Cardiac pacing lead with biodegradable fixation structure

Claim 2

A pervenous cardiac pacing lead, which comprises: an electrically insulating, flexible tubing having proximal and distal ends, said tubing being sized for pervenous introduction into the interior of a heart; electrical conductor means within said tubing for carrying electrical current therein between said proximal and distal ends of said tubing; electrically conductive tip means at said distal end and being in electrical contact with said conductor means for delivering electrical stimulation inside the heart, said tip means including means for enabling long term fixation in the heart; and a plurality of non-tissue penetrating, flexible, biodegradable projections extending outwardly from the side of said tubing for temporarily fixing the distal end of said tubing inside the heart, said biodegradable projections being absorbed over a period of time into blood or tissue of the body as said tip means becomes fixed in place.

Claim 3

A pervenous cardiac pacing lead as described in claim 1, in which said fixation enabling means includes a porous surface exposed on the distal end of said tubing to enable long term fixation of said tip means in place as a result of ingrowth of tissue into said porous surface.

Claim 4

A pervenous cardiac pacing lead as described in claim 1, in which said fixation enabling means includes at least an outer layer of porous conductive material having interstices into which heart tissue can grow for long term fixation of said tip means in the heart without subjecting the adjacent heart tissue to trauma and with a minimal amount of fibrotic tissue growth developing at the interface between said tip means and the adjacent heart tissue.

Claim 5

A pervenous cardiac pacing lead as described in claim 1, in which said biodegradable projections are solid but pliant and extend outwardly from said tubing at a position rearwardly of said tip means so that said biodegradable projections do not interfere with the long term fixation of said tip means in the heart.

Claim 6

A pervenous cardiac pacing lead as described in claim 1, in which said fixation enabling means includes at least an outer layer of porous conductive material on said tip means having interstices into which heart tissue can grow for long term fixation of said tip means in the heart without subjecting the adjacent heart tissue to trauma and with a minimal amount of fibrotic tissue growth developing at the interface between said tip means and the adjacent heart tissue; said biodegradable projections being solid but pliant and extending outwardly from said tubing at a position rearwardly of said tip means so that said biodegradable projections do not interfere with the long term fixation of said tip means in the heart.

Claim 7

A pervenous cardiac pacing lead as described in claim 1, wherein said biodegradable projections comprise a copolymer of a copolymer of glycolic and lactic acid and polycaprolactone.

Claim 8

A pervenous cardiac pacing lead as described in claim 1, in which said flexible tubing has approximately the same diameter throughout its length.

Claim 9

A pervenous cardiac pacing lead as described in claim 1, in which said biodegradable projections each have a generally triangular fin shape.

Claim 10

A pervenous cardiac pacing lead comprising: an electrically insulating, flexible tubing having proximal and distal ends, said tubing being sized for pervenous introduction into the interior of a heart; electrical conductor means within said tubing for carrying electrical current therein between said proximal and distal ends of said tubing; porous electrically conductive tip means at said distal end having at least a porous surface exposed on the distal end of said tubing for enabling long term fixation in the heart and being in electrical contact with said conductor means for delivering electrical stimulation inside the heart; and non-tissue penetrating, flexible, biodegradable anchoring means including at least one generally triangular, fin-shaped projection fixed on and projecting outwardly from the side of said tubing for temporarily fixing the distal end of said tubing inside the heart, said biodegradable anchoring means being absorbed over a period of time into the blood or tissue of the body as said tip means becomes fixed in place as a result of ingrowth of tissue into said porous surface.

Claim 11

A pervenous cardiac pacing lead comprising: an electrically insulating, flexible tubing having proximal and distal ends, said tubing being sized for pervenous introduction into the interior of a heart; electrical conductor means within said tubing for carrying electrical current therein between said proximal and distal ends of said tubing; porous electrically conductive tip means at said distal end having at least a porous surface exposed on the distal end of said tubing for enabling long term fixation in the heart and being in electrical contact with said conductor means for delivering electrical stimulation inside the heart; and non-tissue penetrating, flexible, biodegradable anchoring means including at least one generally triangular, fin-shaped projection fixed on and projecting outwardly from the side of said tubing for temporarily fixing the distal end of said tubing inside the heart, said biodegradable anchoring means being absorbed over a period of time into the blood or tissue of the body as said tip means becomes fixed in place as a result of ingrowth of tissue into said porous surface.

