A snare
By improving the connection method between the snare and the cable and the design of the outer sheath, the connection strength and support were enhanced, solving the problems of easy damage to the outer sheath and insufficient gripping force, thus achieving more stable and efficient lesion resection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU FRANKENMAN MEDICAL EQUIP
- Filing Date
- 2025-08-13
- Publication Date
- 2026-07-28
AI Technical Summary
Existing snare devices are prone to bending, deformation, and breakage at the distal end of the outer sheath during operation. The connection strength between the snare and the cable is insufficient, and the gripping force for flat lesions is inadequate, resulting in prolonged operation time and incomplete resection.
The ferrule, made of metal wire, is connected to the cable and fixed by a connecting tube. The outer sheath has a clamp and barb structure at the far end. It uses a combination of stainless steel and nickel-titanium wire to enhance the connection strength and support. The ferrule is designed with a ring structure and barb structure to increase the gripping force.
The structure of the snare is improved, avoiding damage to the distal end of the outer sheath and breakage of the snare, enhancing the gripping force on the lesion, and ensuring a more complete resection effect.
Smart Images
Figure CN224557515U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of medical device technology, specifically to a snare device. Background Technology
[0002] A snare is a medical device widely used in endoscopic and laparoscopic surgery. It mainly uses mechanical or electrothermal methods to ligate or cut diseased tissues (such as polyps, tumors, etc.). Its core function is to block blood supply or remove target tissue.
[0003] Snares are divided into electric snares and mechanical snares. Electric snares mechanically ligate lesions using a snare, combined with high-frequency current to achieve thermal resection (electrocoagulation). They are suitable for larger lesions or cases requiring hemostasis (such as early-stage gastrointestinal tumors). The typical procedure involves injecting saline solution into the submucosa of the lesion site to raise the lesion base, thus separating the mucosa from the muscularis propria. The snare is then placed around the raised lesion, and electricity is applied to tighten the snare until the lesion is completely removed and the excised tissue is retrieved. Finally, the wound is treated, and hemostatic clips are used for closure if necessary. Mechanical snares are suitable for scenarios where electrocoagulation is not required (such as cold resection). For example, the cold snare technique (CSP) is specifically used to remove sessile polyps ≤9mm, using pure mechanical force to remove tissue and avoiding the risk of perforation caused by electrocautery. Current snare designs can combine both thermal and cold cutting functions; the appropriate mode is selected based on the surgical requirements.
[0004] The basic structure of a snare includes an operating handle, a cable, a snare, and an outer sheath. The outer sheath is a flexible polymer material conduit. The cable passes through the outer sheath, and the snare is fixedly connected to the distal end of the cable. The operating handle drives the cable to move relative to the outer sheath, thereby tightening and releasing the snare. According to existing industry feedback and technical verification, existing snares have more or less the following problems: (1) During operation, the proximal end of the snare will enter and exit the distal end of the outer sheath. The distal end of the outer sheath of existing snares is not strong enough, which easily leads to bending deformation and damage of the distal end of the outer sheath. Especially when cold cutting relies solely on mechanical force, the support strength of the distal end of the outer sheath is required to be even higher. (2) Insufficient connection strength between the snare and the cable can lead to the snare head breaking inside the body. (3) Conventional snares have insufficient gripping force on flat or submucosal lesions, requiring repeated adjustments to the position, prolonging the operation time. Moreover, they are prone to slipping during snare removal, which may not completely snare the polyp, leaving residual edge tissue and resulting in incomplete removal. Utility Model Content
[0005] The purpose of this invention is to provide a snare device with good structural stability, that is not easily damaged during use, and that has a better cutting effect.
[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0007] A snare device comprising:
[0008] An outer sheath tube having a cavity open at both ends extending from one end to the other, wherein a clamp is fixedly provided at the distal end of the outer sheath tube, the inner diameter of the clamp being smaller than the inner diameter of the cavity.
