EP3215032A1

EP3215032A1 - Medical snare instrument

Info

Publication number: EP3215032A1
Application number: EP15790119.0A
Authority: EP
Inventors: Bernhard Uihlein
Original assignee: EPflex Feinwerktechnik GmbH
Current assignee: EPflex Feinwerktechnik GmbH
Priority date: 2014-11-05
Filing date: 2015-11-03
Publication date: 2017-09-13
Also published as: DE102014222600A1; WO2016071320A1; CN107072680A; US20180271546A1

Abstract

The invention relates to a medical snare instrument comprising a snare basket (1) which is designed to be relatively moveable in the axial direction with respect to an instrument tube between an unfolded state, in which said basket is moved distally forward out of the instrument tube, and a folded state, in which said basket is moved proximally back into the instrument tube, and comprising a control tube which can be accommodated in the instrument tube by relative movement in the axial direction with respect to the same, which control tube is coupled in a distal end region to a proximal end region of the snare basket. According to the invention, the snare basket has a distal enclosing section (A₁) which is more close-meshed than a proximal connecting section (B₁), and/or said snare basket has a proximal expanding section which is more close-meshed than a distal connecting section, and/or said snare basket is constructed from wire segments which are substantially rectangular in cross section and which extend at least in one basket subregion in the case of the unfolded snare basket with the non-tangential broad side of the wire. The use is, for example, in endsoscopic technology.

Description

Medical safety wire instrument

The invention relates to a medical catching wire instrument with a safety wire basket, which is adapted to be relatively movable axially between a folded out of an instrument tube forward, unfolded state and a proximal in the instrument tube into the rear, folded state axially relative to the instrument tube, and with a control tube which can be accommodated in the instrument tube relative to the latter in a relatively movable manner and which is coupled in a distal end region to a proximal end region of the safety wire basket. More particularly, the invention relates to such a so-called over-the-wire type of entangling wire instrument in which the catcher basket and the control tube are adapted to be axially slidably slidable onto a guidewire.

A safety wire instrument of this type is disclosed in published patent application WO 93/19679 A1 and is offered by Teleflex Medical as a percutaneous thrombolytic instrument for the removal of thrombi. In this known instrument, the safety wire basket and the control tube are adapted to be rotated during operation by an external drive of an associated catheter system to fragment thrombotic material in an affected tissue channel. For this purpose, the control tube forms a flexible drive shaft, whose proximal end is coupled to the external drive. The safety wire basket is formed from a plurality of individual pieces of wire, which extend continuously from a proximal to a distal end of the safety wire basket and are respectively held there, wherein they can optionally have a twisted around a longitudinal axis of the basket course. Further optionally, the basket-forming wire pieces may be provided with a cutting edge to increase the fragmentation effect of the rotating wire basket.

The patent DE 10 2004 055 375 B4 discloses a safety wire basket, which is cut in one piece from a piece of pipe.

The published patent application WO 2014/086917 A1 discloses a medical catching wire instrument with a special material combination of safety wire basket, this receiving instrument hose and a guided in the latter, rod-shaped control. In this case, the safety wire basket can be cut in one piece from a piece of pipe. Furthermore, the instrument can be provided with a so-called MR marker in order to make it visible in magnetic resonance applications (MR applications), in particular in nuclear magnetic resonance applications (NMR applications) or magnetic resonance tomography (MRI) applications. Applications). The MR marker can be located on the safety wire basket and / or on the control element and / or on the instrument tube, in each case along the entire length of the relevant instrument component or only in sections.

The invention is based on the technical problem of providing a medical Fang- wire instrument of the type mentioned above, which is further improved compared to the above-described prior art and in particular with good fishing properties and / or with relatively low production costs can be realized.

The invention solves this problem by providing a medical safety wire instrument having the features of claim 1. Advantageous further developments are specified in the subclaims, the wording of which is hereby incorporated by reference into the description.

