ES2472542B1 - Directional tissue ablation device - Google Patents

Abstract

Directional tissue ablation device. # The present invention describes a tissue ablation device that allows directing electromagnetic radiation and irradiating a cylindrical volume by controlling the radius and height of the cylinder, which comprises an electromagnetic radiation guide and a body that protects said guide and facilitates tissue penetration.

Description

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FABRIC DIRECTIONAL ABLATION DEVICE

TECHNICAL FIELD OF THE INVENTION

The present invention is framed in the field of surgery and refers to a medical device or instrument, more specifically to an invasive device that allows to conduct a laser beam for tissue ablation.

BACKGROUND OF THE INVENTION

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There are currently many patents in the world related to tumor ablation. Most are related to tumor removal by radiofrequency (RF) and are endoscopes. EP0437183, "Light diffuser for a photodynamic therapy of tumors in the

15 oesophagus of a patient ”describes a device used only in esophageal cancers. The optical fiber of this device is only used to diffuse visible light into the esophagus and to detect the tumor site with greater reliability. WO9824513A1, "Multiple guide for laser fibers in the treatment of tumors in parenchymatous organs," describes another device that lacks fiber optics for

20 laser guided and only eliminates parenchymal tumors. One of its limitations is that the maximum tumor size cannot exceed 2cm in diameter. Nor is it able to focus the laser beam, so it could destroy surrounding healthy tissue. Two other patents, "Tumor ablation apparatus" [US5928229] and "Method and system for trans-lumenal radio-frequency ablation throught an endoscope" [WO9955244] describe

25 devices in which the method used is radiofrequency. In both, endoscopes that work as electrodes are used. These electrodes are fixed and have no movement within the patient. Other devices that use radiofrequency to eliminate tumors are described in the patents "Method for biopsy and ablation of tumor cells" [US6162216] and "Ablation

30 treatment of bone metastases ”[EP1059067]. The latter is applicable in bone tissue and not in any type of tissue. The patent "Gynecological ablation procedure and system using an ablation needle" [WO0211639] uses the term "needle" to describe the ablation device although, actually, the device is not a needle as such, but a pointed end electrode

35 so you can penetrate better. Like all of the above, the device produces RF ablation. This patent is designed only for gynecological tumors, but not for tumors in general. The patent "Modular biopsy and microwave ablation needle delivery apparatus adapted to in situ assembly and method of use" [US20022058932] describes a device that uses

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5 needles, but they are made of microwave antennas that are introduced into the body. To introduce said needle, a small hollow tube is previously introduced and into it, the needles that will act as an antenna. In the case of being used as an instrument to remove tissue and perform biopsies, the needle is reintroduced and the tissue is aspirated. Another possibility is to tear tissue with a harpoon-shaped needle.

10 Other RF tumor ablation devices are described in the patents "Electrosurgical device for treatment of tissue", [US2005177211] and "Flexible endoscope for endo luminar access radio frequency tumor ablation", [WO2006000888]. Non-surgical (although invasive) methods based on radiofrequency are the most used but have not given all the expected good results, since it is almost

Impossible, by radiofrequency, to irradiate a certain and very limited portion of tissue, devices have been invented to minimize the effects produced outside the irradiated area such as those described in "Apparatus and method for shielding tissue during tumor", patent [WO0219895 ] and "Percutaneous surgical instruments and methods using the same" [US2004133195].

20 US2005131399A1, entitled "Devices and methods for directed, interstitial ablation of tissue" describes a device that cannot focus, and to vaporize the area, the laser it uses has to emit different energies, to penetrate more into the tumor. Therefore, if the tumor does not have revolution symmetry, the device has to be introduced at several points of the tumor, causing the patient to be subjected to more than one

25 penetration EP1145686, entitled "Ablation catheter with a directional HF irradiator", describes a device of the type described above in the signal that is introduced into the patient's body is a radio frequency (of the order of GHz) with the problems that this entails. and that have been explained above. Obviously, being two antennas that

30 are introduced, in one session, only the part of the tumor that is between the two antennas can be removed. In the invention described in US2008071256A1, "Cancer treatment using low energy lasers" the laser beam used is non-directional and the beam cannot be focused anywhere. A further problem of this invention is that the optical fiber is

35 enters the patient directly, with the danger of breaking inside as

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These types of fibers are, in general, fragile. WO2008068789A1, "A kit of optical fibers for percutaneous ablative treatment" describes a system in which the optical fiber is introduced without protection into the patient. The ablation that is performed is not directional either.

