Summary: A 48-year-old woman with chronic pulmonary embolism despite anticoagulation presents for
filter placement. Images are best viewed as cines using the DICOM viewer.
Duplicated inferior vena cava
Contrast-enhanced computed tomography (CT) of the chest demonstrates extensive mural thrombus
within the pulmonary arteries (Figure 1). Contrast-enhanced CT of the abdomen
reveals duplication of the inferior vena cava (IVC) with drainage of the left
IVC into the left renal vein (Figures 2 and 3). Venocavography confirms absence
of a left iliac vein inflow defect as well as faint opacification of the left
renal vein and a left-sided IVC (Figure 4).
IVC filters serve to prevent significant pulmonary embolism in cases of venous thromboembolism, in which
standard medical therapy is inappropriate or inadequate. Specifically, well-accepted
indications for filter placement include thromboembolism complicated by failed
anticoagulation (documented progression/recurrence despite anticoagulation),
chronic pulmonary thromboembolism, contraindication to anticoagulation (active
gastrointestinal bleeding, recent surgery or intracranial hemorrhage, vascular
central nervous system metastases), and complications of anticoagulation.1
Variant anatomy of the IVC and its tributaries is relatively common and often has
significant clinical implications, particularly for filter placement planning. Duplication
of the IVC represents one of the more common IVC variants (0.2% to 3%)2
and results from failed regression of the left supracardinal vein during
embryogenesis. Rather than crossing midline to join the right iliac vein, the
left iliac vein continues vertically as a left IVC, which subsequently drains to
the left renal vein. Other common variants include circumaortic left renal
vein, retroaortic left renal vein, and mega cava. Preprocedural cross-sectional
imaging, if available, should be reviewed during treatment staging.
Inferior venocavography in cases of duplication will typically demonstrate absence of a left iliac vein inflow defect.
Occasionally, retrograde contrast will identify the duplicated IVC as it enters
the left renal vein. Prominent communicating pelvic venous moieties are often present. If the routine cavogram is ambiguous,
catheterization of the left renal vein is recommended to confirm or exclude duplication.1
Treatment options include placement of bilateral infrarenal IVC filters or a single suprarenal filter. Although the
later has been historically considered suboptimal due to a theoretical increased
risk of renal vein thrombosis, recent data suggests that suprarenal filter
placement is both safe and effective.3
- Valji K. The practice of interventional radiology. Philadelphia, PA: Elsevier Saunders; 2012.
- Bass JE, Redwine MD, Kramer LA, et al. Spectrum of congenital anomalies of the inferior vena cava: Cross-sectional
imaging findings. Radiographics. 2000;20:639-652.
- Kalva SP, Chlapoutaki C, Wicky S, et al. Superior inferior vena cava filters: A 20-year single-center experience. J Vasc Interv Radiol. 2008;19:1041-1047.