According to one aspect of the invention, the safety wire basket has a distal containment portion that is more close-meshed than a proximal adjacent portion. With this measure, the wire basket is divided into an enclosure section, which, by virtue of its tightness, allows secure trapping and holding of trapped particles, and a section adjoining it proximally, which facilitates the trapping of particles due to its larger opening width. According to a further aspect of the invention, the safety wire basket has a proximal spreading portion which is more narrow-meshed than a distally adjacent portion. Such a spreading section may favor the Auffaltverhalten the safety wire basket and contribute to an advantageous shaping of the wire basket in the unfolded state. In accordance with yet another aspect of the invention, the catching wire basket is constructed from wire sections which are essentially rectangular in cross-section and extend at least in a basket portion with non-tangential wire broad side when the catching wire basket is unfolded. This means that the wire sections in this area have a narrow side or with one of their edges pointing radially outwards and not with their broad side, whereby e.g. the removal of material, such as thrombosis material, which adheres to an inner wall of a body tissue passage can be facilitated.

In a development of the invention, the distal enclosure section is more closely meshed than the proximal expansion section. In the more closely confined enclosure section, trapped particles can be well retained, and the expansion section is useful for achieving a corresponding desired shape of the wire basket in the unfolded state. In a further development of the invention, the catching wire basket between the enclosure section and the expansion section has a catching section which is wider mesh than the enclosure section and the expansion section. This basket design further optimizes the properties of the safety wire basket for its ability to safely capture and hold particles such as thrombogenic material particles to be removed or removed.

In a further development of the invention, the control tube has an inner diameter substantially corresponding to an outer diameter of the guide wire, such that in its position pushed onto the guide wire, it bears axially against the guide wire in an axially movable manner against the latter. The control tube can be performed virtually full surface on the guide wire when it is pushed onto the guide wire and is moved along the same.

In one embodiment of the invention, the catching wire basket is cut in one piece from a piece of pipe. This allows for relatively low cost manufacturing, and the wire basket can be realized with very advantageous configurations to achieve optimum particle trapping and retention performance.

In a further development of the invention, the safety wire basket ends proximally with a rear end sleeve, which is fixed in overlapping manner on a distal end region of the control tube. This represents a very functionally reliable and reliable coupling of the safety wire basket to the control hose. If the safety wire basket is cut from a pipe section, the end sleeve can be formed by a pipe stub of the pipe section, which keeps production costs low.

In a further development of the invention, the safety wire basket ends distally with a front end sleeve, which is fixed in overlapping manner on a proximal end region of a guide tube sleeve. Again, the front end sleeve may be formed by a pipe stub of the pipe section when the safety wire basket is cut from a pipe section. The guide tube sleeve may assist the guide of the safety wire basket in its relative axial movement relative to the guide wire when the safety wire basket is slid onto the guide wire for use.

In one development of the invention, the instrument tube and / or the control tube and / or the safety wire basket and / or the guide tube sleeve is at least partially provided with an MR marker. As a result, the MR visibility of the instrument in a desired area can be specifically improved. In a further development of the invention, the safety wire instrument comprises a guide wire, on which the safety wire basket and the control tube are axially movable pushed and thus completes the instrument.

Advantageous embodiments of the invention are illustrated in the drawings and will be described below. Hereby show:

Fig. 1 is a schematic side view of a safety wire basket for a medical

Over-the-wire type entanglement wire instrument,

Fig. 2 is a view corresponding to Fig. 1 for a safety wire basket with modified basket shape, a schematic Rohrabwicklungsansicht a pipe section pattern for producing the safety wire basket of Fig. 1, a view corresponding to FIG. 3 for the production of the safety wire basket of Fig. 2, a partial cross-sectional view along a line VV of Fig. 1, a schematic sectional view of a thrombosed tissue channel, the view of Fig. 6 with a pushed through the thrombosis occupied area guide wire, the view of Fig. 7 with the safety wire basket of Fig. 1 slid onto the guide wire and deployed in a position behind the thrombosis-occupied area, a schematic longitudinal sectional view of a connecting region of the safety wire basket and the control tube pushed onto it proximal to an end sleeve,

