Helical device and method for aiding the ablation and assessment of tissue
A helical needle is attached to a surgical probe to aid in the insertion of the probe into a tissue mass. The tip of the helical needle penetrates the tissue mass in advance of the tip of the probe. The probe is rotated to push the helical shaft of the needle into the tissue mass in the direction of rotation. As the helical shaft advances into the tissue mass, the probe advances with it. Rotating the probe in the opposite direction causes the helical needle and probe to withdraw from the tissue mass. Rotation of the probe and needle is more effective in penetrating rubbery and calcified growths than the conventional method of pushing the probe, and it enables the precise placement of the probe. The helical needle also enables insertion of the probe in situations where an inconvenient angle of entry makes it difficult to push the probe along.
The present invention relates generally to a surgical device to assess the performance of thermal treatment of diseased tissue. More particularly, a surgical device utilizes a helical needle to facilitate entry of a surgical treatment probe into the diseased tissue with minimal difficulty. The diseased tissue may be malignant or benign.
BACKGROUND OF THE INVENTIONThe laparoscopic surgical technique of thermal ablation has known applications as a minimally-invasive procedure for reducing the volume of diseased tissue masses. In a typical thermal ablation procedure, a probe carrying a thermal energy source is inserted into the targeted tissue mass to a depth where the treatment will be most effective. The tissue is then heated to a temperature at which it coagulates, killing the treated tissue. The probe is removed and the dead tissue is left in place to be resorbed by the affected organ or tissue area. In some treatments, the probe is cooled to a cryogenic temperature to freeze the tissue rather than heat it.
The insertion and proper placement of the probe may become problematic in the treatment of some tissue masses that comprise rubbery and/or calcified tissue, such as fibroid growths of uterine muscular tissue (i.e., myomas). Such tissue masses tend to resist penetration and deflect the movement of the probe. The difficulty of inserting the probe into the tissue mass increases in cases where the laparoscopic opening affords an inconvenient angle of entry for the probe.
Laparoscopic probes in the prior art, including thermal probes, have been made in the form of thin needles, typically about one (1) mm in diameter, such that the probe may be inserted with relatively little resistance from the tissue mass. Unfortunately, these small diameter probes bend easily when inserted into the resisting tissue, resulting in misalignment within the tissue mass and reducing the effectiveness of the thermal ablation treatment. Moreover, straight, needle-like probes that are easily inserted are susceptible to being accidentally displaced during the treatment procedure. Thicker, more rigid probes would be less likely to bend, but, because of their thickness, would be more difficult to insert into a tissue mass than the thinner flexible probes.
There remains a need for a surgical assistance device that aids the surgeon in inserting a laparoscopic probe into a resisting tissue mass. Such a device should allow precise placement of the probe within the tissue mass and resist accidental displacement. It is desirable that the device aid the insertion of relatively thick and rigid probes, in the range of 2-5 mm diameter. The device should be usable for laparoscopic surgery, open surgery, percutaneously or through natural body openings such as the vagina.
SUMMARY OF THE INVENTIONIn one aspect, the present invention comprises a helical needle affixed to a laparoscopic probe so that the distal end of the needle extends beyond the distal end of the probe. A preferred embodiment of the invention comprises a helical needle having a helical shaft section that encompasses the straight shaft of the probe. More preferably, the helical needle is terminated by a sharp tip, for puncturing tissue, located on a common axis with the helical shaft section of the helical needle and the straight shaft section of the probe.
Another aspect of the invention provides a means for assessing the performance of thermal ablation of a tissue mass. In a preferred embodiment of this aspect of the invention, a number of thermal sensors are provided on the helical shaft section of a helical needle affixed to a thermal treatment probe to measure the temperature of the heated tissue.
In another aspect of the invention, the probe is provided with a driving means to selectively rotate the probe in a direction that drives the helical needle into a tissue mass or in an opposite direction to wind the helical needle out of the tissue mass. One preferred embodiment of this aspect of the invention provides a handle with opposed turning tabs at the proximal end of the probe. In another preferred embodiment, the rotation of the probe is driven by a motorized device having a directional control switch. A third preferred embodiment employs a manually operated ratchet assembly with an independently movable ratchet and pawl to control the direction of rotation of the ratchet gear that drives the probe.
A fourth aspect of the invention includes methods for inserting a laparoscopic probe into a tissue mass. The probe is provided with a helical needle affixed thereto such that the distal end of the needle extends past the distal end of the probe. In a preferred method, the tissue mass is punctured with the distal end of the needle and the probe is rotated such that the helical needle advances into the tissue mass in the direction of rotation, thereby advancing the probe into the tissue mass. In another preferred embodiment, the probe is rotated by a driving means that is calibrated to allow precise rotation of the probe.
