CRIOSSONDA

Abstract

The present invention relates to an inventive cryoprobe, comprising a head (20) to which cryofluid is supplied through a capillary tube (22a). A hose (18) serves for removing the cryofluid, into which the capillary tube (22a) extends through the lumen (21) thereof. The capillary tube (22a) comprises a flexible portion (25) formed by a pulling element (26). In this way, a cryoprobe 11, which can be easily handled, is obtained, which can be easily and very widely flexed, and still transmits the traction forces necessary for sample extraction.

Description

[001] The present invention relates to a cryoprobe, which is particularly suitable for inserting a tissue probe into highly branched vessel systems, such as for inserting a tissue sample into the upper urinary tract, especially into the renal calyx system.

[002] Cryoprobes for tissue biopsy are, in principle, known. For example, DE 10 2011 000 004 B4 describes a flexible cryoprobe, which has a hose comprising a lumen, and at the distal end of which a metal head, in the shape of a cup, is disposed, whose diameter corresponds to the diameter of the hose, and which comprises a rounded bottom at its distal end. A capillary tube is disposed in the hose, which extends over the entire length of the hose, and ends inside the head. The capillary tube serves to introduce cryofluid into the head, for its cooling.

[003] Similar cryoprobes are known from EP 2 257 235 B1, EP 2 170 197 as well as EP 2 114 276 B1.

[004] During tissue sampling, the distal end of the probe is cooled to the point where the tissue to be sampled freezes up to the probe head. The tissue must then be separated from the unfrozen tissue, i.e., pulled out and guided out of the patient's lumen along with the probe. In the branched lumen, it additionally depends on being able to flex the probe with a small bending radius, where a bend of significantly more than 90° may be desired.

[005] Starting from there, the objective of the invention is to provide a cryoscape, which is suitable for such required use.

[006] This objective is solved by a cryosonde according to claim 1. Petition 870260000013, dated 02 / 01 / 2026, page 5 / 45 2 / 13

[007] The inventive cryoprobe comprises a hose, which is provided with a head at its end, which serves for tissue sampling. A capillary tube extends through the lumen of the hose in order to supply the head with a cryofluid. The capillary tube is a conductor, the pressure resistance of which matches that of the cryofluid used.

[008] In addition, a wire puller is arranged in the lumen of the hose, which serves to transmit traction forces between the head and the proximal end of the cryoprobe. This makes it possible to use a capillary tube, which is highly flexible in one or multiple sections, or as a whole, and on the other hand, also to transmit the necessary traction forces from the proximal end in the head in order to pull the frozen tissue to the head from the unfrozen tissue and thus to pull a tissue probe.

[009] The inventive cryosonde is flexible, such that it can be bent with the application of low force at large angles, and it combines this with high tensile strength.

[0010] The cryoprobe can be configured in a filigree manner, and can have an outer diameter of less than 1.2 mm, so that it can also be used in very narrow endoscopes. Bending angles, i.e., a bend of more than 150°, preferably more than 160°, can be achieved with the inventive concept. By doing so, due to the high flexibility of the cryoprobe, the angulation can be achieved with little force, which must be applied by the endoscope.

[0011] Preferably, the capillary tube is manufactured from a material in which an increase or decrease in its tensile strength can be achieved through induction, for example, heat treatment. It is further preferred that the capillary tube be treated, or processed, in such a way that it comprises Petition 870260000013, dated 02 / 01 / 2026, page 6 / 45 3 / 13 minus a portion in which the tensile strength of the material, and thus also the bending strength of the capillary tube, is reduced compared to the tensile strength, and thus also the bending strength of the remaining capillary tube. This portion with reduced tensile strength and reduced bending strength is preferably located in the distal portion that is angled by the endoscope in use. The capillary tube consists, for example, of steel or another material that has tensile strength and is resistant to bending. In the portion where the probe must be bent, with a small bending radius, the steel may have a mild annealing, for example. Alternatively, it is possible to form this portion from a piece of capillary tube made of another material, for example plastic, copper, or similar.

[0012] The wire puller serves to transmit traction forces from the proximal end to the probe head. It is arranged to enlarge, at least, the soft portion of the capillary tube. For this purpose, the wire puller is connected to the instrument head at the distal end in a traction-proof manner. For this, the wire puller can be directly coupled to the head, or also to a traction-proof portion of the capillary tube, which is in turn connected to the head.

