with asymmetrical limb weakness.[1] We present a case of
MND presenting with acute hypercapnic respiratory failure.
A previously well 61-year-old black African man who worked as
a trauma nurse complained of breathlessness while at work. He
reported a 3-month history of intermittent shortness of breath and a
2-week history of a non-productive cough. He was initially assessed
as stable with normal vital signs. However, 45 minutes later while
in the emergency department, he became tachypnoeic, hypoxic
and confused. Arterial blood gas (ABG) measurement (Table1)
demonstrated acute hypercapnic respiratory failure. He was initially
started on facemask oxygen and subsequently escalated to continuous
positive-pressure ventilation, resulting in an improvement clinically
and on repeat ABG measurement (Table1).
e initial dierential diagnosis included a pulmonary embolus and an
infective process (including COVID-19). However, further investigations
for these conditions were negative.
A more detailed history revealed motor decits and fasciculations. e
patient reported a 3-month history of diculty opening glass vials of
medication when at work, suggestive of intrinsic hand muscle weakness,
and a 2-month history of ‘jumping’ pectoral muscles. He was also
intermittently confused on awakening, which was suggestive of carbon
dioxide narcosis, with relative hypoventilation during sleep. He had
unintentional weight loss of 25 kg of muscle bulk over the last few months.
On examination, the patient was in respiratory distress and globally
wasted with orid shoulder girdle fasciculations. e cranial nerves
were normal. There was no nystagmus and no ophthalmoplegia.
Bulbar signs were not elicited, and there was a normal jaw jerk. ere
was no extension or neck exion weakness. On motor examination, he
had proximal and distal muscle wasting of the upper limbs with split
hand wasting and fasciculations. He had normal tone with reduced
power of 4/5 in all muscle groups and brisk reexes of 3/4. His lower
limbs had no obvious wasting, normal tone, and reduced power
proximally and preserved power distally. He had brisk knee reexes of
3/4 with no ankle jerks and an upgoing plantar reex on the right. e
ndings on sensory examination were normal, and he was not ataxic.
He was assessed as having a predominant or pure motor syndrome
with combined upper and lower motor neuron signs.
Electrodiagnostic studies were performed. Nerve conduction
studies showed normal latency and conduction velocity, with
decreased amplitude in motor bres. Sensory bres were normal.
Repetitive nerve stimulation of the accessory nerve demonstrated
no decrease in the amplitude of the motor response. e patient was
diagnosed with MND, amyotrophic lateral sclerosis variant. He hadan
atypical presentation with acute hypercapnic respiratory failure.
Table1. Serial blood gas levels and laboratory results
Var i able
Initial
(reference)
Aer non-invasive
ventilation
pH 7.23 (7.35 - 7.45) 7.34
PO2 (mmHg) 50.9 (80 - 100) 185
PCO2 (mmHg) 93.4 (35 - 45) 57
H2CO3 (mEq/L) 29.9 (22 - 26) 32
D-dimers (mg/L) 0.13 (<0.50) n/a
C-reactive protein
(mg/L)
2 (0 - 10) n/a
Procalcitonin (ng/mL) 0.04 (<0.05) n/a
PO2 = partial pressure of oxygen; PCO2 = partial pressure of carbon dioxide;
H2CO3 = bicarbonate; n/a = not applicable.
