RU2470607C2 - Method of biological tissue ablation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to surgery. Method includes impact on tissue. Impact is performed with electric discharge between electrode and tissue surface. Impact is performed by means of needle electrode by burning till gaseous products are formed. Distance between electrode and biological tissue surface constitutes from 0.01 to 30 mm, value of discharge voltage constitutes from 20 to 3000 V and frequency is from 1 to 2000000 sec^-1.

EFFECT: method ensures ablation of biological tissues with various nature of pathology without injuring underlying or adjacent tissues and without formation of cicatrices or scars.

Description

The invention relates to medicine and can be used in the practice of removing various tissues that have pathological changes (tumors, adenomas, cysts, polyps, ulcers, keloid formations, granulation tissues, corns, etc.).

Pathological tissues are formed in the body due to a multitude of both external and internal factors. The causes of the formation of certain types of tumors are not known to science so far.

The presence in the body of cellular structures with a pathology of the structure significantly inhibits vital functions and can even lead to the death of the body.

Therefore, the problem of the destruction of such pathological cellular structures that have arisen in a living organism is very urgent.

Removal of such structures can be a very complex process, for example, if a tumor has formed in the structures of the brain, liver or other parenchymal organs, on the wall or near the wall of a large artery.

There are several ways to remove pathological tissues.

1. Mechanical, by the method of surgical operation, removal of the pathological structure of tissues, followed by ligatures or staples on the intersected vessels, through which blood came to the pathological group of tissues, or by brewing damaged vessels with various types of coagulators, tightening and suturing the edges of the resulting wound.

2. Etching, burning a piece of pathological tissue using various acids or alkalis. Usually used for various skin pathologies. With pathologies of the internal organs, the use of this method is very rare.

3. Mechanical removal of pathological tissue using a cutter. Usually used for bone operations. With amputations.

4. Burning of pathological tissue with any heated object. Also used in our time is very rare.

5. Cryodestruction. Destruction of pathological tissues by freezing. As a result, the water contained in the cellular and intercellular space turns into ice and destroys cells of pathological tissues. It is important that, during its implementation, thermal denaturation of proteins and nucleic acids does not occur in the tissues surrounding destructible pathological tissues.

6. Consistent, in several sessions, exposure to pathological tissues pre-saturated with special chemicals, ionizing radiation (radiotherapy). At the same time, ionizing radiation damages volumes above and below lying tissues not as significantly as pathological tissues pre-saturated with special chemicals.

7. Saturation of pathological tissues with various chemicals (chemotherapy), which, in the end, lead to the death of the treated pathological tissues.

Unfortunately, all these methods often either do not allow to get rid of the pathological tissue completely, or significantly damage healthy healthy tissues, which slows down the recovery process of the operated body, and in some cases, for example, in case of an error when removing the tumor from the wall of an artery, optic or auditory nerve , spinal column, can even lead to death or loss of function of vision, hearing, mobility - severe disability of the patient.

When applying the method of cryodestruction, the presence of special equipment (Dewar vessels), as well as the presence of liquefied nitrogen is necessary. Shelf life of liquefied nitrogen is very limited, which makes it difficult to use the cryodestruction method in remote clinics that do not have expensive compressor stations for producing liquefied nitrogen.

Also, with the cryodestruction method it is quite difficult to determine the time of exposure to the tissue being destroyed. If the exposure time is insufficient, then the pathological structure of the tissue will not completely collapse and subsequently resume its growth again. If the exposure time during cryodestruction is excessive, then healthy healthy tissues will significantly suffer.

When radiotherapy and chemotherapy are used, significant damage is inflicted to the entire patient’s body, which subsequently requires long and expensive rehabilitation treatment.

When heated objects, lasers, electric and plasma coagulators are used for burning pathological tissues, heat is distributed from the heated object, laser radiation, electric or radio discharge to a distance of 3-50 mm into the underlying and adjacent tissues. In this case, complete thermal damage and destruction of the underlying and underlying tissues occurs at a distance of 3-50 mm from the impact site, both in depth and from the sides of the burned volume. In addition, the power of existing medical lasers, electric and radio coagulators does not allow to burn large, more than 5 cubic meters. see, the structure of pathological tissues.

During healing, this subsequently causes the replacement of thermally destroyed tissues with connective scar tissue during healing, which leads to the formation of internal and external scars and scars at the site of the removed structure of pathological tissues.