[0013] The distal end of the wire puller may lead to the distal end of the probe or, as preferred, may be connected to the tensile-resistant portion of the capillary tube. In this way, the wire puller extends at least the portion of the capillary that has reduced bending resistance.

[0014] The wire puller can be connected to the capillary tube in a tensile-proof manner, for example, by means of solder joints, solder splices or other types of connection. Preferably, the wire puller is placed parallel to the tube. Petition 870260000013, dated 02 / 01 / 2026, page 7 / 45 4 / 13 capillary, that is, the connection points between the wire puller and the capillary tube are, in relation to the capillary cross-section, arranged in the same angular position. By doing so, free angular movement of the probe is possible in all radial directions.

[0015] Although it is basically possible to form the flexible angled portion of the capillary tube with multiple wire pullers, it is preferred to provide only one wire puller. By doing so, good mobility of the cryoprobe is obtained in all directions.

[0016] The diameter of the wire puller is preferably smaller than the difference between the diameter of the lumen and the outer diameter of the capillary tube. By doing so, the capillary tube, as well as the wire puller, remains mobile in the radial and circumferential direction within the lumen. During probe bending, in which the wire puller is positioned radially outward relative to the bending radius, at least the central portion of the wire puller can move within the lumen and reach the opposite side of the lumen. By doing so, in this case, the wire puller also does not oppose the resistance to bending.

[0017] Additional details and advantageous embodiments of the invention are derived from the drawings, description, and claims. The drawings show:

[0018] Figure 1 is an endoscope with an inventive probe, in the schematic perspective illustration,

[0019] Figure 2 is the distal end of the endoscope with the probe in the flexed position,

[0020] Figure 3 is the distal end of the probe, in a schematic longitudinal sectional illustration,

[0021] Figure 4 is a portion of the distal end of the probe, in a schematic longitudinal sectional illustration,

[0022] Figures 5 and 6 are schematic illustrations of the probe, according to figure 4, cut along lines VV or VI-VI. Petition 870260000013, dated 02 / 01 / 2026, p. 8 / 45 5 / 13 respectively,

[0023] Figure 7 is an alternative version of the instrument,

[0024] Figure 8 is the instrument, according to figure 7, in cross-section.

[0025] Figure 1 illustrates an endoscope 10, into which a cryoprobe 11 is inserted. It extends from the proximal end 12 of the endoscope to the distal end 14, which is ground by means of the operating elements 13. The endoscope 10 comprises a longitudinal shaft 15, in which the cryoprobe 11 is guided through a channel therein. The distal end 16 of the cryoprobe 11 can be retracted within the shaft 15, or displaced outside the shaft 15. The outer diameter of the cryoprobe 11 is preferably slightly smaller than the inner diameter of the channel provided in the shaft 15.

[0026] The operating elements 13 serve to control the distal end 14 of the shaft 15, particularly to selectively bend it in relation to the axial direction 17 which, as shown in figure 2, extends along the shaft 15. The angle α that can be achieved in this way is preferably greater than 90°, and even more preferably greater than 140°, and in the preferred case greater than 160°. The bending radius is thus less than 20 mm, preferably less than 15 mm, in the case of an outer diameter of the shaft 15 less than 3.3 mm.

[0027] In Figure 3, the cryosonde 11 is illustrated individually, in the area of ​​its distal end 16. It comprises a hose 18, at the distal end 19, in which a head 20 is firmly coupled to the fluid. The hose 18 surrounds a lumen 21, and is at least highly flexible, configured at least in the portion adjacent to the head 20. The head 20 is schematically illustrated in Figure 3. It preferably comprises an outer diameter, which corresponds to the outer diameter of the hose 18. In Petition 870260000013, dated 02 / 01 / 2026, page 9 / 45 6 / 13 at its distal end, the head 20 is closed through a planar, curved or otherwise configured bottom.

[0028] In addition, the hose is supplied with a fluid channel. 22, which serves to guide the coolant to, or into, the head 20. The fluid channel 22 may be formed by a capillary tube 22a, which extends through the lumen 21 of the hose 18. The capillary tube 22a may be connected to the head 20, at its lateral end of the head 23. The connection may be made by means of connecting elements not further illustrated or, as is obvious from figure 3, directly by a solder joint 24, a spot weld or similar.

