A gradient tower spring valve anti-reflux esophageal stent

Abstract

The present invention belongs to the field of medical device technology and discloses a gradient tower spring valve anti-reflux esophageal stent, comprising a stent body, a gradient tower spring valve, a stent stop buckle, and a retrieval line. The stent body is composed of support ribs and connecting ribs, and the connecting ribs are used to connect the support ribs. Each connecting rib at both ends of the stent body is provided with a snap-fit ​​ring, and each support rib at the proximal end of the stent body is provided with a retrieval line matching ring. The gradient tower spring valve is arranged inside the stent body. When compressed, its flow-blocking baffle, tower spring body, and connecting base squeeze each other to close the stent passage. The stent stop buckle is fixed to the stent body with a corresponding snap-fit ​​ring for effective stop within a standard esophageal stent. The retrieval line passes through the retrieval line matching ring in sequence and can be used to reduce the upper opening of the stent body for removal. The present invention is used for secondary treatment after the implantation of a standard esophageal stent, and has a good anti-reflux effect, can prevent stent migration, and avoid esophageal bleeding.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to an anti-reflux esophageal stent. Background Art

[0002] Esophageal cancer is one of the major malignant tumors currently threatening human health. In recent years, the incidence and mortality rates of esophageal cancer have continued to rise, and its complications severely impact patients' quality of life, causing significant suffering. The primary manifestations of esophageal cancer include difficulty swallowing and pain. Most patients are already in the advanced stages of the disease at the time of initial diagnosis, having missed the optimal opportunity for surgical resection. For patients who are unable to undergo surgery, esophageal stent implantation is a well-established palliative treatment option that can alleviate dysphagia and improve their quality of life.

[0003] After esophageal stent implantation, the vast majority of patients experience numerous postoperative complications, such as gastroesophageal reflux, stent migration, esophageal bleeding, and chest pain. Because esophageal cancer lesions are often located near the gastroesophageal junction and cardia, studies have shown that the incidence of gastroesophageal reflux can be as high as 70%–100%. For postoperative complications like gastroesophageal reflux, proton pump inhibitors and other medications are often the first-line treatment. However, some patients taking proton pump inhibitors still experience severe gastroesophageal reflux, even leading to aspiration and death. Over the past two decades, various anti-reflux stents have gradually come into use. However, clinical studies have found that their anti-reflux efficacy is controversial, with conflicting results. Therefore, direct anti-reflux stent implantation is generally not recommended for patients with esophageal cancer. For patients who do not respond well to proton pump inhibitors, secondary anti-reflux stent implantation within the previously placed stent is a promising and research-worthy treatment option. Summary of the Invention

[0004] The present invention aims to solve the technical problems of existing anti-reflux esophageal stents, such as poor anti-reflux effect, stent migration and esophageal bleeding, and provide a gradient tower spring valve anti-reflux esophageal stent for secondary treatment after the implantation of a standard esophageal stent. It has good anti-reflux effect, can prevent stent migration and avoid esophageal bleeding.

[0005] In order to solve the above technical problems, the present invention is implemented through the following technical solutions:

[0006] The present invention provides a gradient tower spring valve anti-reflux esophageal stent, comprising a stent body, a gradient tower spring valve, and a stent hanging buckle;

[0007] The bracket body is composed of support ribs and connecting ribs. A plurality of support ribs are evenly spaced along the axial direction of the bracket. Adjacent support ribs are connected to each other by connecting ribs. A plurality of connecting ribs are evenly distributed circumferentially between adjacent support ribs. Each connecting rib at both ends of the bracket body is provided with a snap-fit ​​ring, which is arranged in the space between adjacent support ribs.