5 WO2009108956A1, "Endoluminal laser ablation device and method for treating veins" describes a device that emits radiation in a 360 ° field and the specific area of radiation cannot be controlled, but the walls of blood vessels are expected to absorb it. . The patent entitled "Device for Localized Thermal Ablation of Biological Tissue,

10 Particularly Tumoral Tissues or the Like ”(US20070305973) describes a device that performs heating ablation but is not able to focus the heating zone and only one probe is inserted without it being protected from liquids or tissue that may remain in the form of waste hampering the output of electromagnetic waves.

15 Other devices use fiber optics, but this is used to transport visible light to the tissue so that the healthcare professional can see. An example is the patent, "Optical apparatus for guided liver tumor treatment and methods", WO2004028353, which describes a device that has an optical fiber, but in this case, uses it to transport light to illuminate the liver when, by

20 different methods, tumors in this organ are studied. Along the same lines, document EP2067447A1 entitled "Steerable catheter device and method for the chemoembolization and / or embolization of vascular structures, tumors and / or organs" describes a device in which the conduction of light is only to visualize the tumor.

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OBJECT OF THE INVENTION

A subject of the present invention is a device for performing tissue ablation, hereinafter "directional tissue ablation device", which allows directing electromagnetic radiation 30 and radiating a cylindrical volume by controlling the radius and height of the cylinder, which comprises a guide of electromagnetic radiation and a body that protects said guide and facilitates tissue penetration. Unlike other radiation modalities such as those that use radiofrequency, this device prevents burns and adverse effects in non-tumor areas that could lead to effects

35 unwanted side.

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DESCRIPTION OF THE FIGURES

5 Figure 1.-Scheme of the device object of the invention. A represents the main body of the device, Ep represents its proximal end, Ed its distal end, O1 represents the longitudinal recess in which the guide is embedded, F, of electromagnetic radiation, O2 indicates the hole through which the beam of electromagnetic radiation and R represents a reflective surface that reflects the radiation beam

10 electromagnetic.

DETAILED DESCRIPTION OF THE INVENTION

The device (Figure 1) object of the present invention comprises a guide of

15 electromagnetic radiation (F) that is embedded in the main body (A) of the device. Said main body is an elongated element, in which in turn a distal end (Ed) and a proximal end (Ep) are distinguished and is characterized in that it has a longitudinal recess (O1) practiced at its proximal end with a depth less than the length of said main body; a second transverse cavity (O2) practiced

20 in a manner substantially perpendicular to the first and communicating with said first cavity; and a reflective surface (R) located at the intersection of both cavities to reflect a beam of electromagnetic radiation.

The diameter of the longitudinal cavity (O1) is determined by the diameter of the guide

25 of electromagnetic radiation (F), preferably optical fiber, which slides inside and conducts electromagnetic radiation, preferably a laser light, which will perform the ablation

Preferably the distal end of the main body (A) comprises a sharp point

30 to penetrate the tissues. This tip is solid and beveled at an angle small enough to facilitate penetration.

The length of the device will depend on the depth to which the structure to which access is needed is located.

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The second cavity (O2), through which the beam of electromagnetic radiation will come out, preferably a laser beam, guided, will be practiced a short distance from the distal end (Ed) and is made to correspond exactly with a reflective surface (R), whose inclination will preferably be 45º with respect to the direction of the guide, of

5 way that allows the electromagnetic radiation beam to exit in the direction substantially perpendicular to the direction of the guide (F).

This second recess (O2) must have a sufficient diameter so that at the exit, the electromagnetic radiation beam does not present diffraction and will be sealed with materials

10 transparent to the wavelengths used and biocompatible, as it will be in contact with human tissues. Transparency is necessary since, if it were not, or the materials had a high transmittance at these wavelengths, the emitted power would have to be greater and therefore, the structures and parts that make up the device, could suffer deterioration.

