Expandable cannula

Claim 2

A cannula comprising a longitudinally extending tubular sheath having a main passage, a variable volume chamber connected with said sheath and disposed adjacent to one end portion of said sheath, said one end portion of said sheath and said variable volume chamber being insertable into body tissue, said variable volume chamber being expandable under the influence of fluid pressure from a contracted condition to an extended condition in which said variable volume chamber projects outward of a side surface of said sheath when said one end portion of said sheath and said variable volume chamber are disposed in body tissue to retard withdrawal of said one end portion of said sheath from body tissue when said one end portion of said sheath is disposed in body tissue, a plurality of wires which are enclosed by said sheath and extend along an inner side of said sheath, and a conduit which is enclosed by said sheath and extends along an inner side of said sheath to said variable volume chamber, said conduit being disposed between adjacent wires of said plurality of wires, said conduit being adapted to be connected in fluid communication with a source of fluid pressure to enable said conduit to conduct fluid pressure to said variable volume chamber to effect expansion of said variable volume chamber from the contracted condition to the extended condition when said one end portion of said sheath and said variable volume chamber are disposed in body tissue.

Claim 3

A cannula as set forth in claim 1 wherein said one end portion of said sheath has a pointed configuration to pierce body tissue.

Claim 4

A cannula as set forth in claim 1 wherein said wires have exposed end portions at said one end portion of said sheath to enable said end portions of said wires to engage body tissue during insertion of said one end portion of said sheath and the variable volume chamber into body tissue.

Claim 5

A cannula as set forth in claim 1 wherein said sheath has a leading end surface which engages body tissue at locations between adjacent wires during insertion of said one end portion of said sheath and the variable volume chamber into body tissue.

Claim 6

A cannula as set forth in claim 1 wherein each of said wires includes a longitudinally extending core and a jacket of polymeric material, said jacket of polymeric material being connected with said sheath, said conduit being formed of polymeric material and having the same configuration as one of said jackets, said conduit being connected with said sheath at a location between a pair of said wires.

Claim 7

A cannula as set forth in claim 5 wherein an end portion of a core of at least one of said wires is exposed at said one end portion of said sheath to enable said core of said one wire to engage body tissue during insertion of said one end portion of said sheath into body tissue.

Claim 8

A cannula as set forth in claim 5 wherein an end portion of a core of at least one of said wires is completely enclosed by said sheath and said jacket at said one end portion of said sheath to block engagement of body tissue with said core of said one wire during insertion of said one end portion of said sheath into body tissue.

Claim 9

A cannula as set forth in claim 5 wherein an end portion of a core of at least one of said wires extends beyond said one end portion of said sheath to enable said core of said one wire to engage body tissue ahead of said sheath during insertion of said one end portion of said sheath into body tissue.

Claim 10

A cannula as set forth in claim 1 wherein at least a portion of each of said wires is integrally formed as one piece with said sheath to interconnect said wires and said sheath, said conduit being integrally formed as one piece with said sheath to interconnect said conduit and said sheath.

Claim 11

A cannula as set forth in claim 1 wherein each of said wires includes a longitudinally extending core having generally circular cross sectional configuration and a jacket which at least partially encloses said core, said jacket being integrally formed as one piece with said sheath to interconnect said core and said sheath.

Claim 12

An expandable cannula as set forth in claim 1 wherein each of said wires includes a longitudinally extending core formed of metal and a jacket which at least partially encloses said core, said jacket, said sheath and said conduit being integrally formed as one piece of polymeric material.

Claim 13

A cannula as set forth in claim 1 further including an insert insertable into the main passage in said tubular sheath to effect expansion of said tubular sheath from a first cross sectional area to a second cross sectional area, said second cross sectional area being larger than said first cross sectional area, each of said wires and said conduit having an outer side surface which is engageable by said insert to enable each of said wires and said conduit to transmit force from said insert to said sheath.

Claim 14

A cannula as set forth in claim 12 wherein said outer side surface of each of said wires and said conduit are integrally formed as one piece with said sheath.

Claim 15

A cannula as set forth in claim 1 wherein said wires and said conduit have longitudinally extending outer side surface areas forming contact surfaces for a member inserted into the main passage in said tubular sheath, each of said wires and said conduit blocking engagement of a longitudinally extending portion of said sheath with the member inserted into the main passage in said sheath.

