Vascular filter with sleeve
A covered vascular filter can be placed in a blood vessel, for the purpose of intercepting thrombus. The filter may be introduced to a desired site for medical treatment through a catheter which defines a lumen or passage and a distal port or opening. The filter tends to resiliently expand from a compressed shape when it is inside the catheter lumen, to an expanded shape when the filter is pushed from the catheter lumen. A cover or sleeve over those portions of the filter that would otherwise contact the vessel wall tends to reduce pressure on the vessel wall. The sleeve also tends to resist growth of the vessel wall among the elements of the filter, called endothelialization. In other words, the sleeve resists incorporation of the filter elements into the vessel wall, enabling the filter to be retrievable for a longer time. The various features of the present invention may be used singly or in any combination, as desired in a particular vascular filter.
1 . A medical device for therapeutic treatment of a patient, comprising:
a filter having a first and second end, and a central expandable portion extending between the ends; the central portion tending to resiliently expand in radially outward directions from a compressed initial shape to an expanded deployed shape;
wherein the filter defines a first and second filtering element in the expanded shape, the first and second filtering elements each being near the first and second end, respectively;
the filter having a plurality of ribs arranged in a pre-selected pattern; such that the ribs expand in radially outward directions when the filter expands from the compressed shape to the expanded shape, thereby causing the first and second ends to move toward each other and;
a flexible sleeve encircling at least a portion of the filter, around a longitudinal axis defined between the first and second ends; the sleeve defining a surface area; the sleeve tending to expand with the filter central portion to an expanded shape in which the sleeve represents a tubular surface for contracting a blood vessel wall.
2 . The medical device of claim 1 , wherein the sleeve is made of foil.
3 . The vascular filter as set forth in claim 1 , wherein the sleeve tends to reduce pressure imparted by the filter on a blood vessel wall.
4 . The medical device of claim 1 , wherein the sleeve is made of biodegradable material.
5 . The medical device of claim 1 , wherein the sleeve extends a time in which the medical device is endothelialized into the blood vessel wall.
6 . The medical device of claim 1 , wherein the sleeve is made of elastic material.
7 . The medical device of claim 1 , wherein the sleeve is made of inelastic material.
8 . The medical device of claim 1 , wherein the filter is retrievable and has a retrieval member.
9 . A medical system for therapeutic treatment of a patient, comprising:
a filter with a sleeve, a catheter, and a pushing wire;
the filter having a first and second end, and a central expandable portion extending between the ends; the central portion tending to resiliently expand in radially outward directions from a compressed initial shape to an expanded deployed shape; wherein the filter defines a first and second filtering element in the expanded shape, the first and second filtering elements each being near the first and second end, respectively;
the filter having a plurality of ribs arranged in a pre-selected pattern; such that the ribs expand in radially outward directions when the filter expands from the compressed shape to the expanded shape, thereby causing the first and second ends to move toward each other and;
a flexible sleeve encircling at least a portion of the filter, around a longitudinal axis defined between the first and second ends; the sleeve defining a surface area; the sleeve tending to expand with the filter central portion to an expanded shape in which the sleeve represents a tubular surface for contracting a blood vessel wall; and
the catheter having a proximal and distal end, and a defining a lumen extending between the proximal and distal ends;
the pushing wire being inserted within the lumen;
wherein the filter and sleeve are within the lumen of the catheter in the initial compressed shape.