JP2007135965A - Internally indwelling multifunctional stent and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internally indwelling multifunctional stent improving a passing property of a content, having a carrying function of the content by peristaltic motion and capable of treating cancer by a thermotherapy in a stent inserted into a lacunar system viscera with stenosis caused by malignant tumor or the like and maintaining the lumen. <P>SOLUTION: This indwelling multifunctional stent can greatly improve the passing property of the content by covering the inside with polymer gel with low friction resistance, carry the content by the peristaltic motion carrying operation using shape memory alloy, and treat the cancer tissue by the thermotherapy by heating the metal stent forming the outer sheath by excitation so as to completely suppress the progress of the cancer into the lumen. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a stent that is placed in the body in a disease such as a malignant tumor, a stent that retains a peristaltic delivery function, a stent that also retains a therapeutic function by thermotherapy, and a method for manufacturing the same.

  Conventionally, when a malignant tumor has occurred in a luminal organ such as the digestive tract, and it has entered a stenotic state or an obstructed state, a stent made of a metal material or the like is inserted to expand the lumen, There are treatments that preserve the inner diameter of the cavity. In this case, a stent that changes its shape according to body temperature using a shape memory alloy so as to be suitable for the shape of the lumen of the luminal internal organs, expands the cross-sectional area of the lumen inside the stent, and maintains the patency, etc. The existence of is also known. In addition, the present inventors have proposed a new artificial visceral treatment method in which an artificial organ retaining a peristaltic function is implanted after excising a tumor-producing digestive tract in Patent Document 1.

JP-A-2005-104722

  However, since a stent using a conventional metal material or the like does not have a content transfer function such as a peristaltic motion, the lumen is often blocked by being caught when the content passes. In addition, since there is no effect of treating cancer tissue, even when a bent stent is inserted, the lumen is often closed again due to the progress of cancer. If the digestive tract such as the esophagus is obstructed, the patient cannot swallow the saliva and vomiting repeatedly, resulting in a problem that greatly interferes with QOL.

  Although a stent using a shape memory alloy such as Nitinol is also used, this is to secure the lumen by aligning the shape with the lumen of the affected area when inserted into the body. There was no stent that allowed peristaltic movement using the actuator as an actuator.

  There have been proposals for a system that transports food with a screw or the like, or squeezes a tube with a rotary motion of a motor, or transports the contents of a lumen with a pump pressure type. Embedding in is not realistic.

  As described above, the conventional technology has no peristaltic action, so the contents are often caught and occluded, and further, there is no power to suppress the progression of cancer, so there is a problem that the cancer eventually grows and becomes occluded. there were. The present invention can convey the contents by a peristaltic motion even if the contents are caught in the stent, and can be implanted in the body because of its volumetric efficiency with an actuator using a shape memory alloy. An object of the present invention is to provide a multifunctional stent that suppresses the progression of cancer by performing hyperthermia for cancer by an exciting action.

  According to the present invention, a stent such as a metal material that is inserted into a luminal viscera such as a digestive tract, a biliary tract, or a ureter to prevent stenosis of the lumen due to progression of cancer or the like and maintain the visceral function. And, it is composed of a coating such as a polymer gel with low frictional resistance that can smoothly move the contents covering the inner surface of the stent, and functions such as swallowing food and transferring contents such as bile and urine, An inner surface-covered luminal visceral stent can be obtained which can be smoothly performed with little friction.

  The inner surface coating used in the present invention has a hydrophilic polymer gel (for example, polyethylene glycol, acrylated polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid) that has low surface friction, easily causes fluid lubrication, and is rich in elasticity. Polymethacrylic acid and polyacrylamide) are desirable, but for polyvinyl alcohol hydrogels, which are most deformable, have low surface friction, and are very inexpensive, the polyvinyl alcohol powder is dissolved in a solvent containing at least water and the solution is then cooled. It is characterized by being obtained by gelling, desolvating, heat-treating, and again absorbing a predetermined amount of water. For example, PVA powder having a saponification degree of 86 to 90 and a polymerization degree of 500 or more and less than 2000 is dissolved in a mixed solvent of dimethyl sulfoxide (DMSO) / water = 80/20 weight ratio while heating at 120 ° C. The shape is adjusted by applying or dipping into a hollow cylindrical mold (mold) for obtaining a product or a mold with a stent attached thereto. Then, it is cooled and gelled, desolvated with ethanol, heat treated at 70 ° C. for 10 to 30 minutes, and if the heat treatment is partially performed, the moisture content of the gel in that part decreases and the elastic modulus increases. A tubular molded product that can be easily crushed and recovered can be produced.

