Self-centering valvulotome

• US 5,658,301 A
• Filed: 04/26/1995
• Issued: 08/19/1997
• Est. Priority Date: 04/26/1995
• Status: Expired due to Term

• Current Assignee: LeMaitre Vascular, Incorporated
• Original Assignee: Vascutech Incorporated
• Inventors: Lemaitre, George D., Lemaitre, George W., de Toledo, Fernando Alvarez
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): RASCHE, PATRICK WILLIAM
• Application Number:
  US08/427,808
• Time in Patent Office: 846 Days
• Field of Search: 606/159, 606/167, 606/170, 604/167, 604/22
• US Class Current: 606/159
• CPC Class Codes: A61B 17/32075 Pullback cutting; combined forward and pullback cutting, e.g. with cutters at both sides of the plaque
• CPC Class Codes: A61B 2017/22097 Valve removal in veins

Abstract

Self-centering valvulotome (V) having a flexible cable (1) partly and slidably disposed within a protective sheath (2), a cutting unit (4), having at least three radially mounted, retractable cutting blades, attached to the cable at its distal end, and a dual-purpose control mechanism attached to the cable at its proximal end. Each retractable cutting blade comprises a free-floating cutting head and a flat spring section, which biases the cutting head against the venous wall. The control mechanism comprises a T-valve segment disposed partly within the proximal end of the protective sheath. A pull handle affixed to the proximal end of the cable can engage the T-valve such that a fluid-tight seal is created, thereby allowing the introduction of a diagnostic or therapeutic fluid to the protective sheath via an access port in the valve.

Claims

1. A self-sizing, self-centering valvulotome comprising:

(a) a protective sheath having a lumen, a flared distal end, and a proximal end;

(b) a flexible cable having a distal end and a proximal end and being partly and slidably disposed within the protective sheath;

(c) a self-sizing, self-centering cutting unit having a base, at least three retractable cutting members, each having a first, attached end equally radially mounted on the base, a second, unattached end defining a free-floating cutting blade, and a self-sizing, self-centering arm disposed therebetween, and a tip capable of accommodating the at least three radially mounted, retractable cutting blades, the self-sizing, self-centering cutting unit being attached to the cable'"'"'s distal end such that the cutting unit is capable of slidably fitting within the flared distal end of the protective sheath such that it can be partially retracted within the protective sheath in a sheathed position and extended to an unsheathed position by means of the flexible cable, the base and the tip are separated by a distance not to exceed the length of the retractable cutting blades, each retractable cutting member being constructed so that the self-sizing, self-centering arm extends outward in a radial direction relative to the cable such that, in the unsheathed position, the radial distance separating the outermost point of each self-sizing, self-centering arm from the cable is greater than the radial distance separating the outermost point of each cutting blade from the cable, and each cutting blade having an upper, non-cutting outermost edge shielding a cutting edge disposed inwardly therefrom relative to the cable such that the cutting edge is oriented toward the proximal end of the cable; and

(d) a dual-purpose control mechanism attached to the protective sheath'"'"'s proximal end and allowing the passage therethrough of the flexible cable, such that the surgeon can sheathe and unsheathe the cutting head by sliding the flexible cable distally or proximally relative to the protective sheath.

2. The self-sizing, self-centering valvulotome, as claimed in claim 1, wherein each retractable cutting member is formed from a flat blank by rotating the cutting blade until it is disposed at about a 90°

angle from the plane of the self-sizing, self-centering arm.

3. The self-centering valvulotome, as claimed in claim 1, wherein the self-sizing, self-centering arm is shaped so that the venous valve is opened upon insertion of the valvulotome cutting head, but that the vein'"'"'s natural bloodflow is allowed to close the valve around the sheathed flexible cable once the cutting head has passed through.

4. The self-centering valvulotome, as claimed in claim 1, wherein the control mechanism comprises a T-valve segment having a terminal end and an upper end disposed at an angle of about 90°

or less from the axis thereof, the T-valve segment being disposed partly within the proximal end of the protective sheath and the terminal end of the T-valve segment being adapted to allow engagement of a pull handle attached to the proximal end of the cable.

5. The self-centering valvulotome, as claimed in claim 4, wherein the upper end of the T-valve has an access port.

6. The self-centering valvulotome, as claimed in claim 5, wherein the pull handle engages the terminal end of the T-valve segment to create a fluid-tight seal, thereby allowing the introduction of a diagnostic or therapeutic fluid to the distal end of the protective sheath via the T-valve access port and the lumen of the protective sheath.

7. A self-sizing, self-centering valvulotome comprising:

(a) protective sheathing means having a lumen, a distal end, and a proximal end;

(b) means partly and slidably disposed within the protective sheathing means for transmitting linear motion;

(c) self-sizing, self-centering means for cutting attached to the distal end of the motion transmitting means and drivable for cutting movement through said motion transmitting means; and

(d) control means attached to the proximal end of the protective sheathing means and allowing the passage therethrough of the motion transmitting means such that the surgeon can sheathe and unsheathe the cutting means by sliding the motion transmitting means proximally or distally relative to the protective sheathing means,

the self-sizing, self-centering means for cutting comprises a base means attached to the motion transmitting means, at least three retractable cutting member means equally radially disposed about the motion transmitting means, and a tip means capable of accommodating the at least three cutting member means, each cutting member means being constructed so that a first end is attached to the base means, a second end having a cutting blade means is not attached to the motion transmitting means, and a self-sizing, self-centering arm means connects the first and second ends and extends outward in a radial direction relative to the motion transmitting means, such that when the cutting means is in the unsheathed position the radial distance separating the outermost point of each self-sizing, self-centering arm means from the motion transmitting means is greater than the radial distance separating the outermost point of each cutting blade means from the motion transmitting means.

