Flexible inner tubular members and rotary tissue cutting instruments having flexible inner tubular members

• US 6,656,195 B2
• Filed: 09/13/2001
• Issued: 12/02/2003
• Est. Priority Date: 09/22/2000
• Status: Active Grant

• Current Assignee: Medtronic Xomed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Xomed Incorporated (Medtronic Plc)
• Inventors: Adams, Kenneth, Peters, Gary
• Primary Examiner(s): TRUONG, KEVIN THAO
• Application Number:
  US09/950,607
• Publication Number:
  US 20020038129A1
• Time in Patent Office: 810 Days
• Field of Search: 606/159, 606/170, 606/180, 606/171, 606/174, 606/169, 604/22
• US Class Current: 606/159
• CPC Class Codes: A61B 17/1631 Special drive shafts, e.g. flexible shafts A61B17/1642, A61B17/164 take precedence
• CPC Class Codes: A61B 17/32002 with continuously rotating, oscillating or reciprocating cutting instruments
• CPC Class Codes: A61B 2017/320032 Details of the rotating or oscillating shaft, e.g. using a flexible shaft

Abstract

A flexible inner tubular member for being rotated in an outer tubular member of a rotary tissue cutting instrument includes an elongate inner tube having a rotatably driveable proximal end, a distal end having a cutting member exposed from the outer tubular member to cut anatomical tissue and a flexible region allowing the inner tubular member to rotate within the outer tubular member while conforming to the shape of the outer member. The flexible region is defined by a helical cut in the inner tube defining a plurality of integrally, unitarily connected tube segments angularly movable relative to one another and a spiral wrap disposed over the helical cut.

Claims

1. A flexible inner tubular member for being rotated in an outer tubular member of a rotary tissue cutting instrument to cut anatomical tissue, said flexible inner tubular member comprising

an elongate inner tube of integral one-piece construction having a central longitudinal axis, a rotatably driveable proximal end, a distal end at which a cutting member is disposed to cut anatomical tissue, a cylindrical wall defining a lumen in said inner tube, and a helical cut formed in said inner tube extending lengthwise along said cylindrical wall in a helical path about said central longitudinal axis and extending radially through said cylindrical wall, said helical cut extending around said central longitudinal axis in a first direction, said helical cut defining a plurality of serially arranged helical tube segments with adjacent ones of said tube segments being integrally, unitarily connected to each other, said helical cut being formed in a dovetail pattern with adjacent ones of said segments interlocked by at least one tenon in interlocking engagement with at least one mortise, said helical cut defining a helix angle of about 70°

with said central longitudinal axis; and

a spiral wrap disposed over said helical cut including a strip of material wound over said inner tube in a second direction, opposite said first direction, and having ends secured to said inner tube, said spiral wrap being oriented on said inner tube at an angle of about 110°

supplementary to said helix angle, said helical cut and said spiral wrap defining a flexible region in said inner tubular member allowing said inner tubular member to be rotated within the outer tubular member while conforming to the shape of the outer tubular member.

2. A flexible inner tubular member as recited in claim 1 wherein said spiral wrap is a first spiral wrap, said strip of material is a first strip of material, and further including a second spiral wrap disposed over said first spiral wrap and including a second strip of material wound over said first strip of material in said first direction and having ends secured to said inner tube, said second spiral wrap being oriented on said inner tube at an angle substantially the same as said helix angle.

3. A flexible inner tubular member as recited in claim 1 wherein said at least one tenon and said at least one mortise have straight inside and outside corners.

4. A flexible inner tubular member as recited in claim 1 wherein said at least one tenon and said at least one mortise have chamfered inside and outside corners.

5. A flexible inner tubular member as recited in claim 1 wherein said at least one tenon and said at least one mortise have radiused inside and outside corners.

6. A flexible inner tubular member as recited in claim 1 wherein said helical cut is formed by laser cutting said inner tube.

7. A flexible inner tubular member for being rotated in a longitudinally bent outer tubular member of a rotary tissue cutting instrument to cut anatomical tissue, said flexible inner tubular member comprising

an elongate inner tube of integral one-piece construction having a central longitudinal axis, a rotatably driveable proximal end, a distal end at which a cutting member is disposed to cut anatomical tissue, a cylindrical wall defining a lumen in said inner tube, and a helical cut formed in said inner tube extending lengthwise along said cylindrical wall in a continuous helical path about said central longitudinal axis and extending radially through said cylindrical wall to define a plurality of integrally, unitarily connected helical tube segments, said helical cut forming interlocked tenons and mortises in adjacent ones of said tube segments, said adjacent ones of said tube segments being movable angularly relative to one another, said helical cut defining a helically cut region in said inner tube having a distal end portion, a proximal end portion and a central portion between said distal and proximal end portions, said helical cut having a uniform first pitch along said central portion and a uniform second pitch, greater than said first pitch, along said distal and proximal end portions;

and

a spiral wrap disposed over said tube segments including a strip of material wound over said inner tube at an angle opposite said helical cut and having ends secured to said inner tube, said helical cut and said spiral wrap defining a flexible region in said inner tubular member allowing said inner tubular member to be rotated within the outer tubular member while conforming to the bend of the outer tubular member.

8. A flexible inner tubular member as recited in claim 7 wherein said helical cut is disposed around said central longitudinal axis of said inner tube with a right hand turn and said strip of material is wound over said inner tube with a left hand turn.

