Medical instrument for ablation of tissue

Abstract

The present application discloses a medical instrument for tissue ablation by a minimally invasive surgical procedure, including a hollow outer shaft, an inner shaft which can be guided longitudinally displaceably in the hollow outer shaft, and a control portion at a proximal end of the medical instrument, in order to position the hollow outer shaft. An attachment for mechanical ablation of tissue is arranged at a distal end of the inner shaft, wherein the attachment does not protrude beyond an inner profile formed by the inner faces of the outer shaft, and wherein at any rate the distal end of the attachment protrudes beyond the distal end of the hollow outer shaft in order to ablate tissue. The medical instrument may be combined with further medical appliances, in particular with an HF coagulation attachment or a laser coagulation attachment for tissue coagulation.

Claims

1. Medical instrument for tissue ablation by a minimally invasive surgical procedure, comprising a hollow outer shaft, an inner shaft configured as a hollow tube, and a control portion at a proximal end of the medical instrument, in order to position the hollow outer shaft, characterized in that an attachment for mechanical ablation of tissue is arranged directly at a distal end of the inner shaft, wherein the attachment does not protrude beyond an inner profile formed by inner faces of the outer shaft, and wherein the distal end of the attachment protrudes axially beyond the distal end of the hollow outer shaft in order to ablate tissue, and further comprising an elongate receiving element with a cutout or seat for temporarily receiving the attachment for mechanical ablation of tissue, wherein the elongate receiving element is axially adjustable relative to the inner shaft between a deployed position, in which the attachment for mechanical ablation of tissue is temporarily received in the cutout or seat, and a retracted position, in which the attachment for mechanical ablation of tissue protrudes axially beyond the distal end of the hollow outer shaft and is accessible for tissue ablation.

2. Medical instrument according to claim 1, wherein the attachment for mechanical ablation of tissue is connected to the distal end of the inner shaft via a rectilinearly extending portion, and a distal end of the attachment extends at an inclination to the rectilinear portion.

3. Medical instrument according to claim 2, wherein the rectilinear portion is adjoined by an arcuately curved portion or an angled portion at whose distal end an ablation edge is provided.

4. Medical instrument according to claim 3, wherein the curved or angled portion encloses an angle (W) of between 115 and 155.

5. Medical instrument according to claim 3, wherein the ablation edge extends substantially perpendicularly with respect to an underside of the distal end of the angled or arcuately curved portion.

6. Medical instrument according to claim 3, wherein the ablation edge has a central portion which is not curved.

7. Medical instrument according to claim 3, wherein the ablation edge has a central portion which is curved symmetrically.

8. Medical instrument according to claim 1, wherein the axial length of the attachment for tissue ablation lies in the range of between 1 mm and 16 mm.

9. Medical instrument according to claim 1, wherein the attachment for tissue ablation extends radially inward by at most 50% of the internal diameter of the hollow outer shaft.

10. Medical instrument according to claim 1, wherein the attachment for mechanical ablation of tissue is welded onto the distal end of the inner shaft.

11. Medical instrument according to claim 1, wherein the inner shaft is guided longitudinally displaceably in the hollow outer shaft, and the control portion is moreover configured for adjusting the position of the inner shaft relative to the hollow outer shaft.

12. Medical instrument according to claim 11, wherein the control portion is coupled to the inner shaft such that the attachment can be retracted fully into the hollow outer shaft and, in order to permit tissue ablation, at least partially protrudes axially beyond a distal end of the hollow outer shaft.

13. Medical instrument according to claim 11, wherein the inner shaft is guided longitudinally displaceably and rectilinearly in the outer shaft.

14. Medical instrument according to claim 13, wherein an outer profile of the inner shaft is not rotationally symmetrical, being configured in particular as an oval or elliptical outer profile, and wherein an inner profile of the outer shaft is configured corresponding to the outer profile of the inner shaft in order to guide the inner shaft rectilinearly during an axial adjustment.

15. Medical instrument according to claim 14, wherein the coil to which the high-frequency voltage can be applied is axially adjustable relative to the inner shaft.

16. Medical instrument according to claim 1, wherein a coil to which a high-frequency voltage can be applied for tissue coagulation is moreover provided at the distal end of the inner shaft, which coil protrudes axially from the distal end of the inner shaft to a lesser extent than the attachment for mechanical ablation of tissue and is electrically insulated from the inner shaft.

