RU2763939C1 - Device for radio-frequency ablation of pulmonary vessels - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to cardiovascular surgery, and concerns devices for radiofrequency ablation of pulmonary arteries for the purpose of their denervation in the treatment of secondary pulmonary hypertension in cardiac surgery patients with mitral valve disease, pulmonary embolism, atrial fibrillation, as well as for isolation orifices of the pulmonary veins in the treatment of ectopic atrial fibrillation. The device for radiofrequency ablation of pulmonary vessels contains two branches, one of which is fixed in the device-handle of the device, and the other with the possibility of parallel translational movement relative to the fixed branch to form sponges perpendicularly located at the ends of the branches, intended to place between them a section of the pulmonary vessel, open or the closed position of the device. Each of the surfaces of the jaws facing each other is made with a central section protruding along the entire length of the jaws, on the surface of which an electrode of rectangular cross-section is flush mounted along it, connected to a source of radio frequency current. In the middle of the protruding central section on the surface intended to accommodate the pulmonary vessel on each sponge, an arcuate notch is made over the entire width of the protruding central section in the section of the sponge with a length (A) from 22 mm to 60 mm, with a radius of an arc of a circle (R) from 80 mm up to 600 mm, selected from the condition of placing a section of the pulmonary vessel in the recess when the device is closed for the radiofrequency ablation procedure. Flush with the surface of the central protruding portion of each of the jaws, a second electrode of rectangular cross-section is installed, isolated from the first electrode. Both electrodes are located on a jaw length (L) from 28 mm to 70 mm. Each electrode has a width (B) of 0.2 mm to 0.5 mm and a height (H) of 2.5 mm to 3.0 mm. On the rectilinear surfaces of the protruding central section of each jaw, the electrodes are located along the surfaces parallel to each other and with a gap (C) between them from 0.5 mm to 0.6 mm, and from the boundaries of the arcuate recess with rectilinear surfaces of the protruding central section of each jaw, the electrodes are symmetrical and arcuate apart relative to the longitudinal axis of the protruding central section to its lateral edges with the formation of a gap (D) between the tops of the arcs formed by the electrodes, equal to 1.6 mm to 1.8 mm. The connection of the electrodes to the radio-frequency current source and to each other is made with the possibility of providing opposite polarity on the two electrodes of each sponge upon their activation, and the unipolar electrodes on the opposite jaws are located on their protruding central sections mirroring each other.

EFFECT: more uniform along the perimeter of the pulmonary vessel, irreversible thermal effect on its wall, a decrease in the depth of influence on the wall, in order to preserve the intimate layer of the vessel to ensure normal regulation of the reflex reaction of the vessels of the pulmonary circulation and prevent complications after circular radiofrequency ablation by ensuring uniform pressure on the vessel along its entire perimeter, as well as practically the same temperature along the perimeter of the pulmonary vessel compressed by sponges and heating its wall to a shallower depth.

1 cl, 2 tbl, 3 ex, 10 dwg

Description

The invention relates to medicine, namely to cardiovascular surgery, and concerns devices for radiofrequency ablation of pulmonary arteries for the purpose of their denervation in the treatment of secondary pulmonary hypertension in cardiac surgery patients with mitral valve disease, pulmonary embolism, atrial fibrillation, as well as for isolation orifices of the pulmonary veins in the treatment of ectopic atrial fibrillation .

Long-term results of assessing the condition of patients after pulmonary thromboendarterectomy surgery show that in 10–40% of patients who underwent such an operation, signs of residual pulmonary hypertension (high blood pressure in the pulmonary artery) remain in the postoperative period, which is clinically manifested by shortness of breath, symptoms of right ventricular failure, which limits physical activity, reduces the quality of life of patients and causes repeated hospitalizations [Chernyavsky A.M., Edemsky A.G., Novikova N.V., Romanov A.B., Artemenko S.N., Rudenko B.A. , Tarkova A.R. The use of radiofrequency ablation of the pulmonary artery in the treatment of residual pulmonary hypertension after pulmonary endarterectomy // Kardiologiya. - 2018. - No. 58(4), p. 15]. Such patients are doomed to take specific drugs for life, the high cost of which limits their widespread use.

Pulmonary hypertension (PH) is also almost always found in long-term rheumatic and degenerative heart disease. Most often it occurs with damage to the mitral valve. Replacing a diseased heart valve with pre-existing PH often does not normalize pulmonary artery blood pressure. And since high residual pulmonary hypertension negatively affects the long-term survival of patients, and even after adequate replacement of the affected heart valve does not disappear, additional procedures are required to reduce pressure in the pulmonary artery [Trofimov N.A., Medvedev A.P., Babokin V.E., Efimova I.P., Kichigin V.A., Dragunov A.G., Nikolsky A.V., Tabaev R.G., Preobrazhensky A.I. Circular sympathetic denervation of the pulmonary arteries in cardiac surgery patients with mitral valve disease, atrial fibrillation and high pulmonary hypertension. Kardiologiya. - 2020. - No. 60(1), p. 36.37].