[0029] The capillary tube 22a may be open at its distal end, or it may be provided with a nozzle. The nozzle may also be formed in the capillary tube. Preferably, the capillary tube 22a consists of a tensile strength-resistant steel, for example X2CrNiMo 1.4404 or X2CrNiMo 1.4401. Preferably, the material of the capillary tube 22a has a tensile strength of more than 900 N / mm2. The capillary tube 22a serves to insert cryofluid into the internal space of the head 20 for cooling, as well as for transmitting tensile forces during biopsy sampling.

[0030] The capillary tube 22a, however, is not continuously configured in a tensile-proof manner. In its portion 25, which is individually illustrated in Figure 4, the capillary tube 22a is reduced in its tensile strength and, thus, also in its bending strength, through a heat treatment, for example, by softening. Preferably, the tensile strength in this portion is less than 700 N / mm². By doing so, the capillary tube 22a, in portion 25, is also able to withstand the pressure load caused by the cryofluid. In addition, it is flexible, such that the cryoprobe can be bent with a small radius. Petition 870260000013, dated 02 / 01 / 2026, page 10 / 45 7 / 13 of bending, as indicated in Figure 2. However, portion 25 does not have sufficient tensile strength to transmit the tensile forces necessary for sampling for biopsy.

[0031] Portion 25 is connected via a pulling element 26, which is a wire puller 27 in the present embodiment. It consists of a tensile-resistant material that transmits the tensile forces necessary for biopsy sampling within its elastic stress, in connection with the capillary tube 22a. The wire puller 27 is connected at its ends, via solder connections 28, 29, for example, the solder portions, to the capillary tube 22a, which also transmits tensile forces within its elastic stress. However, the pulling element 26 maintains tensile stresses for a large extent, outside the softened location of the capillary tube 22a. Measured along the length of the capillary tube 22a, the distance of the solder portions 28, 29 from each other is, however, greater than the length of the portion, which is reduced in its tensile strength and bending strength, compared to the remaining capillary tube 22a.

[0032] This is illustrated in figures 5 and 6, which also make it clear that the soldering connections 28, 29, at the two ends of the wire puller 27, are arranged in the same radial position as the capillary tube 22a. Between the two soldering connections 28, 29, the wire puller 27 is in unstressed (loose) contact, and transversely movable with the capillary tube 22a, or extends a short distance for this purpose, as indicated in figure 3. In this orientation, the wire puller 27 is largely oriented parallel to the capillary tube 22a.

[0033] Through biopsy sampling, the cryoprobe 11 is inserted into a patient lumen, with the endoscope 10, and the distal end 16 is placed in contact with the patient tissue to be sampled, or is penetrated into that place. The insertion of Petition 870260000013, dated 02 / 01 / 2026, page 11 / 45 8 / 13 cryoprobe 11 in endoscope 10, is particularly simplified by the fact that cryoprobe 11 is rigid – corresponding to the rigidity of capillary tube 22a – almost along its entire length, that is, more rigid than portion 25. The instrument is, however, flexible as a whole. Only the portion of the length defined by portion 25 is less than the bending resistance and easier to bend.

[0034] The endoscope can be flexed at an angle of more than 160° if necessary, as illustrated in Figure 2. By doing so, the endoscope 10 and the cryoprobe 11 can be inserted into narrow and highly branched vessels of a patient. In this way, the cryoprobe 11 is sized in such a way that portion 25 is located in the region of the endoscope's flexing point. The length of portion 25 is thus preferably long enough for flexion to be possible, whether the head 20 is still positioned at the opening of the distal end 14 of the shaft 15, or whether the head 20, as shown in Figures 1 and 2, is displaced from the shaft 15. Preferably, the length of portion 25 is more than a few centimeters, preferably more than 10 cm. The bending of the endoscope 10 is only slightly impeded by the stiffness of the capillary tube 22a, because portion 25 is configured in a correspondingly flexible manner.The hose 18 is also made of a flexible material, preferably plastic, preferably PEEK or PA, which only slightly impedes the bending of the endoscope. The wire puller 27, the bending force proof, also does not offer noticeable resistance to bending due to its small diameter. The diameter of the pulling element 26, particularly the wire puller 27, is smaller than the diameter of the capillary tube 22a.

[0035] For sampling, the 20 head is applied with the Petition 870260000013, dated 02 / 01 / 2026, page 12 / 45 9 / 13 cryofluid on the inside, which is inserted into the head 20 through the capillary tube 22a. Due to the cooling of the head 20, portions of the tissue to be sampled freeze onto the head 20.

