WO2004019793A1

WO2004019793A1 - Lithotriptor with a catch basket and a smashing basket

Info

Publication number: WO2004019793A1
Application number: PCT/DE2003/002816
Authority: WO
Inventors: Raimar Boehlke; Werner Schwarz
Original assignee: Medi-Globe Gmbh
Priority date: 2002-08-23
Filing date: 2003-08-22
Publication date: 2004-03-11
Also published as: DE10246531A1

Abstract

The invention relates to a lithotriptor with a catch basket and a smashing basket (1) consisting of a plurality of material strands (2-5), each of which is made up of a plurality of twisted metal wires, and which has, optionally at least one bend area (8,9), wherein all of the material strands (2-5) are combined at the distal end (6) of the catch basket in an assembly area (10) and are received on the proximal catch basket end (7) by a shell (11) and are displaceable therein. The material strands (2-5) are surrounded by at least one material ring (12; 18, 19) in the assembly area (10). Said material ring is embodied such that the tensile strength thereof is less than the mechanical strength properties corresponding to the overall tensile strength of all of the material strands (2-5).

Description

description

Lithotriptor catch and smash cup

The invention relates to a lithotriptor capture and shattering basket, consisting of a plurality of stranded material strands, each of which is formed from a plurality of twisted material wires, in particular metal wires, and optionally has at least one kink region in the basket region, with all stranded material strands at the distal end of the basket are combined with each other in a summarizing area and are received by a sheathing at the proximal end of the basket and are displaceable therein.

Lithotriptor baskets and crushing baskets are used for the minimally invasive removal and crushing of stones in hollow organs and organs, especially the bile duct, by individuals or patients. Catchers of various shapes are used in such treatments.

Thus, lithotriptor collecting baskets and baskets of the type mentioned at the outset are known, for example, from EP 0 391 384 B1, US 6 183 482 A1, US 6 350 266 Bl. In addition to lithotriptor catchers designed in this way, there are also lithotriptor catchers in which the material wires at the distal end of the catcher each have a loop-shaped configuration, that is to say are not combined with one another in a summary region (see, for example, US Pat. No. 6,099,534, US Pat. No. 174,318 Bl, US 6 280 451 Bl). It has been found in practice that individual stranded material strands of the respective lithotriptor catch basket break when the tensile force exerted on the respective lithotriptor catch basket exceeds a certain value. The respective strand of material strand is often torn at the respective proximal end of the basket. Occasionally, however, the respective strand of material strand also tears at any point between the distal and proximal end of the basket of the respective lithotriptor basket. In the event that such tearing of one or more strands of material stranded in a lithotriptor basket inserted into a patient's body opening, when the basket is withdrawn, penetration and snagging of the strand of stranded material that has been torn off is very often associated with patient tissue. This has the consequence that the minimally invasive treatment of the patient planned with the relevant lithotriptor basket is then no longer possible. In such cases, surgical intervention is often the only way to remove not only the stone or stones that should be removed with the basket, but also the lithotriptor basket strands.

The invention is therefore based on the object to show a way how to proceed with a lithotriptor catch and smashing basket of the type mentioned, so that it is ensured that in the event of a certain value being exceeded by the lithotriptor catch in question - and -Drümmerungskorbchen exerted tensile force whose material strand strands do not tear, but rather in a problem-free pulling the lithotriptor catch and -Dishrümmerungskorb is brought into the respective body opening, into which it was previously introduced, shape.

The problem outlined above is solved with a lithotriptor catch and smashing basket of the type described at the beginning. mentioned type according to the invention in that the strand of material strands are enclosed in the aforementioned summarizing region by at least one metal ring which is designed in such a way that its tear strength is less than a strength value corresponding to the total tensile strength of all strands of material strand.

The invention has the advantage that tearing of the strand of material strands of the lithotriptor catch and shattering basket is ruled out in a relatively simple manner in the event that the tensile force exerted on the basket in question with a stone picked up by it exceeds a predetermined value. However, this value, which is below the total tensile strength of all material strand strands, is sufficient to break or tear open the material ring mentioned at precisely this tensile load, so that the material strand strands previously combined with one another at the distal cup end come apart without tearing. Due to this process of the material strand strands coming apart at the distal end of the cup, no problems arise in order to pull the lithotriptor catch and shattering basket, which is no longer functional, back into the sheath from which it had previously been pushed out. The problems mentioned at the outset, which are associated with the previously known lithotriptor trap and shattering cups, do not arise in any case with the lithotriptor trap and shattering cups according to the present invention. The lithotriptor capture and smashing basket according to the invention is thus a safe basket that always enables minimally invasive patient treatment.