[0008] The gradient tower spring valve is arranged inside the supporting rib located in the middle section of the stent body, and includes a tower spring body, a flow blocking baffle and a connecting base, and can realize functional opening and closing through axial expansion and contraction; the connecting base is relatively close to the proximal end of the stent body in the gradient tower spring valve, and is used to realize the fixed connection between the gradient tower spring valve and the stent body; the side of the connecting base close to the proximal end of the stent body is provided with a drainage slope, and the drainage slope is inclined from the outer edge of the connecting base to the center; the flow blocking baffle is relatively close to the distal end of the stent body in the gradient tower spring valve end; a flow-blocking slope is provided on one side of the flow-blocking baffle close to the distal end of the stent body, and the flow-blocking slope is inclined from the outer edge of the flow-blocking baffle toward the center; the two ends of the tower spring body are respectively connected to the flow-blocking baffle and the connecting base as a whole, and are spirally wound and have a diameter that decreases in each circle from the connecting base to the flow-blocking baffle; the elastic modulus of the material of the tower spring body decreases according to a gradient function from the connecting base to the flow-blocking baffle; when the gradient tower spring valve is compressed, the flow-blocking baffle, the tower spring body and the connecting base squeeze each other to close the stent channel;

[0009] The bracket stop buckle is arranged on each of the connecting ribs located at both ends of the bracket body, and cooperates with the corresponding buckle matching ring to fix it to the bracket body; the bracket stop buckle is formed as an integral part of a limit body and a buckle ring; the limit body includes a baffle and a group of positioning pins arranged on the baffle; the buckle ring includes an integrally formed ring rod portion and a double straight rod portion, and the end of the double straight rod portion is fixedly connected to the baffle; the outer diameter of the ring rod portion of the buckle ring is larger than the inner diameter of the buckle matching ring, and can pass through the buckle matching ring after compression deformation and restore its original shape; the double straight rod portion is inserted into the buckle matching ring to form a matching relationship with it, and the positioning pins are clamped on both sides of the connecting rib to limit the rotational movement of the bracket stop buckle relative to the bracket body.

[0010] Furthermore, the support ribs are sinusoidal continuous ring frames formed by integrally forming "positive U"-shaped rods and "inverted U"-shaped rods at intervals; the spacing between adjacent support ribs is equal, and the positions of the "positive U"-shaped rods and the "inverted U"-shaped rods correspond one to one.

[0011] Furthermore, the connecting ribs are straight rod-shaped structures and are staggered in the axial direction.

[0012] Furthermore, the axial directions of the snap-fit ​​ring and the recovery line fitting ring are the same as the radial direction of the bracket body.

[0013] Furthermore, the outer edge of the connection base is cast-connected to the support rib, and the support rib in contact with the connection base is provided with anti-migration corrugations.

[0014] Furthermore, the inclination angles of the diversion slope and the flow blocking slope are both 5°-10°.

[0015] Furthermore, the gradient tower spring valve is made of liquid silicone rubber.

[0016] Furthermore, the gradient function of the decreasing elastic modulus of the material of the tower spring body is a linear function or a power function with different power exponents n.

[0017] Furthermore, the bracket body and the bracket hanging buckle are both made of nickel-titanium alloy.

[0018] Furthermore, a recovery line matching ring is provided at the end of each support rib located at the proximal end of the stent body; the recovery line passes through the recovery line matching ring in a clockwise or counterclockwise order, one positive and one negative; the recovery line can shrink the upper opening of the stent body and remove it.

[0019] The beneficial effects of the present invention are:

[0020] (1) The gradient spring-valve anti-reflux esophageal stent of the present invention utilizes a gradient spring valve. When the patient is eating normally, the gradient spring valve opens in the direction of the flow, allowing swallowed food to pass through. When the patient experiences gastroesophageal reflux, the gradient spring valve is compressed, and the flow-blocking baffle, spring body, and connecting base squeeze each other to close the stent passage, thereby preventing the passage of chyme. The anti-reflux function of the present invention is achieved through the gradient elastic modulus design of the spring body material and the flow-blocking slope design of the flow-blocking baffle.

[0021] (2) The gradient tower spring valve anti-reflux esophageal stent of the present invention has a snap ring that passes through the metal wire gap of the standard esophageal stent previously implanted in the patient's esophagus. At this time, the standard esophageal stent is located between the limiter of the stent stop buckle and the circular ring part of the snap ring, that is, the straight part of the snap ring crosses the stent body of the present invention and the standard esophageal stent previously implanted in the patient's esophagus. The stent body of the present invention and the standard esophageal stent are fitted together. Under the joint action of multiple stent stop buckles, the present invention is stopped in the standard esophageal stent, thereby realizing the anti-migration function of the present invention.