  Further, the present invention provides an inner surface-covered luminal visceral stent that is attached between an outer metal material stent for suppressing the progression of cancer into the lumen and an inner surface material such as a polymer gel that covers the inner surface. The present invention provides a peristaltic delivery stent characterized in that the content can be delivered by changing the cross-sectional area of the lumen by the bidirectional shape memory alloy.

  The present invention also relates to a peristaltic stent placed in a luminal viscera, which heats a metallic material stent that forms an outer shell by exciting from the outside, suppresses the progression of cancer tissue by thermotherapy, and improves the prognosis of the patient's life. A high-performance stent that can be extended to a long leg is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the inner surface covering type | mold lumen type visceral stent which can perform the transfer of the content smoothly by the low frictional resistance which is the characteristics which coating materials, such as a polymer gel, have is obtained.

  In addition, according to the present invention, air pressure, hydraulic pressure, hydraulic pressure, shape between the metal stent that forms the outer shell and suppresses the progression of the cancer into the lumen and the low friction polymer gel coating material that covers the inner surface By providing a shape change actuator such as a memory alloy or a magnetic fluid, a peristaltic motion delivery stent capable of transporting the content by peristaltic motion even when the lumen is blocked with the content is obtained.

  In addition, according to the present invention, the metal stent that forms the outer shell can be heated by exciting from outside the body, the progression of cancer can be suppressed by thermotherapy, and the progression of cancer to the lumen can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a peristaltic delivery stent according to an embodiment of the present invention. Referring to FIG. 1, the inner surface is coated with a polymer gel that retains low frictional resistance, and the outer surface forms an outer shell with a metal material to suppress the progression of the cancer tissue into the lumen. An actuator made of a shape memory alloy is mounted between the outer shell and the inner coating, and the contents can be conveyed by performing a peristaltic motion.

  FIG. 2 is a peristaltic delivery stent combined with a transcutaneous energy transmission unit for supplying energy from outside the body. The stomach is anatomically extracorporeal and can be inserted non-invasively with a secondary coil for a transcutaneous energy transmission system, making it a perfect non-invasive medically , Non-destructive mounting will be realized. In other words, both the stent and the energy transmission coil can be inserted without burdening the patient. Furthermore, if the coil forming the outer shell is heated by excitation, a therapeutic effect as a thermotherapy for the surrounding cancer tissue can be obtained, so that the life prognosis of the patient can be greatly improved.

  3 and 4 show an example of a design of a peristaltic delivery stent and a driving mechanism. The shape memory alloy ring contracts in order from the mouth side to reduce and change the cross-sectional area, realizing a peristaltic motion. FIG. 5 is an animal experiment photograph of a peristaltic motion delivery stent. It is confirmed that the peristaltic movement is embodied in the endoscopic image.

  6, 7 and 8 are secondary coils of the cost energy transmission system of the peristaltic delivery stent. By winding around a ferrite core, the world's highest level of power transportation is realized by magnetic shielding.

  FIG. 9 shows a peristaltic stent having a cancer therapeutic effect. The primary lesion of cancer can be treated with hyperthermia therapy using electromagnetic induction.

  This peristaltic stent can be applied to gastrointestinal tract such as esophagus, large intestine and small intestine, biliary tract, pancreatic tract, ureter, urethra and other luminal organs. Suppresses progress and maintains its function as a luminal organ. Furthermore, the problem of stent occlusion due to the contents due to peristaltic movement is solved. Furthermore, it also has a therapeutic effect on the primary lesion of cancer. Since various application ranges in medicine can be considered, it can be widely used as a new medical device.