The material ring expediently has notches for receiving the strand of material strands running from the proximal cup end to the distal cup end. This has the advantage that the individual strand of material strands ge can be held by the relevant material ring in defined desired positions.

According to an expedient alternative embodiment of the present invention, in addition to the material ring mentioned, a material strand positioning ring is arranged in the direction of the proximal cup end, which holds the individual material strand strands at the distal cup end in fixed positions and which is designed such that its tear strength is less than the tear strength of the material ring in question. As a result of this measure, the stranded material strands are separated in a two-stage manner if a certain predetermined value is exceeded by the tensile force exerted on the lithotriptor catcher basket. First, if this value is exceeded by the tensile force in question, the material strand positioning ring mentioned is disassembled, and then the material ring in question is disassembled. The disassembly of the stranded wire positioning ring for the operator of the lithotriptor trap and shattering basket can be regarded as a warning to the extent that a further increase in the tensile force on the lithotriptor trap and shattering basket in question is likely to result in its strand of material strand be separated at the distal end of the cup.

The individual strands of material strand are preferably each connected to a separate holding element at the distal cup end, and all holding elements are covered by the material ring and, if appropriate, by the positioning ring. This has the advantage of a simple yet secure positioning of the strand of material strand at the distal end of the cup.

In the case of the expedient further development of the lithotriptor trap and shattering basket according to the present invention, the material lit Strands of material strands are positively and / or positively received in their respective receiving element.

The stranded material strands are expediently connected to their receiving elements by a soldered or welded connection. As a result, the material strand strand ends in question are securely connected to their receiving elements.

An alternative connection option comprises crimping the relevant strand of material strand.

A structurally particularly simple, but nevertheless effective lithotriptor cup construction results according to an expedient development of the present invention in that the positioning ring and the metal ring are formed by a single ring.

Exemplary embodiments of the lithotriptor capture and smashing basket according to the invention are explained in more detail with reference to drawings.

Fig. 1 shows a partially sectioned side view of a schematic representation of a first embodiment of a lithotriptor capture and shattering basket according to the invention.

FIG. 2 shows an enlarged view of a material ring used in the lithotriptor capture and shattering basket according to FIG. 1 along the line of sight II-II entered in FIG. 1.

FIG. 3 shows an enlarged sectional view of the summary area at the distal end of the basket of the lithotriptor basket and comminution basket shown in FIG. 1, corresponding to the section line III-III entered there.

Fig. 4 shows a schematic representation of a second embodiment of the lithotriptor capture and Shattering basket according to the present invention.

FIG. 5 shows in an enlarged view a plan view of a positioning ring used in the lithotriptor catch and shattering basket according to FIG. 4 along the line of sight IV-IV entered in FIG. 4.

FIG. 6 shows, in a greatly enlarged view, a schematic illustration of the lithotriptor catch and shattering basket shown in FIG. 4, in which a stone is received, in order to illustrate the mechanism of action that is used according to the invention.

Fig. 1 shows a side view and partly in section a schematic representation of a first embodiment of a lithotriptor catch basket 1, hereinafter only briefly called lithotriptor catch basket 1 according to the invention. The lithotriptor basket 1 consists of a plurality of stranded material strands, in the present case four such stranded material strands 2, 3, 4, 5. The stranded material strands 2 to 5 each consist of a plurality of twisted material wires, in particular through metal wires, such as through Stainless steel or titanium wires are formed; if necessary, they can also be formed by plastic strands. The number of material or metal wires in question can correspond, for example, to the number of strands of material 2 to 5; however, it is also possible for each strand of material strand to consist of a larger or smaller number of material wires.