The use of a helical needle in combination with a laparoscopic probe enables the probe to penetrate a tissue mass by rotation when the condition of the tissue or an inconvenient angle of entry would make it difficult to insert the probe by the conventional method of pushing it in an axial direction. The assistance provided by the helical needle also enables the use of probes having larger diameters than the one (1) mm probes that are presently preferred. The combination of probe and helical needle disclosed herein may be used advantageously in laparoscopic surgery, open surgery, hysteroscopic surgery or for entry through natural body orifices.
BRIEF DESCRIPTION OF THE DRAWINGSFor a more complete understanding of the present invention, reference is made to the following detailed description of the present invention considered in conjunction with the accompanying drawings, in which:
Referring to
Referring to
The helically-shaped shaft 28 of the helical needle 12 is disposed so as to encompass the needle-like element 14 of the probe 10 (see
The helical needle 12 assists the entry of the probe 10 into the tissue mass 28, as the following example illustrates. Referring again to
A second exemplary embodiment 100 of the present invention is shown in
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The motorized device 156 assists the entry of the probe 110 into the tissue mass 128, as the following example shows. Referring again to
A third exemplary embodiment 200 of the present invention is shown in
As can be seen in
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As shown in
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In operation, the ratchet-type screw assembly 262 may be used to rotate the probe 210 and the helical needle 212 so as to insert or withdraw the probe 210 and the helical needle 212 from the tissue mass 228. The following example illustrates the application of the third embodiment 200 with particular attention to the operation of the ratchet-type screw assembly 264.
Referring now to
For the purpose of this illustrative example, it is understood that assembly 262 was set to rotate probe 210 in rotational direction M1 by setting reversing lever 266 to a first position prior to pointing the distal end 216 of the probe 210 with the sharp tip 246 of helical needle 212 in contact with the tissue wall 226. The operator then proceeds to squeeze the pull lever 316 towards the handle section 322 from a first position S1 to a second position S2 several times, thereby pushing ratchet element 272 toward gear member 274 by means of the interconnected elements handle 316 and guide plate 320. The rotation of the probe 210 causes the helically-shaped shaft 238 of helical needle 212 to wind into the tissue mass 228, thereby advancing the probe 210 and the helical needle 212 into the tissue mass 228. After completion of the thermal treatment, the operator then sets the reversing lever in a second position, reversing the direction of rotation, and squeezes the pull lever 316 towards the handle section 322, as described above. The probe 210 is rotated in rotational direction M2, thereby winding helically-shaped shaft 238 out of the tissue mass 228 such as to remove the probe 210 and the helical needle 212 from the tissue mass 228.
The use of a helical needle 12 in combination with a probe 10, as described above, presents numerous advantages compared to the use of the probe 10 by itself. For example, the relatively thin distal end 36 of helical needle 12 penetrates more readily into the rubbery or calcified tissue of a myoma, tumor or other unwanted growth (i.e, tissue mass 28) than does the thicker distal end 16 of probe 10. The helical shape of the shaft 38 of the helical needle 12 causes the helical needle 12 to advance into the tissue mass 28 in an axial direction as it is rotated, pulling the probe 10 in the same direction. The probe 10 can, therefore, be more readily advanced into the tissue mass 28 by rotation when the angle of entry or the condition of the tissue would make it difficult to insert the probe 10 by pushing it in an axial direction. Under typical circumstances, rotational force alone will be sufficient to drive the probe into or out of the tissue mass. The assistance provided to the entry of probe 10 also enables the use of probes having larger diameters than the one (1) mm probes that are presently preferred. Another advantage may be realized because the helical shape of the shaft 38 of the helical needle 12 causes the helical needle 12 to resist being moved within the tissue mass 28 by forces applied in the axial or lateral directions. This resistance to movement acts to stabilize the position of probe 10 within the tissue mass 28 during treatment, reducing the likelihood that the probe 10 will be accidentally withdrawn from the intended treatment location. Moreover, the geometry of the helically-shaped shaft 38 causes the probe 10 to be advanced by a predetermined distance with each complete rotation of the affixed helically-shaped shaft 38. This geometrical relationship allows the depth to which the probe 10 penetrates the tissue mass 28 to be controlled by precisely rotating the probe 10 and helical needle 12. Such precise rotation may be provided by the ratchet-type screw device 262 or other mechanical devices adapted to rotate the probe 10 by predetermined amounts. The helical needle 12 may also serve as a carrier for thermal sensors for monitoring the temperature of the tissue mass 28 during thermal treatment, and, thereby, providing a means to control the temperature of the tissue mass 28 and the progress of the treatment.
