CN117898868A - Biliary pancreatic duct support capable of automatically discharging human body and preparation method - Google Patents

Abstract

The invention relates to the technical field of medical equipment, and provides a biliary pancreatic duct bracket capable of automatically discharging a human body, which comprises: the hollow spherical structure comprises a guide hole and a hollow area, the guide hole and the hollow area are respectively positioned at two ends of the hollow spherical structure, the hollow area comprises a first hollow area and a second hollow area, the support body is connected between the first hollow area and the second hollow area, the second hollow area is positioned outside the support body, the support body comprises grid lines and a supporting layer wrapping the grid lines, the grid lines are non-degradable materials, the supporting layer is made of degradable materials, the support body is in a grid cylindrical framework, and the diameter d1 of one end of the support body, which is close to the hollow area, is smaller than the diameter d2 of one end of the support body, which is far away from the hollow area; the covering layer covers the second hollow area, and is gradually degraded after being implanted into a human body. Solves the technical problem that the non-degradable stent in the prior art needs secondary operation, and the irregular degradation products generated after the degradation of the degradable stent can cause damage to the human body again.

Description

Biliary pancreatic duct support capable of automatically discharging human body and preparation method

Technical Field

The invention relates to the technical field of medical equipment, in particular to a biliary pancreatic duct bracket capable of automatically discharging a human body and a preparation method thereof.

Background

When the human body suffers from biliary tract or pancreatic obstruction, biliary tract obstruction may be caused by gall-stone, biliary tract stenosis, biliary tract tumor, etc., pancreatic duct obstruction may be caused by pancreatitis, pancreatic tumor, etc., and a temporary biliary duct stent or pancreatic duct stent needs to be placed in the human body. The main function of the brackets is that under the condition that biliary tract or pancreas obstruction exists in a patient, the normal drainage of bile can be maintained by placing the bile duct brackets, and jaundice and other symptoms related to biliary tract obstruction are relieved; placement of the pancreatic duct support helps to maintain proper drainage of pancreatic juice. The stent can help keep the liquid unobstructed, alleviate the symptoms of the patient and promote the healing of the tissues. Once the obstruction problem is alleviated, the stent is removed.

While the prior art metallic stents can help maintain proper drainage of fluid, they still require a secondary procedure to remove them after a period of time, which undoubtedly increases patient pain and may increase the likelihood of secondary surgery causing other trauma. And the end of the bracket is positioned at the outer side of the duodenal papilla, so that food residues are likely to enter the bracket through the end of the bracket when the bracket is positioned in the duodenum, and then enter the bile duct to cause infection.

Although degradable stents can degrade in the human body without secondary surgery, in practice, the gradual degradation of the stent is not controllable, and larger degradation fragments can be generated, part of the fragments can remain in the common bile duct to cause blockage, and part of the massive fragments can puncture the duodenum to cause bleeding and infection. These degraded fragments may again cause injury to the human body.

In order to reduce the problems that the injury to the patient is caused by secondary operation, the infection is caused by food residues entering the bracket, and the degradable bracket is possibly damaged again after degradation, the biliary pancreatic duct bracket capable of automatically discharging the human body needs to be comprehensively considered.

Disclosure of Invention

The invention aims to provide a bile and pancreatic duct bracket capable of automatically discharging a human body, which solves the technical problem that the non-degradable bracket in the prior art needs secondary operation and the degradable bracket can damage the human body again after degradation.

In a first aspect, an embodiment of the present invention provides a bile pancreatic duct stent capable of self-discharging a human body, including: the hollow spherical structure comprises a diversion hole and a hollow area, the diversion hole and the hollow area are respectively positioned at two ends of the hollow spherical structure, and the area of the hollow area is not more than one half of the surface area of the hollow spherical structure; the support body, the fretwork district includes first fretwork district and second fretwork district, the support body connect in first fretwork district with between the second fretwork district, the second fretwork district is located outside the support body, the support body includes the gridline, and parcel has the supporting layer of gridline, the gridline is non-degradable material, the supporting layer is degradable material, the support body is the framework of net tube-shape, the diameter d1 of the support body near the one end of fretwork district is less than the diameter d2 of the support body far away from the one end of fretwork district; the covering layer at least covers the second hollow area, and the covering layer is gradually degraded after being implanted into a human body.

Further, in a direction away from the hollow area, the diameter of the bracket body gradually becomes larger; or, in keeping away from the direction of fretwork area, the support body includes first expansion section, second and keeps section and third expansion section, first expansion section is keeping away from the direction of fretwork area is the diameter grow gradually, the diameter of second keeps the section unchanged, the third expansion section is keeping away from the direction of fretwork area is the diameter grow gradually.

Further, the outer diameter of the hollowed-out spherical structure is 3mm-6mm, and the thickness is 0.5mm-1mm.

Further, the aperture of the deflector hole is 1mm-2mm.

Further, the hollowed aperture of the first hollowed-out area is 1mm-2mm, and the ratio of the area of the first hollowed-out area to the area of the second hollowed-out area is 1:4-1:10.

Further, the diameter d1 of the end of the support body, which is close to the hollow area, is 1mm < d1<3mm, and the diameter of the end of the support body, which is close to the hollow area, is 6mm < d2<10mm.

Further, the area of the second hollowed-out area is equal to the product of the surface area of the hollowed-out spherical structure, the hollowed-out coefficient and the chyme viscosity coefficient; the hollowed-out coefficient is less than one half, and the chyme viscosity coefficient is less than one.

Further, the surface roughness of the area of the hollowed-out spherical structure not covered by the covering layer is smaller than 1 micron; the surface roughness of the area of the hollowed-out spherical structure covered by the covering layer is more than 100 micrometers.

Furthermore, the inner surface of the hollowed-out spherical structure is provided with a blocking structure.

Furthermore, the hollow spherical structure is made of polytetrafluoroethylene, polyether-ether-ketone, polymethyl methacrylate, polycarbonate, nylon or nylon elastomer.

Further, the material of the grid lines comprises polypropylene or polyamide.

Further, the material of the supporting layer and the covering layer comprises polylactic acid, polylactic acid-hydroxyl lactic acid copolymer, polycaprolactone, polylactic acid-caprolactone copolymer, polydioxanone, polyglycolic acid or polyhydroxyalkanoate.