The individual strand of material strands 2 to 5 here have in the cup area, that is the area between a distal cup end 6 and a proximal cup end 7, in each case at least one kink area. In the case of the exemplary embodiment according to FIG. 1, there are two buckling areas in each case. before, which are designated with reference to the other strand of material strand 2 as representative of the remaining strand of material strands 3 to 5 with 8 and 9. The material strand strands 2 to 5 are combined with one another at the distal end of the basket 6 in a gathering area 10, and they are received at the proximal end of the basket 7 by a sheath 11 and can be displaced in the longitudinal direction thereof.

In the above-mentioned summary area 10, the material strand strands 2 to 5 are enclosed by at least one material ring 12, which can be made of stainless steel, titanium or high-strength plastic and which is designed and dimensioned such that its tensile strength is lower than the total tensile strength of all material strand strands 2 to 5 This design and dimensioning of the material ring 12 ensures that an obstacle which occurs when the lithotriptor basket 1 with a stone therein is pulled to the left according to FIG. 1 and leads to a heavy load on the material strand strands 2 to 5 will not be sufficient to lead to the tearing of individual strands of material strand 2 to 5. If such a high tensile force is nevertheless exerted on the strand of material strands 2 to 5 of the lithotriptor basket 1, then the material ring 12 will first tear before a single strand of strand of material strand 2 to 5 breaks. The associated mechanism of action will be discussed in more detail below in connection with FIG. 6.

In addition to the material ring 12 mentioned, the previously considered summary area 10 also includes a cover cap 13 which receives and covers the distal ends of the stranded material strands 2 to 5, which can be made of plastic or rubber, for example, and whose tear strength is also lower than the total tensile strength of all stranded material strands 2 to 5 or is even less than the tensile strength of the material ring 12. The covering cap 13 in question and / or the material ring 12 can or can optionally also be easily formed so elastic that only the individual Materiallitzenstränge 2 released to 5 who, without the cap or type of material in question ring tears ^¬.

FIG. 2 shows an enlarged top view of the material ring 12 shown in section in FIG. 1 along the view plane II-II according to FIG. 1. It is clear from FIG. 2 that the material ring 12 on its side facing the proximal end of the basket four Has notches 14, 15, 16 and 17 at equidistant intervals. In these notches 14 to 17, the strand of material strands 2 to 5 lie against the material ring 12 at the distal end of the catcher basket 6, as can be seen from the sectional illustration in FIG. 1.

From the enlarged sectional view of the summary region 10 according to FIG. 1 shown in FIG. 3 along the section plane III-III entered there, it can be seen that the individual strand of material strands 2 to 5 at the distal cup end each have a separate holding element 34, 35, 36 or 37 are connected, which in the present case has the shape of a right-angled angular part. In these holding elements or angular parts 34 to 37, which are made of stainless steel, for example, the associated stranded material strands 2 to 5 are each non-positively and / or positively received. In Fig. 3 it is indicated that the respective connection is a soldered connection (soft or hard soldering). However, it is also possible to connect the individual strand of material strands 2 to 5 to the associated angle parts 14 to 17 by a welded connection or by crimping. With regard to the angular parts 34 to 37 forming the individual receiving elements, it should also be noted that these are slidable or displaceable relative to one another and overall are accommodated by the cover cap 13 mentioned in connection with FIG. 1. 4 shows a schematic side view and partly in section of a second exemplary embodiment of the lithotriptor collecting basket according to the invention. 4, insofar as they correspond to the elements shown in FIG. 1, the same reference numerals are used for the individual elements.

In contrast to the exemplary embodiment of the lithotriptor collecting basket according to the invention shown in FIG. 1, the summarizing region 10 in the exemplary embodiment of the lithotriptor collecting basket 1 shown in FIG. 4 points in the direction next to the material ring, which is designated by 18 in FIG. 4 Towards the proximal cup end 7, there is also a separate material strand positioning ring 19 which holds the individual material strand strands 2 to 5 at the distal cup end in fixed positions and which is designed and dimensioned such that its tear strength is lower than the tear strength of the material ring 18.

The material strand positioning ring 19 can be configured on its side facing the proximal cup end 7 as illustrated in FIG. 2, that is to say provided with notches 14 to 17 in the surface concerned. However, it is also possible to design the material strand positioning ring 19 in a manner as illustrated in FIG. 5, which shows an enlarged plan view of the material strand positioning ring 19 shown in FIG. 4 along the view plane V-V. The material strand positioning ring 19, as shown in FIG. 5, has four equidistantly spaced latching openings 20, 21, 22, 23 in its inner surface, into which the material strand strands 2 to 5 to a certain extent during the assembly of the lithotriptor basket according to FIG. 4 be snapped into place.