10 is a cross-sectional view along a line XX of FIG. 9, 1 is the view of FIG. 9 for a variant with a control tube inserted proximally into an end sleeve of the safety wire basket;

12 is a cross-sectional view along a line Xl l-Xl l of Fig. 1 1,

13 shows a detail longitudinal section view of a distal safety wire basket end region, FIG. 14 shows the view of FIG. 13 for a variant with a guide tube sleeve pushed distally,

15 is the view of FIG. 13 for a variant with distally inserted guide tube sleeve,

16 is a schematic longitudinal sectional view of a distal part of an MR-visible

Guidewire with deferred safety wire basket control tube unit,

17 is a schematic longitudinal sectional view of a distal part of a safety cage basket.

Control tube unit with MR markers arranged proximally and distally of the wire basket,

18 shows the view of FIG. 17 for a variant with MR markers applied to the wire pieces of the wire basket and FIG

19 to 24 are schematic side views of further usable catching wire baskets of different design.

A catching wire basket 1 shown schematically in the unfolded state in FIG. 1 is constructed from a wire structure 2 which extends between a proximal end region 3 and a distal end region 4. The wire basket 1 is divided into a distal confinement section Ai, which is designed comparatively closely meshed with a maximum opening or mesh width w, and a section B-1 adjoining it proximally, with a larger maximum opening or mesh width W _G, on the other hand. The proximal end region 3 of the wire basket 1 is formed by a rear end sleeve 5, from which a plurality of pieces of wire 6 extend in the unfolded state with an axial and a radial component as shown in the figure. In the distal direction, the wire pieces 6 branch out repeatedly, whereby the shown, braided basket wire structure 2 is formed. The structure 2 is chosen so that the wire basket in the distal enclosure section A-ι is much closer meshed than in the proximal section Bi, ie a significantly smaller opening or mesh size w has, for example, a maximum of half as large or at most one third as large opening width w as the opening width W _{G of} the proximal portion Bi. At the distal end region, the corresponding wire sections converge again, in the example shown specifically to form a distal end of the basket 7. The rear end sleeve 5 and the front end sleeve 7 can be pushed along a longitudinal axis 8 a guide wire, which the wire basket 1 makes it suitable for use in an over-the-wire type safety wire instrument. Particles to be captured, for example thrombotic particulate material, can easily be captured by the unfolded wire basket 2 in the proximal section Bi due to its relatively large mesh size. Subsequently, the particles can be securely held and trapped in the more closely meshed distal containment section Ai with its smaller mesh size w, so that they do not come out of the wire basket 2 again. The catching wire basket 1 of Fig. 1 may advantageously be made in one piece from a piece of pipe, in particular in that it is cut from the pipe section, for example by laser cutting. The pipe section is cut for this purpose in a corresponding cut or slot pattern. Fig. 3 shows a accordingly cut or slotted pipe section 9 in a pipe development. It can clearly be seen how the wire structure cut from the tube section 9 comprises a plurality of pieces of wire 6, which depart from the proximal end region 3 and then branch repeatedly to form the proximal capture section Bi, which then enters the distal confinement section A-1 passes, which is formed by a comparatively finer slot pattern. A respective end stub of the tube piece forms the proximal, rear end sleeve 3 and the distal, front end sleeve 4 of the wire basket. Figs. 2 and 4 illustrate in representations corresponding to those of Figs. 1 and 3, a further inventively usable safety wire basket with respect to those of Figs. 1 and 3 modified basket design. Here, for ease of understanding here and in the other figures, the same reference numerals for identical or functionally equivalent elements are used, to the description of which reference may be made to the comments on the previously described figures accordingly.