[0022] (3) The gradient tower spring valve anti-reflux esophageal stent of the present invention has a stent body and a stent hanging buckle made of nickel-titanium alloy, which has good support and flexibility. The ends are designed as arc structures, which can better avoid damage to the esophagus and prevent the occurrence of esophageal bleeding.

[0023] (IV) The gradient tower spring valve anti-reflux esophageal stent of the present invention can be retrieved by grasping the retrieval line with a matching stent extractor or rat tooth forceps under endoscopy during stent retrieval, so that the upper opening of the stent can be reduced and then removed with endoscopy. The present invention can also be removed together with a standard esophageal stent previously implanted in the patient's esophagus. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of the gradient tower spring valve anti-reflux esophageal stent;

[0025] Figure 2 This is a schematic diagram of the deployment of the stent body in the gradient tower spring valve anti-reflux esophageal stent;

[0026] Figure 3 Schematic diagram of the structure of the gradient tower spring valve in the gradient tower spring valve anti-reflux esophageal stent;

[0027] Figure 4 Schematic diagram of the gradient elastic modulus of the main body of the tower spring in the gradient tower spring valve anti-reflux esophageal stent;

[0028] Figure 5 This is a schematic diagram of the full cross-sectional structure of the gradient tower spring valve in the gradient tower spring valve anti-reflux esophageal stent;

[0029] Figure 6 for Figure 1 A schematic diagram of the enlarged structure of the middle part A;

[0030] Figure 7 Schematic diagram of the structure of the stent stop buckle in the gradient tower spring valve anti-reflux esophageal stent.

[0031] In the above figure:

[0032] 1—Stent body; 11—Support rib; 111—Anti-migration corrugation; 12—Connecting rib; 121—Snap-fit ​​ring; 122—Recovery line fitting ring; 2—Gradient tower spring valve; 21—Tower spring body; 22—Flow blocking baffle; 221—Flow blocking slope; 23—Connecting base 231—Drainage slope; 3—Stent stop buckle; 31—Limiting body; 32—Snap-fit ​​ring; 4—Recovery line. DETAILED DESCRIPTION

[0033] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0034] like Figure 1 As shown, this embodiment provides a gradient tower spring valve anti-reflux esophageal stent, which mainly includes a stent body 1, a gradient tower spring valve 2, a stent hanging buckle 3 and a recovery line 4.

[0035] Combine Figure 2 As shown, the bracket body 1 is composed of support ribs 11 and connecting ribs 12. The connecting ribs 12 are used to connect the support ribs 11 into one body.

[0036] Multiple support ribs 11 are evenly spaced along the stent's axial direction, with the number of ribs 11 ranging from 4 to 8 depending on the patient's clinical needs. Each rib 11 is identical in structure, forming a quasi-sinusoidal continuous ring frame with spaced-apart "right U"-shaped and "inverted U"-shaped rods. Adjacent ribs 11 are evenly spaced, and the positions of the "right U"-shaped and "inverted U"-shaped rods correspond one to one.

[0037] Adjacent support ribs 11 are connected to each other by connecting ribs 12. The connecting ribs 12 are straight rod-shaped structures, and multiple connecting ribs 12 are evenly distributed circumferentially between adjacent support ribs 11. The number of connecting ribs 12 between every two adjacent support ribs 11 is set to 3-6 based on mechanical calculations and customization requirements. In order to better balance the support and flexibility of the stent, the connecting ribs 12 are staggered in the axial direction, that is, the staggered intervals between two adjacent rows of connecting ribs 12 are 1-2 "positive U"-shaped rods or "inverted U"-shaped rods. In addition, each connecting rib 12 located at both ends of the stent body 1 is provided with a snap-fit ​​ring 121. The snap-fit ​​ring 121 is set within the space between adjacent support ribs 11 to avoid interference with the support ribs 11. A recovery line matching ring 122 is provided at the end of each support rib 11 located at the proximal end of the stent body 1. The axial direction of the snap-fit ​​ring 121 and the recovery line matching ring 122 is the same as the radial direction of the stent body 1.

[0038] The proximal end of the stent body 1 refers to the end close to the human oral cavity and throat after the stent is implanted in the esophagus, and the distal end of the stent body 1 refers to the end away from the human oral cavity and throat after the stent is implanted in the esophagus.