[0009] A cable, which is movably inserted into the cavity;
[0010] The loop is formed by bending a metal wire, with both ends of the metal wire inserted into the cavity from the distal end of the outer sheath. The portion of the metal wire outside the outer sheath has a ring structure, which is used to loop and cut the lesion.
[0011] A connecting tube is disposed between the distal end of the cable and both ends of the metal wire for fixing the cable and the collar. The connecting tube is located in the cavity and its outer diameter is larger than the inner diameter of the clamp.
[0012] An operating handle, located at the proximal end of the outer sheath and the proximal end of the cable, is capable of driving the cable to move within the outer sheath, causing the collar to be pushed out or retracted from the distal end of the outer sheath. During the pushing out of the outer sheath, the annular structure gradually expands to facilitate the retrieval of the lesion site. During the retraction of the outer sheath, the annular structure gradually shrinks, thereby enabling it to tighten, clamp, and cut the lesion site.
[0013] In some embodiments, the clamp includes an annular portion fitted onto the distal end face of the outer sheath and a connecting portion extending from the annular portion toward the proximal end and inserted into the cavity. The connecting portion is provided with a plurality of barbed structures inserted into the wall of the outer sheath to facilitate a stable and fixed connection between the clamp and the outer sheath.
[0014] In some embodiments, the connecting tube is a hollow tube, the distal end of the cable is inserted from the proximal end of the connecting tube, and both ends of the metal wire are inserted from the distal end of the connecting tube. The sidewalls of the distal end of the cable and the sidewalls of both ends of the metal wire are respectively fixedly connected to the inner wall of the connecting tube, thereby further improving the connection strength between the cable and the collar.
[0015] More preferably, the distal end of the cable is fixedly connected to both ends of the metal wire, and the connection point is located in the middle of the connecting tube, thereby improving the connection strength between the cable and the collar.
[0016] In some specific embodiments, the outer diameter of the cable is greater than twice the outer diameter of the metal wire, and the connecting tube includes a first part fixedly connected to the cable and a second part fixedly connected to both ends of the metal wire. The first part and the second part are integrally formed. The inner diameter of the first part is greater than the inner diameter of the second part. The inner diameter of the first part is approximately equal to the outer diameter of the cable, further ensuring the connection stability between the cable and the collar.
[0017] In some other embodiments, the first part has a first channel with an inner diameter approximately equal to the outer diameter of the cable, and the second part has a second channel and a third channel that are parallel to each other and have inner diameters approximately equal to the outer diameter of the metal wire, respectively. The distal end of the cable is fixedly inserted in the first channel, one end of the metal wire is fixedly inserted in the second channel, and the other end is fixedly inserted in the third channel, so that the connection stability between the cable and the loop is optimal.
[0018] In some embodiments, the length of the connecting tube is 5-6 mm, and the lengths of the first portion and the second portion are each independently one-third to one-half of the length of the connecting tube. While ensuring connection strength, the shorter the connecting tube length, the better, as it does not affect the bending of the distal end of the outer sheath and facilitates movement inside the endoscope.
[0019] In some specific embodiments, the metal wire comprises a first metal wire, a second metal wire, and a third metal wire connected sequentially from one end to the other. The first and third metal wires are made of stainless steel, and the second metal wire is made of nickel-titanium. The first and third metal wires are of equal length, and the second metal wire occupies one-half to four-fifths of the annular structure. The metal wire forming the loop is welded from stainless steel and nickel-titanium wire. Stainless steel has high rigidity and can provide good support, while nickel-titanium wire has a sharper cutting surface compared to stainless steel, which can reduce tissue tearing, reduce the risk of intraoperative bleeding, and better remove polyps. Nickel-titanium has superelasticity and shape memory effect, and does not deform after repeated polyp removal, thus achieving better mechanical removal of in vivo tissue.