A safety wire basket V shown in FIG. 2 has a braided wire structure 2 'modified from that of the basket 1 of FIG. 1 in that it has a substantially constant outside diameter over a major portion of its length. Specifically, it is in a proximal Aufspreizabschnitt C, a distal inclusion section A ₂ and a zwi dense, substantially cylindrical catching section B ₂ articulated. The inclusion section A ₂ with a comparatively small mesh width w substantially corresponds to that of the basket 1 of FIG. 1. The trapping section B ₂ is again the basket section with maximum opening width W _G for easy entry and thus trapping of particles in the basket V transverse to the basket longitudinal axis 8. At this trapping section B ₂ is followed by the basket V of Fig. 2, the proximal Aufspreizabschnitt C, in which the outgoing from the proximal end portion 3 pieces of wire branch after a relatively short length, so that the basket V expands according to already at a relatively short axial distance from the proximal end portion 3 to its maximum basket diameter and merges into the capture section B ₂ . The Aufspreizabschnitt C thus supports the unfolding of the wire basket V in that the basket V reaches its maximum diameter after a short axial length. In addition, the branched spreading portion C stabilizes this basket configuration toward the proximal end portion 3.

In this way, the wire basket 1 of FIG. 2 has a rather cylindrical shape, while the wire basket 1 of FIG. 1 has a conically widening wire structure over the main part of its length and in particular over most of its catching section B-1 , The safety wire basket 1 'of Fig. 2 can be cut in one piece from a piece of pipe. This is shown in Fig. 4 in associated development representation of a corresponding pipe section 9 '. A comparison of FIGS. 3 and 4 shows, in particular, the modified wire basket configuration in the spreading section C of the wire basket 1 'of FIG. 2. Otherwise, the same properties and advantages apply to the safety wire basket 1 'of FIG. 2 as indicated above for the safety wire basket 1 of FIG. 1.

To form the finished wire basket 1, 1 ', the associated, finished cut pipe section 9, 9' is compressed in its length, whereby it unfolds into the desired wire basket 1, 1 '. A superelastic material, such as a nickel-titanium alloy, is preferably used for the pipe section 9, 9 'so that the finished safety wire basket 1, 1' can be elastically moved from the unfolded state into a folded-in state and refolded out of it. For this purpose, it is moved in use in a surrounding instrument tube and thereby folded and can then be moved out of this forward and thus unfolded. This is known to those skilled in the art and requires no further explanation here.

It is understood that other desired basket configurations can be made in one piece by cutting from a piece of pipe, to which the pattern is chosen suitably, as known from the relevant, above-mentioned prior art per se. If the safety wire basket is produced by cutting a pipe section accordingly, the individual wire pieces 6 or wire sections can have a substantially rectangular cross section, their cross-sectional width corresponding to the pipe wall thickness of the pipe section, while their cross-sectional length corresponds to the slot spacing of two adjacent, the wire piece or the Wire section from the pipe section of cutting slots corresponds. The cross-sectional width may be smaller or larger than the cross-sectional length depending on the desired dimensioning. 5 illustrates an exemplary embodiment with a cross-sectional width b of the wire pieces 6 that is smaller than its cross-sectional length I.

By suitable dimensioning, it is possible for the present wire basket structures that the wire pieces 6 or wire sections rotate to some extent about their longitudinal axis when the wire basket is brought into its unfolded state. In the example of FIG. 5, this is represented by a twist angle β, by which the wire pieces 6 in the relevant basket area respectively from their initial position, as it is after slitting the pipe section 9, 9 'and before unfolding the wire basket, in their shown in Fig. 5 position in unfolded wire basket 1, 1 'are twisted.