17. Medical instrument according to claim 16, wherein the coil has a connecting portion and an arcuately curved loop at the distal end of the connecting portion, wherein the arcuately curved loop extends substantially parallel to the distal end of the inner shaft.

18. Medical instrument according to claim 1, wherein, seen in a side view of the distal end of the medical instrument, the arc-shaped loop and the distal end of the inner shaft extend at an inclination and toward the proximal end of the hollow inner shaft.

19. Medical instrument according to claim 1, wherein a laser coagulation attachment for tissue coagulation is moreover provided at the distal end of the inner shaft and protrudes axially from the distal end of the inner shaft.

20. Medical instrument according to claim 19, wherein the laser coagulation attachment protrudes from the distal end of the inner shaft less far than the attachment for mechanical ablation of tissue.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments are described below with reference to the attached drawings, in which:

(2) FIG. 1 shows a schematic view of a medical instrument according to a preferred embodiment of the present invention;

(3) FIG. 2a shows a schematic view of the distal region of the medical instrument with a forwardly curved ablation edge according to a preferred embodiment of the present invention;

(4) FIG. 2b shows a schematic view of the distal region of the medical instrument with a forwardly curved ablation edge according to FIG. 1;

(5) FIG. 3a shows a schematic view of a medical instrument with an additional HF coagulation attachment according to a further embodiment of the present invention;

(6) FIG. 3b shows a greatly enlarged perspective view of the distal region of the medical instrument according to FIG. 3a;

(7) FIG. 3c shows a greatly enlarged side view of the distal region of the medical instrument according to FIG. 3a;

(8) FIG. 4a shows a schematic view of a medical instrument with an additional laser coagulation attachment according to a further embodiment of the present invention;

(9) FIG. 4b shows a greatly enlarged perspective view of the distal region of the medical instrument according to FIG. 4a;

(10) FIG. 4c shows a greatly enlarged side view of the distal region of the medical instrument according to FIG. 4a;

(11) FIG. 5a shows a perspective view of a medical instrument according to a further embodiment of the present invention;

(12) FIG. 5b shows the detail according to FIG. 5a in a greatly enlarged perspective view;

(13) FIG. 6a shows a greatly enlarged perspective view of the distal region of a medical instrument according to a further embodiment of the present invention;

(14) FIG. 6b shows the distal region of the medical instrument according to FIG. 6a in a front view;

(15) FIG. 7a shows a greatly enlarged perspective view of the distal region of a medical instrument according to a further embodiment of the present invention; and

(16) FIG. 7b shows the distal region of the medical instrument according to FIG. 7a in a front view.

(17) In the figures, identical reference signs designate identical or substantially equivalent elements or element groups.

DETAILED DESCRIPTION OF THE DRAWINGS

(18) FIG. 1 shows a medical instrument 1 for ablation of tissue, in particular prostate tissue, by a minimally invasive surgical procedure according to a preferred embodiment of the present invention. The medical instrument 1 has substantially three portions: a front or distal portion 10, a control portion 30 located at a rear or proximal end, and a portion which is formed by the shaft 20, extends between the aforementioned portions and is connected to each of these.

(19) The distal end 10 is located at the front end of the shaft 20 and comprises in particular a front opening of the shaft 20. A lug-shaped attachment 100 is arranged on an outer wall of the shaft 20 and serves for tissue ablation.

(20) The shaft 20 has a substantially cylindrical shape and is of a suitable length and size to be inserted into a human body. In an alternative configuration, the shaft can also have an oval shape or other tube shape, as is described below with reference to FIGS. 6a to 7b. In a minimally invasive surgical procedure, the shaft 20 can be used to insert operating instruments into the human body to the site of an operation.

(21) The control portion 30 has substantially two sub-portions, namely a positioning handle portion 31 and an operating handle portion 35, which are connected to each other in a longitudinally movable manner via a transmission rod, for transmission of a force, and a positioning hinge, for the positioning and guiding of the shaft.