The main way to correct residual chronic thromboembolic pulmonary hypertension in patients after pulmonary thromboendarterectomy and patients with decompensated heart disease is to relieve spasm of the pulmonary vascular wall [Feshchenko D. A., Rudenko B. A., Shanoyan A. S., Drapkina O. M. , Kontsevaya A. V., Gavrilova N. E., Shukurov F. B., Vasiliev D. K. Pulmonary denervation in the treatment of pulmonary hypertension: current state of the method and clinical experience // Russian Journal of Cardiology. - 2019. - No. 24 (12), p. 163].

Since anatomically in the bifurcation of the pulmonary trunk and the mouths of the main pulmonary arteries (LA) there are a large number of baroreceptors, the vascular wall of the LA is constantly under the influence of the autonomic nervous system (sympathetic and parasympathetic), paravasal autonomic ganglia. Innervation begins from the branches of large nerve trunks, which are divided into single fibers at the level of arterioles. Normally, the balance of LA autonomic regulation is predominantly shifted towards the sympathetic nervous system. With PH, sympathetic activity is significantly increased, which leads to a persistent increase in pulmonary vascular resistance (PVR) and an increase in pressure in the pulmonary circulation (ICC). Therefore, in order to reduce the activity of the sympathetic influence and, as a result, reduce the PVR and reduce the pressure in the LA, it is necessary to have a destructive effect on these vegetative ganglia and, thereby, ensure the vegetative denervation of the LA. To do this, radiofrequency ablation of the pulmonary artery (RFA LA) is used, by thermal action on the area of LA bifurcation. The LA RFA procedure leads to a decrease in the activity of the sympathetic part of the lungs. Thus, LA RFA entails autonomic denervation of the pulmonary trunk and, as a result, the removal of spasm of the pulmonary vessel wall, thereby reducing blood pressure in the pulmonary artery and its branches, and correcting pulmonary hypertension in the patient.

However, when conducting RFA of the LA, it must be taken into account that the LA wall consists of three layers of different thicknesses, while the sympathetic fibers are located in the adventitial (superficial) layer of the pulmonary artery wall, immersing as much as possible only up to a third of the middle layer (media). Thus, based on the average thickness of the pulmonary artery wall layers, it can be estimated that complete denervation of the pulmonary trunk requires irreversible damage to the wall of this vessel to a depth of no more than 0.7 mm, which is approximately 60% of the vessel wall thickness. Based on this, two zones of damage to the pulmonary artery wall can be distinguished, which occur with optimal LA RFA:

I zone - zone of irreversible thermal damage to the wall of the pulmonary artery;

II zone - the zone of viability of the pulmonary artery wall.

The division of the wall of the pulmonary artery into two zones during RFA allows guaranteed in the I zone to carry out an irreversible thermal effect on all sympathetic nerve plexuses, thereby causing stable and effective denervation of the pulmonary vascular bed, and in the II zone, due to the preservation of the baroreceptors of the vessel, to give them the ability to continue to exercise a reflex effect on the vessels of the ICC. The main mass of baroreceptors is located in the intimal layer of the pulmonary trunk and the main branches of the LA. With a sharp increase in pressure in the LA, the indicated baroreceptors are excited, located mainly in the area of the bifurcation of the pulmonary trunk, which in turn reflexively reduces pressure in the systemic circulation by slowing down the heart and dilating the vessels of the systemic circulation. This leads to the deposition of blood in the body and a decrease in its flow to the lungs (the so-called Parin reflex). This reflex has a protective function against the harmful effects of sharp significant pressure fluctuations in the circulatory system, preventing the development of pulmonary edema and abnormal effects on the blood supply to the brain, being one of the important links in the cardio-pulmonary-cerebral protective regulatory system of the body.

Known multipolar synchronous radiofrequency ablation catheter, which is used for circular denervation of the pulmonary artery [RF Patent 2692219 C2, IPC A16B 18/12. Appl. 07/10/2015]. It consists of a flexible shaft with a diameter of 2.5 mm and a handle. The catheter shaft at its end has a diameter of not more than 1.67 mm and is made in the form of an open loop (lasso type) located in a plane perpendicular to the axis of the catheter shaft. The outer diameter of this ring is equal to the inner diameter of the pulmonary vessel and can be 20 mm, 25 mm, 30 mm, 35 mm, 40 mm and 45 mm, respectively. Along the circumference of the ring at an equal distance (2 mm) from each other there are 10 electrodes with a width of 0.75 mm each. The electrodes are connected by a connecting cable passing inside the catheter shaft to a radio frequency generator, which has a device for alternately supplying energy to each electrode, regulated by a switch. In the non-working state, the loop in a straightened form is placed on the catheter shaft in a special sheath.

