How long does it take to clog an ivc filter so that both legs swell?

Shouldn't: It's not like a pool filter, more like a shredder. Unless very low blood pressure / flow, should not clot that high, but can clot lower. Helps decrease size so no large (/huge) clot goes to lung. If swelling, more likely edema / "heart failure" and should be seen by dr or in er depending on severity & any other complaints.

Unusual: Ivc filters should not cause legs to swell of and by themselves. Filters can be placed inappropriately initially or may migrate...They are always placed below the renal arteries under xray guidance..Swelling of the legs is a ign of more serious problems that may not be related to the placement of the filter.

Ivc filters: Typically do not clot. If it catches a clot that migrated from your legs , then it can thrombose. Leg swelling can result. Tpa and or mechanical devices can be used to restore flow. Also you can be maintained on Aspirin or low dose Coumadin (warfarin) to help keep the filter patent. Talk to your doctor.