[0039] Combine Figure 3-Figure 5 As shown, the gradient tower spring valve 2 is arranged inside the support rib 11 located in the middle section of the stent body 1, including a tower spring body 21, a flow blocking baffle 22 and a connecting base 23, and can achieve functional opening and closing through axial expansion and contraction.

[0040] The connecting base 23 is a flat cylindrical structure. In the gradient tower spring valve 2, it is relatively close to the proximal end of the stent body 1 and is used to achieve a fixed connection between the gradient tower spring valve 2 and the stent body 1. Specifically, the outer edge of the connecting base 23 is cast-connected to the support rib 11, and the support rib 11 in contact with the connecting base 23 is provided with an anti-migration corrugation 111. The connecting base 23 made of silicone rubber material wraps the anti-migration corrugation 111 to achieve a fixed connection, preventing the gradient tower spring valve 2 from axially displacing along the stent body 1. The shape of the anti-migration corrugation 111 can be wavy or broken line. To avoid interference between the anti-migration corrugations 111, their bending direction remains consistent along the circumference of the stent body 1. In order to enhance the forward drainage effect of the gradient tower spring valve 2, a drainage slope 231 is provided on the side of the connecting base 23 close to the proximal end of the stent body 1. The drainage slope 231 is inclined from the outer edge of the connecting base 23 to the center, and the inclination angle is preferably 5°-10°. The drainage slope 231 can facilitate the smooth passage of food swallowed by the human body.

[0041] The flow baffle 22 is a flattened cylinder located relatively close to the distal end of the stent body 1 in the gradient tower spring valve 2. When chyme refluxes, the larger surface area of ​​the flow baffle 22 better blocks the passage of chyme. Furthermore, the pressure exerted on the flow baffle 22 by the refluxed chyme more effectively promotes the functional closure of the gradient tower spring valve 2. To enhance the reverse anti-reflux effect of the gradient tower spring valve 2, a flow-blocking slope 221 is provided on the side of the flow baffle 22 near the distal end of the stent body 1. The flow-blocking slope 221 is inclined from the outer edge of the flow baffle 22 toward the center, with an angle of preferably 5°-10°.

[0042] The main spring body 21 is a spirally wound structure, integrally connected to the flow baffle 22 and the connecting base 23 at each end. Both the outer and inner diameters decrease in size from the connecting base 23 to the flow baffle 22. As food is swallowed by the patient, the main spring body 21 functionally stretches and opens axially, allowing food to pass smoothly through the gaps in the main spring body 21, completing swallowing. To ensure a more secure compression seal when the gradient spring valve 2 is compressed, the main spring body 21 can have a rectangular, trapezoidal, or elliptical cross-sectional shape.

[0043] The gradient spring valve 2 is made of medical additive-type liquid silicone rubber. When the gradient spring valve 2 is used, when the patient eats normally, the gradient spring valve 2 opens downstream to allow swallowed food to pass through; when the patient has gastroesophageal reflux, the gradient spring valve 2 is compressed, and its flow-blocking baffle 22, spring body 21 and connecting base 23 squeeze each other to close the stent channel, thereby preventing the passage of chyme. The elastic modulus of the material of the spring body 21 decreases according to a preset gradient function from the connecting base 23 to the flow-blocking baffle 22, thereby achieving better anti-reflux closure performance. As a preferred embodiment, the gradient function can be a linear function or a power function with different power exponents n. The power exponent n of the power function is determined according to actual functional requirements, such as 0.2, 0.5, 2 and 5.

[0044] Combine Figure 6-Figure 7 As shown, the bracket anchoring clips 3 are mounted on each connecting rib 12 at each end of the bracket body 1 and engage corresponding snap rings 121 to secure them to the bracket body 1. Like the snap rings 121, the bracket anchoring clips 3 are also located within the space between adjacent support ribs 11 to avoid interference with the support ribs 11.

[0045] The bracket anchor clip 3 is integrally formed of a stopper 31 and a snap ring 32. The stopper 31 includes a baffle and a set of locating pins mounted on the baffle. The locating pins can be shaped like cylinders, rectangular parallelepipeds, or triangular prisms, as long as they can be clamped on both sides of the connecting rib 12. The snap ring 32 is formed by fitting the ends of a rod-shaped body together and bending the middle. After forming, it consists of a bent ring rod portion (which can be circular or elliptical) and two fitted straight rod portions. The ends of the two straight rod portions are fixedly connected to the center of the baffle of the stopper 31.