Further, the grid lines and/or the supporting layer material comprise barium sulfate, bismuth subcarbonate, bismuth trioxide or bismuth oxychloride.

In a second aspect, the embodiment of the invention also provides a preparation method of the biliary-pancreatic duct stent capable of being automatically discharged from a human body, which comprises the following steps of: firstly, preparing a hollowed-out spherical structure; secondly, preparing grid lines; thirdly, wrapping the grid lines with a supporting layer; fourthly, preparing a covering layer; and fifthly, polishing the surface of the hollowed-out spherical structure and the covering layer.

Further, the preparing the grid lines includes: preparing the grid lines by adopting a fused deposition modeling process; or preparing the grid lines by adopting an injection molding process; or, adopting a pouring process to prepare the grid lines.

Further, the wrapping support layer for the grid lines includes: wrapping the grid lines with a supporting layer by adopting a fused deposition modeling process; or, wrapping the grid lines with a supporting layer by adopting a photo-curing process; or, adopting a pouring process to wrap the grid lines on the supporting layer; or, wrapping the grid lines with a supporting layer by adopting a thermal fusion method.

Furthermore, between the first step and the second step, the grid lines are connected with the hollowed-out spherical structure in a thermal fusion mode, and the grid lines are prepared after the connection.

Further, between the second step and the third step, the prepared grid lines are bonded to the hollowed-out spherical structure in a thermal fusion mode.

Further, between the third step and the fourth step, a thermal fusion mode is adopted to bond the prepared bracket body to the hollowed-out spherical structure.

The embodiment of the invention has at least the following technical effects:

The bile and pancreas tube support capable of automatically discharging a human body provided by the invention is clamped at the outer side of a duodenal papilla after being placed into the human body, comprises a diversion hole and a hollowed-out area, wherein the diversion hole and the hollowed-out area are respectively positioned at two ends of the hollowed-out spherical structure, and liquid can flow out through a part of the hollowed-out area and the diversion hole and acts on guiding the liquid to flow out of the hollowed-out spherical structure. The support body is the main part of whole courage pancreas pipe support, connects between the first fretwork district of fretwork spherical structure and second fretwork district, and its main effect lies in providing holding power, maintains the overall structure of support, and liquid can flow to first fretwork district through the internal passage of support body, flows from the water conservancy diversion hole again.

The support body includes gridlines and supporting layer, and wherein the gridlines are non-degradable material, have certain intensity and stability. The supporting layer uses degradable material, and the gridlines provide the basic structure of support but very soft do not possess the holding power as the inner core, and every line in the gridlines is wrapped up or partly wrapped up to the supporting layer whole, and the support body still constitutes net tubular structure, and the structural rigidity that the supporting layer formed is greater than the structural rigidity of gridlines, provides the holding power for the support body, forms the passageway of liquid flow. The diameter d1 of the one end that the support body is close to the fretwork district is less than the diameter d2 of the one end that the support body kept away from the fretwork district, can make the support body fix inside bile duct or pancreatic duct like this, and outside slip is not deviate from bile duct or pancreatic duct. After the drainage function is finished, the supporting layer is attached to the grid line, so that the supporting layer is still attached to the grid line when being degraded, and cannot be broken into uncontrollable fragments due to degradation, so that a human body is scratched. And when the supporting layer is degraded, the grid lines have no supporting force, the bracket body collapses, and then the bracket body is discharged out of the body along with the hollow spherical structure.

The covering layer is a layered structure covering the second hollow area, the second hollow area is covered at the beginning, foreign matters are prevented from entering the hollow spherical structure, the acting force of food residues on the hollow spherical structure is reduced, surrounding tissues of a patient are protected, the second hollow area is prevented from directly contacting a duodenal papilla, friction is reduced, after the second hollow area is exposed after the second hollow area is implanted into a human body to be degraded gradually, at the moment, the supporting layer of the support body is degraded gradually, the support body becomes soft, and the hollow spherical structure gradually falls under the combined action of self gravity and food residues in the duodenum. Meanwhile, the area of the hollowed-out area is not more than one half of the surface area of the hollowed-out spherical structure, so that the hollowed-out spherical structure still has the capability of capturing food residues after the covering layer is degraded, and after the second hollowed-out area is exposed, more food residues can drive the hollowed-out spherical structure and the softened bracket body to move outwards, and finally the food residues are discharged out of the body along with the food residues.

The hollow spherical structure, the bracket body and the cover layer are combined, so that the advantages are obvious, the shape and the structure of the spherical structure can reduce the stimulation to surrounding tissues, and the spherical structure can be smoothly discharged out of the body. Through the net tube-shape framework of support body, effective water conservancy diversion liquid, fretwork globular structure provides water conservancy diversion hole and fretwork district, maintains normal drainage. After the drainage is finished, the supporting layer is made of degradable materials, the covering layer is gradually degraded, and the support can be automatically discharged out of a human body by combining with the design of the hollowed-out spherical structure. The designed support structure aims at maintaining the unobstructed liquid, avoiding the requirement of secondary operation and generating uncontrollable fragments during degradation, reducing the risk and the pain of patients and providing more convenient and safer treatment selection for the patients.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of a first view structure of a biliary-pancreatic duct support capable of self-discharging a human body according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a second view structure of a biliary-pancreatic duct support capable of self-discharging a human body according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a third view structure of a biliary-pancreatic duct support capable of self-discharging a human body according to an embodiment of the present invention;

Fig. 4 is a schematic diagram of a portion of a support structure for a pancreatic duct capable of self-discharging a human body according to an embodiment of the present invention;

Fig. 5 is a schematic view of a state of a bile pancreatic duct stent capable of being self-discharged from a human body when the bile pancreatic duct stent is just implanted into the human body according to an embodiment of the present invention;

Fig. 6 is a schematic diagram of a state of a bile pancreatic duct stent capable of being automatically discharged from a human body when the bile pancreatic duct stent is gradually degraded in the human body according to an embodiment of the present invention;

Fig. 7 is a schematic diagram of a state of a bile pancreatic duct stent capable of being automatically discharged from a human body when the bile pancreatic duct stent completely enters a duodenum according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of another embodiment of a support for a pancreatic duct capable of self-draining from a human body;

FIG. 9 is a schematic view of a portion of another example of a support structure for a pancreatic duct capable of self-draining from a human body;

Fig. 10 is a first schematic cross-sectional view of a stent body according to an embodiment of the present invention;

fig. 11 is a second schematic cross-sectional view of a stent body according to an embodiment of the present invention.