9. A flexible inner tubular member as recited in claim 8 wherein said strip is made from resilient material.

10. A flexible inner tubular member as recited in claim 9 wherein said strip is made from stainless steel.

11. A flexible inner tubular member as recited in claim 10 wherein said spiral wrap is a first spiral wrap, said strip of material is a first strip of material and further including a second spiral wrap disposed over said first spiral wrap including a second strip of material made from stainless steel wound over said first strip of material and having ends secured to said inner tube, said second strip of material being wound over said first strip of material with a right hand turn.

12. A flexible inner tubular member as recited in claim 7 wherein said cutting member includes a bur tip having an aspiration port communicating with said lumen of said inner tube.

13. A flexible inner tubular member as recited in claim 7 wherein said cutting member includes a cutting window communicating with said lumen of said inner tube and a plurality of cutting teeth extending longitudinally on opposing sides of said cutting window.

14. A flexible inner tubular member for being rotated in a longitudinally bent outer tubular member of a rotary tissue cutting instrument to cut anatomical tissue, said flexible inner tubular member comprising

an elongate inner tube of integral one-piece construction having a central longitudinal axis, a rotatably driveable proximal end, a distal end at which a cutting member is disposed to cut anatomical tissue, a cylindrical wall defining a lumen in said inner tube, and a helical cut formed in said inner tube extending along said cylindrical wall in a helical path less than the entire length of said inner tube, said helical cut extending radially through said cylindrical wall to define a plurality of integrally, unitarily connected tube segments angularly movable relative to one another, said helical cut having a pattern defining interlocking tenons and mortises between adjacent ones of said tube segments, said helical cut extending around said central longitudinal axis in a first direction and at a first angle of about 70°

with said central longitudinal axis, said helical cut defining a helically cut region in said inner tube having a distal end portion, a proximal end portion and a central portion between said distal and proximal end portions, said helical cut having a uniform first pitch along said central portion and a uniform second pitch, greater than said first pitch, along said distal and proximal end portions;

an inner spiral wrap disposed over said helically cut region and including a flat strip of material wound over said inner tube and having ends secured to said inner tube, said inner spiral wrap being wound around said inner tube in a second direction, opposite said first direction, and at a second angle of about 110°

with said central longitudinal axis that is the supplement of said first angle; and

an outer second spiral wrap disposed over said inner spiral wrap and including a flat strip of material wound over said inner spiral wrap and having ends secured to said inner tube, said outer spiral wrap being wound over said inner spiral wrap in said first direction and at said first angle with said central longitudinal axis, said helical cut and said outer and inner spiral wraps defining a flexible region in said inner tubular member allowing said inner tubular member to bend while being rotated within the outer tubular member.

15. A rotary tissue cutting instrument comprising

an elongate outer tubular member including a proximal portion extending distally from an open proximal end to a bend, and a distal portion extending distally from said bend to an open distal end;

and

a flexible inner tubular member rotatably disposed in said outer tubular member and including an inner tube of integral one-piece construction having a central longitudinal axis, a rotatably driveable proximal end and a distal end carrying a cutting member exposed from said distal end of said outer tubular member to cut anatomical tissue, said inner tubular member including a flexible region disposed in said bend and being formed by a helical cut formed in said inner tube and a strip of material spirally wrapped over said helical cut and having ends secured to said inner tube, said helical cut extending radially through said inner tube to define a plurality of integrally, unitarily connected tube segments angularly movable relative to one another, said helical cut being formed in a dovetail pattern with adjacent ones of said segments interlocked by at least one tenon in interlocking engagement with at least one mortise, said helical cut being disposed at a first angle of about 70°

with said central longitudinal axis and said strip of material being disposed at a second angle of about 110°

with said central longitudinal axis that is the supplement of said first angle, said strip of material being wound over said inner tube in a direction opposite said helical cut.

16. A rotary tissue cutting instrument as recited in claim 15 wherein said helical cut is formed by laser cutting said inner tube.

17. A rotary tissue cutting instrument as recited in claim 15 wherein said cutting member includes a bur tip.

18. A rotary tissue cutting instrument as recited in claim 17 wherein said bur tip has an aspiration port communicating with said lumen of said inner tube.

19. A rotary tissue cutting instrument as recited in claim 15 wherein said cutting member includes a cutting port communicating with said lumen of said inner tube and a plurality of cutting teeth extending longitudinally on opposite sides of said culling port.

20. A rotary tissue cutting instrument as recited in claim 15 wherein said strip of material is a first strip of material and said flexible region is further formed by a second strip of material spirally wrapped over said first strip of material and having ends secured to said inner tube, said second strip of material being spirally wrapped around said inner tube in said first direction and being disposed at said first angle with said central longitudinal axis.

21. A rotary tissue cutting instrument comprising

elongate outer tubular member means for being introduced at an operative site and including a proximal portion extending distally from an open proximal end to a bend, and a distal portion extending distally from said bend to an open distal end for being positioned adjacent anatomical tissue at the operative site;

and

flexible inner tubular member means for being rotatably disposed in said outer tubular member means, said inner tubular member means including a rotatably driveable proximal end, a distal end carrying cutting means exposed from said open distal end of said outer tubular member means for cutting the anatomical tissue, integrally and unitarily connected tube segment means juxtaposed with said bend for imparting bending movement to said inner tubular member means, and at least one wrap means wound over said tube segment means for forming, with said tube segment means, a flexible region in said inner tubular member means allowing said inner tubular member means to conform to said bend while being rotated in said outer tubular member means, said tube segment means extending along a segmented region of said inner tubular member means and having a first pitch along a central portion of said segmented region for greater flexibility and having a second pitch, greater than said first pitch, along distal and proximal portions of said segmented region close to said distal and proximal ends, respectively, of said inner tubular member means for greater torsional strength.