Compared with the removal of pathological tissues by laser and coagulation methods, it should be noted that when applying radiotherapy and chemotherapy, it is necessary to conduct a large number of treatment sessions of the patient's pathological tissue structures with ionizing radiation or chemicals - at least 2-3 sessions, usually from 5 to 30 sessions. The time interval between sessions is at least 1 month. Accordingly, the time of removal of the structure of pathological tissue, if necessary, say, conducting 5 sessions, is stretched for at least 6-8 months. Sometimes up to 2-3 years.

When using this technique, the removal of structures of pathological tissue occurs 1 time. 2-4 weeks after healing, the structure of the pathological tissue is already absent.

A known method of removing pathological tissues by radiofrequency ablation, which consists in introducing a needle electrode or electrodes into the tissue and using them to create a high-frequency current in the tissue, causing heating and destruction of the tissue (see, for example, WO 2008/127910 A1, 23.10 .2008; WO 2008/142686 A2, November 27, 2008; US 2009/0082762, March 26, 2009; Description of the radiofrequency ablation technique http://www.reepl.ru/index.php&p=MC8xOC81My8xNjOvNjUx).

The disadvantage of this method is the presence of tissue decomposition products and, as in the previous methods, thermal damage to the underlying and adjacent tissue. As already mentioned, this subsequently causes, during healing, the replacement of thermally destroyed tissues with connective scar tissue, which leads to the formation of internal and external scars and scars at the site of the removed structure of pathological tissues.

Closest to the proposed one is a method for endoscopic removal of polyps of the gastrointestinal tract by single or multiple exposure of the polyp to a high-frequency electric arc discharge created between the end of the rod electrode with a diameter of 2-5 mm and the removed polyp at a distance between them of 0.1-1 mm, to the full removal of the polyp (see RU 2238057 C2, publ. 20.06 2004).

The technical result of the claimed invention is to ensure the removal of biological tissue with a minimum depth of thermal damage to the tissue.

The technical result is achieved by the fact that in the method of removing biological tissue, namely, that they act on the tissue by creating an electric discharge between the electrode located at a distance from the surface of the tissue and the surface of the tissue, according to the invention, the effect on the tissue is carried out using a needle electrode by burning the fabric to the formation of gaseous products, while the distance between the electrode and the surface of the biological tissue is from 0.01 to 30 mm, the magnitude of the discharge voltage composition yaet from 20 to 30000 V and frequency from 1 to 2,000,000 s ^-1 (from 1 Hz to 2 MHz).

The use of a needle electrode and an electric discharge of low and medium frequency (in contrast to the HF electric arc discharge in the closest analogue) makes it possible to reduce the depth of thermal damage to tissue to 0.1-0.2 mm, that is, to practically eliminate it.

With small sizes of pathologically altered tissue, tissue is burned at one point to form a hole.

With large sizes of pathologically altered tissue, burning is carried out repeatedly at various points on the surface of the tissue with the formation of holes at each point and removal of tissue by successively forming multiple holes connected to each other.

Burning can also be done layer by layer by scanning the tissue with a needle electrode while maintaining a discharge between them.

When an organ or part of an organ is amputated, burning is carried out by deepening into the tissue along the amputation line until the organ or part of the organ is completely separated.

In this case, the distance between the electrode and the surface of biological tissue from 0.5 to 10 mm is most desirable.

It is desirable that before exposure to the structure of biological tissues carried out their preliminary cooling at 5-50 ° C.

The proposed method for removing biological tissue is that to remove the structures of pathological tissues using a source of low-frequency or mid-frequency voltage with one needle electrode. For example, such a voltage source can be a device described in RF patent No. 2191113, in which the needle electrode protrudes beyond the edges of the nozzle opening. In this case, the operation mode of the device without gas supply is used. To implement the claimed method, the device according to the patent of the Russian Federation No. 2100013, in which the needle electrode protrudes beyond the edges of the nozzle opening, can also be used. An ac quasistatic electric field is created on the needle electrode. The operator brings the needle electrode of the radiating head closer to the surface of the removed portion of the pathological tissue at a distance of 0.01 mm to 30 mm. When the density of quasistatic charges is achieved on the needle electrode, which is sufficient for electric breakdown of the distance from the patient’s skin to the tip of the needle electrode, a quasistatic discharge occurs.

Such discharges occur from 1 to 2,000,000 per second, depending on the electric power supplied to the radiating head, and on the distance from the tip of the needle electrode to the skin of the patient.

