Keywords
esophageal atresia - tracheoesophageal fistula - interrupted inferior vena cava
Introduction
Esophageal atresia (EA) is a congenital abnormality of the esophagus that is caused
by incomplete embryonic compartmentalization of the foregut. EA commonly occurs with
a tracheoesophageal fistula (TEF).[1] The overall worldwide prevalence of EA as calculated from national and international
databases for congenital anomalies is 2 to 4 per 100,000 births.[1] Interrupted inferior vena cava (IVC) is a rare disease. According to postnatal series,
interrupted IVC with azygos or hemiazygos continuation is a rare disorder occurring
in 0.6 to 3% of the population with congenital heart disease.[2] Therefore, the association of interrupted IVC, EA with TEF, is exceedingly rare.
EA and TEF accompanied by interrupted IVC that underwent successful repair in a few
pediatric cases has been described.[1]
[3] Before undertaking TEF surgery, most authors advise dividing the azygos vein.[1]
[4] References do not routinely recommend checking for an interrupted IVC preoperatively.[1]
[5] However, dividing the azygos vein in the presence of an interrupted IVC may result
in death. The aim of this study was to analyze the clinical and radiological features
of EA and TEF accompanied by interrupted IVC in newborns. It emphasizes the importance
of diagnosing interrupted IVC before undertaking TEF surgery and raises awareness
of the importance of diagnosing vascular anomalies prior to EA and TEF repair ([Supplementary Material 1], available in the online version).[4]
[5]
Case Report
Patient history: A 2.85-kg female infant was delivered at 39 weeks of gestation by natural labor (November
19, 2020), with a 1-minute Apgar score 10 points. Maternal health in good. A fetal
echocardiogram performed at 35 weeks demonstrated EA and an interrupted IVC with azygos
continuation to the right-sided superior vena cava. A postnatal echocardiogram confirmed
the interrupted IVC, which does not involve the hepatic segment of the IVC, and light
cardiac anomalies with small atrial septal defect and mildly tricuspid regurgitation.
Diagnosis: The patient was intubated at birth but resistance was noted during orogastric tube
insertion. Chest X-ray revealed ([Fig. 1]) the gastric tube at the upper pouch of the esophagus with the presence of intestinal
gas, which is a classic feature of type C EA. Thoracotomy repair of EA was scheduled
for the next day following stabilization.
Fig. 1 Chest radiograph on lateral view showed the orogastric tube inserted at the proximal
esophageal pouch (short arrow) with distal bowel gas, esophageal atresia with distal tracheoesophageal fistula
(long arrow).
Surgical procedure: The patient was positioned in a semi-prone position with the right chest slightly
elevated. She was put on conventional ventilation without single lung ventilation.
The patient underwent right intrapleural thoracotomy, based on the echocardiographic
findings of an interrupted IVC and azygos continuation to the superior vena cava.
The pediatric surgeon preserved the azygos vein connection at the time of the TEF
repair to prevent obstruction of the venous return from the lower body. Through a
right intrapleural thoracotomy, 5–0 Monocryl was used as anastomotic suture material
and end-to-end esophageal anastomosis. All operations were performed by three qualified
pediatric surgeons. A 10-Fr chest drain was inserted at the end of the procedure.
The operation was uneventful and completed in 145 minutes.
Postoperative care: After surgery, the patient was managed in the neonatal intensive care unit according
to our usual protocol. The patient was extubated successfully on day 4 after surgery.
She was discharged home at the age of 15 days. At 6 months of age, enhanced computed
tomography (CT) showed ([Fig. 2]) the hepatic segment of the IVC draining hepatic veins and not continuing further
caudally. Iliac and renal veins drained via the distended azygos vein within the abdomen,
entering the thorax and draining into the superior vena cava within the thorax, and
by 12 months of age her small atrial septal defect, measured by Doppler echocardiography,
was normal. At the follow-up visit until April 5, 2024, she was doing well, she had
good weight gain with full oral feeding, and no clinical gastroesophageal reflux.