(22) At the positioning handle portion 31 located at the distal end of the control portion 30, a positioning handle 32 is in particular arranged which can be rigidly connected to the outer part of the shaft 20. In this way, the positioning handle 32 can be used to insert the medical instrument 1 into the human body and to position it at the operating site.

(23) An eyepiece 36 and an operating handle 37 are arranged on the operating handle portion 35 at the proximal end of the control portion. The operator (i.e. the surgeon) is now able to guide his thumb through the operating handle 37 and the other fingers of one hand through the positioning handle 32 and, by opening and closing his hand, to execute a forward and rearward movement of an inner shaft relative to the hollow outer shaft of the shaft 20, such that the operator is able to operate with just one hand.

(24) With the aid of the operating handle 37, parts of the medical instrument 1 can additionally be rotated.

(25) Consequently, the medical instrument 1 according to this embodiment is thus a resectoscope with an additional attachment 100 for mechanical ablation of tissue. However, the attachment 100 can also be arranged on other similar medical instruments, particularly if they have the movable inner shaft 21 described below.

(26) FIG. 2a shows a detailed view of the distal end 10 of a preferred embodiment of the present invention. An attachment 100 for tissue ablation is arranged at the distal end of an inner shaft 21, which is guided longitudinally displaceably in a hollow outer shaft 22. The aforementioned shaft 20 thus comprises an outer shaft 22 and an inner shaft 21, which is guided movably, in particular longitudinally displaceably, in the outer shaft 22. At its front end, the outer shaft 22 has a multiplicity of orifice holes 25, which are arranged all the way round on the outer wall of the outer shaft 22. A rinsing liquid is guided back through the orifice holes 25.

(27) At its distal end, the inner shaft 21 has a rectangular cutout 141 in which, by way of a fastening portion 140, a correspondingly configured end of an attachment 100 for tissue ablation is fitted, in particular welded. Adjoining this fastening portion 140, a rectilinear portion 130 extends parallel to the center line M of the inner shaft 21 as far as the distal end. The rectilinear portion 130 is adjoined by an angled or curved portion 110, which extends at an inclination relative to the rectilinear portion 130 and whose distal end forms an ablation edge 111 for tissue ablation.

(28) In the embodiment according to FIG. 2a, the ablation edge 111 is rounded symmetrically at the sides. By means of this arrangement, an applied force can be concentrated in a small front region of the ablation edge 111. In particular, the ablation edge 111 can be curved uniformly and symmetrically. This embodiment is thus suitable as a device for precise ablation of tissue. In particular, tissue fragments can be removed in a targeted manner. The whole attachment 100 is accordingly (relatively) long, so as also to guide the ablation edge 111 far forward. For this purpose, the axial length of the attachment 100 for tissue ablation is in the range of between 1 mm and 16 mm, preferably in the range of between 3 mm and 13 mm, and more preferably in the range of between 5 mm and 11 mm.

(29) In addition, a lateral ablation edge 113 can be provided on one of the two sides of the angled portion 110, or two corresponding ablation edges 113 can also be provided on both sides of the angled portion 110.

(30) FIG. 2b shows a detailed view of the distal end 10 of the embodiment according to FIG. 1, in which the shape of the angled portion 110 differs. According to FIG. 2b, the angled portion 110 has an ablation edge 112 which is rectilinear over the greater part and has lateral roundings at the distal end. Thus, a rectilinear ablation edge 112 is provided at the distal end of the angled portion 110. With this embodiment, the operator can apply a force over a wider surface. Therefore, this embodiment is also suitable for wide-reaching ablation of tissue. In this embodiment, the attachment can in particular be relatively short so as to make it controllable.

(31) As in the above illustrative embodiment, at least one corresponding lateral ablation edge 113, with which tissue can likewise be separated, can be provided on the angled portion 110. In the aforementioned embodiments, the transition region between the rectilinear portion 130 and the angled portion 110 can in particular be arcuately curved.