[0046] The stent body 1 and the stent hanging buckle 3 are both made of nickel-titanium alloy, which has good support and flexibility; moreover, the ends of the stent body 1 and the stent hanging buckle 3 are designed as arc structures, which can better avoid damage to the esophagus and prevent esophageal bleeding.

[0047] The outer diameter of the stem of the shape-memory nickel-titanium alloy snap ring 32 is larger than the inner diameter of the snap ring 121. After compression deformation, the stem passes through the snap ring 121, then returns to its original shape. This prevents the stent anchor buckle 3 from falling out of the stent body 1 and effectively anchors the stent within the standard esophageal stent. The dual straight stems of the snap ring 32 fit within the snap ring 121, forming a mating relationship. The positioning pins of the stopper 31 are clamped on both sides of the connecting rib 12, limiting the rotational movement of the stent anchor buckle 3 relative to the stent body 1. The baffle of the stopper 31 also serves a limiting function.

[0048] The retrieval line 4 is preferably made of nylon and is passed through the retrieval line matching ring 122 in a clockwise or counterclockwise order, one forward and one backward. Thus, when retrieving the stent, the retrieval line 4 can be grasped under endoscopy with a matching stent extractor or rat-tooth forceps to reduce the upper opening of the stent body 1 and then be removed with the endoscope. Alternatively, the entire stent can be removed along with a standard esophageal stent previously implanted in the patient's esophagus.

[0049] The gradient tower spring valve anti-reflux esophageal stent of the present invention is used as follows:

[0050] Using an endoscope, the stent of the present invention is delivered to a standard esophageal stent previously implanted in the patient's esophagus via a guidewire. The stent of the present invention is adjusted in position so that the snap ring 32 passes through the wire gap of the previous standard esophageal stent, thereby achieving the stent of the present invention being suspended in the previous standard esophageal stent. The stent body 1 is compressed in vitro and placed in a delivery system. The structural gap of the gradient tower spring valve 2 allows the guidewire to pass through. The two are moved with the delivery system into the standard esophageal stent previously implanted in the patient's esophagus. The stent of the present invention is adjusted in position so that the snap ring 32 passes through the wire gap of the previous standard esophageal stent. The stent of the present invention is released and deployed, so that the standard esophageal stent is positioned between the limiting body 31 of the stent suspension buckle 3 and the circular ring portion of the snap ring 32. That is, the double straight rod portion of the snap ring 32 crosses the stent body 1 of the present invention and the standard esophageal stent previously implanted in the patient's esophagus, achieving the stent of the present invention being suspended in the previous standard esophageal stent. The delivery system is then withdrawn, completing the stent implantation procedure of the present invention.

[0051] The stent body 1 fits in line with previous standard esophageal stents. When the patient is eating normally, the gradient spring valve 2 opens to allow swallowed food to pass through. When the patient experiences gastroesophageal reflux, the gradient spring valve 2 is compressed, and the flow-blocking baffle 22, spring body 21, and connecting base 23 squeeze together to seal the stent passage, thereby preventing the passage of chyme. The anti-reflux function of the present invention is achieved through the gradient elastic modulus design of the spring body 21 and the flow-blocking slope 221 of the flow-blocking baffle 22.

[0052] According to medical needs, when stent retrieval is required, a matching stent extractor or rat-tooth forceps is used under endoscopy to grasp the retrieval line 4 of the stent of the present invention, so that the upper opening of the stent is reduced and then removed with endoscopy. The present invention can also be removed together with a standard esophageal stent previously implanted in the patient's esophagus.

[0053] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms of specific changes without departing from the scope of protection of the invention and the claims. These all fall within the scope of protection of the present invention.