In the initial position, the rectangular cross-section wire pieces 6 are with their main sides H parallel to the associated tangential plane of the pipe section 9, 9 ', while the narrow sides formed by the cut edges S lie in perpendicular radial planes. The tangential planes to the pipe section 9, 9 'correspond to parallel tangential planes of the basket circumference KU indicated by dash-dotted lines in the section of FIG. Consequently, in this case, the wire pieces 6 are in unfolded wire basket 1, 1 'in corresponding basket areas with their main sides H not parallel to the basket circumference KU, but are in contrast rotated by the angle ß about its longitudinal axis. This also has the consequence that the wire pieces 6, as shown in FIG. 5, with one of its two narrow sides S or with a bordering to this edge line KL radially outward. These outwardly facing wire edges KL and the outwardly facing wire narrow sides S of the wire sections 6, 6 'can advantageously reinforce a removal effect when the wire basket 1, V is used with its outside to remove material adhering to a body tissue channel and then should be captured after removal in the catcher and held in this. This reinforcing effect compared to a wire basket, in which the wire pieces do not twist in this way when unfolding the wire basket or are used in the circular cross-section pieces of wire, thus results without corresponding additional wire processing measures, such as an additional grinding of the wire pieces to achieve more or less sharp cutting edge. FIGS. 6 to 8 illustrate a typical application for the safety wire instrument according to the invention, wherein in the example shown, the safety wire basket 1 of FIG. 1 is used, which is fixed to the distal end of a control tube 14. 6 shows a region of a body tissue channel 10 to be treated, on the inner wall of which a thrombus has typically formed by deposition of thrombotic material 11, which reduces the effective cross section of the tissue channel 10. First, a guidewire 12 is advanced into and across the tissue channel 10 through the thrombus 11, as shown in FIG.

Subsequently, the unit consisting of safety wire basket 1 and control tube 14 with surrounding instrument tube 13 is pushed onto the guide wire 12 from its proximal end and advanced along it until the instrument tube 13 has a distal portion in which the safety wire basket 1 is received in its folded-in state , behind the thrombus 1 1 is located. Then, the safety wire basket 1 is moved distally forward out of the instrument tube 13, whereby it widens in its unfolded state, as shown in Fig. 8. For this purpose, with the instrument tube 13 held, the control tube 14 together with the distally coupled catching wire basket 1 can be pushed axially forward, or the instrument hose 13 is retracted while the control hose 14 and catching wire basket 1 are held until it releases the wire basket 1. Control elements which can be used for these control movements, to which the instrument tube 13 and the control tube 14 are coupled with their proximal end region, are known per se to a person skilled in the art and therefore require no further explanation here.

Starting from the positioning of the unfolded catching wire basket 1 behind the thrombus 11 shown in FIG. 8, the catching wire basket control hose unit 1, 14 together with the instrument hose 13 is then moved back axially along the guide wire 12. As soon as the wire basket 1 reaches the thrombus 1 1, it can detach or ablate it from the inner wall of the tissue channel 10, and the removed thrombotic material 11 can pass through the wide openings of the trapping section B-1 into the wire basket 1, where it is from closer meshing section A-ι is securely retained and remains trapped. Then, if required, the wire basket 1 can again be moved into the instrument tube 13 until it encloses the particles trapped in it tightly with its wire mesh. This is done by the above-described moving out of the wire basket 1 from the instrument tube 13 inverse control movement, ie by actively retracting control tube 14 and wire basket 1 or active advancing the instrument tube 13. Finally, the control tube wire basket unit 1, 14 together with surrounding instrument Mentenschlauch 13 with the captured in the wire basket 1 particles from the tissue channel 10th moved out. Depending on the application case, the guide wire 12 is withdrawn from the tissue channel 10 again, alternatively it can remain therein.

