Medical device for removing an implanted object
Methods and devices for separating an implanted object, such as a pacemaker lead, from tissue surrounding such object in a patient's vasculature system. Specifically, the surgical device includes a handle, an elongate inner sheath and a circular cutting blade that extends from the distal end of the sheath upon actuating the handle. The circular cutting blade is configured to engage the tissue surrounding an implanted lead and cut such tissue in a coring fashion as the surgical device translates along the length of the lead, thereby allowing the lead, as well as any tissue remaining attached to the lead, to enter the device's elongate shaft. The surgical device has a barrel cam cylinder in the handle assembly that imparts rotation of the blade and a separate cam mechanism in the tip of outer sheath assembly that imparts and controls the extension and retraction of the blade. The barrel cam cylinder and cam mechanism cooperate to cause the blade to rotate in a first direction and extend from and retract in the outer sheath due to a first actuation of the handle and to rotate in a second direction and extend and retract in the outer sheath due to a second actuation of the handle. The inner sheath and outer sheath are constructed of laser-cut hypotubes, thereby allowing the surgical device, particularly the sheath assembly, to have a smaller profile for navigating smaller sized vasculature.
1. A device for removing an implanted object from a body vessel, the device comprising:
a sheath assembly comprising an outer sheath assembly and an inner sheath assembly, and a pin;
the outer sheath assembly comprising an outer sheath and an outer band, the outer band coupled to the pin;
the inner sheath assembly comprising an inner sheath and a tip, wherein the tip has a cutting surface;
the inner sheath comprising a proximal end and a distal end, wherein the distal end of the inner sheath is coupled to the tip;
the tip comprising a cam slot for receipt of and cooperation with the pin; and
a handle assembly comprising a trigger and a barrel cam cylinder, the trigger comprising a trigger pin, the barrel cam cylinder comprising a barrel cam cylinder slot for receipt and cooperation with the trigger pin, wherein the proximal end of the inner sheath is coupled to the barrel cam cylinder such that:
(1) upon a first actuation of the trigger to proximally move the trigger pin in a longitudinal direction and translate the trigger pin within the barrel cam cylinder slot, the barrel cam cylinder rotates in a first direction, thereby causing the tip to rotate in the first direction while the tip moves longitudinally; and
(2) upon a second actuation of the trigger to proximally move the trigger pin in the longitudinal direction and translate the trigger pin within the barrel cam cylinder slot, the barrel cam cylinder rotates in a second direction, thereby causing the tip to rotate in the second direction while the tip moves longitudinally;
the handle assembly further comprising a one-way translation mechanism that partially inhibits translation of the trigger pin within the barrel cam cylinder slot.
2. The device of claim 1 , wherein the outer sheath assembly is stationary and the inner sheath assembly is capable of rotating.
3. The device of claim 1 , wherein the pin couples the tip of the inner sheath assembly to the outer band of the outer sheath assembly.
4. The device of claim 1 , wherein the barrel cam cylinder slot comprises an intersection in which a path defined by the barrel cam cylinder slot crosses itself, and wherein the barrel cam cylinder slot comprises:
first slot actuation portion;
a first slot return portion coupled to the first slot actuation portion;
a second slot actuation portion coupled to the first slot return portion, the second slot actuation portion and the first slot actuation portion together defining the intersection; and
a second slot return portion coupled to the second slot actuation and the first slot actuation portion.
5. The device of claim 4 , wherein upon the first actuation of the trigger the one-way translation mechanism inhibits the trigger pin from traversing the second slot return portion, and wherein upon the second actuation of the trigger the one-way translation mechanism inhibits the trigger pin from traversing the first slot return portion.
6. The device of claim 5 , wherein the one-way translation mechanism includes a first gate pivotably coupled to the barrel cam cylinder, and upon the first actuation of the trigger the first gate inhibits the trigger pin from traversing the second slot return portion.
7. The device of claim 6 , wherein the one-way translation mechanism further includes a second gate pivotably coupled to the barrel cam cylinder, and upon the second actuation of the trigger the second gate inhibits the trigger pin from traversing the first slot return portion.
