Staged release of IVC filter legs

1. A catheter, comprising:

an elongated tubular member having a proximal section, a distal section, and an inner lumen;

an intravascular filter disposed within the lumen;

a first set and a second set of notches or slits radially disposed about the distal end of said distal section, said first set of notches or slits extending proximally from the distal end of the elongated tubular member, said second set of notches or slits extending proximally from the distal end of the elongated tubular member to a greater depth than the first set of notches or slits, said first and second sets of notches or slits being located adjacent to each other to form a crenellated surface, said first and second sets of notches or slits being radially disposed at equidistant intervals about the distal end of said distal section; and

one or more grooves or indentations formed along an inner surface of the distal section, said one or more grooves or indentations corresponding in number and arrangement with said first and second sets of notches or slits, each of the one or more grooves or indentations being radially aligned with a corresponding one of the first and second sets of notches or slits.

2. The catheter of claim 1 , wherein said first and second sets of notches or slits comprise two sets of opposing notches.

3. The catheter of claim 1 , wherein said intravascular filter is a vena cava filter.

4. The catheter of claim 3 , wherein said vena cava filter is front-loaded into the catheter for placement through a femoral artery.

5. The catheter of claim 3 , wherein said vena cava filter is back-loaded into the catheter for placement through the jugular vein.

6. The catheter of claim 3 , wherein said vena cava filter includes a plurality of expandable filter legs coupled to an apical head.

7. The catheter of claim 6 , wherein each of said plurality of expandable filter legs includes a hook region.