In this case, the tip of the needle electrode and the plane of the skin of the patient create a system similar to a vacuum diode.

When a positive half-wave of an alternating quasistatic electric field passes, a breakdown occurs from the tip of the needle electrode, which is an analog of the anode in a vacuum diode, to the patient's skin.

With the passage of the negative half-wave of an alternating quasistatic electric field at the tip of the needle electrode, breakdown from the patient’s skin to the needle electrode does not occur. There is the effect of rectification of an alternating quasistatic electric field.

Each single electrical discharge from a needle electrode to the patient’s skin burns out a microscopic hole in the structure of the patient’s pathological tissues, evaporating, burning out all organic tissue at the site of exposure.

However, since such discharges occur up to 2.000.000 per second, the total effect of this combination of discharges creates a well-marked hole in the structure of the pathological tissues of the patient, with a depth of 0.1 to 5-15 mm. But since such a total well consists of a huge number of microwells, thermal damage does not extend in depth and to the sides of this total well.

The amount of thermal damage to surrounding tissues is not more than 0.3 mm (usually 0.05-0.1 mm).

Accordingly, there is no replacement of damaged tissues with connective tissue and there are no scars and scars in the adjacent tissues.

Here, one more physical feature of using a needle electrode to create an electric discharge between the electrode and the tissue should be noted.

Electric discharges from the tip of the needle electrode to the patient's skin are quasistatic in nature, i.e. completely analogous to static electric discharge.

It is known that static electricity can propagate only on the surface of a conductor or semiconductor, without penetrating deep into. Accordingly, when treating the patient’s skin with such quasistatic discharges, the discharges, due to their nature, cannot penetrate deep into the patient’s skin and cause any damage to underlying and adjacent tissues.

Therefore, the effect of applying the proposed method when removing structures of pathological tissues is incomparably better than when using to remove structures of pathological tissues of all the above methods.

Also, in the process of removing the structures of pathological tissues, instant brewing occurs - coagulation of all interstitial blood vessels, which significantly reduces operational blood loss, and also leaves the site of the manipulation visually clean from blood. This is extremely important during both conventional and microsurgical operations. There is no need to apply ligatures and various metal staples, as in the case of the removal of structures of pathological tissues by surgery with a scalpel.

There are no scars when removing structures of pathological tissues using a discharge at all. When the holes are healed, the patient’s body regenerates a small amount of connective tissue at the site of the removed volume.

A particularly positive effect is obtained if, before starting the removal of biological tissue in accordance with the proposed method, lower the temperature of the treated tissue site in any way by at least 10-20 degrees or more degrees Celsius.

More than 1,500 different laboratory animals were processed to optimize the operating modes of the device while removing structures of pathological tissues.

First of all, studies were conducted on the dependence of the quality of removal of biological tissues from the discharge frequency.

The frequency of operation of the high-voltage resonant transformer used in the device changed.

The data were obtained, in 347 cases of using the device, that a change in the frequency of the electronic converter supplying the resonant transformer, in the range from 1000 Hz to 1.000.000 Hz, does not have any noticeable effect on the quality of removal of structures of pathological tissues.

However, with higher frequencies, the size and cost of the resonant transformer are reduced. Therefore, from the point of view of reducing the cost of the device, it is optimal to operate at frequencies of more than 50,000 Hz.

Studies have also been conducted on the effect of the voltage of an electric discharge created by the device used on the quality of removal of biological tissues.

109 experiments were conducted.

In this case, results were obtained showing that with a voltage between the needle electrode and the surface of the biological tissue of more than 30,000 volts, burns of adjacent tissues with subsequent scarring are possible.

Studies have also been conducted to optimize the distance from the needle electrode to the structure of pathological tissues (346 experiments).

The data were obtained that the optimal distance is not more than 8-10 mm from the needle electrode to the surface of the biological tissue. With an increase in the distance to 30 mm, “sputtering” of the electrostatic discharge was observed. It was difficult to get into the selected area of the pathological tissue structure, the total area of exposure increased, which entailed unnecessary treatment of the surrounding healthy tissues.

With an increase in the distance between the needle electrode and the surface of biological tissue by more than 30 mm, the electric power required for electrical breakdown of such a distance turned out to be so large that in 100% of cases it caused burns with subsequent formation of scars and scars (26 experiments were performed).