(32) As can be seen from FIGS. 2a and 2b, the curved or angled portion 110 encloses an angle W of between 115 and 155, preferably of between 120 and 150, more preferably of between 130 and 140, with the rectilinear portion 130. The distal end of the inner shaft 21 can enclose a corresponding angle of between 25 and 65, preferably of between 30 and 60 and more preferably of between 40 and 50 with a perpendicular to the center line M. The ablation edge 111, 112 extends substantially perpendicularly with respect to an underside of the distal end of the angled or arcuately curved portion 110, as a result of which tissue can be enucleated by axial adjustment of the medical instrument 1 since, in the axial adjustment, the ablation edge 111, 112 is displaced at an angle of approximately 45 over the tissue that is to be ablated. As can be seen from FIGS. 2a and 2b, the attachment 100 for tissue ablation extends radially inward by at most approximately 50% and preferably by at most approximately 40% of the internal diameter of the hollow outer shaft 22, such that any desired location in the axial continuation of the outer shaft can be reached by rotation of the outer shaft 22 about the center line. The attachment 100 is at all times arranged within an inner profile formed by the inner faces of the outer shaft 22, which in principle may be sufficient for inserting the distal end into a human body without damaging tissue, particularly if the attachment 100 does not protrude too far beyond the distal end of the inner shaft 21.

(33) FIG. 3a shows a medical instrument 1 according to a further embodiment of the present invention, in which an HF coagulation attachment is additionally provided at the distal end 11, the details of which HF coagulation attachment are shown in the greatly enlarged views according to FIGS. 3b and 3c.

(34) As is shown in FIG. 3b, an HF coagulation attachment 200 is moreover provided at the distal end of the inner shaft 21, proximally with respect to the attachment 100 for tissue ablation. The HF coagulation attachment 200 is formed here by a loop-shaped coil which can be subjected to a high-frequency voltage and which has a lower coil portion 210 and a central portion 230, the latter extending at an inclination with respect to the center line of the instrument and being connected via an upper connecting portion 220 to a current supply line 240. A high-frequency voltage can be applied to the HF coagulation attachment 200 via the current supply line. The current supply line 240 is electrically insulated from the inner shaft 21 and the hollow outer shaft 22, which applies also to the HF coagulation attachment 200.

(35) The upper connecting portion 220 and the inclined, central connecting portion 230 both serve as connecting segments for the positioning of the arcuately curved coil portion 210. The actual tissue coagulation is carried out with the arcuately curved coil portion 210, if appropriate additionally with the inclined, central connecting portion 230, by means of a high-frequency voltage being applied to the coil.

(36) FIG. 3c shows the distal end 11 according to FIG. 3b in a side view, where the axial and radial positions of the attachment 100 for tissue ablation are shown in relation to the HF coagulation attachment 200 and to the inner shaft 21. The attachment 100 for tissue ablation forms the outermost distal end of the medical instrument 1. The HF coagulation attachment 200 is proximally offset with respect to the attachment 100 for tissue ablation and, for tissue coagulation, protrudes axially from the inner shaft 21 less far than the attachment 100 for tissue ablation. Thus, the attachment 100 for tissue ablation in some ways protects the HF coagulation attachment 200 from mechanical damage, for example during the axial adjustment of the medical instrument 1 in the body tissue.

(37) The attachment 100 for tissue ablation and the HF coagulation attachment 200 are also spaced apart from each other in the radial direction, in order to reliably provide electrical insulation. The HF coagulation attachment 200 and the attachment 100 for tissue ablation are both inclined downward, pointing toward the instrument center line of the medical instrument. While the HF coagulation attachment 200 slopes with the inclined, central portion 230 at an acute angle with respect to the instrument center line and points toward the distal end of the inner shaft 21, the attachment 100 for tissue ablation extends obliquely forward toward the distal end of the medical instrument. The attachment 100 for tissue ablation expediently does not extend beyond the instrument center line, whereas the HF coagulation attachment 200 expediently extends beyond it, as is shown in FIG. 3c. However, seen in a front view, the HF coagulation attachment 200 is also arranged within the profile of the inner shaft 21.

(38) Of course, according to a preferred embodiment, only the attachment 100 for mechanical ablation of tissue may be provided, and the HF coagulation attachment 200 may be additionally advanced to the operation site if so required, for which purpose the medical instrument has a further instrument port. In this case, the HF coagulation attachment 200 can be arranged rigidly and axially immovably in the inner shaft 21. According to a preferred embodiment, the HF coagulation attachment 200 can if necessary be axially adjusted and/or rotated independently of the inner shaft 21, for example if tissue damage and/or bleeding is established via an optical insert introduced into the inner shaft 21, in order to be positioned exactly at the site of the damage and/or bleeding. To this end, the HF coagulation attachment 200 can be introduced as a separate insert into the inner shaft 21, for example together with the optical insert.