To select the optimal diameter of the distal catheter ring, the diameter of the pulmonary artery trunk is estimated using MRI and CT angiography before surgery. Repeatedly, the diameter of the pulmonary trunk is specified immediately before radiofrequency denervation using angiopulmonography. After that, the catheter shaft is inserted through the femoral vein and advanced into the pulmonary artery trunk, after which the catheter shaft is gently removed and by pressing the catheter, the loop (lasso) is released from the sheath and fits snugly against the inner wall of the pulmonary artery trunk. After that, with the help of a radio-frequency current generator, electrical energy is alternately supplied to the electrodes, which causes heating of the vessel wall. The ablation parameters are set in advance by the manufacturer of this equipment: the vessel tissue heating temperature is > 50°C, the power supplied by the generator is no more than 10 W, the electrical resistance is no more than 140 Ohm, the duration of exposure is 60 s.

Based on observations of a small number of patients (21 people), after 3 months, most of them experienced a decrease in pressure in the LA, both systolic and mean, a decrease in the symptoms of chronic heart failure, an improvement in the results of the 6-minute walk test (WST) [ Shao-Liang Chen, Feng-Fu Zhang, Jing Xu, Du-Jiang Xie, Ling Zhou, Thach Nguyen, Gregg W. Stone. Pulmonary Artery Denervation to Treat Pulmonary Arterial Hypertension The Single-Center, Prospective, First-in-Man PADN-1 Study (First-in-Man Pulmonary Artery Denervation for Treatment of Pulmonary Arterial Hypertension) / Journal of the American College of Cardiology.- 2013. - Vol. 62. - No. 12.-pp. 1092].

However, when using the above ablation catheter, a continuous line of ablation of the wall of the pulmonary trunk is not created, because radiofrequency exposure is carried out in a point way, by influencing sections of the inner layer of the vessel located between adjacent electrodes of the catheter. Thus, in the future, part of the impulses will continue to pass through the affected area, and the effectiveness (reduction of pulmonary hypertension) of this operation will be insufficient. But the main disadvantage of this catheter is that it provides radiofrequency exposure primarily to the inner (intimal) layer of the vessel wall, in which baroreceptors, after their irreversible thermal damage, will not be able to regulate the reflex reaction of the vessels of the pulmonary circulation and, thereby, prevent the development of pulmonary edema and decompensation of pulmonary circulation.

Known clamping device for the formation of circular lesions of the pulmonary veins or lesions around other structures of the body with radiofrequency exposure outside the vessel (exovasally) [US Patent 6692491 B1. IPC A61B 18/14. Appl. February 17, 2004]. This device consists of a forceps apparatus and a tissue thermocoagulation apparatus. The tong-shaped apparatus includes two handles-levers that are articulated with each other by means of a pin, which allows the device to be opened or closed. The distal parts of the levers are curved and support the tissue thermocoagulation apparatus, which includes a support element with a diameter of 1.67 mm to 3.0 mm made of an insulating, biocompatible thermoplastic material and a working element installed on it, which is a plurality of electrodes spaced along its length at equal distances . Spaced electrodes can be made in the form of wound spiral turns or in the form of rings of electrically conductive materials with a length of 2 mm to 10 mm. The tissue thermocoagulation apparatus is connected with an electrical wire to an electrical connector that can be connected to a source of radio frequency energy (generator).

When closed, the distal portions of the curved arms of the tissue thermocoagulation device form around the body of the RF ablated structure, such as the pulmonary vein or pulmonary artery, a continuous contour of round, oval, or any other closed shape required for a particular procedure.

The electrodes can operate in a unipolar (unipolar) mode, when an electric discharge is supplied from the radio frequency generator to the patient's pulmonary vessel through the electrodes and then returns to the generator through an indifferent (neutral) electrode in the form of, as a rule, a wide plate attached to the outside of the patient's skin. The electrodes can also operate in a bipolar (bipolar) mode, when the energy emitted by one or more electrodes of one polarity is returned through the treated tissue of the vessel to the electrodes of another polarity and then to the generator.

To create continuous elongated sections of thermal damage to the vessel tissue, the electrodes should be located close enough to each other - from 1 mm to 3 mm. In this case, additive heating effects may occur with simultaneous transfer of ablation energy to neighboring electrodes. Additive heating effects between adjacent electrodes enhance the desired heating of vessel tissue in contact with these electrodes. Additive heating effects occur when adjacent electrodes are operated simultaneously in bipolar mode. In addition, additive heating effects also occur when the electrodes are operated simultaneously in a unipolar mode, transferring energy through the treated vascular tissue to the neutral electrode.

