Tissue extraction devices and methods
The tissue cutting device comprises an elongated assembly including both an outer sleeve and an inner sleeve. The outer sleeve has a tissue-receiving window, and the inner sleeve has a distal end which cuts tissue as the inner sleeve is advanced past the window. The tissue is received into a lumen of the inner sleeve, and the inner sleeve lumen is typically enlarged in a proximal direction to reduce the tendency of resected tissue to lodge therein. The tissue displacement member is optionally provided at a distal end of the outer sleeve to further aid in dislodging tissue which becomes captured in a distal end of the inner sleeve of the lumen.
1. A tissue extraction device, comprising:
an outer sleeve including an outer sleeve lumen extending therein, wherein the outer sleeve includes a side-facing window through a wall of the outer sleeve and communicating with the outer sleeve lumen; and
an inner sleeve disposed within the outer sleeve lumen and configured to axially reciprocate relative to the outer sleeve between a window-open position and a window-closed position, the window-open position and the window-closed position defining a total stroke length of the inner sleeve;
wherein in the window-closed position, the inner sleeve extends distal of the side-facing window by at least a first distance, the first distance being at least 5% of the total stroke length.
2. The tissue extraction device of claim 1 , further comprising:
a closed distal tip member fixedly attached to a distal end of the outer sleeve; and
a projecting element extending proximally from the closed distal tip member.
3. The tissue extraction device of claim 2 , wherein the closed distal tip member is disposed a first axial length distal of the side-facing window;
wherein the projecting element extends a second axial length proximally from the closed distal tip member that is greater than the first axial length.
4. The tissue extraction device of claim 1 , wherein the inner sleeve defines a tissue extraction lumen having a proximal portion extending from a proximal end to a distal region and a distal portion extending from the distal region to a distal end of the inner sleeve, wherein the proximal portion of the tissue extraction lumen has a first cross-sectional area and the distal portion of the tissue extraction lumen has a second cross-sectional area less than the first cross-sectional area.
5. The tissue extraction device of claim 4 , wherein the second cross-sectional area is less than 95% of the first cross-sectional area.
6. The tissue extraction device of claim 4 , wherein the second cross-sectional area is less than 90% of the first cross-sectional area.
7. The tissue extraction device of claim 4 , wherein the second cross-sectional area is less than 85% of the first cross-sectional area.
8. The tissue extraction device of claim 4 , wherein the second cross-sectional area is less than 80% of the first cross-sectional area.
9. The tissue extraction device of claim 4 , wherein the distal portion of the tissue extraction lumen has an axial length of about 2 millimeters to 20 millimeters.
10. The tissue extraction device of claim 1 , wherein the side-facing window has an axial length between 10 millimeters and 30 millimeters.
11. A tissue extraction device, comprising:
an outer sleeve including an outer sleeve lumen extending therein, wherein the outer sleeve includes a closed distal tip and a side-facing window opening into the outer sleeve lumen, the side-facing window being proximally spaced apart from the closed distal tip; and
an inner sleeve disposed within the outer sleeve lumen and configured to axially reciprocate relative to the outer sleeve between a window-open position and a window-closed position, the window-open position and the window-closed position defining a total stroke length of the inner sleeve;
wherein in the window-closed position, the inner sleeve extends distal of the side-facing window by at least a first distance, the first distance being at least 10% of the total stroke length.
12. The tissue extraction device of claim 11 , wherein the inner sleeve defines a tissue extraction lumen having a proximal portion extending from a proximal end to a distal region and a distal portion extending from the distal region to a distal end of the inner sleeve, wherein the proximal portion of the tissue extraction lumen has a first cross-sectional area and the distal portion of the tissue extraction lumen has a second cross-sectional area less than the first cross-sectional area.
13. The tissue extraction device of claim 12 , wherein a projecting element extends proximally from the closed distal tip along a central longitudinal axis of the outer sleeve lumen.
14. The tissue extraction device of claim 13 , wherein the distal portion of the tissue extraction lumen defines a first axial length and the projecting element has a second axial length at least as long as the first axial length.
15. The tissue extraction device of claim 13 , wherein the projecting element extends proximal of a distal edge of the side-facing window.
16. The tissue extraction device of claim 11 , wherein the first distance is at least about 3 millimeters.
17. The tissue extraction device of claim 11 , wherein the first distance is at least about 4 millimeters.
18. The tissue extraction device of claim 11 , wherein the first distance is at least about 5 millimeters.
19. A tissue extraction device, comprising:
an outer sleeve including an outer sleeve lumen extending therein, wherein the outer sleeve includes a closed distal tip and a side-facing window opening into the outer sleeve lumen, the side-facing window being proximally spaced apart from the closed distal tip;
an inner sleeve disposed within the outer sleeve lumen and configured to axially reciprocate relative to the outer sleeve between a window-open position and a window-closed position, the window-open position and the window-closed position defining a total stroke length of the inner sleeve; and
a projecting element fixedly attached to and extending proximally from the closed distal tip coaxially with the outer sleeve lumen, the projecting element having a proximal end disposed proximal of a distal edge of the side-facing window;
wherein in the window-closed position, the inner sleeve extends distal of the distal edge of the side-facing window by at least a first distance, the first distance being at least 5% of the total stroke length.
20. The tissue extraction device of claim 19 , wherein the inner sleeve defines a tissue extraction lumen having a proximal portion extending from a proximal end to a distal region and a distal portion extending from the distal region to a distal end of the inner sleeve, wherein the proximal portion of the tissue extraction lumen has a first cross-sectional area and the distal portion of the tissue extraction lumen has a second cross-sectional area less than the first cross-sectional area;
wherein the projecting element extends to the proximal portion of the tissue extraction lumen when the inner sleeve in disposed in the window-closed position.