Icon: 1-a hollowed-out spherical structure; 2-a bracket body; 3-a cover layer; 11-deflector holes; 12-hollow areas; 21-grid lines; 22-a support layer; 121-a first hollow region; 122-second hollowed-out area.

Detailed Description

The technical solutions of the present invention will be clearly and completely described in connection with the embodiments, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It will be understood by those skilled in the art that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs unless defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless expressly stated otherwise, as understood by those skilled in the art. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The term "and/or" as used herein includes all or any element and all combination of one or more of the associated listed items.

In a first aspect, referring to fig. 1 to 11, an embodiment of the present invention provides a bile pancreatic duct stent capable of self-discharging a human body, comprising: the hollow spherical structure 1 comprises a diversion hole 11 and a hollow area 12, wherein the diversion hole 11 and the hollow area 12 are respectively positioned at two ends of the hollow spherical structure 1, and the area of the hollow area 12 is not more than one half of the surface area of the hollow spherical structure 1; the support body 2, the fretwork district 12 includes first fretwork district 121 and second fretwork district 122, the support body 2 is connected between first fretwork district 121 and second fretwork district 122, second fretwork district 122 is located outside the support body 2, the support body 2 includes gridlines 21, and the supporting layer 22 of parcel gridlines 21, gridlines 21 are non-degradable material, supporting layer 22 is degradable material, the support body 2 is the net tubular structure, diameter d1 of the one end that the support body 2 is close to the fretwork district 12 is less than diameter d2 of one end that the support body 2 kept away from the fretwork district 12; and the covering layer 3 covers at least the second hollow area 122, and the covering layer 3 is gradually degraded after being implanted into a human body.

In this embodiment, the hollow spherical structure 1 is clamped on the outer side of the duodenal papilla after being placed into a human body, and comprises a diversion hole 11 and a hollow area 12, wherein the diversion hole 11 and the hollow area 12 are respectively positioned at two ends of the hollow spherical structure 1, and liquid can flow out through a part of the hollow area 12 and the diversion hole 11, and the liquid is guided to flow out of the hollow spherical structure 1. The bracket body 2 is a main body of the whole bile pancreatic duct bracket, is connected between the first hollow area 121 and the second hollow area 122 of the hollow spherical structure 1, and mainly has the function of providing supporting force to maintain the integral structure of the bracket, and liquid can flow to the first hollow area 121 through the internal channel of the bracket body 2 and then flow out from the diversion hole 11.

The support body 2 comprises grid lines 21 and a support layer 22, wherein the grid lines 21 are made of non-degradable materials, the support layer 22 is made of degradable materials, the grid lines 21 serve as an inner core to provide a basic structure of the support, but the support layer 22 is very soft and does not have supporting force, each line in the grid lines 21 is wrapped wholly (shown in fig. 10) or partially (shown in fig. 11), the support body 2 still forms a grid cylindrical framework, the structural rigidity of the support layer 22 is greater than that of the grid lines 21, supporting force is provided for the support body 2, and a liquid flow channel is formed. As shown in fig. 5, the diameter d1 of the end of the support body 2 near the hollow area 12 is smaller than the diameter d2 of the end of the support body 2 far away from the hollow area 12, so that the support body 2 is fixed inside the bile duct or pancreatic duct and does not slide outwards, and is separated from the bile duct or pancreatic duct. After the drainage, the supporting layer 22 is attached to the grid lines 21, so that when the supporting layer 22 is degraded, the supporting layer is still attached to the grid lines 21, the whole stent body 2 can be softened, but the supporting layer cannot be broken into uncontrollable fragments due to degradation, so that the human body is scratched. As shown in fig. 6, when the supporting layer 22 is degraded and the grid lines 21 have no supporting force, the stent body 2 collapses, and then the stent is driven by the hollow spherical structure 1 to exit the bile duct or pancreatic duct, and the grid lines 21 entering the duodenum part can still play a role of a net to capture food residues while the stent gradually exits the bile duct or pancreatic duct. Finally, as shown in fig. 7, when the stent is completely removed from the bile duct or the pancreatic duct and enters the duodenum, the grid lines 21 become soft clusters under the action of chyme and are discharged out of the body along with the hollow spherical structure 1.

The cover layer 3 is a layered structure covering the second hollow area 122, and covers the second hollow area 122 at the beginning, preventing foreign matters from entering the hollow spherical structure 1, reducing the acting force of food residues on the hollow spherical structure 1, protecting the surrounding tissues of a patient, preventing the second hollow area 122 from directly contacting the duodenal papilla, and reducing friction. After the cover layer 3 is gradually degraded when being implanted into a human body, the second hollow area 122 is exposed, at this time, the supporting layer 22 of the bracket body 2 is also gradually degraded, the bracket body 2 becomes soft, and the hollow spherical structure 1 gradually falls under the combined action of self gravity and food residues in the duodenum. Meanwhile, the area of the hollowed-out area 12 is not more than one half of the surface area of the hollowed-out spherical structure 1, so as to ensure that the hollowed-out spherical structure 1 still has the capability of capturing food residues after the cover layer 3 is degraded, and after the second hollowed-out area 122 is exposed, more food residues can drive the hollowed-out spherical structure 1 and the softened bracket body 2 to move outwards, and finally the food residues are discharged out of the body along with the food residues.

The hollow spherical structure 1, the bracket body 2 and the cover layer 3 are combined, so that the advantages are obvious, the stimulus to surrounding tissues can be reduced due to the shape and the structure of the spherical structure, and meanwhile, the hollow spherical structure can be smoothly discharged out of the body. Through the net tubular framework of the bracket body 2, liquid is effectively guided, and the hollow spherical structure 1 provides a guiding hole 11 and a hollow area 12 to maintain normal drainage. Referring to fig. 5, since bile duct or pancreatic duct in human body is inclined upward, hollow spherical structure 1 is downward, and food residues can not enter the inside of the bracket along diversion holes 11 to cause infection. After the drainage is finished, the supporting layer 22 is made of degradable materials, the covering layer 3 is gradually degraded, and the support can be automatically discharged out of a human body by combining the design of the hollow spherical structure 1. The designed support structure aims at maintaining the unobstructed liquid, avoiding the necessity of taking out the support by secondary operation, reducing the operation risk of a patient, avoiding uncontrollable fragments generated during degradation, reducing the damage risk and providing more convenient and safer treatment selection for the patient.