[0020] In other embodiments, the metal wire is further bent to form multiple first V-shaped barbs and second V-shaped barbs extending into the interior of the annular structure. The first and second V-shaped barbs are located from the middle to the distal portion of the annular structure and are asymmetrically distributed on opposite sides of the annular structure. The first and second V-shaped barbs increase the contact area with the polyp, and their hook-like shape increases the gripping force, making it less prone to slippage during removal. This solves the problem of slippage when removing flat polyps and allows for more complete lesion removal.
[0021] In some embodiments, the outer sheath is made of a polymer material, including PTFE (polytetrafluoroethylene) or HDPE (high-density polyethylene), and the specific material can be selected according to the type of snare. For example, an electric snare uses an insulating outer sheath made of PTFE, while a cold snare uses an outer sheath made of HDPE.
[0022] In some embodiments, the cable is made of metal, such as 304 stainless steel.
[0023] In some embodiments, the clamp is made of stainless steel or an insulating polymer material, depending on the type of snare. For example, the clamp of an electric snare uses an insulating polymer material, such as PTFE; the clamp of a cold snare needs to use a higher strength metal material, such as 304 stainless steel.
[0024] In some embodiments, the connecting tube is made of metal and is fixedly connected to the cable and the metal wire by welding or riveting.
[0025] In some embodiments, the ring structure is generally elliptical or other symmetrical in shape.
[0026] In some embodiments, the wire is also bent to form a V-shaped guide located at the distal end of the annular structure and extending outward from the annular structure.
[0027] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:
[0028] The snare provided by this invention features a high-strength connection between the cable and the loop, making it resistant to breakage. The distal end of the outer sheath with a clamp is also strong, preventing bending, deformation, and damage, resulting in a stable structure during use. Furthermore, the loop of the snare provided by this invention can more completely remove lesions, including flat polyps that are difficult to snare and cut. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of the overall appearance of the snare in Example 1;
[0030] Figure 2 This is a schematic diagram of a partial cross-sectional view of the distal end of the snare in Example 1;
[0031] Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure with the outer sheath removed;
[0032] Figure 4 This is a cross-sectional view of a connecting sleeve.
[0033] Figure 5This is a cross-sectional view of another type of connecting sleeve.
[0034] Figure 6 for Figure 5 A schematic diagram of the distal side view of the connecting sleeve shown;
[0035] Figure 7 This is a schematic diagram of the overall structure of the snare in Example 2;
[0036] Figure 8 This is a partial cross-sectional view of the distal end of the snare in Example 2.
[0037] The components are: 1. Outer sheath; 11. Clamp; 2. Cable; 3. Loop; 31. First metal wire; 32. Second metal wire; 33. Third metal wire; 34. V-shaped guide; 35. First V-shaped barb structure; 36. Second V-shaped barb structure; 4. Connecting tube; 41. First part; 411. First channel; 42. Second part; 421. Second channel; 422. Third channel; 5. Operating handle; 51. Finger ring; 52. Electrode head. Detailed Implementation
[0038] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.
[0039] In the description of the embodiments of this utility model, it should be understood that the distal end refers to the end of the instrument or component that is far away from the operator, and the proximal end refers to the end of the instrument or component that is close to the operator; the inner and outer are positions defined by the distance relative to the center of the instrument or component, wherein the inner is the position close to the center of the instrument or component, and the outer is the position far away from the center of the instrument or component.
[0040] In the description of the embodiments of this utility model, it should be understood that "first", "second" and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated.
[0041] The foregoing disclosure provides many different implementations or examples for carrying out different structures of the present invention. To simplify the disclosure of the present invention, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the present invention. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the present invention; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.
[0042] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.
[0043] Example 1: This example provides a cold sleeve device, such as... Figures 1 to 3 As shown, it includes an outer sheath tube 1, a cable 2, a collar 3, a connecting tube 4, and an operating handle 5.
