Where should IVC filters be placed?

The appropriate placement of inferior vena cava (IVC) filters is distal to the renal veins. This positioning is crucial because it minimizes the risk of the filter obstructing the renal veins and allows for the safe capture of thrombi that may travel from the lower extremities. By placing the filter distal to the renal veins, the filter can effectively intercept potential emboli without interfering with the normal venous drainage of the kidneys, thereby preventing complications such as renal vein thrombosis.

Other placements may lead to adverse outcomes or reduced efficacy of the filter. For instance, placing a filter above the renal veins could increase the risk of clots reaching the kidneys. Additionally, positioning it at the level of the renal veins might not optimally capture thrombi while still posing a risk to renal vascular flow. Therefore, the most prudent placement is indeed distal to the renal veins to ensure both efficacy and safety.