Alternatively, the diameter of the stent body 2 gradually becomes larger in a direction away from the hollowed-out area 12; or, in the direction of keeping away from the hollow area 12, the bracket body 2 includes a first expansion section, a second holding section and a third expansion section, the diameter of the first expansion section is gradually increased in the direction of keeping away from the hollow area 12, the diameter of the second holding section is unchanged, and the diameter of the third expansion section is gradually increased in the direction of keeping away from the hollow area 12.

In this embodiment, as shown in fig. 8, the diameter of the stent body 2 becomes larger gradually in the direction away from the hollow-out region 12 to enhance the fixation stability, and the increased diameter helps the stent to be more firmly embedded into the wall of the bile duct or pancreatic duct, and provides better support and fixation in the direction away from the hollow-out region 12 to prevent the stent from being unstable during implantation or use. Reduction of irritation and injury: the diameter gradually becomes larger, so that the stimulation and friction of the bracket to the inner wall of the pipeline can be reduced, the potential damage to the tissues of the patient can be reduced, and the comfort of the patient can be improved. The drainage efficiency is improved: through the design that increases gradually, the support can maintain the unobstructed of pipeline better, promotes the normal drainage of liquid, helps alleviateing bile or pancreatic juice and detains the problem.

Or as shown in fig. 4, the stent body 2 comprises a first expansion section, a second holding section and a third expansion section in a direction away from the hollow section 12, the segmented design providing more accurate support, through which the stent is divided into different segments in a direction away from the hollow section 12, each segment having a specific function, for example the first expansion section providing a moderate expansion, the second holding section providing a stable support, the third expansion section again providing a moderate expansion. The design enables the bracket to be more accurately adapted to different parts of the pipeline, and provides targeted support. Holding force that remains relatively constant: the constant diameter of the second retaining segment helps to maintain a relatively constant holding force, ensuring that the stent provides durable support at the location of this segment, preventing variation therein. Optimizing the adaptability to the pipeline: the progressively larger designs of the first and third expansion sections help optimize the adaptability to changes in the diameter of the pipe, providing support for a more flexible and conformable pipe. Reducing local irritation: the sectional design can slow down the diameter change, reduce local stimulation and stress, and help to alleviate discomfort of patients. Preferably, the ratio of the length L1 of the first expansion section, the length L2 of the second holding section and the length L3 of the third expansion section is 1:1:1.

Optionally, the outer diameter of the hollow spherical structure 1 is 3mm-6mm, and the thickness is 0.5mm-1mm. In the embodiment, the outer diameter is 3mm-6mm, the thickness is 0.5mm-1mm, and the physiological structure of the bile duct or pancreatic duct of a human body is mainly designed and considered, so that the bracket can adapt to the size of a corresponding pipeline, and the smoothness of insertion and discharge is ensured. The moderate thickness ensures enough structural strength, is beneficial to the flexibility of the bracket, and is better suitable for the bending and physiological activities of the pipeline. Simultaneously can also promote the self-discharge, in prescribed external diameter and thickness scope, the support can be more easily by oneself outside the body, and the moderate size of fretwork globular structure 1 combines the characteristic of support body 2, helps discharging outside the body along with food waste more smoothly in the in-process of degradation gradually. And reducing the risk of surgery, by precisely sizing the bulb, the potential problems caused by too large or too small bulb can be reduced, reducing the risk of surgery for stent implantation and ejection. The outer diameter of the hollow spherical structure 1 is related to the delivery mode, if the hollow spherical structure is delivered through an ERCP endoscope, the outer diameter cannot exceed 4mm, if the hollow spherical structure is delivered through a laparoscope, the outer diameter can be slightly larger, in the embodiment, the difference of the two delivery modes is considered, and the actual outer diameter can be appropriately selected within the range according to the difference of the operation modes.

Alternatively, the aperture of the diversion aperture 11 is 1mm-2mm. In this embodiment, the provision of the aperture of the deflector hole 11 of 1mm to 2mm has mainly the following effects: the diversion holes 11 with the aperture of 1mm-2mm can limit foreign matters (mainly food residues) to enter the bracket, prevent the foreign matters from blocking the diversion channel and ensure free circulation of liquid. Avoid excessive flowing back: the setting of the aperture can avoid excessive drainage, which may lead to increased burden on the bile duct or pancreatic duct, and the provision of the aperture range helps to maintain proper drainage speed, avoiding adverse effects on the patient. Preventing infection: the design of the small aperture is helpful for preventing bacteria or other microorganisms from entering the bracket, reducing the risk of infection and improving the safety of treatment.

Optionally, the hollow aperture of the first hollow area 121 is 1mm-2mm, and the ratio of the area of the first hollow area 121 to the area of the second hollow area 122 is between 1:4 and 1:10. In this embodiment, the ratio of the area of the first hollow area 121 to the area of the second hollow area 122 is between 1:4 and 1:10, so as to flexibly control the liquid discharge speed: the relatively small aperture and area of the first hollow region 121 may limit the discharge rate of the liquid to some extent, so that the discharge rate is more controllable. This is beneficial for gradually adapting or adjusting the drainage rate during the treatment. Adapt to different conditions: the design provides a certain flexibility for doctors while adapting to different patient conditions, and the used bracket specification can be adjusted according to actual conditions, so that the treatment requirements of patients are better met. Preferably, the hollow aperture of the first hollow area 121 is consistent with the aperture of the diversion hole 11.