[0044] In this embodiment, the outer sheath 1 has an open cavity extending from one end to the other, with a clamp 11 fixedly mounted at its distal end. The inner diameter of the clamp 11 is smaller than the inner diameter of the cavity. The outer sheath 1 is made of HDPE. The clamp 11 includes an annular portion fitted onto the distal surface of the outer sheath 1 and a connecting portion extending from the annular portion to the proximal end and inserted into the cavity. The connecting portion has multiple barbed structures that insert into the wall of the outer sheath 1, facilitating a stable and fixed connection between the clamp 11 and the outer sheath 1. The clamp 11 is made of 304 stainless steel.
[0045] In this embodiment, the cable 2 is a 304 stainless steel rope, which can be single-stranded or multi-stranded. The cable 2 is movably inserted into the cavity of the outer sheath tube 1.
[0046] In this embodiment, the collar 3 is formed by bending a metal wire. Both ends of the metal wire are inserted into the cavity from the distal end of the outer sheath 1. The portion of the metal wire outside the outer sheath 1 has a ring structure, which is used to loop and cut the lesion. Specifically, the metal wire includes a first metal wire 31, a second metal wire 32, and a third metal wire 33 connected sequentially from one end to the other. The first metal wire 31 and the third metal wire 33 are made of stainless steel, which has high rigidity and provides good support. The second metal wire 32 is made of nickel-titanium, which has a sharper cutting surface, reducing tissue tearing, lowering the risk of intraoperative bleeding, and better removing polyps. Nickel-titanium also has superelasticity and shape memory effect, preventing deformation even after repeated polyp removal, thus achieving better mechanical removal of in vivo tissue. More specifically, in this embodiment, the first metal wire 31 and the third metal wire 33 are of equal length, and the second metal wire 32 occupies two-thirds of the ring structure. The metal wire forming the collar 3 is made by welding stainless steel wire and nickel-titanium wire. More specifically, the ring structure is roughly elliptical in shape, and the metal wire is bent to form a V-shaped guide 34 located at the distal end of the ring structure and extending outward from the ring structure, which facilitates travel within the body to reach and capture the lesion site.
[0047] In this embodiment, the connecting tube 4 is disposed between the distal end of the cable 2 and both ends of the metal wire, for fixing the cable 2 and the collar 3 together. The connecting tube 4 is located in the cavity and its outer diameter is larger than the inner diameter of the clamp 11. Specifically, the connecting tube 4 is a hollow tube. The distal end of the cable 2 is inserted from the proximal end of the connecting tube 4, and both ends of the metal wire are inserted from the distal end of the connecting tube 4. The sidewalls of the distal end of the cable 2 and the sidewalls of both ends of the metal wire are fixedly connected to the inner wall of the connecting tube 4, further improving the connection strength between the cable 2 and the collar 3. In this embodiment, the distal end of the cable 2 and both ends of the metal wire are also fixedly connected by welding, with the connection point located in the middle of the connecting tube 4, further improving the connection strength between the cable 2 and the collar 3. The outer diameter of the cable 2 is greater than twice the outer diameter of the metal wire. The connecting tube 4 includes a first part 41 fixedly connected to the cable 2 and a second part 42 fixedly connected to both ends of the metal wire. The first part 41 and the second part 42 are integrally formed. The inner diameter of the first part 41 is greater than the inner diameter of the second part 42. The inner diameter of the first part 41 is approximately equal to the outer diameter of the cable 2, as shown in the figure. Figure 4 As shown, this further ensures the connection stability between the cable 2 and the collar 3. In other embodiments, the first part 41 has a first channel 411 with an inner diameter approximately equal to the outer diameter of the cable 2, and the second part 42 has a second channel 421 and a third channel 422 that are parallel to each other and have inner diameters approximately equal to the outer diameters of the wire, respectively. The distal end of the cable 2 is fixedly inserted in the first channel 411, one end of the wire is fixedly inserted in the second channel 421, and the other end is fixedly inserted in the third channel 422. The connection stability between the cable 2 and the collar 3 is optimized, as shown in the following figure. Figure 5 and Figure 6 As shown. More specifically, the length of the connecting tube 4 is 5mm, and the lengths of the first part 41 and the second part 42 are each independently half the length of the connecting tube 4. While ensuring connection strength, the shorter the length of the connecting tube 4, the better, so as not to affect the bending of the distal end of the outer sheath 1, facilitating movement inside the endoscope. More specifically, the connecting tube 4 is made of metal, such as stainless steel tubing machined, and is fixedly connected to the cable 2 and the metal wire by riveting or welding.