Thus, when using this clamping device, it is possible to provide a radiofrequency exovasal effect on the pulmonary veins and arteries and form circular irreversible thermal lesions of their walls. In this case, the operation can be performed when the heart is beating.

However, it should be noted that when using in this clamping device the above-mentioned tissue thermocoagulation apparatus with several electrodes spaced along the length of the support element, it will never be possible to ensure the same heating temperature of its wall over the entire surface (perimeter) of the vessel, because the temperature of the tissue in the areas under the electrodes will differ from the temperature in the areas between the electrodes, despite the presence of the above additive heating effects. This means that in some areas the temperature may differ from that which is necessary to ensure irreversible thermal damage to the wall of the pulmonary vessel, and in these areas its denervation will not be provided. In the case of using a clamping device when its electrodes are operated in a unipolar mode, not exovasal, but transmural thermal damage to the pulmonary vessel wall will occur, which will lead to damage to the baroreceptors located in its intimate layer with all the previously indicated consequences. But the main disadvantage of this clamping device is its inability to guarantee a tight circular fit of the electrodes to the surface of the vessel. In particular, with a smaller diameter of the vessel, a gap is formed between it and the working surface of two curved, for example, in half rings, distal parts of the levers with a tissue thermocoagulation apparatus. With a larger diameter of the vessel, when it is clasped by the distal parts of the two levers, a fold forms on it, and a large gap will be created in this place. The presence of gaps in both cases leads to uneven radiofrequency exposure to the wall of the pulmonary vessel and, accordingly, to uneven thermal damage to its wall and, consequently, to non-guaranteed radiofrequency denervation of the patient's pulmonary veins or arteries. In addition, in the presence of gaps, there is no tight contact between the electrodes and the vessel tissue, and blood enters these gaps, which, as a result of radiofrequency exposure, forms a thin transparent coating of dehydrated blood protein on the electrode surface. If the temperature continues to rise, this dehydrated layer of blood gradually thickens, which leads to a pronounced coagulation of blood on the surface of the electrodes, creating carbon deposits on them, and to the formation of blood clots (thrombi), which interfere with normal blood circulation, and sometimes put the patient's life to death. danger [Bashilov S.A. Comparative analysis of modern catheter methods for the treatment of patients with paroxysmal atrial fibrillation // Diss. for the competition uch. Art. cand. honey. Sciences. - M .: NMHC im. N.I. Pirogov, 2019, p. 28].

Closest to the claimed device in technical essence is a device for radiofrequency ablation [US patent 6932811 B2. MPK A16V 18/18. Appl. 08/23/2005], which is intended for the treatment of cardiac arrhythmias, by providing denervation of hollow organs such as pulmonary veins. This device contains a handle with movable and fixed jaws installed in it, each of which is rigidly connected, respectively, with jaws perpendicular to it and parallel to each other, which, when moving the movable jaw, form an open or closed position of the device, while each jaw has an isolated mating outer surface with a protruding central section, moreover, in the closed position of the device, the mating outer surfaces on these protruding central sections completely coincide, and an electrode is located along the protruding central section of each of the jaws, while the electrodes are connected to a radio frequency energy source in such a way that, when activated, they have opposite polarity. In a preferred embodiment, the electrodes are 30 mm to 80 mm long and 0.12 mm to 0.6 mm wide.

After the cardiac surgeon places the device outside the pulmonary vessel and squeezes it between two sponges, radiofrequency energy is applied to the electrodes, which, due to the bipolarity of the electrodes, will be released in the compressed walls of the vessel when activated, creating a focus of thermal damage in them. Using the present invention, it is possible to achieve a lesion depth of 5 mm with a width of less than 2 mm.

When using such a device, a clamping zone is created, which is approximately three times wider than the electrode-tissue contact zone. This allows ablation with minimal contact between the electrodes and any blood cells, which significantly reduces the likelihood of blood clots. The design also allows for a minimum distance between the electrodes, further facilitating the creation of a continuous circular lesion of the pulmonary vessel wall with a single RF energy discharge.

However, it should be noted that the above damage to the tissue of the vessel wall for the purpose of its denervation has a transmural character, i.e. not only the adventitial and middle layers of the pulmonary vessel wall are subjected to thermal damage, but also the intimal layer with baroreceptors located in it, damage to which, as previously shown, is unacceptable.