The described removal and trapping of the thrombotic material 1 1 is supported by the special, articulated design of the catching wire basket 1 with its catching section B-1 and its close-meshed inclusion section A-1. For a good detachment of possibly on the inner wall of the tissue channel 10 slightly more adhesive material may also contribute to the above described Fig. 5, twisted or twisted position of rectangular cross-section wire sections 6 contribute, as present in corresponding embodiments at least in a Korbteilbereich. This may be, for example, a partial area in which the wire basket 1 has its maximum basket diameter, as in the transition region of the inclusion section A-ι and capture section B-ι in the basket 1 of Fig. 1 or the wire basket V of Fig. 2 in addition over virtually the entire catching section B ₂ proximally to the spreading section C. The narrow sides S or wire piece edges KL turned radially outwards in this way provide a non-smooth or edge-profiling of the outer circumference of the wire basket 1, which is a material-removing May have effect. In the present catching wire instrument, therefore, the catching wire basket 1, 1 'for removing material adhering to a tissue channel, such as the thrombotic material 11 of FIGS. 6 to 8, does not need to be set in a rotational movement adapted thereto. It is sufficient a simple retraction of the unfolded wire basket 1, V, which can be supported in case of need by gently turning back and forth by an angle less than 360 ° by hand.

FIGS. 9 to 15 show advantageous embodiments for the Steuerschlauch- wire basket coupling and the front, distal Drahtkorbgestaltung the example of a one piece of a piece of pipe cut cut wire basket 1 i, in which it is for example one of the above two to Figs 2 discussed wire basket types can act. The wire basket 1 i is preferably cut in one piece from a piece of pipe, and its wire sections 6 terminate proximally in a rear end sleeve 5i and distally in a front end sleeve 7i, as described above for the wire baskets 1, 1 'of Figs.

In the exemplary embodiment of FIGS. 9 and 10, the catching wire basket 1 i is fixed with its rear end sleeve 5i overlapping it to a distal end region of a control tube 4i so that the control tube 4i encloses the rear end sleeve 5i with its distal end region. For this purpose, the control hose 4i can be shrunk onto the end sleeve 5i, for example, or it is otherwise firmly fixed to the end sleeve 5i in the overlap region. bound, eg by gluing. The rear end sleeve 5i leaves a passageway 15i for passing a guide wire.

In the embodiment of FIGS. 11 and 12, the rear end sleeve 5i of the wire basket 1i is plugged onto the distal end region of a control tube 14 ₂ . Once again, the proximal end sleeve 5i of the wire basket 1i and the distal end region of the control tube 14 _{2 are} firmly fixed to one another, eg by gluing. The control tube 14 ₂ determined in this case, the diameter of a corresponding passage channel 15 ₂ for a guidewire to be performed.

Fig. 13 shows the front, distal end portion of the wire basket 1 i, in which the basket-forming wire sections 6 converge in a front, distal end sleeve 7-i. The distal end sleeve 7-i leaves a through-channel 15 ₃ for passing a guide wire along the longitudinal axis 8 of the basket.

In the embodiment of FIG. 14, a distal guide tube sleeve 16i is provided, which is fixed with a proximal end region overlapping on the front end sleeve 7-i. For this, in the example shown, it surrounds the front end sleeve 7-i and encloses it closely, e.g. by shrinking. Alternatively, the guide tube sleeve 16i is otherwise fixedly secured in the overlap region to the distal end sleeve 7-i, e.g. by gluing.

In the exemplary embodiment of FIG. 15, a guide tube sleeve 16 _{2 is} provided, on the proximal end region of which the distal end sleeve 7 i of the wire basket 1 i is placed. Again, the distal basket end sleeve 7-i and the guide tube sleeve 16 _{2 are} firmly fixed to each other in the overlapping area, for example by gluing. In this embodiment, the guide tube sleeve 16 ₂ defines a passageway 15 ₄ for passing a guide wire in this area.

