Tissue extraction devices and methods
Tissue may be cut and extracted from an interior location in a patient's body using a probe or tool which both effects cutting and causes vaporization of a liquid or other fluid to propel the cut tissue through an extraction lumen of the cutting device. The cutting may be achieved using an electrosurgical electrode assembly, including a first electrode on a cutting member and a second electrode within a cutting probe or tool. Thus, over a first cutting portion, radio frequency current may help cut the tissue and over a second or over transition region, the RF current may initiate vaporization of the fluid or other liquid to propel the tissue from the cutting device.
1. An electrosurgical system for resecting tissue, said system comprising:
an elongated probe including:
an outer sleeve including a lumen and a tissue-receiving window opening into the lumen of the outer sleeve;
an inner sleeve movably disposed within the lumen of the outer sleeve, wherein the inner sleeve is configured to move across the tissue-receiving window between a window-open position to a window-closed position to resect tissue extending into the tissue-receiving window;
a distal tip attached to a distal end of the outer sleeve;
a first polarity electrode positioned at a distal end region of the inner sleeve; and
a second polarity electrode positioned at a distal end region of the outer sleeve;
wherein an outer surface of the outer sleeve comprises the second polarity electrode when the inner sleeve is in the window-open position and a surface of the distal tip within the lumen of the outer sleeve comprises the second polarity electrode when the inner sleeve is in the window-closed position;
wherein the first and second polarity electrodes are configured to operate in a first mode to resect tissue with RF energy and in a second mode to vaporize a fluid volume within the lumen of the outer sleeve with RF energy to expel tissue proximally through a tissue extraction lumen of the inner sleeve.
2. The system of claim 1 , further comprising a tissue displacement member disposed within the lumen of the outer sleeve and extending proximally from the distal tip.
3. The system of claim 2 , wherein the tissue displacement member extends into a distal opening of the inner sleeve in the window-closed position.
4. The system of claim 3 , wherein the tissue displacement member comprises a ceramic material.
5. The system of claim 2 , wherein a proximal end of the tissue displacement member is proximal of a distal edge of the first polarity electrode in the window-closed position.
6. The system of claim 5 , wherein the first polarity electrode is a ring electrode.
7. The system of claim 6 , wherein the ring electrode has an inner diameter less than an inner diameter of the inner sleeve proximal of the ring electrode.
8. The system of claim 2 , wherein the distal tip includes a post extending into a bore of the tissue displacement member.
9. An electrosurgical system for resecting tissue, said system comprising:
an elongated probe including:
an outer sleeve including a lumen and a tissue-receiving window opening into the lumen of the outer sleeve;
an inner sleeve movably disposed within the lumen of the outer sleeve, the inner sleeve including a tissue extraction lumen extending therethrough, wherein the inner sleeve is configured to longitudinally reciprocate across the tissue-receiving window between a window-open position to a window-closed position to resect tissue extending into the tissue-receiving window;
a distal tip attached to a distal end of the outer sleeve;
a first polarity electrode positioned at a distal end region of the inner sleeve; and
a second polarity electrode positioned at a distal end region of the outer sleeve;
wherein the first and second polarity electrodes are configured to operate in a first mode to resect tissue extending into the tissue-receiving window with RF energy and in a second mode to vaporize a fluid volume within the lumen of the outer sleeve with RF energy to expel tissue proximally through the tissue extraction lumen of the inner sleeve.
10. The system of claim 9 , wherein an outer surface of the outer sleeve comprises the second polarity electrode when the inner sleeve is in the window-open position and a surface of the distal tip within the lumen of the outer sleeve comprises the second polarity electrode when the inner sleeve is in the window-closed position.
11. The system of claim 9 , wherein an outer surface of the outer sleeve comprises the second polarity electrode in the first mode and a surface of the distal tip within the lumen of the outer sleeve comprises the second polarity electrode in the second mode.
12. The system of claim 9 , further comprising a tissue displacement member disposed within the lumen of the outer sleeve and extending proximally from the distal tip.
13. The system of claim 12 , wherein the tissue displacement member extends into the tissue extraction lumen of the inner sleeve in the window-closed position.
14. The system of claim 13 , wherein the tissue displacement member comprises a ceramic material.
15. The system of claim 12 , wherein a proximal end of the tissue displacement member is proximal of a distal edge of the first polarity electrode in the window-closed position.
16. The system of claim 12 , wherein the distal tip includes a post extending into a bore of the tissue displacement member.
17. The system of claim 9 , wherein the first polarity electrode is a ring electrode.
18. The system of claim 17 , wherein the ring electrode has an inner diameter less than an inner diameter of the tissue extraction lumen proximal of the ring electrode.