CN211962289U - A biliary metal stent for thermal ablation of tumors under magnetic field - Google Patents

Abstract

The utility model discloses a biliary metal stent for thermal ablation of tumors under a magnetic field. The groove is provided with iron oxide solid particles, and the surface of the main body bracket is wrapped with an insulating and thermally conductive silica gel layer. The device provided by the utility model has two functions: one is to expand the narrow bile duct to relieve the symptoms of jaundice; the other is to have the function of thermal ablation to kill local tumor tissue. It provides treatment opportunities for patients with advanced extrahepatic bile duct tumors who have no chance of surgery and extrahepatic bile duct tumors who cannot tolerate surgical treatment, eliminating the need for surgery, eliminating local tumors, improving the quality of life of patients, and prolonging the survival period. Human tissue will not produce adverse reactions such as allergic irritation. According to the monitoring of the patient's condition changes and tumor recurrence, multiple treatments can be performed, which greatly prolongs the patient's survival period.

Description

A biliary metal stent for thermal ablation of tumors under magnetic field

technical field

The utility model belongs to the field of bile duct stents, in particular to a bile duct metal stent for thermal ablation of tumors under a magnetic field.

Background technique

Scientific research has found that no matter what kind of cancer cells are intolerable to high temperature, the tumor tissue can be damaged and apoptotic in the high temperature that the normal tissue cells of the human body can tolerate. After the human body is heated, the temperature in the tumor tissue is often 5°C-10°C higher than that of the adjacent normal tissue. When the tumor temperature reaches above 41°C and maintains it for a certain period of time, the cancer cells can be killed. Normal tissue can tolerate 46°C without irreversible damage due to its good thermoregulatory system and tolerance. But the human body itself cannot sustain a temperature above 41 degrees Celsius for a long time. When the body temperature rises, the blood vessels expand and the blood flow accelerates in the normal tissues of the human body. Due to this regulating effect of the body, it is ensured that when the body temperature rises, even when it reaches 41.5 to 43 ℃, the normal cells and tissues are not damaged. However, the tumor tissue is not the case. The blood vessels in the tumor are abnormal in shape, distorted, and easily deformed by compression, and form thrombus or embolism. In addition, the blood vessels in the tumor are mostly composed of a single layer of cells, which are fragile and easily broken. Because these new blood vessels are underdeveloped abnormal blood vessels, they lose their self-regulating effect after being heated, and the veins cannot speed up the reflux. raised. The temperature of malignant tumor tissue is often 8 to 10°C higher than that of normal adjacent tissue. Local heating is also performed. If the temperature of normal tissue rises to 40°C, the temperature in the tumor can be raised to about 48°C, which is enough to heat the tumor cells to death, while the normal tissue is not damaged in any way.

Induction heating is to use the induced current (eddy current loss) generated by the conductor under the action of the high frequency magnetic field and the action of the magnetic field in the conductor (hysteresis loss) to cause the conductor to heat up by itself.

When the metal conductor is in a high-frequency alternating electric field, according to Faraday's law of electromagnetic induction, an induced electromotive force will be generated in the metal conductor, and a strong induced current will be generated due to the small resistance of the conductor. According to the Joule-Lenz law, the alternating magnetic field will cause the current in the conductor to flow toward the surface of the conductor, causing the skin effect. The density of the current is proportional to the frequency. The more serious the skin effect is, the effective conductive area is reduced and the resistance is increased, so that the conductor heats up rapidly.

When the conductor has a current passing through it, a magnetic field is generated around it at the same time, and the high-frequency current flows to the inductance coil that is wound into a ring or other shapes. As a result, a strong magnetic beam with an instantaneous change in polarity is generated in the coil, and the heated metal material is placed in the induction coil, and the magnetic beam will penetrate the entire heated material, and a large amount of magnetic flux will be generated inside the heated material in the opposite direction to the heating current. Eddy currents, due to the electrical resistance of the heated metal substance, generate Joule heat, which rapidly increases the temperature of the metal substance itself.

In June 2004, the American "Proceedings of the National Academy of Sciences" reported a major progress made by a research team at Rice University: they designed and fabricated gold-plated nanoshells that can seek and kill malignant tumor cells, and have been obtained in experimental mice. success. The nanoshell uses a non-conductive silica particle with a diameter of 110 nanometers as a core and is coated with a metal shell 10 nanometers thick. The researchers "delivered" the nanoshells into the cancerous tissue, and then irradiated the cancerous tissue with near-infrared light from outside the body. When near-infrared rays pass through normal tissues of the human body to cancerous tissues, they can be absorbed by nano-bullets buried in cancerous tissues. As the amount of absorption increased, the temperature of the nanobullet began to rise, causing the cancerous tissue around it to heat up and die.

The "Charit" clinical hospital in Berlin, Germany, tried to use magnetic nanoparticles to treat cancer, and achieved good results in animal experiments. Researchers at the hospital are using magnetic nanoparticles to treat cancer by injecting some extremely tiny iron oxide nanoparticles into a patient's tumor, then subjecting the patient to a variable magnetic field. Under the influence of the magnetic field, the iron oxide nanoparticles in the patient's tumor warmed to 45 to 47 degrees Celsius, a temperature high enough to burn cancer cells. Since the magnetic particles are not present in the body tissue near the tumor, the temperature of these healthy tissues will not increase and will not be harmed.

