Radiographic findings in VACTERL association

Clinical History

A female neonate (gestational age 37 weeks 4 days) was referred to our hospital with the antenatal diagnosis of polyhydramnios, single umbilical artery and suspected oesophageal and anal atresia, the latter clinically confirmed after delivery.
Inability to insert a nasogastric tube prompted further radiological examination.
Physical examination was otherwise unremarkable.

Imaging Findings

Chest radiograph depicted coiling of the nasogastric tube inside the proximal air-filled and mildly dilated oesophageal pouch. Air in the stomach was indicative of the presence of a tracheoesophageal fistula in the context of oesophageal atresia (Fig 1).

Radiograph of the chest and abdomen depicted multiple osseous abnormalities comprising rib anomalies as well as vertebral formation and segmentation anomalies: hypoplastic left 4th and 5th ribs and wavy contour of the 6th rib, bilateral supernumerary 13th ribs and fused 6th and 7th thoracic vertebrae with a butterfly appearance of the 7th vertebra, presence of a 3rd sacral hemivertebra accompanied by fusion with the overlying 2nd sacral vertebra, as well as dysplastic lower sacral vertebrae with vertical clefts (Fig 2).

Abdominal and cerebral ultrasonography were unremarkable.
Echocardiography disclosed multiple cardiac anomalies—atrial and ventricular septal defects and hypoplastic aortic arch.
No radial or limb malformations were noted clinically.

Discussion

A. Background

VATER association was suggested in 1973 by Quan et al and was later renamed VACTERL, including additional features to describe the non-random co-occurrence of the following congenital malformations [1, 2]:

• Vertebral anomalies
• Anal atresia
• Cardiac defects
• Tracheoesophageal fistula and/or oesophageal atresia
• Renal and/or radial anomalies
• Limb defects

Reported incidence varies from 1 in 10, 000 to 1 in 40, 000 live-born infants, owing to controversy over diagnostic criteria [2]. VACTERL association occurs sporadically with little evidence for inheritance and relation to some genetic factors [3, 4]. At least three core defects are required for the diagnosis [5, 6].

Vertebral anomalies occur in 60-80% of patients. These include supernumerary or absent vertebrae, segmentation defects (vertebral fusions which may be complete, known as block vertebra, or partial), formation defects (hemivertebrae, butterfly vertebrae, wedge vertebrae) or a combination. Co-existing rib anomalies are common [2].

Anal atresia occurs in 55-90% of patients. The spectrum of anorectal malformations ranges from complete imperforate anus to mild anal stenosis, the latter occasionally missed and present as delayed obstruction [2].
Congenital heart defects constitute a debatable definite feature of the association with ventricular septal defects being the most frequent [2, 7].

Tracheoesophageal fistula (TEF) with or without oesophageal atresia (EA) occurs in 50-80% of patients [6, 8]. Complications may occur postoperatively and include recurrence, tracheomalacia, oesophageal stricture, gastroesophageal reflux and airway hyperreactivity/recurrent respiratory tract infections [8, 9].
Renal anomalies (primarily structural renal defects) occur in 60% of patients. These include renal agenesis, horseshoe kidney, cross fused renal ectopia and dysplastic kidneys, sometimes combined with genitourinary defects. Delayed diagnosis may result in chronic kidney disease [10, 11].

Limb malformations occur in 40-50% of patients and comprise radial ray anomalies with/without thumb dysplasia. Additional non-specific limb anomalies (predominantly fingers) have also been reported [2, 12].

B. Clinical Perspective
Potentially life-threatening conditions (TEF/EA, anorectal malformations, cardiac anomalies) should be promptly recognised and managed. Thorough investigation for occult coexisting pathology is required to improve morbidity and avoid long term sequelae.

C. Imaging Perspective
Imaging is mandatory for antenatal and complete postnatal evaluation of neonates with suspected VACTERL association. Oesophageal atresia/TEF and costovertebral malformations are evaluated with radiographs (with inserted nasogastric tube). In anorectal malformations, the proximity of rectum to perineum is assessed with a prone cross-table lateral pelvic X-ray and/or perineal ultrasound. Genitourinary defects are evaluated with abdominal ultrasonography and cardiac and vascular anomalies with transthoracic echocardiography. Cross-sectional imaging (MRI/CT) may be necessary to delineate complex malformations [13].

D. Outcome
Prognosis depends on identification of all coexisting defects and on appropriate management with improved surgical techniques in experienced centres [2, 13].

Differential Diagnosis List

Final Diagnosis

VACTERL association

URL:	https://eurorad.org/case/15691
DOI:	10.1594/EURORAD/CASE.15691
ISSN:	1563-4086