Optionally, the diameter d1 of the end of the support body 2 near the hollow area 12 is 1mm < d1<3mm, and the diameter of the end of the support body 2 near the hollow area 12 is 6 mm < d2<10mm. In this embodiment, the diameter ranges of both ends of the stent body 2 are defined, mainly in that: improving the fixation: the smaller diameter d1 helps to ensure better fixation of the end of the stent body 2 adjacent to the hollow-out region 12 between the duodenal papilla and the bile duct or pancreatic duct, and the larger diameter d2 prevents the stent from sliding outwards. This helps to prevent the stent from slipping or falling off after implantation, improving the stability of the stent at the target site. Reducing the risk of injury: the smaller diameter d1 may reduce the contact surface between the stent and the wall of the canal, reducing irritation to surrounding tissue, thereby reducing discomfort to the patient and reducing risk of injury. Adapting to pipeline changes: the diameter d1 of the end of the bracket body 2, which is close to the hollow area 12, is smaller, so that the bracket is beneficial to adapting to the curvature or change of a pipeline which may exist, ensuring that the bracket can be tightly attached to the inner wall of the pipeline, and effectively maintaining the smoothness.

Optionally, the area S2 of the second hollowed-out area 122 is equal to the product of the surface area S of the hollowed-out spherical structure 1, the hollowed-out coefficient k and the chyme viscosity coefficient f; the hollowed-out coefficient k is less than one half, and the chyme viscosity coefficient f is less than one. I.e. s2=sxk×f. In this embodiment, considering that the distribution of food residues of different types of patients (such as different ages) is mainly different in the viscosity of the chyme, such as the difference between the particle and the fluidity of chyme of infants, adults and the elderly, the viscosity of the chyme is affected, the area S2 of the second hollow-out area 122 is related to the viscosity coefficient f of the chyme, and the area S2 of the corresponding second hollow-out area 122 is set in the corresponding different food residue scenes, so as to play the role of the second hollow-out area 122, such as the smaller the viscosity coefficient f of the chyme is, please refer to fig. 8 and 9, the smaller the area S2 of the corresponding second hollow-out area 122 is, and of course, the area covered by the first cover layer 3 is also small, so that the whole chyme is not easy to flow out if the chyme falls into the hollow-out spherical structure 1, and the acting force of the hollow-out spherical structure 1 can be improved; when the viscosity coefficient f of the chyme is larger, referring to fig. 1 and 4, the area S2 of the corresponding second hollowed-out area 122 is larger, so that the probability that the large-particle chyme falls into the hollowed-out spherical structure 1 can be increased, and the probability that the chyme falls into the hollowed-out spherical structure 1 can be improved. In a word, the area S2 of the second hollow-out area 122 is combined with the chyme viscosity coefficient f, so that the overall acting force of chyme on the support can be changed more finely, the support can be adapted to different types of patients more pertinently, and the second hollow-out area 122 can better capture chyme or drive the support to be discharged out of a human body under the pushing of chyme.

Specifically, the method for determining the value of the chyme viscosity coefficient f is as follows: the viscosity of chyme is first experimentally determined for different conditions (e.g., people of different ages). For example, a viscometer can be used to measure the viscosity of chyme at a particular temperature, pressure and shear rate; then, according to the viscosity of the chyme in different states, the range of different viscosity is set as a grading standard, the viscosity is divided into a plurality of grades, and each grade corresponds to a different chyme viscosity coefficient f. For example, the viscosity may be divided into 3 or 5 levels or even finer levels, each level corresponding to a certain chyme viscosity coefficient f-number, of course the higher the viscosity the greater the chyme viscosity coefficient f-number, but the chyme viscosity coefficient f is always less than 1; and finally, dividing corresponding value grades between 0 and 1 according to the set multiple grades for value of the chyme viscosity coefficient f. For example, dividing the viscosity into 4 levels, then the chyme viscosity coefficient f will have four values f1, f2, f3 and f4, f1, f2, f3 and f4 will take values between 0 to 0.25,0.26 to 0.50,0.51 to 0.75,0.76 to 1 (excluding 1), if f1 takes 0.1, f2, f3 and f4 take 0.35, 0.6 and 0.85 in order, if f1 takes 0.2, f2, f3 and f4 take 0.45, 0.7 and 0.95 in order, respectively. The specific viscosity grade and chyme viscosity coefficient f should be appropriately adjusted according to the actual situation.

Optionally, the surface roughness of the area of the hollow spherical structure 1 not covered by the cover layer 3, and the surface roughness of the cover layer 3 is less than 1 micrometer; the surface roughness of the area of the hollowed-out spherical structure 1 covered by the cover layer 3 is more than 100 micrometers. In this embodiment, the surface roughness of the area of the hollow spherical structure 1 not covered by the cover layer 3, and the hollow spherical structure 1 with the surface roughness of the cover layer 3 smaller than 1 micrometer can reduce friction and irritation to the duodenal papilla, reduce the risk of inflammation or injury possibly caused after implantation, and improve the comfort of patients. Meanwhile, during the period that the bracket mainly plays a role in drainage, the hollowed-out spherical structure 1 and the cover layer 3 with smaller surface roughness have smaller resistance to food residues, reduce the adhesion of foreign matters on the surface of the spherical structure, and are beneficial to keeping the position of the bracket. After the drainage function of the stent is finished, the covering layer 3 is degraded, so that the surface roughness of the area covered by the covering layer 3 of the hollow spherical structure 1 is more than 100 microns, the resistance of the hollow spherical structure 1 and food residues can be improved, and the stent can be pushed to deviate from a bile duct or a pancreatic duct as soon as possible. The cover layer 3 at least covers the second hollow area 122, but of course, the cover layer 3 may also cover the whole hollow spherical structure 1 except the diversion holes 11 and the first hollow area 121, and after the cover layer 3 is degraded, the friction between the hollow spherical structure 1 with the surface roughness greater than 100 micrometers and the food waste becomes larger.

Optionally, a blocking structure is arranged on the inner surface of the hollow spherical structure 1. In this embodiment, the blocking structure may be designed into a small thorn, protrusion or mesh structure inside the hollow spherical structure 1, so as not to block bile or pancreatic juice from flowing, but effectively catch food residues entering the hollow spherical structure 1, which is helpful for pushing the hollow spherical structure 1 to drive the degraded stent body 2 to automatically discharge.

