Newton's Law to the rescue: therapeutic effects of gravity aiding the management of a migratory venous foreign body--a case report.

The management of intravascular metallic foreign bodies (FB) can be difficult and challenging. We report a case of a migrating FB, initially within the femoral vein which subsequently migrated to the intrahepatic vena-cava. Following a change of posture, the metallic FB moved with gravity against the normal venous blood flow to the left renal vein. It was finally fixed in position in a peripheral branch of the renal vein using an intravascular stent. Employing gravity as a therapeutic intervention and the technique used in isolating the FB has not, to our knowledge, been reported before. A case is described, and the literature is reviewed.