(39) To ensure that the axial adjustment length of the HF coagulation attachment 200 is minimized, the inclined central connecting portion 230 preferably extends parallel to the distal end of the inner shaft 21, as is shown in FIG. 3c.

(40) FIGS. 4a to 4c show a medical instrument 1 according to a further embodiment of the present invention having a laser coagulation attachment 300 in addition to the attachment 100 for tissue ablation.

(41) As is shown in FIG. 4b, a laser coagulation attachment 300 is moreover provided at the distal end of the inner shaft 21, proximally with respect to the attachment 100 for tissue ablation. The laser coagulation attachment 300 in this case likewise protrudes from the inner shaft 21. In relation to the center line of the hollow outer shaft 22, the laser coagulation attachment 300 is arranged diametrically opposite the attachment 100 for mechanical tissue ablation. Thus, the attachment 100 for tissue ablation in some ways protects the laser coagulation attachment 300 from mechanical damage, for example during the axial adjustment of the medical instrument 1 in the body tissue. The laser coagulation attachment 300 can in particular be formed by the distal end of an optical fiber, which is routed to the distal end of the medical instrument 1 in order to coagulate tissue. For this purpose, the laser coagulation attachment 300 can in principle also be arranged inside the inner shaft 21, at the distal end thereof.

(42) Of course, according to a preferred embodiment, only the attachment 100 for mechanical ablation of tissue may be provided, and the laser coagulation attachment 300 may be additionally advanced to the operation site if so required, for which purpose the medical instrument has a further instrument port. In this case, the laser coagulation attachment 300 can be arranged rigidly and axially immovably in the inner shaft 21. According to a preferred embodiment, the laser coagulation attachment 300 can if necessary be axially adjusted and/or rotated independently of the inner shaft 21, for example if tissue damage and/or bleeding is established via an optical insert introduced into the inner shaft 21, in order to be positioned exactly at the site of the damage and/or bleeding. To this end, the laser coagulation attachment 300 can be introduced as a separate insert into the inner shaft 21, for example together with the optical insert.

(43) FIGS. 5a and 5b show a medical instrument 1 according to a further embodiment, in which the attachment 100 for tissue ablation can additionally be covered in order to prevent undesired tissue damage, for example during the insertion of the instrument attachment into human tissue, for example into a urethra for procedures on prostate tissue.

(44) As is shown in FIG. 5b, a receiving element or closure piece 150 is provided at the distal end of the inner shaft 21 and can be axially adjusted relative to the inner shaft 21, as is indicated by the double arrow. The distal end of the receiving element 150 is dome-shaped. A cutout 151 is formed therein, corresponding to the shape of the attachment 100 for tissue ablation. In the deployed position according to FIG. 5a, the attachment 100 for tissue ablation is received in the cutout 151 at any rate to such an extent that its ablation edges are covered, in particular at the portion 111 as shown in FIG. 5b, as a result of which undesired tissue damage can be prevented, for example during the insertion of the instrument attachment into human tissue. A gentle insertion of the instrument attachment into human tissue is supported by the dome shape of the distal end of the receiving element 150.

(45) The receiving element 150 can be retracted axially into the inner shaft 21 to such an extent that the attachment 100 for tissue ablation is exposed in order to ablate tissue, for example in order to enucleate human prostate tissue by means of the ablation edge 111, by axial adjustment of the inner shaft 21 or of the entire instrument attachment. The receiving element 150 can also be configured such that an HF coagulation attachment or a laser coagulation attachment is exposed in the retracted position, in order also to be able to coagulate tissue if necessary.

(46) The receiving element 150 can in particular be configured as an obturator which completely closes the distal end of the instrument 1 during insertion into human tissue and thus sufficiently covers or receives the attachment 100 for tissue ablation but which can thereafter also be withdrawn completely from the hollow inner shaft 21, such that, for example, an optical insert, a coagulation insert, as described above, or other instruments can then be introduced into the hollow inner shaft 21.