15 The electromagnetic radiation guide (F) will be embedded, but not fixed, in the main body (A), thus being protected and preventing its possible rupture. Said guide (F) will have a connector placed at one of its ends to be able to connect it to an electromagnetic radiation generator. Its other end, closer to the distal end of the

20 device, will carry an optical quality polishing. The polishing will be carried out in such a way that it has the same properties as a lens (spherical, astigmatic, spherocylindrical, etc.) depending on the desired focal point for each type of irradiation.

The electromagnetic radiation guide (F), which has a diameter slightly smaller than

The diameter of the longitudinal cavity (O1), slides inside so that, having a carved tip in the form of a lens, it allows focusing the electromagnetic beams at a certain distance by moving the guide through the inside of the device.

At the proximal end (Ep), a cone made in a

30 material compatible with the standards used for syringes with hypodermic needles.

Once the device has penetrated the tissue, turning it results in the ablation of a circular plane whose center is the device itself and will have a diameter that will depend on distance from the tip of the radiation guide to the reflective surface (R ).

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Thus, by moving the device, the ablation of a chosen height and radius cylinder is achieved.

Regardless of the structure, shape or depth of the tumor that you want to remove from the body, the structure of the device does not vary.

To perform tissue ablation, the described device is part of a more complex system that also includes:

• an electromagnetic radiation generator, 10 • and a coupler to which the electromagnetic radiation guide is connected

The electromagnetic radiation generator can radiate at any wavelength, depending on the components and devices. With this you can select the range

15 frequencies for each specific case.

The coupler is used to connect the electromagnetic radiation guide, preferably optical fiber, to the emitting source, preferably a laser emitter.

20 EMBODIMENT OF THE INVENTION

To construct the directional tissue ablation device, capable of deflecting electromagnetic radiation perpendicular to its main axis, it is based on a hollow cylindrical stainless steel rod. This rod will give rise to the main body of the

25 device once machined.

A hole is drilled near one end of the rod and in the direction of the rod radius as follows: the rod is completely immersed in a paraffin bath so that it is completely covered by

30 outside and inside, and the paraffin melts in an area where the hole will be made using a low intensity laser. Once this part has been exposed from the paraffin, the rod is immersed in acid so that, through chemical corrosion, the necessary hole is made.

Subsequently, it is extracted from the acid, washed, dried and immersed in a solvent to completely remove the paraffin.

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The following process involves the manufacture of the mirror and the placement inside the rod. For which another solid stainless steel rod whose diameter is used

5 outside is equal to the inside diameter of the previous rod. This rod is cut with a 45º angle and then polished to obtain an optical quality termination. This part will act as a mirror inside the rod and the beam will deflect an angle of 45º that will come out perpendicularly to it, for which, the mirror will have to be centered later and that it coincides with the hole made in the hollow rod.

10 The termination of the hollow main rod, together with the protruding part of the solid rod, is cut and polished at an angle that allows intramuscular penetration and does not cause tissue tearing.

15 To prevent the entry of cellular tissue into the device, the hole must be covered with some biocompatible material, with this we prevent the inside of the rod from penetrating tissue when the hole is sealed.

The fiber optic connection is made by placing a standard female cone in the base

20 of the rod, similar to that used for hypodermic needles, and sealing it with biocompatible ultraviolet curing resin for medical use.

The laser light generator, the light guide, as well as the fiber optic connector needed to perform the ablation, will be chosen based on the needs of the process, the

25 which will be defined by electromagnetic radiation (wavelength and emission power).

Other characteristics, such as the type of guide, refractive indexes or numerical aperture, will also depend on the laser chosen and the tumor to be treated.

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Claims (3)

image 1 1.-Directional tissue ablation device comprising an electromagnetic radiation guide that is embedded in the main body of the device in which said main body is an elongated element, which in turn distinguishes one end
distal and a proximal end and has a longitudinal cavity practiced at its proximal end with a depth less than the length of said main body, a second transverse cavity practiced substantially perpendicular to the first and communicating with said first cavity, and a surface reflective located in the 10 intersection of both cavities to reflect a beam of electromagnetic radiation. 2. Device according to previous claim characterized in that the distal end of the main body comprises a sharp point to penetrate the tissues 3. Device according to any of the preceding claims characterized in that the reflective surface is placed at an angle of 45 ° with respect to the direction of the guide. 4. Device according to any of the preceding claims characterized in that the electromagnetic radiation guide is optical fiber. twenty