The number of cases of obstructive jaundice caused by tumors is increasing year by year. For inoperable patients, the most commonly used treatment method is the placement of biliary metal stents to relieve obstructive symptoms and improve the quality of life of patients. However, cases of postoperative jaundice recurrence still occur from time to time. The reason is mainly because the used bare metal stent can expand the bile duct in a short time after implantation, forming a smooth passage, but with the development of the tumor, the tumor tissue climbs along the stent to the edge and grows in the mesh, making the bile duct. Restenosis occurs and bile drainage is blocked, causing jaundice to reappear. In order to solve the problem of restenosis of bile duct stents, there are the following solutions in the industry: one is to coat the metal stent with polyurethane, which can prevent the tumor from growing inward through the mesh, but can not solve the problem of tumor tissue spreading and growing through climbing Obstruction of stent ports and tumor growth squeeze stent restenosis. One is a drug-loaded stent-graft, which has pharmacological side effects on normal cells without cancer cell metastasis. One is a covered stent that can be loaded with radioactive particles, which can negatively affect normal cells in the human body. At the same time, the indwelling of the bile duct stent leads to water, electricity and acid-base disorders, indigestion, and drainage port infection.

Utility model content

According to the technical problem proposed above, a metal stent for thermal ablation of tumors under magnetic field is provided. The technical means adopted by the utility model are as follows:

A biliary metal stent for thermal ablation of tumors under a magnetic field includes a stent body, the stent body is formed by winding a metal wire that is elastic and can be magnetically adsorbed, and the outer wall of the body stent is provided with a plurality of grooves, and the The grooves are provided with iron oxide solid particles, and the surface of the main body support is wrapped with an insulating and thermally conductive silica gel layer.

The wire is made of alloy material including high elastic steel, stainless steel or titanium alloy.

In the state of use: The thermal ablation biliary metal stent is placed on the tumor site of the bile duct through ERCP (duodenoscopy) and the stent pusher, and the stent returns to its original shape, using the strength and elasticity of the metal to support the bile duct. The human body is placed in the magnetic field of the high-frequency induction generator, the position of the thermal ablation bile duct metal stent is aligned with the center of the magnetic field, and the high-frequency induction generator is controlled by the controller to generate a high-frequency magnetic field. The stent body and the iron oxide solid particles generate eddy currents, thereby generating Joule heat, which rapidly increases the temperature of the metal stent and heats cancer cells near the stent support site, thereby destroying the cancer cells.

Because the main body of the stent and the iron oxide solid particles generate eddy currents under the action of the magnetic field in the high-frequency magnetic field, the silica gel material plays an insulating role. In addition, different human body constitutions may cause allergies and other adverse reactions caused by the stimulation of the metal stent, and this embodiment utilizes the excellent biocompatibility of silica gel with human tissues, and does not produce any allergic reactions with cells. At the same time, using the soft properties of the silicone material, the insulating layer can be deformed with the deformation of the titanium alloy bracket without causing damage to the insulating layer.

The utility model solves the industrial problem that the growth of cancer cells needs to be operated by surgery, does not need to be operated by surgery, avoids the secondary injury to the patient, and improves the quality of life of the patient. At the same time, it has excellent biocompatibility, and human tissues will not produce adverse reactions such as allergic irritation. By increasing the frequency of angiographic exploration and monitoring the composition of bile duct cells, secondary treatment can be achieved, which greatly prolongs the survival period of patients.

Based on the above reasons, the utility model can be widely promoted in the fields of biliary stent and the like.

Description of drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative work.

FIG. 1 is a schematic structural diagram of a biliary metal stent for thermal ablation of tumors under a magnetic field in a specific embodiment of the present invention.

FIG. 2 is a schematic diagram of the structure of the main body of the stent in the specific embodiment of the present invention.

FIG. 3 is an enlarged view of part B in FIG. 2 .

FIG. 4 is a cross-sectional view taken along the line A-A in FIG. 1 .

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. The embodiments described above are a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

As shown in FIGS. 1 to 4 , a metal stent for thermal ablation of biliary tract under a magnetic field includes a stent body 1 . The stent body 1 is formed by winding an elastic metal wire that can be magnetically adsorbed. The body stent 1 There are a plurality of grooves 2 on the outer wall of the frame, and iron oxide solid particles 3 are arranged in the grooves 2, and the surface of the main support 1 is wrapped with an insulating and thermally conductive silica gel layer 4.

The wire is made of alloy material including high elastic steel, stainless steel or titanium alloy.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model, but not to limit them; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that : it can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the various embodiments of the present utility model Scope of technical solutions.

Claims (2)

1. The utility model provides a tumour heat ablation biliary tract metal support under magnetic field, includes the support main part, its characterized in that: the support body is formed by winding and processing metal wires which have elasticity and can be magnetically adsorbed, a plurality of grooves are formed in the outer wall of the support body, iron oxide solid particles are arranged in the grooves, and the surface of the main body support is wrapped with an insulating heat-conducting silica gel layer.

2. The metal stent for tumor thermal ablation of biliary tract under magnetic field according to claim 1, wherein: the metal wire is made of alloy material including high elastic steel, stainless steel or titanium alloy.

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