Inferior vena caval filter is deployed:
a) Above the renal veins
b) At the renal veins
c) Below the renal veins
d) Below the hepatic veins
Correct answer: c) Below the renal veins
Inferior vena caval (IVC) filter is usually deployed to prevent migration of venous thrombus from lower limb or pelvic veins to the right heart and the lung, with an aim to prevent pulmonary embolism. Both temporary retrievable and permanent IVC filters are available from different manufacturers. The filters have barbs or hooks to prevent migration within the IVC. The filters are usually deployed below the renal veins under fluoroscopic guidance.
Filters with delivery systems suitable for trans femoral, trans jugular and trans cephalic vein delivery are available.
Rarely thrombus formation can occur above the filter and sometimes embolisation can still occur through large collaterals which can form once the filter is clogged by thrombi. IVC filters are considered in case of recurrent massive pulmonary embolism, especially when there is a contraindication to long term anticoagulation. Short term anticoagulation is needed after implantation of an IVC filter.
Rare case of IVC filter inadvertently deployed in the aorta being successfully retrieved by simultaneous trans brachial and trans femoral approach has also been reported . Another case of endovascular retrieval of IVC filter penetrating the aorta and causing abdominal pain has also been reported .
- Naidu SG, Stone WM, Sweeney JP, Money SR. Endovascular retrieval of a TrapEase permanent inferior vena cava filter from the aorta. J Vasc Surg. 2012 Jan;55(1):237-9.
- Yeung LY, Hastings GS, Alexander JQ. Endovascular retrieval of inferior vena cava filter penetrating into aorta: an unusual presentation of abdominal pain. Vasc Endovascular Surg. 2010 Nov;44(8):683-6.