Optionally, the hollow spherical structure 1 is made of polytetrafluoroethylene, polyether-ether-ketone, polymethyl methacrylate, polycarbonate, nylon or nylon elastomer. In this embodiment, the hollow spherical structure 1 is made of one of the above materials, and is mainly characterized by good biocompatibility, good mechanical properties, strong corrosion resistance, high surface smoothness and high workability. The materials have good biocompatibility, can reduce the immune response and rejection risk caused by the stent in the human body, and are beneficial to reducing the uncomfortable feeling of patients. The selected material has good mechanical properties, can provide enough strength and stability, ensures that the stent can effectively guide flow after implantation, and simultaneously keeps the stability of the shape and structure of the stent. Materials such as polytetrafluoroethylene have superior corrosion resistance, can resist corrosion and erosion of internal liquid, prolong the life of support, reduce the risk that arouses because of the material loss. The spherical structure with higher surface smoothness is helpful for reducing friction and irritation of the hollowed-out spherical structure 1 with the duodenal papilla part. The selected material has better processability, is convenient for preparing the shape and the size of the spherical structure conforming to the regulations through different manufacturing processes, and improves the flexibility and the precision of manufacturing.

Optionally, the material of the grid lines 21 comprises polypropylene, or polyamide. In this embodiment, the grid lines 21 are made of the above material, which has the following advantages: mechanical properties: these materials are all materials with good mechanical properties, and the strength of the materials is good, so that the materials are not easy to break, and the stent can stably work in the body and can be completely discharged. Workability: these materials have good workability and are suitable for various manufacturing processes including 3D printing, injection molding, etc., thereby helping to achieve accurate manufacturing of the stent. Biocompatibility: these materials generally have good biocompatibility, can reduce the immune response and rejection risk induced in the human body, and help to improve the biocompatibility after implantation. Corrosion resistance: these materials exhibit good corrosion resistance in the context of in vivo fluids, and can maintain the stability and integrity of the stent. Light weight: these materials are relatively lightweight materials that help reduce the weight of the overall stent and reduce the burden on the patient. Cost effectiveness: these materials are widely used engineering plastics with high cost effectiveness, which can reduce the cost of manufacturing the stent and increase the feasibility of the stent in medical applications.

Optionally, the material of the support layer 22 and the cover layer 3 includes polylactic acid, or polylactic acid-glycolic acid copolymer, or polycaprolactone, or polylactic acid-caprolactone copolymer, or polydioxanone, or polyglycolic acid, or polyhydroxyalkanoate. In this embodiment, the supporting layer 22 and the covering layer 3 may be made of the same material, or may be made of different materials, but these materials have the following advantages: degradability: the materials are degradable materials, which is helpful for supporting the gradual degradation of the stent in the body and avoids the need of secondary operation. Biocompatibility: the materials have good biocompatibility, are helpful for reducing immune response and rejection risks caused in human bodies, and promote the biocompatibility of the stent. The degradation products are nontoxic: the degradation products of the degradable materials are nontoxic, do not have negative effects on human bodies, and reduce adverse reactions possibly caused in the degradation process of the stent. Controllability: the degradation speed of the degradable materials is relatively controllable, and the degradation process of the stent in the body can be regulated through the selection and the allocation of the materials so as to adapt to the specific situation of a patient. Of course, the materials have respective advantages, such as wide sources of polylactic acid (PLA), high transparency and good processability; polylactic acid-glycolic acid copolymer (PLGA) can regulate the degradation rate by adjusting the ratio of lactic acid and glycolic acid; the biological degradation speed of Polycaprolactone (PCL) is low, and the Polycaprolactone (PCL) is suitable for long-term use; polylactic acid-caprolactone copolymer (PLA-PCL) combines the advantages of PLA and PCL, and the adjustable degradation rate improves the toughness of PLA; the strength of the polydioxanone (PPDO) is high; the polyglycolic acid (PGA) has high biodegradation speed and is suitable for biomedical materials used for a short period of time; polyhydroxyalkanoate (PHA) has various structures and high selectivity. By using these degradable materials, the support layer 22 and the cover layer 3 can be gradually degraded in the body while maintaining the structure and function of the stent, so as to realize self-discharge of the stent, thereby avoiding the pain and risk of secondary operation of patients and providing a more convenient and safe choice for treatment.

Optionally, the gridlines 21 and/or support layer 22 material include barium sulfate, or bismuth subcarbonate, or bismuth trioxide, or bismuth oxychloride. In this embodiment, at least one of the grid lines 21 and the support layer 22 includes an X-ray developing material, so that after the stent is placed in a human body, the position of the stent can be conveniently detected, and the risk caused by unknown position of the stent can be timely monitored and avoided.

Optionally, the shape of the second hollowed out area 122 includes one or more combinations of a rectangle, or a circle, or a trapezoid, or a triangle. The main feature is that the shape and arrangement of the second hollow area 122 should be seen from different grabbing effects of chyme in human body according to actual needs, so that the second hollow area 122 can better capture chyme or drive the bracket to be discharged out of human body under the pushing of chyme. Of course, the second hollowed-out area 122 may be provided with an irregular shape, so long as the arrangement and adjustment are convenient, and the effect of the hollowed-out spherical structure 1 is improved.

In a second aspect, an embodiment of the present invention provides a method for preparing a biliary-pancreatic duct stent capable of self-discharging a human body, including any one of the foregoing biliary-pancreatic duct stents, including the steps of: firstly, preparing a hollowed-out spherical structure 1; second, preparing grid lines 21; step three, wrapping the grid lines 21 with the supporting layer 22; fourth, preparing a cover layer 3; and fifthly, polishing the surface of the hollowed-out spherical structure 1 and the cover layer 3.

In this embodiment, the hollow spherical structure 1 is first prepared, for example, the hollow spherical structure 1 can be prepared in a customized manner by adopting a fused deposition modeling process, which means that a bracket adapting to individual differences can be accurately designed and prepared according to specific requirements and anatomical structures of patients. When the grid lines 21 are prepared, the supporting layer 22 can be directly wrapped on the grid lines 21, and the integrated structure can improve the overall strength and stability of the stent and ensure that the stent can effectively fulfill the functions of supporting and guiding flow when being implanted into a body. And then preparing the cover layer 3, and directly combining the cover layer 3 with the bracket integrally to form an integrated structure, so as to ensure the matching degree of the cover layer 3 and the hollow spherical structure 1. The surface polishing of the last step can improve the surface smoothness of the hollow spherical structure 1 and the cover layer 3, and reduce the resistance of the hollow spherical structure 1 and the cover layer 3 to food residues when the bracket supports and guides.