8. The self-sizing, self-centering valvulotome, as claimed in claim 7, wherein each retractable cutting member is formed from a flat blank by rotating the cutting blade means until it is disposed at about a 90°

angle from the plane of the self-sizing, self-centering arm means.

9. The self-centering valvulotome, as claimed in claim 7, wherein the control means comprises a valve means having a terminal end, the valve means being disposed partly within the proximal end of the protective sheathing means and the terminal end of the valve means being adapted to allow engagement of a handle means attached to the proximal end of the flexible cable means.

10. The self-centering valvulotome, as claimed in claim 9, wherein the valve means has an access port means.

11. A self-centering valvulotome, as claimed in claim 10, wherein the handle means engages the terminal end of the valve means to create a fluid-tight seal, thereby allowing the introduction of a diagnostic or therapeutic fluid to the distal end of the protective sheathing means via the access port means and the lumen means of the protective sheathing means.

12. A cutting device with a self-centering capability for use within a tubular passageway, comprising, in combination:

(a) a flexible cable having a distal end and a proximal end;

(b) self-centering means for cutting;

(c) means for attaching said means for cutting to said flexible cable;

wherein the self-centering means for cutting is attached to the flexible cable via the means for attachment such that said means for attaching and said means for cutting are axially disposed with relation to said flexible cable, and further wherein the self-centering means for cutting is a unit that comprises a base means, at least three retractable cutting blade means attached to the base means and equally, radially disposed about the flexible cable, and a tip means capable of accommodating the retractable cutting blade means, the unit constructed such that the base means and the tip means are separated by a distance not to exceed the length of the retractable cutting blade means, each retractable cutting blade means being constructed so that it defines a first end suitable for attachment to the base means, a second end forming a cutting head means, and a self-sizing, self-centering arm means extending therebetween and outwardly in a radial direction relative to the cable such that, in the unsheathed position, the radial distance separating the outermost point of each self-sizing, self-centering arm from the cable is greater than the radial distance separating the outermost point of each cutting head from the cable.

13. The self-sizing, self-centering cutting device, as claimed in claim 12, wherein each retractable cutting blade means is formed from a flat blank by rotating the cutting blade means until it is disposed at about a 90°

angle from the plane of the retractable self-sizing, self-centering arm means.

14. A method of preparing a vein for in situ arterial bypass surgery comprising:

(a) selecting a suitable vein for the procedure;

(b) accessing the vein at both a distal and a proximal point and segmenting it thusly;

(c) inserting a valvulotome into the vein segment at its distal access point, wherein the valvulotome comprises;

(i) a flexible cable having a distal end and a proximal end; and

a cutting unit having a base, at least three equally radially mounted, retractable cutting blades attached to the base, and a tip capable of accommodating the at least three radially mounted retractable cutting blades, the cutting unit being attached to the cable'"'"'s distal end such that the base and the tip are separated by a distance not to exceed the length of the retractable cutting blades, each retractable cutting blade being constructed so that it defines a cutting head and a self-sizing, self-centering arm extending outward in a radial direction relative to the cable such that the radial distance separating the outermost point of each self-sizing, self-centering arm from the cable is greater than the radial distance separating the outermost point of each cutting blade from the cable;

(d) feeding the valvulotome into the vein segment until the cutting unit is past the most proximal valve in the vein segment; and

(e) withdrawing the valvulotome from the vein segment, thereby severing each valve in the segment.

15. A self-sizing, self-centering device for clearing a tubular passageway, comprising:

(a) a flexible cable having a distal end and a proximal end;

(b) a cutting unit having a base, at least three equally radially mounted retractable cutting blades attached to the base, and a tip capable of accommodating the at least three radially mounted retractable cutting blades, the cutting unit being attached to the cable'"'"'s distal end such that the base and the tip are separated by a distance not to exceed the length of the retractable cutting blades, each retractable cutting blade being constructed so that it defines a cutting head and a self-sizing, self-centering arm extending outward in a radial direction relative to the cable such that the radial distance separating the outermost point of each self-sizing, self-centering arm from the cable is greater than the radial distance separating the outermost point of each cutting blade from the cable;

(c) a control mechanism attached to the flexible cable'"'"'s proximal end such that the cutting unit can be inserted into or withdrawn from the tubular passageway to be cleared by means of the control mechanism.

16. The self-centering device for clearing a tubular passageway, as claimed in claim 15, wherein each retractable cutting member is formed from a flat blank by rotating the retractable cutting blade until it is disposed at about a 90°

angle from the plane of the self-centering, self-sizing arm.

17. The device for clearing a tubular passageway, as claimed in claim 15, wherein the flexible cable is partly and slidably disposed within a protective sheath having a lumen, a distal end, and a proximal end.