Thus, it is obvious that the optimal distance between the needle electrode and the surface of the biological tissue of the patient is from 0.01 mm to 10 mm. The maximum permissible distance is not more than 20 mm.

Over 7 years, about 1000 operations were performed in 16 veterinary clinics in Moscow and St. Petersburg using the device described in RF patent No. 2191113. Specialists of veterinary stations in Dzerzhinsk, Zelenograd and the Moscow State Aviation and Biological Institute named after K.I.Skryabin developed methods for implementing the proposed method using the device described in the patent of the Russian Federation No. 2191113, in animal diseases.

1. In dogs (most often in animals of lop-eared breeds - cocker spaniels, setters, etc.), chronic otitis externa with obliteration of the external auditory canal - verrucous dermatitis (otophyma) is accompanied by proliferation of tumor-like skin formations on the inner surface of the auricle and ear canal, the release of a catarrhal-purulent exudate of yellow-gray color with a sharp unpleasant odor.

The use of conservative and surgical methods (palliative surgery, antibiotic therapy, etc.) is laborious. This is due to the fact that instrumental access to the affected auditory canal and excision of neoplasms are accompanied by extensive dissection of tissues mainly of the auricle, deformation of the cartilage, heavy bleeding due to the passage of a network of large and small blood vessels in this area. Treatment in the postoperative period is also fraught with considerable difficulties, since daily treatments are laborious and very painful.

Using the proposed method for verrucous dermatitis eliminated the need for extensive surgical access to neoplasms in the lumen of the external auditory canal, which is very important during the operation. The risk of such postoperative complications as facial paralysis, bleeding, divergence of sutures, fistula development, hearing loss disappeared.

The application of the proposed method in the treatment of sick animals with verrucous dermatitis not only shortened and simplified postoperative care, but in some cases completely eliminated it. Silver ions as a result of thermal emission occurring under the influence of an electrostatic field, were released from the coagulating needle and, getting into the wound, changed the electric potential of the wound surface for a long time. This accelerated the regeneration processes, and also further disinfected the tissue.

When using this method, there was no need for deep curettage of the surface of the auricle. Mechanical cleaning of tissues was replaced by thermal atraumatic treatment using the proposed method. The distance between the electrode and the wound surface was maintained from 0.5 to 5 mm, a discharge with a frequency of 1, 15, 300, 2000 Hz and a voltage of 20, 500, 1000, 5000 V was used. Injury in all cases was 0.1-0.2 mm in the depth of the fabric.

2. At the veterinary station in Zelenograd, the proposed method using the device described in the patent of the Russian Federation No. 2191113, was used in various operations, including abdominal and bone. Preparing it for work took no more than 4 minutes. The head of the device was treated with a 0.5% solution of chlorhexidine abigluconate in 70% alcohol (exposure for at least 2 minutes). The needle of the device can also be placed in an alcohol solution of chlorhexidine. Direct contact of the coagulating head of the device with the treated tissue does not occur. A low-frequency discharge (5 kHz, 20 kHz, 100 kHz) is formed when the needle approaches the tissue at a distance of 0.1 to 10 mm. The discharge voltage is 10 kV. All operations were atraumatic, the depth of the lesion was not more than 0.2 mm, and the high healing rate.

3. Particularly significant results were achieved when applying the described method in ophthalmology. In MGAVMiB them. K.I.Skryabin the proposed method was used for a number of eye diseases in dogs and cats, especially for keratitis, which are not treatable by conventional methods.

In 132 dogs with creeping corneal ulcer blepharospasm, epithelial defect (corneal erosion), lacrimation, photophobia, pericorneal injection were observed. To recover, it took 1-2 times cauterization of the edges of the ulcer using the proposed method with an interval of 1 week, followed by the use of jelly solcoseryl and colbiocin ointment 3 times a day.

In 92 dogs of the German shepherd breed with herpes-virus keratitis (scrofulous form), moderate spasm of the eyelids, slight excretion of serous-mucous exudate was noted, the cornea was penetrated by blood vessels, uneven, tuberous, pigmented. Treatment included 1-3 times cauterization of connective tissue, blood vessels and pigment with an interval of 2 weeks, subconjunctival administration of a 0.5% solution of novocaine, lidase, dexamethasone and gentamicin 1 time per week and daily treatment with ointment prenacid. Dogs recovered after 25-35 days. Some observed relapse after 3-4 months.