However, this device has found application not only in radiofrequency ablation of the pulmonary veins, but also in the conduct of circular sympathetic radiofrequency denervation of the pulmonary arteries in the 51st cardiac surgical patient with mitral valve disease, atrial fibrillation and high pulmonary hypertension [Trofimov N.A., Medvedev A.P., Babokin V.E., Efimova I.P., Kichigin V.A., Dragunov A.G., Nikolsky A.V., Tabaev R.G., Preobrazhensky A.I. Circular sympathetic denervation of the pulmonary arteries in cardiac surgery patients with mitral valve disease, atrial fibrillation and high pulmonary hypertension. Kardiologiya. - 2020. - No. 60(1), p. 35-42], [RF patent 2661710 C2. A61B 18/12. Appl. December 27, 2016]. At the same time, it was found that circular radiofrequency denervation of the trunk and ostia of the pulmonary arteries using this device contributes to a significant reduction in the degree of pulmonary hypertension (p=0.018), reverse remodeling of the heart cavities, in particular, the left atrium (p=0.010), and also improves the results Maze IV procedure (p=0.022) by restoring and maintaining sinus rhythm in patients with mitral valve defects complicated by atrial fibrillation and high pulmonary hypertension.

However, radiofrequency ablation of the trunks of the pulmonary artery by the indicated device of the trunks of the pulmonary artery of those who died at the age of 47 to 66 years with practically no changes in the walls of the pulmonary artery showed that the disorganization of the connective tissue of the vessel wall is more pronounced in its subadventitial layer (fibrinoid necrosis) and with the penetration of radio frequencies to the intimal layer decreases to mucoid swelling in the subendothelial layer. In places of the greatest deformation (compression) of the vessel by the sponges of the clamp-ablator (two "marginal zones"), subsequent radiofrequency exposure causes damage to the entire wall of the pulmonary artery, including its intimate layer, and in these "marginal zones" the area of tissue disorganization of the vessel wall reaches 100% (see Fig. 1).

It follows that when using the prototype device for conducting circular radiofrequency ablation outside (exovasally) of the pulmonary vessels (pulmonary veins and pulmonary arteries) in order to denervate them during surgical treatment in patients with secondary pulmonary hypertension, firstly, uneven irreversible transmural thermal damage occurs the walls of the vessel, and secondly, the intimate layer is also irreversibly affected and, accordingly, the baroreceptors located in it are damaged, which will not be able to regulate the reflex reaction of the vessels of the pulmonary circulation and, thereby, prevent the development of pulmonary edema and decompensation of pulmonary circulation.

The objective of the claimed invention is to create a device for performing circular radiofrequency ablation outside (exovasally) of pulmonary vessels (pulmonary veins and pulmonary arteries) in order to denervate them during surgical treatment in patients with secondary pulmonary hypertension, providing an irreversible thermal effect on its wall that is uniform along the perimeter of the vessel. Moreover, denervation should be carried out to a shallower depth, at which the functions of the intimal layer of the vessel are preserved, which should ensure normal regulation of the reflex reaction of the vessels of the pulmonary circulation and prevent complications after the procedure, for example, prevent the development of pulmonary edema and decompensation of the pulmonary circulation.

The technical result of the invention is a more uniform along the perimeter of the pulmonary vessel, an irreversible thermal effect on its wall, a decrease in the depth of exposure to the wall, in order to preserve the intimal layer of the vessel to ensure normal regulation of the reflex reaction of the vessels of the pulmonary circulation and prevent complications after circular radiofrequency ablation by providing the time of radiofrequency exposure to uniform pressure on the vessel along its entire perimeter, as well as almost the same temperature along the perimeter of the lung vessel compressed by sponges and heating its wall to a shallower depth.

This technical result is achieved by the fact that in the device for radiofrequency ablation of pulmonary vessels, containing two branches, one of which is fixedly installed in the body-handle of the device, and the other with the possibility of parallel translational movement relative to the fixed branch to form sponges perpendicularly located at the ends of the branches, designed for placing between them a section of a pulmonary vessel, an open or closed position of the device, moreover, each of the surfaces of the sponges facing each other is made with a central section protruding in height along the entire length of the sponges, on the surface of which an electrode of rectangular cross section is placed flush along it, connected to source of radio frequency current, in accordance with the claimed invention , in the middle of the protruding central section on the surface intended for the placement of the pulmonary vessel on each sponge, the entire width of the protruding central section is made arcuate a recess in the sponge section with a length (A) from 22 mm to 60 mm, with a radius of the circular arc (R) from 80 mm to 600 mm, selected from the condition of placement in the recess of the pulmonary vessel section with the device for the radiofrequency ablation procedure closed, while , flush with the surface of the central protruding section of each of the jaws, a second electrode of rectangular cross section is installed, isolated from the first electrode, both electrodes are placed on the sponge section with a length (L) from 28 mm to 70 mm¸ each electrode has a width (B) from 0.2 mm to 0.5 mm, height (H) from 2.5 mm to 3.0 mm, moreover, on the rectilinear surfaces of the protruding central section of each sponge, the electrodes are located along the surfaces parallel to each other and with a gap (C) between them from 0, 5 mm to 0.6 mm, and from the boundaries of the arcuate recess with straight surfaces of the protruding central section of each sponge, the electrodes are symmetrically and arcuately separated relative to the longitudinal axis of the protruding central section and to its side faces with the formation of a gap (D) between the tops of the arcs formed by the electrodes, equal to from 1.6 mm to 1.8 mm, while the connection of the electrodes to the source of radio frequency current and to each other is made with the possibility of providing opposite polarity on two electrodes of each sponge when they are activated, and unipolar electrodes on opposite sponges are located on their protruding central sections mirror to each other.