[0036] For sampling, the cryoprobe 11 is moved in the proximal direction. By doing so, the frozen tissue for the head 20 is pulled from the remaining tissue. The force required for this is first transmitted through the capillary tube 22a to the solder connection 29, and then through the wire puller 27 to the solder connection 28. From there, the force flows through the capillary tube 22a to the head 20. The wire puller 27 thus forms the bending force-proof portion 25 with respect to force transmission.

[0037] It is also possible to connect the pull element 26 only at the connection point 28, with the capillary tube 22a, and guide it through the entire length of the cryoprobe 11 to its proximal end. In this case, the capillary tube 22a can be configured completely, from the proximal end to the connection point 28, or in one or more portions of a metallic or non-metallic material that is more flexible than the capillary tube 22a that remains.

[0038] It is also possible to connect the distal end of the pulling element 26 directly to the head 20, while the proximal end of the pulling element is connected via the solder connection 29, or another connection with the capillary tube 22a. In this case, the capillary tube 22a can be configured originating from the solder connection 29, or from another connection point, to the distal end completely or partially, from a material that is more flexible and less resistant to the tensile force of the remaining capillary tube 22a.

[0039] It is also possible that the capillary tube 22a is formed, completely or in one or more portions, of a flexible material, Petition 870260000013, dated 02 / 01 / 2026, page 13 / 45 10 / 13 resistant to non-bending, and non-tensile torque proof. In this case, the pulling element 26 is coupled with its distal end to the head 20, or an element connected to it, since its proximal end is connected to the proximal end of the cryosonde 11.

[0040] It is indicated that instead of a wire puller 27, a tensile-resistant metal strip, wire bundle, rope, tube or similar may also be used as pulling elements 26. Furthermore, instead of a metallic pulling element 26, a non-metallic pulling element may be used, the ends of which are also connected with the capillary tube 22a in order to form at least portion 25, or longer portions, of the capillary tube 22a or the entire capillary tube 22a. The pulling element 26 may also be configured as a monofilament, or as a rope of non-metallic material, or of a composite material, for example, a fiber composite material.

[0041] In a preferred embodiment, the capillary tube is only flexible in its portion 25. Portion 25 typically has a length of 10 cm to 30 cm, and is limited to a length obtained by summing the length of the actively flexible endoscope portion and the maximum extension length of the cryoprobe 11, outside the endoscope 10, during use. The length of the pulling element 26 is dimensioned in such a way that at least the entire length of the flexible portion 25 of the capillary tube 22a is formed. By doing so, the pulling element 26 is fixed, approximately, in a force transmission manner to the capillary tube 22a, and distally to the head 20, or to the capillary tube 22a if the flexible portion does not extend to that location. Because the capillary tube 22a is soft only in portion 25, and rigid thereafter, the cryoprobe 11 can be manipulated in the usual manner. It is also ensured that the Petition 870260000013, dated 02 / 01 / 2026, page 14 / 45 11 / 13 pulling element 26 limits the cross-section of the lumen 21 only along a small length of the hose 18, and thus does not noticeably increase the resistance to flow at that location.

[0042] Figure 7 illustrates a modified embodiment of instrument 11, to which the above description applies in this manner, based on the reference numerals introduced. However, instrument 11, according to Figure 7, is modified in comparison with instrument 11, according to Figures 3 to 6. Its hose 18 is configured with two lumens, due to the fact that the fluid channel 22 is arranged parallel to the lumen 21. Figure 8 illustrates, in an enlarged cross-section, an exemplary channel arrangement. While the fluid channel 22 may comprise, for example, a circular cross-section, the cross-section of the lumen 21 may be configured in a manner deviated from the circular shape, as illustrated in Figure 8, or it may also be circular.

[0043] In the embodiment of instrument 11, according to figures 7 and 8, again a pulling element 26 is determined for the hose 28, for example, in the form of a wire puller 27 that can extend, for example, through the lumen 21, and that can be connected with its distal end to the head 20, in a welding joint 24. The wire puller 27 can extend to the proximal end of the hose 18 in order to transmit pulling forces from there to the head 20.