The combination of probe and helical needle disclosed herein is not limited to uses in laparoscopic surgery. It may also be used advantageously in open surgery, hysteroscopic surgery or for entry through natural body orifices such as the mouth, the ear, the vagina, the uterus, the rectum, or the penis.
It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. For example, the helical needle 12 may be solid instead of having an interior channel 44. The helical needle 112 may also be solid and the thermal sensors 152 and their respective conductive leads 154a and 154b attached to the exterior wall surface 142 of the helical shaft section 138 of helical needle 112. Alternatively, in embodiments where the helical needle 112 has an interior channel 144, the openings 150 may be omitted and the thermal sensors 152 and conductive leads 154a, 154b embedded in a plastic rod or tube within the interior channel 144. The helical needle 112 may also be used as a carrier for sensors other than the thermal sensors 152. The probe 10 may be provided with means for rotatably inserting and removing the probe 10 other than the motor device 156 or ratchet-type screw assembly 262. All such variations and modifications, including those discussed above, are intended to be included within the scope of the invention as defined in the appended claims.
Claims
1. A surgical device, comprising
- a surgical probe having a substantially straight shaft section and a distal end; and
- a helical needle having a distal end and a helical shaft section, the helical needle being affixed to the probe such that the distal end of the helical needle extends beyond the distal end of the probe and the helical shaft section encompasses the shaft section of the surgical probe.
2. The surgical device of claim 1, wherein the surgical probe includes a source of thermal energy.
3. (cancelled).
4. The surgical device of claim 2, wherein the shaft section of the surgical probe has a diameter in the range of about 2 mm to about 5 mm.
5. The surgical device of claim 4, wherein the helical shaft section has the shape of a circular cylindrical helix, the helical shaft section of the helical needle and the shaft section of the surgical probe being aligned along a common axis.
6. The surgical device of claim 5, wherein the distal end of the helical needle is terminated by a sharp tip for puncturing tissue, the sharp tip being located on the common axis.
7. The surgical device of claim 2, wherein the helical needle has a proximal end including an attachment section, said attachment section being affixed to the shaft section of the surgical probe.
8. The surgical device of claim 2, wherein the helical shaft section of the helical needle has an exterior surface and at least one thermal sensor exposed at the exterior surface.
9. The surgical device of claim 2, wherein the helical needle has an interior channel and at least one thermal sensor within the interior channel.
10. The surgical device of claim 1, wherein the helical needle is made of a rigid material.
11. The surgical device of claim 1, wherein the helical needle is made of a resilient material.
12. The surgical device of claim 1, wherein the helical needle is made of a shape-memory alloy.
13. The surgical device of claim 1, wherein the surgical device has a proximal end and a driving means for selectively rotating the surgical device in a first rotational direction and in a second rotational direction opposite to the first rotational direction, the driving means being located at the proximal end of the surgical device.
14. The surgical device of claim 13, wherein the driving means comprises a handle including two opposed turning tabs.
15. The surgical device of claim 13, wherein the driving device comprises a motorized device for rotating the surgical probe.
16. The surgical device of claim 13, wherein the driving device comprises a ratchet assembly having a ratchet gear interconnected with a movable handle, said ratchet assembly being adapted such that the ratchet gear is rotated by movement of the handle.
17. (cancelled).
18. A method for inserting a surgical probe into a tissue mass, the surgical probe having a substantially straight shaft section, a distal end and a helical needle affixed to the surgical probe, the helical needle having a distal end that extends beyond the distal end of the probe, the method comprising the steps of
- puncturing the tissue mass with the distal end of the helical needle; and
- rotating the surgical device in a rotational direction such that the helical needle advances into the tissue mass in the rotational direction, thereby advancing the surgical probe in an axial direction, thereby advancing the distal end of the surgical probe into the tissue mass.
19. The method of claim 18, wherein the surgical probe has a proximal end and a driving means for selectively rotating the surgical probe in a first rotational direction and in a second rotational direction opposite to the first rotational direction, the driving means being located at the proximal end of the surgical probe.
20. The method of claim 19, wherein the driving means is calibrated for providing precise depth of penetration of the surgical probe.
Type: Application
Filed: Nov 4, 2004
Publication Date: Mar 24, 2005
Inventor: Thomas Ryan (Flemington, NJ)
Application Number: 10/981,096