The essence of the claimed invention is illustrated by drawings.

Fig. 1 schematically displays, according to histological studies, the areas of distribution and the degree of irreversible damage to the wall of the pulmonary artery (in percent) after its transmural radiofrequency ablation with a prototype device.

Fig. 2 is a general view of the proposed device for radiofrequency ablation of pulmonary vessels.

Fig. 3 shows the design of the fixed and movable jaws of the device for radiofrequency ablation of pulmonary vessels in accordance with the claimed invention in the open position.

Fig. 4 illustrates the electrical interconnection of all four electrodes of the device for radiofrequency ablation of pulmonary vessels according to the claimed invention and their connection to the radiofrequency current source.

Fig. 5 shows the distribution graphs (diagrams) of temperature T _i ( l ) from the side of the intimal layer of the wall of the pulmonary artery with an outer diameter of 28.3 mm, temperature T _a ( l ) from the side of the adventitia layer and temperature T _lim ( l ) at the border of the zone of permissible injury to the vessel wall during RF exposure energy of 112 J, and the gap between (C) the electrodes of different polarities on the straight portion of each jaw equal to 0.6 mm.

Fig. 6 presents graphs of the dependence of the average temperature at the boundary of the zone

allowable damage to the wall of the pulmonary vessel from the average amount of energy supplied from the RF generator to the treated volume of the wall of the pulmonary vessel,

at different values of the gap (C) between the rectilinear sections of the electrodes of different polarity.

Fig. 7 - design of the sponges of the device according to the claimed invention for radiofrequency ablation of the pulmonary veins with an outer diameter of 14 ± 0.8 mm (the pulmonary vessel is not indicated on the section B-B).

Fig. 8 is a graph of distribution (epure) temperature T _lim (l) at the border area damage tolerance pulmonary vein wall with an outer diameter of 14.4 mm at an RF impact energy of 80 J, and the structure of the electrode assembly of sponges shown in Figure 7.

Fig. 9 is a graph of distribution (epure) temperature T _lim (l) at the border area damage tolerance pulmonary artery wall with an outer diameter of 35.8 mm at an RF impact energy equal to 313 J, and the structure of the electrode assembly jaws shown in FIG. 7.

Fig. 10 is a photograph of the wall of the pulmonary artery with an outer diameter of 35.8 mm with a zone of irreversible thermal damage, where 1 is the preserved zone of the wall of the pulmonary artery; 2 - zone of irreversible thermal damage to the wall of the pulmonary artery (staining with hematoxylin-eosin, x 100).

The device for radiofrequency ablation of pulmonary vessels according to the claimed invention is shown in Fig. 2. The dimensions of the device elements during its manufacture correspond to the average standard sizes used depending on the dimensions of the vessels corresponding to the physiological parameters of the patients.

The device contains a hollow body-handle 1, in which branches 2 and 3 are installed, moreover, the branch 2 is fixedly installed, and the branch 3 is installed with the possibility of parallel movement relative to the fixed branch 2. 5 movable jaws, which, when moving the movable jaw 3, form an open (shown in Fig. 2) or closed position of the device. The lever 6 is connected to the mechanism 7 for driving the movable jaw 3 (not shown), designed to bring the jaws into the open or closed position of the device and create pressure on the portion of the vessel located in the jaws. The device can also be equipped with a stopper 8, made with the possibility of fixing the closed position of the device.

Each of the surfaces of jaws 4 and 5 facing each other (Fig. 3) is made with a central section 10 protruding in height along the entire length of the jaws, on the surface of which each of the jaws along it flush with this surface has two electrodes 11 of a rectangular section made of conductive material, isolated from each other, except for their upper surface, for example, epoxy compound 11.1. Using an electrical cable, the electrodes 11 are connected to a high-frequency current source (not shown), moreover, the electrodes are electrically interconnected and connected to a radio-frequency current source (Fig. 4) in such a way that the electrodes 11 of each pair on each sponge, when activated, have the opposite polarity , and unipolar electrodes on opposite jaws are located on their protruding central sections mirror to each other, for example, both shown in Fig. The 4 left electrodes will have one polarity when activated, and both right electrodes will have the other polarity.