Claim 16

A cannula as set forth in claim 14 wherein said longitudinally extending outer side surface areas on said wires and said conduit are integrally formed as one piece with said sheath.

Claim 17

A cannula as set forth in claim 1 wherein said wires and said conduit have parallel longitudinal central axes which extend parallel to a longitudinal central axis of said sheath.

Claim 18

A cannula as set forth in claim 1 wherein said conduit is integrally formed as one piece with said sheath.

Claim 19

A cannula as set forth in claim 1 wherein at least a portion of each of said wires is integrally formed as one piece with said sheath.

Claim 20

A cannula comprising a longitudinally extending tubular sheath having a main passage, a variable volume chamber connected with said sheath and disposed adjacent to one end portion of said sheath, a plurality of wires which are enclosed by said sheath and extend along an inner side of said sheath, surface means disposed on said one end portion of said sheath and on end portions of said wires for piercing body tissue, and a conduit which is enclosed by said sheath extends along an inner side of said sheath to said variable volume chamber, said conduit being adapted to be connected in fluid communication with a source of fluid pressure to enable said conduit to conduct fluid pressure to said variable volume chamber to effect expansion of said variable volume chamber from the contracted condition to the extended condition when said one end portion of said sheath and said variable volume chamber are disposed in body tissue.

Claim 21

A cannula comprising a longitudinally extending tubular sheath having a main passage, a variable volume chamber connected with said sheath and disposed adjacent to one end portion of said sheath, a plurality of wires which are enclosed by said sheath and extend along an inner side of said sheath, surface means disposed on said one end portion of said sheath and on end portions of said wires for piercing body tissue, and a conduit which is enclosed by said sheath extends along an inner side of said sheath to said variable volume chamber, said conduit being adapted to be connected in fluid communication with a source of fluid pressure to enable said conduit to conduct fluid pressure to said variable volume chamber to effect expansion of said variable volume chamber from the contracted condition to the extended condition when said one end portion of said sheath and said variable volume chamber are disposed in body tissue.

Claim 22

A cannula as set forth in claim 19 wherein said conduit is integrally formed as one piece with said sheath.

Claim 23

A cannula as set forth in claim 19 wherein at least a portion of each of said wires is integrally formed as one piece with said sheath.

Claim 24

A cannula as set forth in claim 19 wherein said wires and said conduit have parallel longitudinal central axes which extend parallel to a longitudinal central axis of said sheath.

Claim 25

A cannula comprising a longitudinally extending tubular sheath formed of a material capable of being expanded from a contracted condition in which a longitudinally extending passage through the tubular sheath has a relatively small cross sectional size to an expanded condition in which the passage has a relatively large cross sectional size, a plurality of wires enclosed by said sheath, said wires being disposed in a longitudinally extending array along an inner side of said sheath, said longitudinally extending array of wires having a relatively small cross sectional size when said sheath is in the contracted condition and a relatively large cross sectional size when said sheath is in the expanded condition, said wires having longitudinal central axes which are disposed in a parallel relationship when said sheath is in the contracted condition and when said sheath is in the expanded condition, and a flexible portion is connected with said sheath and is expandable outward of an outer side surface of said sheath to engage body tissue when said sheath is in the expanded condition.

Claim 26

A cannula comprising a longitudinally extending tubular sheath formed of a material capable of being expanded from a contracted condition in which a longitudinally extending passage through the tubular sheath has a relatively small cross sectional size to an expanded condition in which the passage has a relatively large cross sectional size, a plurality of wires enclosed by said sheath, said wires being disposed in a longitudinally extending array along an inner side of said sheath, said longitudinally extending array of wires having a relatively small cross sectional size when said sheath is in the contracted condition and a relatively large cross sectional size when said sheath is in the expanded condition, said wires having longitudinal central axes which are disposed in a parallel relationship when said sheath is in the contracted condition and when said sheath is in the expanded condition, and a flexible portion is connected with said sheath and is expandable outward of an outer side surface of said sheath to engage body tissue when said sheath is in the expanded condition.

