Congenitally absent IVC: A rare cause of recurrent DVT and non-healing leg ulcers

Clinical History

The patient was referred with long-standing history of a swelling of both legs, repeated DVT and PE. She was on life-long anticoagulation. Examination showed massive leg oedema up to the upper third of the abdominal wall with distended veins and ulcers on both legs. CT abdomen with I.V. contrast performed to rule out compressing nodes revealed another diagnosis.

Imaging Findings

CT abdomen and pelvis with I.V. contrast:
There was generalised oedema of the abdominal wall, worse inferiorly, which is in keeping with the history of lymphoedema. Extensive varices at the abdominal wall were noted. There were also intraabdominal varices at the paraaortic region. A grossly enlarged azygous vein was fed by collateral vessels from the abdominal wall. The vena cava was absent and replaced by multiple collateral veins around the paraaortic region. The liver, spleen, adrenals, kidneys and pancreas were normal. No para-aortic and no pelvic masses were found. No abnormality was seen in the abdominopelvis.

Discussion

Congenitally absent Inferior Vena Cava (IVC) has been associated with other cardiovascular abnormalities [1] and includes a spectrum ranging from presence of bilateral IVC to its complete absence [2].
In search of a cause for the so-called idiopathic Deep Vein Thrombosis (DVT), researchers have pointed towards association between recurrent DVT and absent IVC; furthermore the absence of IVC is associated with right renal aplasia [3]. Taking it further some investigators have linked IVC absence and renal hypoplasia with perinatal renal vein thrombosis [4]. The condition of renal aplasia, absent IVC and DVT has been named KILT (Kidney and IVC abnormalities with Leg Thromboses) syndrome [5] by some investigators. Ruggeri M et al and Chee YL et al have given special attention to the association between the so-called idiopathic DVT and IVC anomalies and both teams have concluded that IVC anomalies with DVT are commoner than reported in the literature [6, 7].
Absence of IVC cannot be diagnosed on ultrasound. Some clues may point towards the diagnosis like dilated azygous and hemi-azygous veins and prominent collateral veins in abdominal wall [8].
The most reliable investigations for the diagnosis of anomalous or absent IVC are CT with I.V. contrast or MRI. CT provides a good interpretation of retroperitoneal organs and in cases of stenosed or absent IVC, retroperitoneal venous plexus is also well developed and helps with the diagnosis [9]. Venography can also be used, but is helpful mainly in cases where surgical intervention is planned.
When the association between absence or stenosed IVC and recurrent DVT is questioned, most of the investigators have the opinion that despite development of adequate collateral channels the venous stasis and resulting chronic venous hypertension can precipitate thrombosis.
Gayer et al advocate that all patients with IVC abnormality should undergo thrombophilia screening as well because in their series 7 of 9 patients with IVC anomaly and DVT had a positive thrombophilia screen [10].
Very little evidence is available on the treatment options for the symptomatic patients. One case report documents treatment with surgical intervention with good results [4]. Life-long anticoagulation, however, is suggested even if thrombophilia screen is negative.
Literature review suggests that any young patient with either non-healing leg ulcers or recurrent DVT should be investigated for IVC anomalies with CT abdomen with I.V. contrast if there are no other clues to the diagnosis. Surgical intervention has a limited role and patients should be offered life-long anticoagulation for ongoing risks of DVT and pulmonary embolism.

Differential Diagnosis List

Final Diagnosis

Congenitally absent IVC: A rare cause of recurrent DVT and nonhealing leg ulcers

URL:	https://www.eurorad.org/case/12672
DOI:	10.1594/EURORAD/CASE.12672
ISSN:	1563-4086