In the middle of the protruding central section (Fig. 3) of each sponge, an arcuate recess 13 is made with a width equal to the width of the protruding central section, the radius of the arc R of which is selected from the condition of the possibility of placing a section of the pulmonary vessel in the recess when the device is closed during the radiofrequency ablation procedure. The length of the section of each sponge at the location of the concave arcuate curved surface 13, taking into account the standard sizes of the vessels, is from 20 mm to 60 mm, and the radius of the circle R describing the concave curved surface is, respectively, from 80 mm to 600 mm. The edges of the protruding central section of each sponge are made in the form of two rectilinear surfaces 12. The electrodes 11 on both rectilinear surfaces 12 of the protruding central section 10 of each sponge are located longitudinally, rectilinearly and symmetrically relative to the central longitudinal axis Z with a gap (C) between them from 0.5 mm up to 0.6 mm, and from the boundaries of the arcuate recess 13 with straight surfaces of the protruding central section, the electrodes are symmetrically and arcuately separated along the longitudinal axis Z of the protruding central section to its side faces with the formation of a gap (D) between the tops of the arcs formed by the electrodes, equal to 1 .6 mm to 1.8 mm, also taking into account the standard sizes and the achievement of a technical result with each of them.

The electrodes are electrically connected to each other and connected to a source of radio frequency current (Fig. 4) in such a way that the electrodes 11 of each pair on each sponge, when activated, have the opposite polarity, and the unipolar electrodes on the opposite sponges are located on their protruding central sections mirror to each other, for example , both left electrodes shown in figure 4 will have one polarity when activated, and both right electrodes will have a different polarity.

In this case, taking into account the dimensions of all the other elements above, the length of these electrodes is from 28 mm to 70 mm with a width of 0.2 mm to 0.5 mm and a height of 2.5 mm to 3.0 mm each.

Radiofrequency ablation of pulmonary vessels using the proposed device is carried out as follows. The device is connected to a source of RF current. Sponge 4 of the cardiosurgeon starts on the side of the pulmonary vessel, under it, after which, holding the device by the handle 1, pressing the lever 6 sets in motion the movable jaw 3 with the movable sponge 5 connected to it, as a result of which the pulmonary vessel 14 is placed in the arcuate recesses 13 both sponges and tightly pressed around its entire perimeter to the protruding central sections of 12 sponges with pairs of electrodes installed on them. After that, the cardiac surgeon presses the latch 8 and, thereby, ensures the retention of the closed position of the jaws of the device.

When the sponges are closed and this condition is recorded, the cardiac surgeon activates the radio frequency generator, and the radio frequency energy is applied to the electrodes, and then passes through the tissue of the vessel wall between the opposite electrodes of each sponge, thus ablating the tissue between these electrodes. After the ablation cycle is completed, the cardiac surgeon first turns off the RF generator, then sequentially presses the latch 8, the lever 6, and thereby sets the movable jaw 5 in motion, resulting in the release of the pulmonary vessel from the device.

The empirically selected dimensions of the device elements were confirmed as a result of approbation of the claimed device in the process of radiofrequency ablation of the pulmonary vessels of those who died at the age of 47 to 66 years with practically unchanged walls of the pulmonary vessels. The vessels had an outer diameter from 12±0.8 mm to 36±1.3 mm.

So, to ensure circular irreversible thermal damage to the walls of the vessel along its entire perimeter, the electrodes are made longer than the width of the lung vessel squeezed by sponges. This achieves a snug fit of the vessel to the protruding central portion of each sponge along the entire perimeter of the vessel.

