Retrieval systems and methods for use thereof
The devices and methods described herein relate to improved structures for removing obstructions from body lumens. Such devices have applicability in through-out the body, including clearing of blockages within the vasculature, by addressing the frictional resistance on the obstruction prior to attempting to translate and/or mobilize the obstruction within the body lumen.
1. A funnel device for securing debris and/or devices within a vessel, the funnel device comprising:
an elongated shaft having a flexibility to navigate through tortuous anatomy; and
a funnel comprising a folded distal end surrounding a distal opening, a proximal portion connected to the shaft, and a cavity therebetween such that when the funnel is expanded the funnel tapers in a proximal direction towards the shaft, the funnel comprising an inverted tubular mesh having an exterior mesh wall and an interior mesh wall that are continuous at the folded distal end of the funnel, wherein: (a) a proximal end of the exterior mesh wall and a proximal end of the interior mesh wall are fixed at the shaft relative to one another, (b) the inverted tubular mesh is shape set, and (c) a cross-sectional dimension of the funnel at its folded distal end is a maximum cross-sectional dimension of the funnel,
wherein at least a portion of the mesh is porous to permit fluid flow therethrough.
2. The device of claim 1 , where the funnel is shape set such that there is a gap between the interior mesh wall and the exterior mesh wall.
3. The device of claim 1 , where the inverted tubular mesh is a compliant material and where the interior mesh wall and the exterior mesh wall are slidable relative to each other such that withdrawal of the device or debris proximally into the interior mesh wall of the funnel causes movement of the interior mesh wall while a portion of the exterior mesh wall remains stationary when positioned against the vessel.
4. The device of claim 1 , wherein the funnel is everted proximally over the shaft when positioned within a delivery sheath.
5. The device of claim 1 , where a portion of the funnel at or adjacent to the distal opening comprises a bulbous shape.
6. The device of claim 1 , where the funnel comprises a first porous section having a first porosity and at least a second porous section having a second porosity, where the first and second porosity are different such that the ability of fluid to flow through the first porous section and second porous section differs.
7. The device of claim 1 wherein the exterior mesh wall conforms to the interior mesh wall when the funnel is expanded.
8. An obstruction removal system for removing obstructions from a body lumen; the removal system comprising:
a retrieval device for securing the obstruction;
an elongated shaft having a flexibility to navigate through tortuous anatomy; and
a funnel comprising a folded distal end surrounding a distal opening, a proximal portion connected to the shaft, and a cavity extending between the distal opening and the proximal portion such that when the funnel is expanded the funnel tapers in a proximal direction towards the shaft, the funnel comprising an inverted tubular mesh having an exterior mesh wall and an interior mesh wall that are continuous at the folded distal end of the funnel, wherein: (a) a proximal end of the exterior mesh wall and a proximal end of the interior mesh wall are fixed relative to one another at the shaft, (b) the inverted tubular mesh is shape set, and (c) a cross-sectional dimension of the funnel at its folded distal end is a maximum cross-sectional dimension of the funnel, and
wherein at least a portion of the mesh is porous to permit fluid flow therethrough, and
wherein the retrieval device is slidable along the elongated shaft relative to the funnel, or vice versa.
9. The system of claim 8 , where the inverted tubular mesh is a compliant material and where the interior mesh wall and the exterior mesh wall are slidable relative to each other such that withdrawal of the retrieval device or obstructions proximally into the interior mesh wall of the funnel causes movement of the interior mesh wall while a portion of the exterior mesh wall remains stationary when positioned against the body lumen.
10. The system of claim 8 , wherein the funnel is everted proximally over the shaft when positioned within a delivery sheath.
11. The system of claim 8 , where a portion of the funnel adjacent to the distal opening comprises a bulbous shape.
12. The system of claim 8 , where the funnel comprises a first porous section having a first porosity and at least a second porous section having a second porosity, where the first and second porosity are different such that the ability of fluid to flow through the first porous section and second porous section differs.
13. The device of claim 8 wherein the exterior mesh wall conforms to the interior mesh wall when the funnel is expanded.