Claim 27

A cannula as set forth in claim 23 further including a fluid conduit enclosed by said sheath and connected in fluid communication with said flexible portion, said fluid conduit being disposed along the inner side of said sheath and having a longitudinal central axis which extends parallel to the longitudinal central axes of said wires.

Claim 28

A cannula as set forth in claim 23 wherein said flexible portion includes a chamber which is expandable relative to said sheath under the influence of fluid pressure, said cannula further including means for conducting fluid pressure to said chamber to expand said chamber while said sheath is in the expanded condition.

Claim 29

A cannula as set forth in claim 25 wherein said means for conducting fluid pressure to said chamber to expand said chamber includes a conduit which is integrally formed as one piece with said sheath.

Claim 30

A cannula as set forth in claim 26 wherein said wires have longitudinally extending outer side surface areas which are integrally formed as one piece with said sheath.

Claim 31

A cannula as set forth in claim 23 wherein said cannula includes a pointed end portion to pierce body tissue, said pointed end portion of said cannula being formed by an end portion of said sheath and by end portions of said wires.

Claim 32

A cannula as set forth in claim 23 wherein each of said wires has a core formed of a first material and a jacket which extends at least part way around said core and is formed of a material which is different than said first material, said cannula further including a fluid conduit which is disposed in the longitudinally extending array of wires and has a side wall formed of the same material as the jackets of said wires.

Claim 33

A cannula comprising a longitudinally extending tubular sheath formed of a material capable of being expanded from a contracted condition in which a longitudinally extending passage through the tubular sheath has a relatively small cross sectional size to an expanded condition in which the passage has a relatively large cross sectional size, a plurality of wires enclosed by and connected with said sheath, said wires being disposed in a longitudinal extending array along an inner side of said sheath, said longitudinally extending array of wires has a relatively small cross sectional size when said sheath is in the contracted condition and a relatively large cross sectional size when said sheath is in the expanded condition, a flexible portion is connected with said sheath and is expandable under the influence of fluid pressure to engage body tissue when said sheath is in the expanded condition, and a fluid conduit enclosed by and connected with said sheath and extending along an inner side of said sheath to said flexible portion, said conduit being effective to conduct fluid pressure to said flexible portion to effect expansion of said flexible portion, said conduit being spaced a first distance from a longitudinal central axis of said sheath when said sheath is in the contracted condition and being spaced a second distance from the longitudinal central axis of said sheath when said sheath is in the expanded condition, said second distance being greater than said first distance, said conduit being disposed between adjacent wires in said longitudinally extending array of wires when said sheath is in the contracted condition and when said sheath is in the expanded condition.

Claim 34

A cannula comprising a longitudinally extending tubular sheath formed of a material capable of being expanded from a contracted condition in which a longitudinally extending passage through the tubular sheath has a relatively small cross sectional size to an expanded condition in which the passage has a relatively large cross sectional size, a plurality of wires enclosed by and connected with said sheath, said wires being disposed in a longitudinal extending array along an inner side of said sheath, said longitudinally extending array of wires has a relatively small cross sectional size when said sheath is in the contracted condition and a relatively large cross sectional size when said sheath is in the expanded condition, a flexible portion is connected with said sheath and is expandable under the influence of fluid pressure to engage body tissue when said sheath is in the expanded condition, and a fluid conduit enclosed by and connected with said sheath and extending along an inner side of said sheath to said flexible portion, said conduit being effective to conduct fluid pressure to said flexible portion to effect expansion of said flexible portion, said conduit being spaced a first distance from a longitudinal central axis of said sheath when said sheath is in the contracted condition and being spaced a second distance from the longitudinal central axis of said sheath when said sheath is in the expanded condition, said second distance being greater than said first distance, said conduit being disposed between adjacent wires in said longitudinally extending array of wires when said sheath is in the contracted condition and when said sheath is in the expanded condition.

Claim 35

A cannula as set forth in claim 30 wherein said flexible portion includes a chamber which is expandable relative to said sheath under the influence of fluid pressure conducted to said chamber through said conduit.

Claim 36

A cannula as set forth in claim 30 wherein said conduit is integrally formed as one piece with said sheath.

Claim 37

A cannula as set forth in claim 32 wherein said wires have longitudinally extending outer side surface areas which are integrally formed as one piece with said sheath.