[0048] In this embodiment, the operating handle 5 is located at the proximal end of the outer sheath 1 and the proximal end of the cable 2, enabling the cable 2 to move within the outer sheath 1. This causes the loop 3 to be pushed out or retracted from the distal end of the outer sheath 1. During the pushing out process, the annular structure gradually expands, facilitating the capture of the lesion. During the retraction process, the annular structure gradually shrinks, thereby tightening and clamping the lesion. The operating handle 5 is a prior art design. The operating handle 5 is equipped with a finger ring 51, which is directly or indirectly connected to the cable 2. The finger ring 51 can slide along the proximal direction of the operating handle 5 under the drive of an external force, causing the cable 2 to slide along the outer sheath 1, thereby pushing or retracting the loop 3 from the distal end of the outer sheath 1.
[0049] Example 2: This example provides an electric coil holder, such as... Figure 7 and Figure 8 As shown, its structure is basically the same as that of Embodiment 1, except that the materials of the collar 3, outer sheath 1 and clamp 11, as well as the operating handle 5, are slightly different from those of Embodiment 1.
[0050] In this embodiment, the metal wire forming the loop 3 is a stainless steel wire. Both ends of the stainless steel wire are inserted into the cavity from the distal end of the outer sheath 1. The portion of the stainless steel wire outside the outer sheath 1 has an annular structure, which is used to loop and cut the lesion. The annular structure is generally elliptical in shape. The stainless steel wire is also bent to form a V-shaped guide portion 34 located at the distal end of the annular structure and extending outwards. The stainless steel wire is also bent to form multiple first V-shaped barbs 35 and second V-shaped barbs 36 extending inwards into the annular structure. The first V-shaped barbs 35 and second V-shaped barbs 36 are located from the middle to the distal end of the annular structure and are asymmetrically distributed on opposite sides of the annular structure. The first V-shaped barbs 35 and second V-shaped barbs 36 increase the contact area with the polyp, and their hook-like shape increases the gripping force, making it less prone to slippage during looping. This solves the problem of slippage when looping flat polyps and allows for more complete removal of the lesion.
[0051] In this embodiment, both the outer sheath 1 and the clamp 11 are made of insulating polymer material PTFE, and the distal end of the outer sheath 1 with the clamp 11 is not easily deformed or damaged during use.
[0052] In this embodiment, the operating handle 5 is a prior art device, and the operating handle 5 is equipped with a ring 51 and an electrode head 52. The ring 51 is directly or indirectly connected to the cable 2, and the ring 51 can slide along the proximal direction of the operating handle 5 under the drive of an external force, driving the cable 2 to slide along the outer sheath 1, thereby driving the collar 3 to be pushed out or retracted from the distal end of the outer sheath 1. The electrode head 52 is directly or indirectly connected to the cable 2 and is used to connect an external high-frequency electrosurgical unit to achieve the thermal ablation function.
[0053] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.
