Apparatus for atherectomy

• US 5,409,454 A
• Filed: 05/02/1994
• Issued: 04/25/1995
• Est. Priority Date: 02/19/1991
• Status: Expired due to Fees

• Current Assignee: Arrow International Incorporated (Teleflex Incorporated)
• Original Assignee: Arrow International Investment Corporation (Teleflex Incorporated)
• Inventors: Harding, Richard L., Fischell, Tim A., Thompson, James J., Fischell, David R., Fischell, Robert E.
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US08/236,249
• Time in Patent Office: 358 Days
• Field of Search: 606/159, 606/170, 606/171, 128/751, 128/753, 128/754, 604/22
• US Class Current: 604/22
• CPC Class Codes: A61B 17/320783 through side-hole, e.g. sliding or rotating cutter inside catheter
• CPC Class Codes: A61B 2017/22038 with a guide wire
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61B 2017/320052 Guides for cutting instruments

Abstract

A catheter is disclosed which is capable of cutting obstructive tissue from a vessel of a living body while shielding a portion of the wall of the vessel from being exposed to the cutting blade at the catheter'"'"'s distal end. An essentially continuous outer surface at the catheter'"'"'s distal end allows it to be readily advanced through an introducer sheath and through a tight stenosis in an artery. The shield at the catheter'"'"'s distal end could subtend an arc from as little as 45 degrees to as large as 270 degrees depending on the extent of the vessel wall that is to be protected from being cut. A vacuum source at the catheter'"'"'s proximal end can cause a suction to exist at a cutout at the catheter'"'"'s distal end in order to pull obstructive tissue into the cutout as the cutting cylinder is pulled back in a retrograde direction, this suction being capable of enhancing the removal of the obstructive tissue.

Claims

1. A catheter for excision of obstructive tissue from a vessel of a living body comprising:

a flexible guide wire adapted to be advanced through the obstructive tissue in the vessel of the living body so that the guide wire'"'"'s distal end is positioned beyond the obstructive tissue;

a cut/collect catheter having a hollow torque cable surrounding said flexible guide wire and displaceable with respect thereto, said hollow torque cable having a proximal end adapted to lie outside of the living body and a distal end fixedly coupled to a central support of a cutting cylinder at a distal end thereof for rotative displacement of said cutting cylinder, said cutting cylinder having at least one tapered sharpened cutting edge at the cutting cylinder'"'"'s proximal end, the cutting edge being capable of cutting obstructive tissue off the vessel wall as it is pulled back in a retrograde direction, the cutting cylinder having attached at its distal end a hollow, tapered, flexible, elastomer tip which is adapted to penetrate through and beyond the obstructive tissue, the interior surface of the cutting cylinder forming a tissue collection chamber which is completely closed except at its proximal end and into which collection chamber all of the cut off obstructive tissue is collected, the cut/collect catheter further having a continuous central passageway which is adapted to be advanced over the guide wire, the continuous central passageway extending from the proximal end of the hollow torque cable to the distal end of the hollow elastomer tip so as to prevent contact between the outer surface of the guide wire and the cut off obstructive tissue; and

a shielding catheter adapted to move slideably over and to fit concentrically around the cut/collect catheter for most of the length of the cut/collect catheter that is adapted to lie inside the vessel, the shielding catheter consisting for most of its length of a plastic cylinder which has a metal cutout cylinder having a proximal ring portion, said metal cutout cylinder being fixedly attached to the plastic cylinder'"'"'s distal end, the metal cutout cylinder having a longitudinal cutout wherein the metal is removed except for a partial-cylindrical arc portion which forms a shield to prevent cutting of an arc of the vessel wall, said longitudinal cutout being shorter in length as compared to the length of the cutting cylinder at its outermost diameter, said flexible tip having a shoulder formed therein for engagement of the distal edge of the metal cutout cylinder thereto.

2. The catheter of claim 1 wherein the metal cutout cylinder has a distal guiding ring at the cutout cylinder'"'"'s distal end, the guiding ring being adapted to surround and move slideably over the cut/collect catheter'"'"'s cutting cylinder.

3. The catheter of claim 1 further comprising a rotating means situated outside of the living body and attached to the proximal end of the torque cable, the rotating means being adapted to rotate the cutting cylinder as the cutting edge is pulled back in a retrograde direction through the obstructive tissue.

4. The catheter of claim 1 further comprising a blade guide located at the proximal end of the shielding catheter'"'"'s metal cutout cylinder, the blade guide being adapted to force the cutting edge of the cutting cylinder to nest within said proximal ring portion of the metal cutout cylinder.

5. The catheter of claim 1 wherein an annular lumen is formed between the outer surface of the cut/collect catheter'"'"'s torque cable and the inner surface of the shielding catheter'"'"'s plastic cylinder so that fluid communication is obtained from the shielding catheter'"'"'s proximal end through to the shielding catheter'"'"'s distal end.

6. The catheter of claim 5 further comprising a source of fluid operably connected to the shielding catheter'"'"'s proximal end for injecting fluid through the annular lumen and out of the shielding catheter'"'"'s distal end portion.

7. The catheter of claim 5 including a source of suction operably connected to the shielding catheter'"'"'s proximal end for establishing a vacuum at the distal end of the shielding catheter.

