Complication post IVC filter insertion

Clinical History

76-year-old man who recently underwent an IVC filter insertion for a Proximal Deep Vein Thrombosis (DVT) due to contraindications to anticoagulation. Represented shortly after with collapse episodes on mobilising, painful, discoloured legs and confusion.

Imaging Findings

Initially due to acute renal failure this gentleman had a non-contrast CT to exclude filter migration. As seen in figure 1, the filter was in an ideal anatomical position in the IVC, just distal to the level of the left renal vein. The calibre of the IVC proximal to the filter was reduced and below the filter was prominent. However due to this being an unenhanced study, the patency of the filter or thrombus formation could not be commented on with confidence.

After discussion with the renal team regarding the need for dialysis post contrast administration, a contrast CT was undertaken (figure 2). This time IVC thrombus was clearly seen at the level of renal veins. This extended proximally to the intrahepatic IVC. No thrombus was seen in the right atrium. The IVC itself and the iliac veins didn't demonstrate enhancement distal to the thrombus and had an enlarged calibre.

Discussion

The most common indication for IVC filter insertion is for patients with a DVT or PE and a contraindication to anticoagulation, such as: recent haemorrhagic stroke/surgery, unsteady gate and falls, intracranial neoplasm, Ateriovenous malformations (as was the case with our patient), bleeding diathesis etc [1, 4].

Whilst IVC filters have been shown to be a safe and effective alternative to anticoagulation in preventing pulmonary embolism they confer no long term survival benefit and are associated with certain minor and more major complications [2].

These include: IVC trauma and perforation (leading to retroperitoneal haematoma and rarely bowel injury), filter migration <1.5% / infection <1% / fracture 1-2% / tiling 0.5-5%, caval thrombosis 0-3%, ipsilateral DVT 2-20%, new PE 1-2% or DVT 6-39% and have an associated 30 day mortality rate <1% [2, 3].

As in our case this gentleman presented with acute haemodynamic compromise shortly following insertion. The initial worry to the clinician in this scenario would be of filter perforation or extensive thrombosis. As time progressed he displayed more features of acute iliofemoral venous thrombosis as his legs became progressively more painful, cyanotic and mottled. This clinical feature is classically described as phlegmasia cerulae dolens and is a sign of extensive venous ischaemia of an extremity due to thrombotic occlusion of the major veins and collaterals [2].

Unfortunately in our scenario this gentleman was not a candidate for attempted thrombolysis due to the presence of a large cerebral arteriovenous malformation and given other significant co-morbidites was unable to proceed to theatre for filter retrieval and embolectomy.

Differential Diagnosis List

Final Diagnosis

IVC filter thrombosis

URL:	https://eurorad.org/case/10480
DOI:	10.1594/EURORAD/CASE.10480
ISSN:	1563-4086