Fig. 2 Contrast-enhanced computed tomography on sagittal view showed a hepatic segment of
the inferior vena cava draining hepatic veins (short arrow) and not continuing further caudally. Iliac and renal veins drained via the distended
azygos vein within the abdomen, entering the thorax and draining into the superior
vena cava within the thorax (long arrow).
Discussion
Interrupted IVC with azygos or hemiazygos vein continuation is a rare congenital anomaly.[2] It usually involves the hepatic segment of the IVC. According to a postnatal series,
its estimated prevalence is 0.15%.[2] EA with or without TEF is the most common anomaly of the esophagus (incidence of
2–4/10,000 births).[1] The infrahepatic interruption of the IVC with azygos and hemiazygos continuation
is a rare finding especially when it is associated with EA and TEF.[2]
[6] Interrupted IVC is associated with congenital heart disease in approximately 85%
of cases, and frequently with the polysplenia syndrome. Our patient demonstrated light
cardiac anomalies with small atrial septal defect, without polyspenia.[2]
[3]
[7] To the best of our knowledge, there has only been one report of this combination
in a patient who survived surgery and continues to do well,[8] but there are few studies analyzing the radiological features of EA and TEF accompanied
by interrupted IVC. This study analyzed the clinical and radiological features of
EA and TEF accompanied by interrupted IVC, reported the successful outcome of the
rare presentation of EA with TEF and an interrupted IVC, and emphasized that all EA
patients should undergo a detailed evaluation of IVC during preoperative assessment.
The most commonly involved segment of interrupted IVC is the hepatic segment. It is
due to the failure of the development of the hepatocardiac canal during the embryo,
in its 10 to 15 mm length.[2] This patient's infrahepatic part was atretic; the iliac and renal veins drained
via the distended azygos vein within the abdomen, entering the thorax and draining
into the superior vena cava. IVC interruption can be diagnosed through prenatal or
postnatal imaging. Noninvasive imaging modalities such as contrast-enhanced CT and
magnetic resonance imaging are the most reliable methods for identification of these
anomalies in an asymptomatic patient, and contrast-enhanced CT scan and venography
can be helpful. Note was made of interrupted IVC, which drained only the hepatic veins
before entering the right atrium.[9] The infrahepatic IVC continues as the azygos vein. Recognizing this venous anomaly
is important for the pediatric surgeon, especially for conditions such as a paracardiac
or mediastinal mass on chest radiography.
Although EA can be diagnosed antenatally, most patients (>90%) are diagnosed after
birth. EA is prenatally diagnosed in a minority of cases and is usually only suspected
on the basis of the presence of indirect or direct signs on ultrasonography. MRI with
dynamic sequence and biochemical evaluation of the amniotic fluid have been developed
to help in the diagnosis of EA.[5]
[6]
[10]
Different surgical techniques are available. The optimal approach is dependent on
the type of EA. Division of the azygos has been part of the TEF repair since Cameron
Haight's report of the first successful procedure.[6] However, references do not routinely recommend checking for an interrupted IVC preoperatively.
Dividing the azygos vein in the presence of an interrupted IVC may result in death.[9]
[10] Some suggest inspecting the size of the azygos vein prior to division, as a large
azygos vein may be consistent with an interrupted IVC.[9]
[10]
[11] Patients born with EA should ideally be evaluated in a multidisciplinary team consisting
of a pediatric surgeon, a gastroenterologist, a pulmonologist, and an otolaryngologist.
For TEF repair, it is important to be aware of the patients' vascular anatomy before
surgery.[3]
[6]
[12] Accurate diagnosis of an abnormal IVC position and course can help the pediatric
surgery expert in surgical planning, avoid unnecessary treatment measures, and prevent
accidental injury caused by complications.
In conclusion, this case highlights the complexity of managing EA with TEF in the
presence of an interrupted IVC. Early and accurate diagnosis of vascular anomalies
through prenatal or postnatal imaging is essential for optimal surgical planning and
avoiding potentially fatal complications. The preservation of the azygos vein during
repair was critical in ensuring a successful outcome. This report emphasizes the importance
of multidisciplinary care and comprehensive imaging in rare congenital cases to improve
patient survival and outcomes.