8. A catheter for excision of obstructive tissue from a vessel of a living body comprising:

a flexible guide wire adapted to be advanced through the obstructive tissue in the vessel of the living body so that the guide wire'"'"'s distal end is positioned beyond the obstructive tissue;

a cut/collect catheter having a hollow torque cable surrounding said flexible guide wire and displaceable with respect thereto, said hollow torque cable having a proximal end adapted to lie outside of the living body and a distal end fixedly coupled to a central support of a cutting cylinder at a distal end thereof for rotative displacement of said cutting cylinder, said cutting cylinder having at least one tapered sharpened cutting edge at the cutting cylinder'"'"'s proximal end, the cutting edge being capable of cutting obstructive tissue off the vessel wall as it is pulled back in a retrograde direction, the cutting cylinder having attached at its distal end a hollow, tapered, flexible elastomer tip having a shoulder section, said flexible tip adapted to penetrate through and beyond the obstructive tissue, the interior surface of the cutting cylinder forming a tissue collection chamber which is completely closed except at its proximal end and into which collection chamber all of the cut off obstructive tissue is collected the cut/collect catheter further having a continuous central passageway which is adapted to be advanced over the guide wire, the continuous central passageway extending from the proximal end of the hollow torque cable to the distal end of the hollow elastomer tip so as to prevent contact between the outer surface of the guide wire and the cut off obstructive tissue; and

a shielding catheter adapted to move slideably over and to fit concentrically around the cut/collect catheter for most of the length of the cut/collect catheter that is adapted to lie inside the vessel, the shielding catheter consisting for most of its length of a plastic cylinder which has a metal cutout cylinder having a proximal ring portion, said metal cutout cylinder being fixedly attached to the plastic cylinder'"'"'s distal end, said flexible tip shoulder section being engaged to the distal edge of the cutout cylinder for preventing said cutting cylinder cutting edge from contacting said cutout cylinder proximal ring portion, the metal cutout cylinder having a longitudinal cutout wherein the metal is removed except for a partial-cylindrical arc portion which forms a shield to prevent cutting of an arc of the vessel wall, said cutting cylinder having an outer surface which fits snugly inside the cutout cylinder of the shielding catheter so as to form an essentially continuous exterior surface of the catheter so as to minimize the force required to push the cutout through the obstructive tissue and further minimize the torque required when the catheter'"'"'s distal end where the cutout is placed is rotated within the obstructive tissue.

9. The catheter of claim 8 wherein the cutting cylinder of the cut/collect catheter has a central passageway formed from a metal cannula which cannula prevents the cut obstructive tissue that is cut and collected within the cutting cylinder from making contact with the outer surface of the guide wire.

10. The catheter of claim 8 wherein the included angle of the partial-cylindrical arc of the shield is less than 180 degrees.

11. The catheter of claim 8 wherein the included angle of the partial-cylindrical arc of the shield is less than 120 degrees.

12. The catheter of claim 8 wherein the shielding catheter includes an inflatable balloon located just proximal to the proximal end of the cutout.

13. A catheter for excision of obstructive tissue from a vessel of a living body comprising:

a flexible guide wire adapted to be advanced through the obstructive tissue in the vessel of the living body so that the guide wire'"'"'s distal end is positioned beyond the obstructive tissue;

a cut/collect catheter having a hollow torque cable whose proximal end is adapted to lie outside of the living body and whose distal end is fixedly connected to the distal end of a cutting cylinder which has at least one sharpened cutting edge at the cutting cylinder'"'"'s proximal end, the cutting edge being capable of cutting obstructive tissue off the vessel wall as it is pulled back in a retrograde direction, the cutting cylinder having attached at its distal end a hollow, tapered, flexible, elastomer tip which is adapted to penetrate through and beyond the obstructive tissue, the interior surface of the cutting cylinder forming a tissue collection chamber which is completely closed except at its proximal end and into which collection chamber all of the cut off obstructive tissue is collected, the cut/collect catheter further having a continuous central passageway which is adapted to be advanced over the guide wire, the continuous central passageway extending from the proximal end of the hollow torque cable to the distal end of the hollow elastomer tip so as to prevent contact between the outer surface of the guide wire and the cut off obstructive tissue; and

a shielding catheter adapted to move slideably over and to fit concentrically around the cut/collect catheter for most of the length of the cut/collect catheter that is adapted to lie inside the vessel, the shielding catheter consisting for most of its length of a plastic cylinder which has a metal cutout cylinder having a proximal ring portion, said metal cutout cylinder being fixedly attached to the plastic cylinder'"'"'s distal end, the metal cutout cylinder having a longitudinal cutout wherein the metal is removed except for a partial-cylindrical arc portion which forms a shield to prevent cutting of an arc of the vessel wall, said longitudinal cutout being shorter in length as compared to the length of the cutting cylinder at its outermost diameter, said tip having a radially extending shoulder adapted to engage the distal edge of the shielding catheter'"'"'s metal cutout cylinder in order to prevent the cutting cylinder'"'"'s cutting edge from contacting the metal cutout cylinder'"'"'s proximal ring portion thereby preventing dulling of the cutting edge.