It is sectional drawing of the luminal system visceral stent which has a peristaltic function by embodiment of this invention. 1 is a conceptual diagram of a peristaltic delivery stent equipped with a transcutaneous energy transmission system according to an embodiment of the present invention. An example of a peristaltic delivery stent design, peristaltic delivery stents of varying lengths can be designed and adapted depending on the condition. With the drive mechanism of the peristaltic motion delivery stent, the shape memory alloy actuator, and the like, the cross-sectional area can be reduced and changed in order from the mouth side to realize peristaltic motion and transport the contents. Endoscopic image of peristaltic motion delivery stent in animal experiment, Endoscopic image of peristaltic motion delivery stent in animal experiment. The shape memory alloy actuator reduces the cross-sectional area in order from the mouth side, realizing a peristaltic motion. Secondary coil for peristaltic delivery stent transcutaneous energy transmission system, rod-like secondary coil that can be inserted with endoscope. It has a diameter of 10mm and a major axis of 50mm, and can be easily inserted into the stomach bag invasively with an endoscope. The ferrite core embodies the world's highest efficiency power transport. The peristaltic delivery stent transcutaneous energy transmission system has a transmission efficiency, can be easily inserted into the stomach bag non-invasively with an endoscope, and the ferrite core embodies the world's highest efficiency power transport, around 5W Power transportation is easy. Animal experiment of the secondary coil of the prototype transdermal energy transmission system. Peristaltic motion delivery stent with hyperthermia cancer treatment function.

Claims (13)

  Stents such as metal materials that are inserted into the luminal internal organs such as the digestive tract, biliary tract, ureter, etc., and prevent the constriction of the internal lumen due to the progression of cancer, etc. and maintain the internal organ function, and the inner surface of the stent are covered It is composed of a film such as a polymer gel with low frictional resistance that can smoothly move the contents to be moved, and the contents such as food, bile and urine can be smoothly transferred. Luminal visceral stent.   An inner surface coated luminal visceral stent according to claim 1 wherein the content transfer is smoothed by low frictional resistance. A suitable method for producing the inner surface coating is low surface friction and fluid lubrication. It is desirable to use a hydrophilic polymer gel (for example, polyethylene glycol, acrylated polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polymethacrylic acid, and polyacrylamide) that has a high elasticity and is highly elastic. Covered luminal visceral stent.   The inner surface-covered luminal visceral stent according to claim 1 or 2, wherein the cross-sectional area of the lumen is reduced and changed in order from the mouth side to the caudal side by an actuator attached between the outer shell and the inner surface material. By this, the inner surface-covered peristaltic motion delivery stent can transport contents by peristaltic motion.   4. The inner surface-covered peristaltic delivery stent according to claim 3, wherein a change in air pressure, water pressure, and hydraulic pressure is used as a drive actuator to change the cross-sectional area of the lumen in order from the mouth side to the caudal side. An inner surface-coated peristaltic motion delivery stent characterized in that the contents can be transported by motion.   In the inner surface-coated peristaltic delivery stent according to claim 3, by using a bidirectional shape memory alloy as a drive actuator, by reducing the cross-sectional area of the lumen sequentially from the mouth side to the caudal side, An inner surface-covered peristaltic motion delivery stent characterized in that the contents can be transported by peristaltic motion.   5. The inner surface-covered peristaltic delivery stent according to claim 3, wherein the shape of the magnetic fluid is changed by electromagnetic force and used as a drive actuator, whereby the cross-sectional area of the lumen is reduced and changed in order from the mouth side to the tail side. Therefore, the inner surface-covered peristaltic motion delivery stent can transport the contents by peristaltic motion.   6. The inner surface-coating peristaltic motion delivery stent according to claim 5, wherein the shape memory alloy is installed around the inner surface material.   6. The inner surface-covered peristaltic delivery stent according to claim 5, wherein a shape memory alloy is attached to the open end of the stent.   6. The inner surface-covered peristaltic delivery stent according to claim 5, wherein the shape memory alloy is installed along the tube direction of the stent.   The stent according to any one of claims 1 to 9, wherein energy is applied to a secondary coil placed in a lumen such as a digestive tract by electromagnetic induction from a primary coil outside the body without penetrating the skin to perform peristaltic movement. High-function stent that can.   The high-performance stent according to claim 1, wherein a metal material stent that forms an outer shell is heated by being excited from the outside, and the progression of cancer tissue is suppressed by thermotherapy, thereby extending the patient's life prognosis to long legs. .   A stent inserted into a lumen, wherein the stent is provided with a coating having a low frictional resistance on the inner surface thereof.   A stent inserted into a lumen, wherein the stent includes an actuator capable of reducing and changing an inner diameter thereof.