In the exemplary embodiments of FIGS. 14 and 15, the guide tube sleeve 16 ₂ can support the guidance of the safety wire basket 1 i on a guide wire onto which the wire basket 1 i is pushed in use. The guide tube sleeve 16 ₂ may be made of the same material or tubing as the control tube 14-i, 14 _second The latter then automatically provides a passageway of equal diameter for a guidewire to be performed both in the proximal area of the instrument, in which the control tube 14-1, 14 ₂ is located, and in the distal area of the wire basket 1 i. Alternatively, however, the use of different hoses or materials for the control hose on the one hand and the guide tube sleeve on the other hand possible. 16 shows an exemplary embodiment with the safety wire basket 1 i in a position pushed onto a guide wire 12-1 in the embodiment variant with the control hose 14 ₂ according to FIGS. 11 and 12 and the distal guide hose sleeve 16 ₂ according to FIG. 15. The guide wire 12-i has a known construction of a core wire 17, which is closely surrounded by a more rigid sheath 18 except for a distal end. In the distal end region, this envelope 18 is adjoined by a more flexible envelope 19, as is also known per se. The guidewire 12-i is designed for use in MR applications, for which purpose the core wire 17 preferably consists of a plastic material and in the distal end region an MR marker 20 is provided, which in this case is formed by an MR occupancy on the core wire 17 which is embedded in the truer wrapper 19.

As can be seen from FIG. 16, the inner diameter of the control tube 14 ₂ and the distal guide tube sleeve 16 ₂ substantially corresponds to the outer diameter of the guide wire 12-1 such that the control tube 14 ₂ and the guide tube sleeve 16 _{2 are completely} against the guide wire 12. i abut, but remain axially movable relative to this still with a sufficiently low actuation force. Alternatively, it may be provided for suitable applications to leave a small annular gap between control hose 14 ₂ or guide hose sleeve 16 ₂ on the one hand and guide wire 12-i on the other hand. As further seen in Fig. 16, the guide tube sleeve 16 ₂ improves the guidance of the safety wire basket control tube assembly as it moves along the guidewire 12- , For the sake of clarity, the instrument hose is omitted in FIG. 16, in which the wire basket control hose unit is accommodated.

It is understood that if necessary, the safety wire basket control tube unit and / or the instrument tube can be provided with an MR marker. By way of example, FIGS. 17 and 18 show two exemplary embodiments as variants of the safety wire basket control hose unit of FIG. 16. In the exemplary embodiment of FIG. 17, an MR marker 20i is applied to the outside of the guide tube sleeve 16 ₂ in the region in front of the distal end of the safety wire basket 1 i. In addition, an MR marker 20 _{2 is} applied to the control tube 14 ₂ in a section proximal to the proximal end of the safety wire basket 1 1.

In the exemplary embodiment of FIG. 18, an MR marker 20 _{3 is provided} on a so far modified catching wire basket 1 ₂ , in that its basket-forming wire sections 6 are covered with the MR marker material, as represented in FIG. It is understood that any other assignments of safety wire basket, control hose and / or optional guide wire tube sleeve can be realized with MR marker material, in order to improve the visibility of the instrument in MR applications selectively, in regions or over the entire instrument length, if necessary. For this purpose, the instrument tube can also be provided in a manner known per se with a suitable MR marker occupancy, for which reference may be made, for example, to corresponding embodiments of an instrument tube or an instrument tube sheath, as disclosed in the aforementioned WO 2014/086917 A1 are. In any of the above-mentioned cases, the MR marker can be embodied as a so-called active MR marker or alternatively as a so-called passive MR marker, as is familiar to the person skilled in the art. It is further understood that the invention includes, in addition to the basket designs, as shown in Figs. 1 and 2, numerous other basket designs with different basket shapes, as needed and application. For this purpose, FIGS. 19 to 24 illustrate by way of example some further possible embodiments, which can all be made in one piece by cutting out a piece of pipe, if desired. The basket variants of FIGS. 19 to 24 can also be partially or completely provided with an MR marker as needed to improve their MR visibility.