At this point, it should be noted that, in principle, the material ring 12 in the first embodiment shown in FIG. Example of the lithotriptor basket according to the invention can be designed in its inner circumference as shown in Fig. 5.

In Fig. 6, the lithotriptor basket according to the invention shown in Fig. 4 is shown in a schematic view enlarged to illustrate the mechanism of action that is used according to the invention to avoid tearing of the stranded material strands under excessive tensile load. The same reference numerals are used in FIG. 6 for the designation of the individual elements as in FIG. 4. In contrast to FIG. 4, the lithotriptor basket 1 according to FIG. 6 is in a body opening 24 of a body tissue 25 together with one of the stone basket 26 is shown, which is to be pulled with the relevant lithotriptor basket 1 through the tissue opening 24 according to FIG. 6 from right to left.

If, as illustrated in FIG. 6, the lithotriptor basket 1 is pulled to the left together with the sheathing 11 using a tensile force Pg, then tensile forces occur in the longitudinal direction in the individual material strand strands 2 to 5, which are relative to the material strand strands 2 and 5 are denoted by Pz. It is assumed here that the respective tensile forces are of the same magnitude and are also present in the remaining stranded material strands 3 and 4, although this is not shown in FIG. 6. In addition to these tensile forces Pz, when the lithotriptor basket 1 is still intact, forces Pr which act approximately radially on the positioning ring 19 and act from the point of contact of the respective material strand 2 to 5 on the positioning ring 19 on its side facing the proximal basket end in an approximately radial direction , as indicated in Fig. 6. If these radial forces Pr, which are also only indicated with regard to the stranded material strands 2 and 5 in FIG. 6, and are assumed to be the same size for all material strand strands 2 to 5 and are thus also effective from the other material strand strands 3 and 4, in total exceeding the strength of the positioning ring 19, then this positioning ring 19 will break. Since, according to the present invention, the tearing or tearing strength of the positioning ring 19 is lower than the tearing or tearing strength of the material ring 18, this material ring 18 becomes the stranded material strands 2 to 5 according to FIG. 6 after the positioning or tearing of the positioning ring 19 stick together.

If, however, the tensile force Pg continues to increase, so that the tensile forces Pz 'effective in the individual stranded wire strands also increase, which are only indicated with regard to stranded material strands 2 and 5, but are also correspondingly effective in the remaining stranded material strands 3 and 4, then they become effective effective radial forces Pr 'corresponding to the material ring 18 increase accordingly. If these radial forces Pr 'of the stranded material strands 2 to 5 exceed the tensile strength of the material ring 18, then this material ring 18 will break apart and thus enable the separation of all stranded material strands 2 to 5. The covering cap 13 surrounding the distal ends of the strand of material strands 2 to 5 will then no longer be able to hold them together, but the relevant strand of material strands 2 to 5 will detach from this covering cap 13 or cause it to tear. This ensures that the relevant strand of material strands 2 to 5 themselves are not torn and thus do not lead to damage to the tissue of the tissue opening or to penetration and entanglement in the tissue in question, as a result of which the lithotriptor basket is withdrawn. The parts of the positioning ring 19, the material ring 18 and the cover cap 13 remaining in the body opening 24 of the body tissue 25 initially remain in the relevant body opening 24 from which the patient then undergoes natural invasive treatment. which are minimally invasively removed or removed with endoscopic foreign body forceps.

The operating mechanism explained above in connection with FIG. 6, which is used in the present invention, naturally also applies to the first exemplary embodiment of the present invention illustrated in FIG. 1. Instead of the above-described two-stage effect of an excessive tensile force Pg on the two rings 18 and 19 according to FIG. 6, in the case of the exemplary embodiment according to FIG. 1 there is only a corresponding one-stage effect on the single material ring 12 provided there, which practically holds the positioning ring 19 and forms the material ring 18 according to FIGS. 4 and 6.