Optionally, preparing grid lines 21 includes: preparing grid lines 21 by using a fused deposition modeling process; or, preparing the grid lines 21 by an injection molding process; alternatively, the grid lines 21 are prepared using a casting process. In this embodiment, the grid lines 21 are three different preparation methods, and have different advantages. Advantages of using a fused deposition modeling process to prepare grid lines 21: the accurate control structure is as follows: the fused deposition modeling process allows for the addition of material layer by layer, thus allowing for highly accurate control of the structure of gridlines 21. Is suitable for complex structures: the fused deposition modeling is suitable for preparing complex three-dimensional structures, can realize more flexible and personalized design, and ensures that the stent can meet specific medical requirements in function and shape. The advantage of using an injection molding process to prepare grid lines 21: high-efficiency mass production: the injection molding process is suitable for large-scale production and has the characteristics of high efficiency and high speed. If a similar stent is to be mass produced, it may be more economical and practical to use an injection molding process. Cost effectiveness: injection molding processes generally offer cost advantages over fused deposition modeling, particularly in the case of mass production, to help reduce the overall cost of preparing the scaffold. The advantage of using a casting process to prepare grid lines 21: good internal stress distribution: during casting, the material gradually cools and solidifies within the mold, which helps to form a good internal stress profile. Compared with other forming methods, the casting process has lower internal stress, and is beneficial to improving the mechanical property and durability of the bracket. Is suitable for complex shapes: since the material is poured into the mold in a liquid or semi-liquid state, the corners and details of the mold can be easily filled, making the fabrication of complex shapes relatively easy. In a comprehensive view, the grid lines 21 can be prepared individually and accurately by adopting a fused deposition modeling process, and the method is suitable for the requirements of small batch and customization; the grid lines 21 are prepared by adopting an injection molding process, so that the method is more suitable for mass production, and has lower cost and high efficiency; the use of casting processes to prepare the grid lines 21 provides a greater advantage in improving the mechanical properties and durability of the stent.

Optionally, wrapping the grid lines 21 with the support layer 22 includes: wrapping the grid lines 21 with the supporting layer 22 by adopting a fused deposition modeling process; or, coating the grid lines 21 with the supporting layer 22 by adopting a photo-curing process or coating the grid lines 21 with the supporting layer 22 by adopting a pouring process; alternatively, the grid lines 21 are wrapped around the support layer 22 by a thermal fusion method. In this embodiment, the supporting layer 22 is wrapped by the grid lines 21 in different preparation modes, and the advantages are different. Advantages of wrapping the grid lines 21 with the support layer 22 using a fused deposition modeling process: and (3) stacking: the fused deposition modeling process allows for the addition of material layer by layer, and the support layer 22 can be layered on top of the grid lines 21 to achieve a high degree of customization of the internal structure of the stent to meet different needs. Design flexibility: by fused deposition modeling, the shape, density, and structure of the support layer 22 can be more flexibly adjusted to suit the particular function and strength requirements of the stent. The advantage of using a photo-curing process to wrap the grid lines 21 around the support layer 22: high-precision preparation: the photo-curing process can achieve high precision preparation, and the shape and structure of the support layer 22 can be precisely controlled, ensuring the stability and functionality of the stent. And (3) fast curing: the photo-curing process has a relatively high curing speed, is beneficial to improving the production efficiency, and is suitable for the situation of large-scale production. The advantage of using a casting process to wrap the grid lines 21 around the support layer 22 is that: good internal stress distribution and suitability for complex shapes. The advantage of using a thermal fusion method to wrap the grid lines 21 around the support layer 22 is that: seamless connection: the thermal fusion technology can realize seamless connection between two layers of substances, ensure tight combination between the grid lines 21 and the supporting layer 22, and avoid the existence of gaps or clearances, thereby improving the overall stability of the bracket.

Optionally, between the first step and the second step, the grid lines 21 are connected with the hollowed-out spherical structure 1 by adopting a thermal fusion mode, and the grid lines 21 are prepared after connection. In this embodiment, the grid lines 21 and the hollow spherical structure 1 are connected in a thermal fusion manner, so that a strong physical connection can be realized, which is conducive to improving the structural consistency and stability of the whole bracket, and falling or loosening is not easy to occur. The heat fusion mode can enable the grid lines 21 and the hollow spherical structure 1 to be in seamless connection, and the problem that liquid leakage or food residues are retained due to gaps at the connection positions is avoided. Meanwhile, the whole preparation flow is simplified, the connection step is placed at the earlier stage of preparing the grid lines 21, the preparation of the grid lines 21 can be directly carried out after connection, the support layer 22 can be coated by the grid lines 21 and the preparation of the covering layer 3 can be prepared by adopting the same process, for example, a fused deposition modeling process, a photocuring process or a thermal fusion method can be adopted to prepare the support layer 22 and the covering layer 3.

Optionally, between the second step and the third step, the prepared grid lines 21 are bonded to the hollowed-out spherical structure 1 by adopting a thermal fusion mode. In this embodiment, the prepared grid lines 21 are bonded to the hollow spherical structure 1 by thermal fusion, and then the support layer 22 is wrapped by the grid lines 21 and the cover layer 3 is prepared by the same process, for example, the support layer 22 and the cover layer 3 may be prepared by fused deposition modeling process, photo-curing process, or thermal fusion.

Optionally, between the third step and the fourth step, the prepared bracket body 2 is bonded to the hollowed-out spherical structure 1 by adopting a thermal fusion mode. In this embodiment, the prepared stent body 2 is bonded to the hollowed-out spherical structure 1 by adopting a thermal fusion method, and then the cover layer 3 is prepared, so that more methods can be adopted to prepare the stent body 2 without considering the influence on the hollowed-out spherical structure 1, and the stent body 2 and the hollowed-out spherical structure 1 can be prepared simultaneously in different devices, and then assembled, thereby improving the manufacturing efficiency of the whole stent.

