Polypectomy snare instrument

1. A medical device, comprising:

a tubular member having a distal end;

a shaft disposed within the tubular member;

an end effector coupled to the shaft;

a first handle coupled to the shaft;

a second handle coupled to the shaft;

wherein the second handle further comprises a stationary member and a spool member slidable relative to the stationary member, wherein sliding the spool member results in longitudinal movement of the shaft, and wherein the first handle remains stationary while the spool member is longitudinally moved; and

a tubular sheath extension disposed between and longitudinally separating the first handle from the second handle, wherein the tubular sheath extension includes a first connector attached to the first handle and a second connector attached to the second handle, wherein the tubular sheath extension has a length and wherein the first handle and the second handle are longitudinally spaced from each other by a fixed distance that is substantially equal to the length of the tubular sheath extension.

2. The medical device of claim 1 , wherein the end effector includes a snare.

3. The medical device of claim 1 , wherein the first handle includes a body and a knob, and wherein rotation of the knob results in rotation of the shaft.

4. The medical device of claim 3 , wherein the knob defines a bore and wherein the shaft extends through the bore.

5. The medical device of claim 4 , wherein the bore has a non-circular cross section.

6. The medical device of claim 5 , wherein the shaft further comprises a key portion provided with a non-circular cross section engageable with the non-circular cross section of the bore.

7. The medical device of claim 1 , further comprising mounting means for mounting the first handle to an endoscope such that the shaft extends through a working channel of the endoscope.

8. The medical device of claim 7 , wherein the mounting means is adapted to adjustably fix a distal end of the tubular member relative to a distal end of the endoscope.

9. The medical device of claim 1 , further comprising means for providing a cautery current to the shaft.

10. The medical device of claim 1 , wherein the first handle is located distal of the second handle.

11. A medical device, comprising:

a tubular member having a distal end;

a shaft disposed within the tubular member;

an end effector coupled to the shaft;

means for rotating the shaft;

means for longitudinally shifting the position of the shaft relative to the sheath;

wherein the means for longitudinally shifting the position of the shaft relative to the sheath further comprises a stationary member and a spool member slidable relative to the stationary member, wherein sliding the spool member results in longitudinal movement of the shaft, and wherein the means for rotating the shaft remains axially stationary while the spool member is moved; and

a tubular sheath extension disposed between and longitudinally separating the means for rotating the shaft from the means for longitudinally shifting the position of the shaft relative to the sheath, wherein the tubular sheath extension includes a first connector attached to the means for rotating the shaft and a second connector attached to the means for longitudinally shifting the position of the shaft relative to the sheath, wherein the tubular sheath extension has a length and wherein the means for rotating the shaft and the means for longitudinally shifting the position of the shaft relative to the sheath are longitudinally spaced from each other by a fixed distance that is substantially equal to the length of the tubular sheath extension.

12. The medical device of claim 11 , wherein the end effector includes a snare.

13. The medical device of claim 11 , wherein the means for rotating the shaft includes a first handle having a body and a knob, and wherein rotation of the knob results in rotation of the shaft.

14. The medical device of claim 13 , wherein the knob defines a bore and wherein the shaft extends through the bore.

15. The medical device of claim 14 , wherein the bore has a non-circular cross section.

16. The medical device of claim 15 , wherein the shaft further comprises a key portion provided with a non-circular cross section engagable with the non-circular cross section of the bore.

17. The medical device of claim 11 , further comprising mounting means for mounting the means for rotating the shaft to an endoscope such that the shaft extends through a working channel of the endoscope.

18. The medical device of claim 17 , wherein the mounting means is adapted to adjustably fix a distal end of the tubular member relative to a distal end of the endoscope.

19. The medical device of claim 11 , further comprising means for providing a cautery current to the shaft.

20. The medical device of claim 11 , wherein the means for rotating the shaft is located distal of the means for longitudinally shifting the position of the shaft relative to the sheath.

21. A medical device, comprising:

a sheath having a distal end;

a shaft slidably disposed within the sheath;

a snare coupled to the shaft; and

a control member coupled to the shaft for controlling the position of the shaft relative to the sheath, the control member including a first handle, a second handle, and a tubular sheath extension disposed therebetween;

wherein the first handle is configured to be actuated independently of the second handle such that the second handle maintains its axial position relative to the first handle when the first handle is actuated;

wherein the tubular sheath extension has a length and wherein the first handle and the second handle are longitudinally spaced from each other by a fixed distance that is substantially equal to the length of the tubular sheath extension; and

wherein the tubular sheath extension includes a first connector attached to the first handle and a second connector attached to the second handle.