The tensile strength of the material ring 12 in the exemplary embodiment according to FIG. 1 and the tensile strength of the material ring 18 and the positioning ring 19 in the exemplary embodiment according to FIGS. 4 and 6 are determined by the choice of material and design of the respective ring in such a way that they are lower than one of the total tensile strength of the stranded material strands 2 to 5 strength value corresponding to the respective basket design. The effect is exploited here that the tensile load Pz or Pz 'in each individual strand of material strand 2 to 5 results in a load component Pr or Pr' acting approximately radially on the positioning and / or material ring, and that this load component Pr or Pr 'depends on the relevant tensile load Pz or Pz' or corresponds to this. According to the relationship between Pz, Pz 'and Pr, Pr', the approximately radially acting force or load component Pr or Pr 'depends on the angle between the respective strand of material strand 2 to 5 at the distal end 6 of the basket and that at the proximal end Basket end 7 facing side of the positioning and / or material ring forms. This means that the respective force Pr or Pr 'will be greater in the presence of a larger stone 26 in the basket 1 than if a smaller stone is present 26. In the case of a larger stone 26, the catch basket 1 is bulged more than if a smaller stone 26 is present. This means that the angle mentioned between the strand of material strands 2 to 5 at the distal catch basket end 6 and the side of the positioning device facing the proximal catch basket end 7 and / or material ring in the presence of a larger stone 26 in the basket smaller than in the case of the presence of a smaller stone 26. In this way, the mechanism of action used in the present invention takes into account the fact that the risk of tearing stranded material strands of a lithotriptor basket The larger the stone to be removed is, the larger it is because of the associated greater resistance to a pulling movement of the collecting basket in question.

The action mechanism explained above ensures that the material ring 12 or the positioning ring 19 and the material ring 18 only break open when the total pulling force Pg exerted on the respective lithotriptor collecting basket according to the invention exceeds a pulling force value corresponding to this tear resistance value, without any the strand of material strands 2 to 5 breaks. In this way, a safe lithotriptor basket is created, which is free from the problems which, as discussed at the outset, are inherent in the previously known lithotriptor basket.

Claims

claims

1. Lithotriptor capture and shattering basket (1), consisting of a plurality of stranded material strands (2 to 5), each of which is formed from a plurality of twisted material wires, in particular metal wires, and optionally at least one kink region (8,

9), whereby all of the stranded material strands (2 to 5) at the distal end of the basket (6) are combined with one another in a gathering area (10) and at the proximal end of the basket (7) are received by a sheathing (11) and are displaceable therein, characterized in that Material strand strands (2 to 5) are enclosed in the summarizing area (10) by at least one material ring (12; 18, 19) which is designed in such a way that its tear strength is less than a strength value corresponding to the total tear strength of all material strand strands (2 to 5).

2. lithotriptor capture and shattering basket according to claim 1, characterized in that the material ring (12) notches (14, 15, 16, 17) for receiving the from the proximal cup end (7) to the distal cup end (6) extending material strand strands (2 to 5).

3. lithotriptor capture and shattering basket according to claim 1, characterized in that in addition to the material ring (18) towards the proximal end of the cup (7) a material strand positioning ring (19) is arranged, which the individual material strand strands (2 to 5) holds at the distal cup end (6) in fixed positions and is designed so that its tear strength is less than the tear strength of the material ring (18).

4. lithotriptor capture and shattering basket according to claim 3, characterized in that the individual strands of material (2 to 5) at the distal end of the cup (6) are each connected to a separate holding element (34, 35, 36, 37) and that all holding elements (34, 35, 36, 37) are covered by a cover cap (13).

5. lithotriptor capture and smashing basket according to claim 4, d a d u r c h g e k e n n e e c h n e t that the material strand strands (2 to 5) in their respective receiving element (34, 35, 36, 37) are non-positively and / or positively received.

6. lithotriptor capture and shattering basket according to claim 5 or 6, characterized in that the strand of material strands (2 to 5) with their receiving elements (34, 35, 36, 37) each by a soldered or welded connection (31, 32, 33 , 34) are connected.

7. lithotriptor capture and smashing basket according to one of claims 3 to 6, d a d u r c h g e k e n n z e i c hn e t that the positioning ring (19) and the material ring (18) are formed by a single ring (e.g. 12).