Claims

1. A gradient tower spring valve anti-reflux esophageal stent, characterized by: It includes a stent body, a gradient tower spring valve, and a stent stop buckle; The bracket body is composed of support ribs and connecting ribs. A plurality of support ribs are evenly spaced along the axial direction of the bracket. Adjacent support ribs are connected to each other by connecting ribs. A plurality of connecting ribs are evenly distributed circumferentially between adjacent support ribs. Each connecting rib at both ends of the bracket body is provided with a snap-fit ​​ring, which is arranged in the space between adjacent support ribs. The gradient tower spring valve is arranged inside the supporting rib located in the middle section of the stent body, and includes a tower spring body, a flow blocking baffle and a connecting base, and can realize functional opening and closing through axial expansion and contraction; the connecting base is relatively close to the proximal end of the stent body in the gradient tower spring valve, and is used to realize the fixed connection between the gradient tower spring valve and the stent body; the side of the connecting base close to the proximal end of the stent body is provided with a drainage slope, and the drainage slope is inclined from the outer edge of the connecting base to the center; the flow blocking baffle is relatively close to the distal end of the stent body in the gradient tower spring valve end; a flow-blocking slope is provided on one side of the flow-blocking baffle close to the distal end of the stent body, and the flow-blocking slope is inclined from the outer edge of the flow-blocking baffle toward the center; the two ends of the tower spring body are respectively connected to the flow-blocking baffle and the connecting base as a whole, and are spirally wound and have a diameter that decreases in each circle from the connecting base to the flow-blocking baffle; the elastic modulus of the material of the tower spring body decreases according to a gradient function from the connecting base to the flow-blocking baffle; when the gradient tower spring valve is compressed, the flow-blocking baffle, the tower spring body and the connecting base squeeze each other to close the stent channel; The bracket stop buckle is arranged on each of the connecting ribs located at both ends of the bracket body, and cooperates with the corresponding buckle matching ring to fix it to the bracket body; the bracket stop buckle is formed as an integral part of a limit body and a buckle ring; the limit body includes a baffle and a group of positioning pins arranged on the baffle; the buckle ring includes an integrally formed ring rod portion and a double straight rod portion, and the end of the double straight rod portion is fixedly connected to the baffle; the outer diameter of the ring rod portion of the buckle ring is larger than the inner diameter of the buckle matching ring, and can pass through the buckle matching ring after compression deformation and restore its original shape; the double straight rod portion is inserted into the buckle matching ring to form a matching relationship with it, and the positioning pins are clamped on both sides of the connecting rib to limit the rotational movement of the bracket stop buckle relative to the bracket body.

2. The gradient tower spring valve anti-reflux esophageal stent according to claim 1, characterized in that: The support ribs are a quasi-sine continuous ring frame formed by integrally forming a "positive U"-shaped rod body and an "inverted U"-shaped rod body at intervals; the spacing between adjacent support ribs is equal, and the positions of the "positive U"-shaped rod body and the "inverted U"-shaped rod body correspond one to one.

3. The gradient tower spring valve anti-reflux esophageal stent according to claim 1, characterized in that: The connecting ribs are straight rod-shaped structures and are staggered in the axial direction.

4. The gradient tower spring valve anti-reflux esophageal stent according to claim 1, characterized in that: A recovery line matching ring is provided at the end of each support rib located at the proximal end of the stent body; the axial direction of the snap-fitting ring and the recovery line matching ring is the same as the radial direction of the stent body.

5. The gradient tower spring valve anti-reflux esophageal stent according to claim 4, characterized in that: The recovery line passes through the recovery line matching ring in a clockwise or counterclockwise order, one forward and one reverse; the upper opening of the stent body can be reduced and taken out through the recovery line.

6. The gradient tower spring valve anti-reflux esophageal stent according to claim 1, characterized in that: The outer edge of the connection base is cast-connected to the support rib, and the support rib in contact with the connection base is provided with anti-migration corrugations.

7. The gradient tower spring valve anti-reflux esophageal stent according to claim 1, characterized in that: The inclination angles of the diversion slope and the flow blocking slope are both 5°-10°.

8. The gradient tower spring valve anti-reflux esophageal stent according to claim 1, characterized in that: The gradient tower spring valve is made of liquid silicone rubber.

9. The gradient tower spring valve anti-reflux esophageal stent according to claim 1, characterized in that: The gradient function of the decreasing elastic modulus of the material of the tower spring body is a linear function or a power function with different power exponents n.

10. The gradient tower spring valve anti-reflux esophageal stent according to claim 1, characterized in that: The bracket body and the bracket hanging buckle are both made of nickel-titanium alloy.

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