Claim 38

A cannula as set forth in claim 30 wherein said cannula has a pointed end portion to pierce body tissue, said pointed end portion of said cannula being formed by an end portion of said sheath and by end portions of said wires.

Claim 39

A cannula as set forth in claim 30 wherein said wires and said conduit have longitudinal central axes which extend parallel to a longitudinal central axis of said sheath.

Claim 40

A cannula comprising a longitudinally extending tubular sheath formed of a material capable of being expanded from a contracted condition in which a longitudinally extending passage through the tubular sheath has a relatively small cross sectional size to an expanded condition in which the passage has a relatively large cross sectional size, a plurality of wires enclosed by said sheath, said wires being disposed in a longitudinally extending array along an inner side of said sheath, said longitudinally extending array of wires having a relatively small cross sectional size when said sheath is in the contracted condition and a relatively large cross sectional size when said sheath is in the expanded condition, a flexible portion connected with said sheath and expandable outward of an outer side surface of said sheath to engage body tissue when said sheath is in the expanded condition, and surface means disposed on said sheath and on said wires for piercing body tissue when said sheath is in the contracted condition.

Claim 41

A cannula comprising a longitudinally extending tubular sheath formed of a material capable of being expanded from a contracted condition in which a longitudinally extending passage through the tubular sheath has a relatively small cross sectional size to an expanded condition in which the passage has a relatively large cross sectional size, a plurality of wires enclosed by said sheath, said wires being disposed in a longitudinally extending array along an inner side of said sheath, said longitudinally extending array of wires having a relatively small cross sectional size when said sheath is in the contracted condition and a relatively large cross sectional size when said sheath is in the expanded condition, a flexible portion connected with said sheath and expandable outward of an outer side surface of said sheath to engage body tissue when said sheath is in the expanded condition, and surface means disposed on said sheath and on said wires for piercing body tissue when said sheath is in the contracted condition.

Claim 42

A cannula as set forth in claim 36 further including a fluid conduit enclosed by said sheath and connected in fluid communication with said flexible portion, said fluid conduit being disposed along the inner side of said sheath in the longitudinally extending array of wires.

Claim 43

A cannula as set forth in claim 36 wherein said flexible portion includes a chamber which is expandable relative to said sheath under the influence of fluid pressure, said cannula further including means for conducting fluid pressure to said chamber to expand said chamber while said sheath is in the expanded condition.

Claim 44

A cannula as set forth in claim 38 wherein said means for conducting fluid pressure to said chamber to expand said chamber includes a conduit which is integrally formed as one piece with said sheath.

Claim 45

A cannula as set forth in claim 36 wherein said wires have longitudinally extending outer side surface areas which are integrally formed as one piece with said sheath.

Claim 46

An expandable cannula as set forth in claim 36 wherein each of said wires has a core formed of a first material and a jacket which extends at least part way around said core and is formed of a material which is different than said first material, said cannula further including a fluid conduit which is disposed in the longitudinally extending array of wires and has a side wall formed of the same material as the jackets of said wires.

Claim 47

A cannula as set forth in claim 36 further including a conduit to conduct fluid pressure to said flexible portion to effect expansion of said flexible portion when said sheath is in the expanded condition, each of said wires includes a longitudinally extending outer side surface area which is integrally formed as one piece with said sheath, said conduit having a longitudinally extending outer side surface area which is integrally formed as one piece with said sheath, said conduit being connected with said sheath at a location between adjacent wires in said longitudinally extending array of wires.

Claim 48

A cannula as set forth in claim 36 further including a conduit to conduct fluid pressure to said flexible portion when said sheath is in the expanded condition, said conduit being effective to conduct fluid pressure to said flexible portion to effect expansion of said flexible portion, said conduit being spaced a first distance from a longitudinal central axis of said sheath when said sheath is in the contracted condition and being spaced a second distance from the longitudinal central axis of said sheath when said sheath is in the expanded condition, said second distance being greater than said first distance.

Claim 49

A cannula as set forth in claim 43 wherein said conduit is enclosed by said sheath and is disposed between adjacent wires in said longitudinally extending array of wires.

Claim 50

A cannula as set forth in claim 36 wherein said wires have longitudinal central axes which extend parallel to a longitudinal central axis of said sheath when said sheath is in the contracted condition and when said sheath is in the expanded condition.