IVC FILTER RETRIEVAL SYSTEM SHEATH IMPROVEMENTS
Funnel-trap type delivery and/or retrieval devices for Inferior Vena Cava (IVC) filters or other medical implants are described with associated sheaths. The sheaths are used in progressive recapture and/or embolic protection methods or in association with such features.
1 . An apparatus for delivery or retrieval of a vascular medical device, the apparatus comprising:
an elongate shaft having an axis having a flexible distal extension comprising braid, the extension folded-back inwardly at a distal opening and forming a more proximal opening, the proximal opening sized to receive and pass an end of the medical device therethrough, and
an elongate sleeve, the sleeve sized for the end of the medical device to be secured in a pocket within the distal extension when the elongate sleeve is advanced over the distal extension,
wherein the sleeve includes a varying inner diameter portion adjacent a distal end.
2 . The apparatus of claim 1 , wherein the varying inner diameter portion is conical in shape.
3 . The apparatus of claim 2 , further comprising a distal cylindrical section.
4 . The apparatus of claim 3 , wherein the distal cylindrical section incorporates a marker band.
5 . The apparatus of claim 2 , wherein the distal cylindrical section is characterized by an included angle of between about 5 and about 30 degrees.
6 . The apparatus of claim 5 , wherein the included angle is between about 5 and about 15 degrees.
7 . The apparatus of claim 6 , wherein the included angle is between about 7 and about 12 degrees.
8 . The apparatus of claim 1 , wherein the varying inner diameter has a curvilinear profile.
9 . The apparatus of claim 1 , wherein the profiles are S-shaped.
10 . The apparatus of claim 1 , wherein the varying inner diameter portion is provided by a balloon within a lumen of the elongate sleeve at a distal end thereof.
11 . The apparatus of claim 10 , wherein the balloon is toroidal.
12 . The apparatus of claim 1 , wherein the varying inner diameter is provided by a plurality of internal members, the plurality of internal members being either leaf springs or fins.
13 . The apparatus of claim 1 , wherein the varying inner diameter portion is provided by flexibility set with a stent-like body.
14 . The apparatus of claim 1 , further comprising an expandable funnel mounted on the shaft proximal to the extension.
15 . The apparatus of claim 1 , further comprising an expandable funnel mounted on the elongate sleeve.
16 . The apparatus of claim 15 , wherein the funnel is mounted proximal to the adjustable inner diameter.
17 . A method of vascular medical device retrieval, the method comprising:
positioning a retrieval device comprising a shaft and a folded-back extension defining an interior pocket with the pocket receiving an end of a medical device; and
sliding a sheath over the extension, compressing the extension progressively with a varying diameter of the sheath and capturing the end.
18 . The method of claim 17 , wherein the progressive compression is by a tapered section.
19 . The method of claim 18 , wherein the tapered section has a profile selected from conical and curvilinear shapes.
20 . The method of claim 17 , wherein the progressive compression is by inflation of a balloon within the sheath.