Eversion resistant sleeves
The invention relates to improved means for preventing eversion and subsequent obstruction of thin-walled, floppy gastrointestinal liners implanted in the digestive tract of an animal. The implantable devices include an anchor adapted for attachment within a natural body lumen and a thin-walled, floppy sleeve open at both ends and defining a lumen therebetween. A substantial length of the sleeve has material characteristics that result in the sleeve being prone to eversion in the presence of retrograde pressures. Exemplary eversion-resistant features provide an increased stiffness and/or an increased friction coefficient between the anchor and the proximal end of the sleeve to resist eversion. In some embodiments, the eversion-resistant feature includes an anti-buckling element, such as a wire coupled along the substantial length of the sleeve.
1. A device for implanting within a lumen having a longitudinal axis, the sleeve comprising:
an anchor adapted for attachment with the lumen;
a sleeve coupled to a distal end of the anchor and adapted for extension within a gastrointestinal tract, the sleeve including:
a crumple zone coupled to the distal end of the anchor and having walls of the sleeve adapted to collapse concentrically upon themselves in the presence of retrograde pressure;
a reinforced zone coupled to a distal end of the crumple zone, the reinforced zone having walls stiffer than the walls of the crumple zone; and
a thin-walled zone extending from a distal end of the reinforced zone to a distal end of the device, the thin-walled zone being prone to eversion in the presence of retrograde pressure.
2. The device of claim 1 wherein, when in a relaxed state, the anchor has a diameter of at least about 40 mm.
3. The device of claim 1 wherein, when collapsed concentrically, the crumple zone forms a valve that allows flow in an antegrade direction and inhibits flow in a retrograde direction.
4. The device of claim 1 wherein the crumple zone tapers from a first diameter at a proximal opening to a second diameter at a distal opening, the first diameter being larger than the second diameter.
5. The device of claim 4 wherein the distal opening of the crumple zone is coupled to a proximal opening of the reinforced zone.
6. The device of claim 4 wherein the first diameter is about 50 mm or more and the second diameter is about 25 mm.
7. The device of claim 1 wherein the crumple zone has a length of about 1.5 inches and the reinforced zone has a length of about 1.0 inch.
8. The device of claim 1 wherein a surface of the reinforced zone has a coefficient of friction greater than that of a corresponding surface of the thin-walled zone.
9. The device of claim 1 wherein the walls of the reinforced zone have a thickness within a range of between about 0.0008 inch and about 0.0040 inch.
10. The device of claim 1 wherein walls of the thin-walled zone have a thickness of about 0.0005 inch.
11. The device of claim 1 wherein the device is configured to provide a concentric eversion pressure of at least 30 inches H 2 O.
12. A device for implanting within an animal body comprising:
an anchor adapted for attachment within a gastrointestinal tract;
a sleeve coupled to a distal end of the anchor and adapted for extension within the gastrointestinal tract, the sleeve including:
an eversion-resistant feature coupled to a distal end of the anchor, the eversion-resistant feature being a taper of the sleeve from a first diameter at a proximal opening to a second diameter at a distal opening, the first diameter being larger than the second diameter, at least part of the eversion-resistant feature being configured to collapse concentrically upon itself in the presence of retrograde pressure; and
a thin-walled zone coupled to the distal opening of the eversion-resistant feature, the thin-walled zone being adapted for extension into the gastrointestinal tract and prone to eversion in the presence of retrograde pressure.
13. The device of claim 12 wherein the first diameter is about 50 mm or more and the second diameter is about 25 mm.
14. The device of claim 12 wherein, when in a concentrically collapsed state, the eversion-resistant feature forms a valve that allows flow in an antegrade direction and inhibits flow in a retrograde direction.
15. A device for implanting within a lumen having a longitudinal axis, the sleeve comprising:
an anchor adapted for attachment within a gastrointestinal tract; and
a sleeve adapted for extension into the gastrointestinal tract, the sleeve comprising:
a thin-walled zone configured to be deployed within a gastrointestinal tract, the thin-walled zone being prone to eversion in the presence of retrograde pressure; and
a tapered segment of the sleeve disposed between a proximal end of the thin-walled zone and a distal end of the anchor, the tapered segment of the sleeve collapsing concentrically upon itself in the presence of retrograde pressure.
16. The device of claim 15 wherein the thin-walled zone extends to a distal end of the device.
17. The device of claim 15 wherein walls of the thin-walled zone have a thickness of about 0.0005 inch.
18. The device of claim 15 wherein, when collapsed from a first diameter to a second diameter, the tapered segment forms a valve that allows flow in an antegrade direction and inhibits flow in a retrograde direction.
19. The device of claim 15 wherein the tapered segment has a proximal opening with a diameter of about 50 mm or more and a distal opening with a diameter of about 25 mm.