Claim 12

A pervenous cardiac pacing lead comprising: an electrically insulating, flexible tubing having a central lumen and proximal and distal ends, said tubing being sized for pervenous introduction into the interior of a heart; electrical conductor means within said central lumen of said tubing for carrying electrical current therein between said proximal and distal ends of said tubing; electrically conductive tip means at said distal end in electrical contact with said conductor means for delivering electrical stimulation inside the heart; said tip means including first anchoring means for long term anchoring of said tip means in the heart, said first anchoring means being disposed on said tip means; second anchoring means for short term anchoring of said tip means in the heart, said second anchoring means comprising a plurality of solid but pliant, non-tissue-penetrating biodegradable projections fixed on and extending outwardly from a side of said tubing for temporarily fixing said tip means in the heart and for holding said tip means against a wall of the heart upon initial insertion of said tip means in the heart; said biodegradable projections extending outwardly from said tubing at a position rearwardly of said tip means so that said biodegradable porjections do not interfere with long term anchoring of said tip means; said biodegradable projections being absorbed over a short period of time by heart tissue so that, after said short time period, there are substantially no projections protruding outwardly from the outer surface of said tubing at said distal end of said tubing, and said distal end of said tubing can be pulled through a lumen formed in tissue surrounding the distal end of said tubing to pull said tip away from and out of engagement with the heart wall to which it is attached without any engagement of projections on the outer surface of said distal end of said tubing with the tissue wall of the lumen thereby to minimize trauma to heart tissue during removal of said lead and to facilitate removal of said lead.

Claim 13

A pervenous cardiac pacing lead comprising: an electrically insulating, flexible tubing having a central lumen and proximal and distal ends, said tubing being sized for pervenous introduction into the interior of a heart; electrical conductor means within said central lumen of said tubing for carrying electrical current therein between said proximal and distal ends of said tubing; electrically conductive tip means at said distal end in electrical contact with said conductor means for delivering electrical stimulation inside the heart; said tip means including first anchoring means for long term anchoring of said tip means in the heart, said first anchoring means being disposed on said tip means; second anchoring means for short term anchoring of said tip means in the heart, said second anchoring means comprising a plurality of solid but pliant, non-tissue-penetrating biodegradable projections fixed on and extending outwardly from a side of said tubing for temporarily fixing said tip means in the heart and for holding said tip means against a wall of the heart upon initial insertion of said tip means in the heart; said biodegradable projections extending outwardly from said tubing at a position rearwardly of said tip means so that said biodegradable porjections do not interfere with long term anchoring of said tip means; said biodegradable projections being absorbed over a short period of time by heart tissue so that, after said short time period, there are substantially no projections protruding outwardly from the outer surface of said tubing at said distal end of said tubing, and said distal end of said tubing can be pulled through a lumen formed in tissue surrounding the distal end of said tubing to pull said tip away from and out of engagement with the heart wall to which it is attached without any engagement of projections on the outer surface of said distal end of said tubing with the tissue wall of the lumen thereby to minimize trauma to heart tissue during removal of said lead and to facilitate removal of said lead.

Claim 14

A pervenous cardiac pacing lead as described in claim 10, in which said flexible tubing has approximately the same diameter throughout its length.

Claim 15

A pervenous cardiac pacing lead as described in claim 10, in which said first anchoring means comprises an outer layer of porous conductive material disposed on said tip means and having interstices into which heart tissue can grow for fixing said tip means in the heart without subjecting the adjacent heart tissue to trauma and with a minimal amount of fibrotic tissue growth developing at the interface between said tip means and the adjacent heart tissue.

Claim 16

A pervenous cardiac pacing lead as described in claim 12, wherein said tip means is only porous in a conductive surface layer thereof, and whereby said biodegradable projections temporarily anchor said distal end allowing ingrowth of tissue into said conductive surface layer to achieve long term fixation.

Claim 17

A pervenous cardiac pacing lead as described in claim 10, in which said biodegradable projections comprise a plurality of generally triangular-shaped fins.

Claim 18

A pervenous cardiac pacing lead as described in claim 10, wherein said biodegradable projections comprise a copolymer of a copolymer of glycolic and lactic acid and polycaprolactone.

Claim 19

A pervenous cardiac pacing lead as described in claim 10, wherein said biodegradable projections are attached to said tubing adjacent the distal end thereof and project radially outwardly and rearwardly from said distal end, whereby upon insertion of said distal end into the heart, said projections become entangled therein and eventually dissolve while temporarily anchoring said distal end.