19 shows a safety wire basket 1 ₂ , in which a capture section B ₃ opens in a cup-shaped manner from the proximal end sleeve 5 and then extends cylindrically and merges into a rosette-shaped inclusion section A _{3 in} front of the distal end sleeve 7. Fig. 20 shows a safety wire basket 1 ₃ with balloon-like capture portion B ₄ , which merges into a rosette-shaped enclosure section A ₄ with a so-called tipless end. Such tipless designs are known per se and are preferred for certain applications. FIG. 21 shows a uniformly ball-shaped catcher box 1 _4, likewise with a distal end without a center, this wire basket 1 _4, like most other wire baskets, being constructed of wire sections of substantially rectangular cross-section, which in the unfolded wire basket state extend at least in a portion of the wire basket 1 ₄ with non-tangential wire broadside, as explained for Fig. 5 above.

Fig. 22 shows a safety wire basket 1 ₅ with a balloon or bell-shaped trapping section B ₅ , which merges into a rosette-shaped enclosure section A ₅ similar to that of the basket 1 ₂ of FIG. FIG. 23 shows a safety wire basket 1 ₆ with a pear-shaped expanding catching section B ₆ , which merges into a relatively short enclosure section A ₆ . 14 shows a safety wire basket 1 ₇ with a quasi-center-symmetrical onion shape, whereby this wire basket 1 ₇ again comprises wire sections which are essentially rectangular in cross-section. is constructed, which extend in the unfolded basket state shown at least in a basket portion with non-tangential wire broadside, as explained for Fig. 5 above.

Claims

claims

1 . Medical safety wire instrument with

a safety wire basket (1, 1 '), which is adapted to be relatively movable axially between an inflated from an instrument tube (13) to the front, unfolded to-stand and a proximally moved into the instrument tube to the rear, folded state axially relative to the instrument tube , and

a control hose (14), which can be accommodated relatively axially in the instrument hose relative to the latter and which is coupled in a distal end region to a proximal end region (3, 5) of the safety wire basket,

wherein the safety wire basket and the control hose are adapted to be axially movable on a guidewire (12),

characterized in that

the safety wire basket has a distal containment portion (A1, A2) that is more closely meshed than a proximally adjacent portion (B1, B2), and / or

the safety wire basket has a proximal spreading portion (C) narrower than a distally adjacent portion (B2), and / or

the safety wire basket is constructed of wire sections (6) which are substantially rectangular in cross-section and extend at least in a basket section with non-tangential wire broad side (H) when the catch wire basket is unfolded.

The medical heddle instrument of claim 1, further characterized in that the distal confinement section is more closely meshed than the proximal expansion section.

The medical heddle instrument according to claim 1 or 2, further characterized in that the safety wire basket has a trapping portion (B2) between the confining portion (A2) and the spreading portion (C), the trapping portion being wider mesh than the confining portion and the expanding portion.

4. Medical safety wire instrument according to one of claims 1 to 3, further characterized in that the control tube has a substantially an outer diameter of the guide wire corresponding inner diameter such that it abuts in its pushed onto the guide wire position relative to the guide wire axially movable fully against this.

5. Medical safety wire instrument according to one of claims 1 to 4, further characterized in that the catching wire basket is cut in one piece from a piece of pipe.

The medical retrieval wire instrument of any one of claims 1 to 5, further characterized in that the capture wire basket terminates proximally with a rear end sleeve (5) overlapped at a distal end portion of the control tube.

7. A medical retrieval wire instrument according to any one of claims 1 to 6, further characterized in that the safety wire basket ends distally with a front end sleeve which is overlapped at a proximal end portion of a guide tube sleeve (161, 162) fixed.

8. Medical safety wire instrument according to one of claims 1 to 7, further characterized in that the instrument tube and / or the control tube and / or the catch wire basket and / or the guide tube sleeve is at least partially provided with an MR marker (201, 202, 203) ,

9. Medical safety wire instrument according to one of claims 1 to 8, further characterized by a guide wire (12) on which the catch wire basket and the control tube are axially movable pushed.