Those of skill in the art will appreciate that the various operations, methods, steps in the flow, acts, schemes, and alternatives discussed in the present invention may be alternated, altered, combined, or eliminated. Further, other steps, means, or steps in a process having various operations, methods, or procedures discussed herein may be alternated, altered, rearranged, disassembled, combined, or eliminated. Further, steps, measures, schemes in the prior art with various operations, methods, flows disclosed in the present invention may also be alternated, altered, rearranged, decomposed, combined, or deleted.

In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meanings of the above terms in the present invention can be understood in specific situations by those of ordinary skill in the art.

In the description of the present specification, a particular feature, structure, material, or characteristic may be combined in any suitable manner in one or more embodiments or examples.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (19)

1. A biliary pancreatic duct support capable of self-discharging a human body, comprising:

The hollow spherical structure comprises a diversion hole and a hollow area, the diversion hole and the hollow area are respectively positioned at two ends of the hollow spherical structure, and the area of the hollow area is not more than one half of the surface area of the hollow spherical structure;

the support body, the fretwork district includes first fretwork district and second fretwork district, the support body connect in first fretwork district with between the second fretwork district, the second fretwork district is located outside the support body, the support body includes the gridline, and parcel has the supporting layer of gridline, the gridline is non-degradable material, the supporting layer is degradable material, the support body is the framework of net tube-shape, the diameter d1 of the support body near the one end of fretwork district is less than the diameter d2 of the support body far away from the one end of fretwork district;

the covering layer at least covers the second hollow area, and the covering layer is gradually degraded after being implanted into a human body.

2. The self-draining pancreatic duct stent of claim 1 wherein said stent body has a progressively larger diameter in a direction away from said hollow region;

Or, in keeping away from the direction of fretwork area, the support body includes first expansion section, second and keeps section and third expansion section, first expansion section is keeping away from the direction of fretwork area is the diameter grow gradually, the diameter of second keeps the section unchanged, the third expansion section is keeping away from the direction of fretwork area is the diameter grow gradually.

3. The bile and pancreatic duct support capable of being automatically discharged from a human body according to claim 2, wherein the outer diameter of the hollowed-out spherical structure is 3mm-6mm, and the thickness is 0.5mm-1mm.

4. The self-draining pancreatic duct stent of claim 3 wherein said deflector aperture is 1mm-2mm.

5. The self-draining pancreatic duct support according to claim 3, wherein the hollowed aperture of the first hollowed-out area is 1mm-2mm, and the ratio of the area of the first hollowed-out area to the area of the second hollowed-out area is between 1:4 and 1:10.

6. A self-draining pancreatic duct support according to claim 3 wherein the diameter d1 of the end of the support body adjacent to the hollow region is 1mm < d1<3mm and the diameter of the end of the support body adjacent to the hollow region is 6 mm < d2<10mm.

7. The liner pancreatic duct support capable of self-draining a human body according to claim 1, wherein the area of the second hollowed-out area is equal to the product of the surface area of the hollowed-out spherical structure, the hollowed-out coefficient and the chyme viscosity coefficient;

the hollowed-out coefficient is less than one half, and the chyme viscosity coefficient is less than one.

8. The self-draining pancreatic duct stent of claim 1, wherein the hollowed-out spherical structure has a surface roughness in an area not covered by the cover layer, and the cover layer has a surface roughness of less than 1 micron;

The surface roughness of the area of the hollowed-out spherical structure covered by the covering layer is more than 100 micrometers.

9. The bile and pancreatic duct stent capable of being automatically discharged from a human body according to claim 1, wherein a blocking structure is arranged on the inner surface of the hollowed-out spherical structure.

10. The self-draining pancreatic duct support according to claim 1, wherein the hollow spherical structure comprises polytetrafluoroethylene, polyether-ether-ketone, polymethyl methacrylate, polycarbonate, nylon, or nylon elastomer.

11. The self-draining pancreatic duct stent of claim 1 wherein said gridline material comprises polypropylene or polyamide.

12. The self-draining pancreatic duct stent of claim 1, wherein the material of said support layer and said cover layer comprises polylactic acid, or a polylactic acid-glycolic acid copolymer, or polycaprolactone, or a polylactic acid-caprolactone copolymer, or polydioxanone, or polyglycolic acid, or polyhydroxyalkanoate.

13. The self-draining pancreatic duct stent of claim 1 wherein said grid lines or/and said support layer material comprises barium sulfate, or bismuth subcarbonate, or bismuth trioxide, or bismuth oxychloride.

14. A method for preparing a biliary-pancreatic duct support capable of self-discharging a human body, comprising the biliary-pancreatic duct support according to any one of claims 1-13, characterized by the steps of:

Firstly, preparing a hollowed-out spherical structure;

Secondly, preparing grid lines;

thirdly, wrapping the grid lines with a supporting layer;

Fourthly, preparing a covering layer;

and fifthly, polishing the surface of the hollowed-out spherical structure and the covering layer.

15. The method for preparing a self-draining pancreatic duct stent according to claim 14, wherein preparing grid lines comprises:

Preparing the grid lines by adopting a fused deposition modeling process;

or preparing the grid lines by adopting an injection molding process;

Or, adopting a pouring process to prepare the grid lines.

16. The method for preparing a self-draining pancreatic duct stent according to claim 14, wherein said wrapping said grid lines with a supporting layer comprises:

wrapping the grid lines with a supporting layer by adopting a fused deposition modeling process;

or, wrapping the grid lines with a supporting layer by adopting a photo-curing process;

or, adopting a pouring process to wrap the grid lines on the supporting layer;

or, wrapping the grid lines with a supporting layer by adopting a thermal fusion method.

17. The method for preparing a self-draining pancreatic duct stent according to claim 14, wherein said gridding lines are connected to said hollowed-out spherical structure by thermal fusion between said first step and said second step, and said gridding lines are prepared after connection.

18. The method for preparing a self-draining pancreatic duct stent according to claim 14, wherein said gridlines are bonded to said hollowed-out spherical structure by thermal fusion between said second step and said third step.

19. The method for preparing a self-draining pancreatic duct stent according to claim 14, wherein a thermal fusion method is adopted between the third step and the fourth step to bond the prepared stent body to the hollowed-out spherical structure.