8. The device of claim 1 , wherein the barrel cam cylinder slot comprises an intersection in which a path defined by the barrel cam cylinder slot crosses itself, and wherein the handle assembly further comprises a follower guide rotatably carried by the barrel cam cylinder, the follower guide engaging the trigger pin to guide the trigger pin straight through intersection during both the first actuation of the trigger and the second actuation of the trigger.
9. The device of claim 8 , wherein the follower guide comprises:
a first wall that engages the trigger pin to guide the trigger pin straight through intersection during the first actuation of the trigger; and
a second wall that engages the trigger pin to guide the trigger pin straight through intersection during the second actuation of the trigger.
10. The device of claim 9 , wherein the first wall is a first diagonally-extending wall and the second wall is a second diagonally-extending wall.
11. The device of claim 10 , wherein the first diagonally-extending wall is a first curved wall and the second diagonally-extending wall is a second curved wall.
12. A device for removing an implanted object from a body vessel, the device comprising:
a sheath comprising a proximal end and a distal end;
a tip coupled to the distal end of the sheath, wherein the tip has a cutting surface;
a handle assembly rotatably carrying the sheath, the handle assembly comprising:
a trigger comprising a trigger pin;
a barrel cam assembly comprising:
a barrel cam cylinder comprising a barrel cam cylinder slot for receipt and cooperation with the trigger pin, the barrel cam cylinder slot comprising a first slot actuation portion, a first slot return portion, a second slot actuation portion, and a second slot return portion;
a follower guide rotatably carried by the barrel cam cylinder;
a one-way translation mechanism for partially inhibiting translation of the trigger pin within the barrel cam cylinder slot;
wherein upon a first actuation of the trigger to proximally move the trigger pin in a longitudinal direction, the follower guide urges the trigger pin to traverse the first slot actuation portion and the one-way translation mechanism inhibits the trigger pin from traversing the second slot return portion, thereby causing the barrel cam cylinder and the tip to rotate in a first direction; and
wherein upon a second actuation of the trigger to proximally move the trigger pin in a longitudinal direction, the follower guide urges the trigger pin to traverse the second slot actuation portion and the one-way translation mechanism inhibits the trigger pin from traversing the first slot return portion, thereby causing the barrel cam cylinder and the tip to rotate in a second direction.
13. The device of claim 12 , wherein the follower guide comprises an aperture through which the trigger pin extends for receipt in and cooperation with the barrel cam cylinder slot.
14. The device of claim 13 , wherein the follower guide further comprises:
a first wall that defines, in part, the aperture, the first wall engaging the trigger pin to urge the trigger pin to traverse the first slot actuation portion during the first actuation of the trigger; and
a second wall that defines, in part, the aperture, the second wall engaging the trigger pin to urge the trigger pin to traverse the second slot actuation portion during the second actuation of the trigger.
15. The device of claim 12 , wherein the barrel cam cylinder slot comprises an intersection in which the first slot actuation portion crosses the second slot actuation portion, and the follower guide (1) inhibits the trigger pin from traversing the second slot actuation portion during the first actuation of the trigger, and (2) inhibits the trigger pin from traversing the first slot actuation portion during the second actuation of the trigger.
16. The device of claim 15 , wherein the first slot actuation portion includes a first end and a second end, the second slot actuation portion includes a first end and a second end, the first slot return portion couples the second end of the first slot actuation portion to the first end of the second slot actuation portion, and the second slot return portion couples the second end of the second slot actuation portion to the first end of the first slot actuation portion.
17. The device of claim 12 , wherein the follower guide is rotatable from a first position to a second position and vice versa relative to the barrel cam cylinder, in the first position the follower guide urges the trigger pin to traverse the first slot actuation portion upon the first actuation of the trigger, thereby causing the barrel cam cylinder and the tip to rotate in the first direction, and in the second position the follower guide urges the trigger pin to traverse the second slot actuation portion upon the second actuation of the trigger, thereby causing the barrel cam cylinder and the tip to rotate in the second direction.