[0044] Additional elements of the tensile strength test may be considered as pulling elements 26, such as tapes, profile wires, wire bundles, ropes and the like. The material of the pulling element 26 may be a metal or also a non-metal, such as carbon fibers, aramid fibers or the Petition 870260000013, dated 02 / 01 / 2026, page 15 / 45 12 / 13 similar. As an alternative, the pulling element 26 can be embedded in the wall of the hose 18. However, preferably, the pulling element 26 is, in all embodiments, according to figures 3 to 8, arranged in a longitudinal direction of the instrument 11, wherein the pulling element 26 is preferably arranged in a straight orientation. Preferably, the pulling element does not encircle the lumen 21, nor the fluid channel 22, but is arranged substantially parallel to it.

[0045] An inventive cryoprobe comprises a head 20, to which cryofluid is supplied through a capillary tube 22a. A hose 18 serves for the removal of cryofluid, into which the capillary tube 22a extends, through the lumen 21 parallel to it. The capillary tube 22a comprises a flexible portion 25, which is formed by a pulling element 26. In this way, a cryoprobe 11, which can be handled, is obtained, which can be easily and very widely flexed, and still transmits the traction forces necessary for the extraction of the sample. List of reference signs: 10 endoscope 11 cryoprobe 12 proximal end of endoscope 10 13 operating element 14 distal end of endoscope 10 15 axis 16 distal end of cryoprobe 11 17 longitudinal direction of axis 15 α angle 18 hose 19 distal end 18 20 Kopf Petition 870260000013, dated 02 / 01 / 2026, p. 16 / 45 13 / 13 21 hose lumen 18 22 fluid channel 22a capillary tube 23 capillary tube head side end 22a 24 solder joint 25 portion 26 pull element 27 wire puller 28, 29 solder connection

Claims

CLAIMS 1. Cryoprobe (11), particularly for tissue sampling in the upper urinary tract of a patient, having a hose (18) comprising a lumen (21), and which is provided with a head (20) at its distal end (19), a fluid channel (22) which is disposed at its distal end (23), in a manner communicating with the head (20), at least one pulling element (26) which is disposed in the hose (18), and is disposed in a manner extending over at least a portion of the length of the hose (18), characterized in that the fluid channel (22) is formed by a capillary tube (22a), which extends through the lumen (21), and is disposed in the lumen (21) so as to transmit tensile forces, wherein the capillary tube (22a) consists of a material, in which the tensile strength can be increased or decreased by means of a treatment, wherein the capillary tube (22a) comprises at least one portion (25), in which the tensile strength,and / or the flexibility of the material is reduced, compared with the tensile strength of the capillary tube (22a) remaining, wherein the capillary tube (22a) consists of steel, and portion (25) is smoothed.

2. Cryosonde, according to claim 1, characterized in that the pulling element (26) is arranged to encompass at least a portion (25) of the capillary tube (22a), preferably without pre-tension.

3. Cryosonde, according to any of claims 1 or 2, characterized in that the pulling element (26) comprises two ends, wherein at least one of which is connected with the capillary tube (22a).

4. Cryosonde, according to claim 3, characterized in that both ends of the pulling element (26) are connected, preferably welded, to the capillary tube (22a), such that the pulling element (26) extends the portion (25).

5. Cryosonde, according to claim 4, characterized in that the ends of the pulling element (26) are connected with the capillary tube (22a), preferably through external solder joints (28, 29) of portion (25).

6. Cryosonde, according to claim 5, characterized in that the solder joints (28, 29) are oriented longitudinally in the capillary tube (22a).

7. Cryosonde, according to any one of claims 5 or 6, characterized in that the probe joints (28, 29) are arranged in the same angular position, with reference to the cross-sectional capillary cut.

8. Cryosonde, according to any of the preceding claims, characterized in that the pulling element (26) is formed from one of multiple high-strength steel wires, particularly stainless steel, having a tensile strength of >900 N / mm2.

9. Cryosonde, according to any of the preceding claims, characterized in that the pulling element (26) is arranged broadly parallel to the capillary tube (22a).

10. Cryosonde, according to any of the preceding claims, characterized in that only one pulling element (26) is disposed in the lumen (21).

11. Cryosonde, according to any of the preceding claims, characterized in that the diameter of the pulling element (26) is smaller than the difference between the diameter of the lumen (21) and the outer diameter of the capillary tube (22a).

12. Cryosonde, according to claim 1, characterized in that the hose (18) is configured having two lumens, the two lumens being the lumen (21) and the fluid channel (22), wherein the pulling element (26) extends through the lumen (21), or the fluid channel (22), or through the wall of the hose (18).

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