Superior venacaval thrombosis in children

Clinical History

A 12 year old male child with known cystic fibrosis was admitted for administration of intravenous antibiotics. He had an indwelling catheter inserted into the left internal jugular vein 3 months back and positioned in the right atrium. Mum noticed fullness of the face and prominent neck veins. Examination revealed prominent jugular veins on the left side and collaterals on the chest.

Imaging Findings

A 12 year old male child with known cystic fibrosis was admitted to the paediatric ward for administration of intravenous antibiotics. Three months back he had an indwelling catheter inserted into the left internal jugular vein and positioned in the right atrium. Mum noticed fullness of the face and prominent neck veins. Examination revealed prominent jugular veins on the left side and collaterals on the chest. Doppler examination of the neck revealed thrombosis of right internal jugular, brachiocephalic and subclavian veins and also left internal jugular and subclavian veins. MR venogram revealed prominent collateral veins in the paravertebral area and draining into the azygous vein .No flow is seen superior to the junction of the azygous with the SVC. Echocardiogram showed reduced flow pattern in the SVC. A diagnosis of SVC thrombosis was made.The child was treated with thrombolytics initially followed by low molecular weight heparin and Warfarin. Gradually the facial swelling began to decrease and the general condition improved.

Discussion

Patients with cystic fibrosis (CF) frequently require IV antibiotic therapy for treatment of acute exacerbations of their pulmonary disease for which they may require the placement of an indwelling catheter. The most common complication of indwelling catheters in children is thrombosis. Obstruction of blood flow may result in superior venacaval syndrome (SVCS). Other complications include infection & mechanical complications (migration of catheter tip, erosion of the vessel wall). Apart from central catheters other causes of SVCS in children include malignant or benign tumours of the mediastinum (2/3 cases caused by lymphomas), congenital heart diseases, cardiac surgical procedures and ventriculo-atrial shunts. The clinical presentation of SVCS depends primarily on the acuity of SVC obstruction. With slowly progressive obstruction of the SVC, adequate collateral circulation may develop, and patients may have only mild symptoms. In acute SVC obstruction, collateral pathways do not have time to develop, and patients are more symptomatic. Symptoms also depend on the level of SVC obstruction relative to the insertion of the azygous vein. Obstruction of the SVC above the insertion of the azygous vein may cause fewer symptoms, as the azygous vein provides venous drainage for the head and upper extremities. If the level of obstruction is below the azygous vein then venous drainage occurs via collaterals to the inferior vena cava. Symptoms of SCVT in children include fullness of head and neck, blurred vision, vertigo, shortness of breath and cough. Clinical signs include tachycardia, oedema of the face and neck, engorged jugular veins & visible collaterals on the chest. The investigations of a patient with suspected SVCS depends on the age of the child and previous medical history. All patients should undergo chest radiography and Doppler ultrasonographic evaluation of the central veins.Ultrasonography is useful for excluding thrombus in the internal jugular, axillary, subclavian, and brachiocephalic veins in most patients. The SVC cannot be directly imaged because of the lack of an adequate acoustic window. SVC patency can be indirectly determined with normal waveforms in the subclavian and brachiocephalic veins. If normal venous waveforms are seen in the brachiocephalic, subclavian, and internal jugular veins, the presence of a significant SVC stenosis is unlikely. Colour Doppler permits direct visualization of thrombus, collateral vessels, catheters, and stents. Contrast-enhanced venography may be required to exclude central venous thrombosis in patients with suboptimal or inconclusive ultrasonographic findings. MR imaging may provide more comprehensive information on central venous anatomy and blood flow and may be helpful in cases in which other methods may give inadequate findings or may be impossible to perform. If the findings of non-invasive imaging studies are inconclusive, catheter venography and pressure measurements are extremely useful.Transesophageal echocardiography can also be used to image the SVC and right atrium. In patients with suspected malignancy, CT of the thorax should be performed. If a malignant disease of the haematopoietic system is suspected, bone marrow biopsy is indicated. The treatment of patients with SVCS is determined by the aetiology and severity of the obstruction. The various treatment options include medical management with thrombolytics and anticoagulants, endovascular stents, angioplasty and surgical bypass of SVC obstruction. In obstruction due to malignancy, radiotherapy and chemotherapy are undertaken.

Differential Diagnosis List

Final Diagnosis

Superior venacaval thrombosis

URL:	https://eurorad.org/case/2712
DOI:	10.1594/EURORAD/CASE.2712
ISSN:	1563-4086