(47) For precise positioning of the instrument attachment, the inner shaft 21 is preferably guided rectilinearly relative to the outer shaft 22, i.e., during the axial adjustment of the inner shaft 21 relative to the outer shaft 22, the inner shaft 21 does not rotate in an uncontrolled manner. This can be achieved in principle by guide structures on the inner shaft 21 being in form-fit engagement with correspondingly shaped guide structures on the outer shaft 22, for example by the engagement of axially extending guide rails or guide strips. However, such rectilinear guiding is preferably obtained automatically through the profile of inner shaft 21 and outer shaft 22 itself, as is shown in FIGS. 6a to 7b.

(48) According to FIG. 6b, the inner shaft 21 has an elliptic or oval profile, which is defined by a large semi-axis a and a small semi-axis b. The inner profile of the outer shaft (not shown) is designed corresponding to this. During the axial adjustment of the inner shaft 21 relative to the outer shaft, a rotation of the inner shaft is thereby reliably prevented.

(49) In the illustrative embodiment according to FIGS. 7a and 7b, the orientations of the large semi-axis a and of the small semi-axis b are swapped around compared to the illustrative embodiment in FIGS. 6a and 6b, otherwise with the same position and orientation of the attachment 100 for tissue ablation.

(50) The handling of the above-described medical instrument 1 during a surgical procedure is described below.

(51) First of all, a medical instrument 1 is made available as described above with an attachment 100 for mechanical ablation of tissue, which attachment 100 is arranged directly at the distal end 10 of the inner shaft 21, wherein the attachment 100 is arranged within an inner profile formed by the inner faces of the outer shaft 22 and, in order to permit tissue ablation, the distal end of the inner shaft 21 protrudes axially beyond the distal end of the hollow outer shaft 22.

(52) The shaft 20 is then inserted into the human tissue, in particular into a urethra, such that the attachment 100 for tissue ablation is positioned near the prostate. During the insertion, the attachment 100 for tissue ablation is sufficiently covered by or received within a receiving element 150, in particular an obturator. Thereafter, the receiving element 150 or the obturator is axially retracted to such an extent that the attachment 100 for tissue ablation is sufficiently exposed. By axial adjustment of the shaft 20, preferably of the inner shaft 21 together with the tissue ablation attachment 100 provided thereon, relative to the hollow outer shaft 22, the ablation edge of the attachment 100 is moved relative to the tissue, as a result of which a peeling or enucleating movement is executed for peeling off or enucleating tissue, in particular prostate tissue.

(53) By the retraction or deployment of the receiving element 150 or obturator, an HF or laser coagulation attachment as described above can be sufficiently exposed in order to be able to perform tissue coagulation. For visual monitoring and control, a suitable lens system can in particular be guided through the hollow inner shaft 21 to the operating site.

(54) After tissue has been ablated, the shaft 20 is withdrawn again from the human tissue in reverse sequence. Here, the attachment 100 for tissue ablation is advantageously once again sufficiently covered by or received in a receiving element 150, in particular an obturator, in order to prevent undesired tissue damage.

LIST OF REFERENCE SIGNS

(55) 1 medical instrument

(56) 10 distal end

(57) 11 distal end with HF coagulation attachment

(58) 12 distal end with laser coagulation attachment

(59) 20 shaft

(60) 21 inner shaft

(61) 22 outer shaft

(62) 23 receiving notch

(63) 25 orifice holes

(64) 30 control portion

(65) 31 positioning handle portion

(66) 32 positioning handle

(67) 35 operating handle portion

(68) 36 eyepiece

(69) 37 operating handle

(70) 100 attachment for tissue ablation

(71) 110 angled portion/arcuately curved portion

(72) 111 symmetrically curved ablation edge

(73) 112 (substantially) non-curved ablation edge

(74) 113 lateral ablation edges

(75) 120 angled separating or bending line

(76) 130 rectilinearly extending portion

(77) 140 fastening portion

(78) 141 cutout

(79) 150 obturator/receiving element

(80) 151 cutout/seat

(81) 200 HF coagulation attachment

(82) 210 lower end of HF coagulation coil

(83) 220 upper connecting portion

(84) 230 inclined/central portion of HF coagulation coil

(85) 240 current supply line

(86) 300 laser coagulation attachment

(87) M instrument center line

(88) W angle