In 76 dogs of different breeds with punctate keratitis (herpes virus), a round-shaped spot with a pearlescent shade was centrally or paracentral. After cauterization once a month, followed by subconjunctival injection of a 0.5% solution of novocaine, lidase, gentamicin, dexamethasone and glycopine, 68 animals recovered.

With pigmented keratitis, characterized by moderate spasm of the eyelids, secretion of yellow purulent exudate, an uneven, tuberous cornea with areas covered with dark brown pigment with total lesion of the cornea (n = 10) and partial pigmentation of 2/3 of the cornea (n = 14), cauterization was performed once, subsequently, solcoseryl jelly was used, colbiocin and dexamethasone, lidase and novocaine were administered subconjunctively.

Corneal enlightenment occurred in 19 of 54 dogs with total lesion and in 81 of 104 animals with partial pigmentation.

Corneal sequestration in cats is one of the pathologies that leads to a complete loss of visual functions, sometimes to corneal perforation. Clinical signs: necrotic area of the cornea from dark brown to black, blepharospasm, lacrimation. Cauterization of the edges in the initial stage (erosion of the cornea) once every 2 weeks suspended the development of the corneal sequestration. After that, a complex immunoprotector (CIP), solcoseryl jelly and colbiocin ointment were used daily for 2 weeks. Animals recovered after 2-3 months.

Dermoid of the conjunctiva and cornea is a benign neoplasm of the components of the skin, covered with hair, which often injures the cornea, leading to conjunctival hyperemia, the development of keratitis of corneal ulcers and loss of vision.

To remove the dermoid, the proposed method was used, with which bleeding was also stopped and the edges of the wound were cauterized.

In eye operations, a discharge with a frequency of 500-1000 kHz and a voltage of 1-2 kV was used.

4. There are more than 200 cases of application of the proposed method using the device described in the patent of the Russian Federation No. 2191113, to remove papillomas, genital warts. In all cases, relapse was not observed.

The proposed method was carried out more than 40 removal of corns. Including the so-called "cloves." There were no relapses.

Also, the proposed method was carried out 34 removal of ingrown nails. Repeated removal was required in 2 cases.

5. The proposed method has been successfully used to amputate animal organs. In experiments on rats, 23 tail amputations were performed. The tails were amputated at distances from 5 mm from the body of the animal to 5 mm from the tip of the tail. The discharge voltage was 20-30 kV, the frequency was 50 kHz - 2 MHz. Amputations were carried out both through the intervertebral space and directly along the vertebral bone. In all cases, good results of subsequent healing were obtained. Moreover, in 18 cases, no ligatures, brackets or other means of stopping bleeding were applied to the obtained stumps, since no bleeding from the received stump was observed. Thermal damage to the underlying tissue was practically absent (no more than 0.2 mm).

The proposed method in various veterinary clinics of Moscow made 7 amputations of the hind and front legs of cats and 4 amputations of the legs of small dogs. In all cases, good or satisfactory results of subsequent healing of the stumps were obtained.

Thus, as follows from the materials presented, the proposed method for removing pathological tissue structures allows for effective removal of various types of biological tissues with different nature of pathologies. Removal is carried out in the shortest possible time and does not lead to complications, since the removed tissue sections are not exposed to excessive thermal stress.

Claims (6)

1. The method of removing biological tissue, namely, that they act on the tissue by creating an electric discharge between the electrode located at a distance from the surface of the tissue and the surface of the tissue, characterized in that the effect on the tissue is carried out using a needle electrode by burning to form gaseous products, the distance between the electrode and the surface of the biological tissue is from 0.01 to 30 mm, the magnitude of the discharge voltage is from 20 to 30,000 V, and the frequency is from 1 to 2,000,000 s ^-1 . 2. The method according to claim 1, characterized in that the burning of small volumes of tissue is carried out at one point with the formation of the hole. 3. The method according to claim 1, characterized in that the burning is carried out repeatedly, at various points on the surface of the tissue, with the formation at each point of the hole and the removal of tissue by sequentially forming multiple holes connected to each other. 4. The method according to claim 1, characterized in that the burning is carried out in layers by scanning the fabric with a needle electrode, while maintaining between the surface of the fabric and the discharge electrode. 5. The method according to claim 1, characterized in that for the amputation of an organ or part of an organ, burning is carried out by deepening into the tissue along the amputation line until the organ or part of the organ is completely separated. 6. The method according to claim 1, characterized in that before exposure to the biological tissue carry out its preliminary cooling at 5-50 ° C.