Claims
1. A snare device, characterized in that, It includes: An outer sheath (1) has a cavity that is open at both ends extending from one end to the other, and a clamp (11) is fixedly provided at the distal end of the outer sheath (1), the inner diameter of the clamp (11) being smaller than the inner diameter of the cavity; A cable (2) is movably inserted into the cavity; The collar (3) is formed by bending a metal wire, with both ends of the metal wire inserted into the cavity from the distal end of the outer sheath (1), and the portion of the metal wire outside the outer sheath (1) has a ring structure; A connecting tube (4) is disposed between the distal end of the cable (2) and both ends of the metal wire for fixing the cable (2) and the collar (3). The connecting tube (4) is located in the cavity and its outer diameter is larger than the inner diameter of the clamp (11). The connecting tube (4) is a hollow tube. The distal end of the cable (2) is inserted from the proximal end of the connecting tube (4), and both ends of the metal wire are inserted from the distal end of the connecting tube (4). The sidewalls of the distal end of the cable (2) and the sidewalls of both ends of the metal wire are respectively connected to the... The inner wall of the connecting tube (4) is fixedly connected, the outer diameter of the cable (2) is greater than twice the outer diameter of the metal wire, the connecting tube (4) includes a first part (41) fixedly connected to the cable (2) and a second part (42) fixedly connected to both ends of the metal wire, the first part (41) and the second part (42) are integrally formed, the inner diameter of the first part (41) is greater than the inner diameter of the second part (42), and the inner diameter of the first part (41) is approximately equal to the outer diameter of the cable (2); The operating handle (5), which is located at the proximal end of the outer sheath (1) and the proximal end of the cable (2), can drive the cable (2) to move in the outer sheath (1) and drive the collar (3) to be pushed out or pulled in from the distal end of the outer sheath (1).
2. The snare device according to claim 1, characterized in that, The clamp (11) includes an annular portion fitted on the distal end face of the outer sheath (1) and a connecting portion extending from the annular portion to the proximal end and inserted into the cavity. The connecting portion is provided with a plurality of barbed structures inserted into the wall of the outer sheath (1).
3. The snare device according to claim 1, characterized in that, The distal end of the cable (2) is fixedly connected to both ends of the metal wire, and the connection point is located in the middle of the connecting tube (4).
4. The snare device according to claim 1, characterized in that, The first part (41) has a first channel (411) with an inner diameter approximately equal to the outer diameter of the cable (2). The second part (42) has a second channel (421) and a third channel (422) that are parallel to each other and have inner diameters approximately equal to the outer diameter of the metal wire, respectively. The distal end of the cable (2) is fixedly inserted in the first channel (411), one end of the metal wire is fixedly inserted in the second channel (421), and the other end is fixedly inserted in the third channel (422).
5. The snare device according to claim 1, characterized in that, The length of the connecting tube (4) is 5~6mm, and the lengths of the first part (41) and the second part (42) are each one-third to one-half of the length of the connecting tube (4).
6. The snare device according to claim 1, characterized in that, The metal wire comprises a first metal wire (31), a second metal wire (32), and a third metal wire (33) connected sequentially from one end to the other. The first metal wire (31) and the third metal wire (33) are made of stainless steel, and the second metal wire (32) is made of nickel-titanium. The first metal wire (31) and the third metal wire (33) are of equal length, and the second metal wire (32) occupies one-half to four-fifths of the annular structure.
7. The snare device according to claim 1, characterized in that, The metal wire is also bent to form a plurality of first V-shaped barb structures (35) and second V-shaped barb structures (36) extending into the interior of the annular structure. The first V-shaped barb structures (35) and second V-shaped barb structures (36) are located in the middle to the far end of the annular structure, respectively, and are asymmetrically distributed on opposite sides of the annular structure.
8. The snare device according to claim 1, characterized in that, The outer sheath (1) is made of polymer material; And / or, the cable (2) is made of metal; And / or, the clamp (11) is made of stainless steel or insulating polymer material; And / or, the connecting pipe (4) is made of metal; And / or, the ring structure is generally elliptical in shape; And / or, the wire is also bent to form a V-shaped guide (34) located at the distal end of the annular structure and extending outward from the annular structure.