The need to perform the above-described shape of the sponges with the electrodes installed in them was confirmed by the detection in the process of preparing for ablation of a uniform compression of the lung vessel by the sponges during its shape change under the action of a transverse force applied to it by the sponges. To do this, a strip of heated plasticine (TU 2389-001-00322175-2007) of small thickness was placed on a fixed sponge of the proposed device along its entire length. After that, the surface of the plasticine strip was lubricated with castor oil (GOST 6757-96). Then the trunk of the pulmonary artery or pulmonary vein was laid on it, on which the same strip of plasticine was also laid, the surface of which, facing the pulmonary vessel, was smeared with castor oil. Then, a calibrated load was applied to the movable jaw, which created pressure between the wall of the squeezed vessel and the protruding central part of each jaw in contact with the vessel wall. The load was applied to the movable sponge until complete closure (contact) of the inner wall of the vessel along its entire perimeter occurred. In this case, the assessment of the full contact of the wall was recorded using a single-beam electron-optical system. At the moment of complete closure of the inner wall of the vessel, the transverse area of the laser beam became equal to zero, and this was displayed on the oscilloscope screen as the absence of a signal. At this moment, the force applied to the movable sponge was recorded, as well as its vertical movement. At the same time, it was recorded that the inner wall of the pulmonary vessel is in contact along its entire perimeter at a pressure of 0.04 MPa to 0.05 MPa. At the same time, the wall thickness of the pulmonary vessel decreased by an average of 15%, which indicates a tight contact of the squeezed vessel with the electrodes. With such tight contact, the risk of blood coagulation on the surface of the electrodes and the formation of blood clots (thrombi) is reduced. After applying such pressure, it was concluded that its optimal value does not cause destruction of the vascular tissue. The fact that the pressure over the entire outer surface of the squeezed vessel, exerted on it by the sponges of the device, was the same was confirmed by the fact that the thickness of both plasticine strips after opening the sponges, removing them from the device and curing in the refrigerator, measured with a step of 3 ... 5 mm , decreased almost equally along their entire length (see Table 1).

In table. 1 reflects the following indicators:

A - the length of the sponge section with an arcuate recess from 22 mm to 60 mm,

R - radius of the arc of the circle of the notch from 80 mm to 600 mm,

L is the length of the sponge section on which the electrodes are located with a length of 28 to 70 mm¸

B - the width of each of the electrodes from 0.2 mm to 0.5 mm,

H - the height of each of the electrodes is from 2.5 mm to 3.0 mm,

C is the gap between the electrodes on the rectilinear extreme sections;

D is the gap between the tops of the arcs formed by electrodes located in the recess flush with its surface, from 1.6 mm to 1.8 mm.

Table 1

No.
p/p A,
mm R,
mm L
mm V,
mm H,
mm WITH,
mm D,
mm The thickness of the plasticine plate as a result of the application of pressure, mm On a moving sponge On a motionless sponge one 22 80 28 0.2 3.0 0.5 1.6 0.54 ^+0.07 0.51 ^+0.05 2 60 600 70 0.5 2.5 0.6 1.8 0.48 ^+0.08 0.45+ ^0.06

From the analysis of the table. 1, it can be established that when squeezing a pulmonary vessel of small diameter (12 ± 0.8 mm) with sponges, the deviations of the thickness of plasticine plates from its minimum value range from 10% to 13%, and when squeezing with sponges of a pulmonary vessel of large diameter (36 ± 1.3 mm) deviations of the thickness of plasticine plates from its minimum value range from 13% to 16%. Accordingly, the pressure along the perimeter of the compressed vessel has the same deviations. Given the insignificance of such deviations, it can be assumed that the pressure over the entire outer surface of the squeezed vessel exerted on it by the jaws of the device is almost the same.

Thus, the specified configuration and dimensions of the protruding central sections of the jaws provide, firstly, the creation of a clamping zone that is much wider than the zone of contact of the electrodes with the tissue of the wall of the squeezed vessel, and secondly, it guarantees tight contact of the protruding central sections of the jaws with the wall of the squeezed vessel. , which prevents the electrodes from coming into contact with any tissue, including blood, except for the tissue of the compressed vessel wall, which must be denervated. This greatly reduces the likelihood of blood clots during radiofrequency ablation.

The presence of two additional electrodes of the specified geometry and dimensions and their connection to each other and to a source of radiofrequency current makes it possible to carry out circular radiofrequency ablation outside (exovasal) of the pulmonary vessel, but unlike the prototype device, irreversible thermal damage to the vessel wall will not be transmural (through vessel wall), but only to a predetermined depth, in accordance with the selected technological dimensions of the exposure mode, in which the intimal layer of the vessel wall will be preserved. In this case, the radio frequency current will flow from one sponge electrode through the surface and middle layers of the tissue of the vessel wall to another electrode of the same sponge, and the electric field strength and, accordingly, the wall heating temperature will be maximum on its surface adjacent to the electrodes.

The need to make electrodes 11 (Fig. 3) from the boundaries of the arcuate recess 13 with straight surfaces 12 of the protruding central section 10 of each sponge, spaced symmetrically and arcuately relative to the longitudinal axis of the protruding central section to its side faces with the formation of a gap (D) between the tops of the arcs formed by the electrodes , equal to from 1.6 mm to 1.8 mm, is due to the fact that during high-frequency ablation by a device in which the electrodes on each sponge are parallel to each other and with a gap (C) between them from 0.5 mm to 0.6 mm, not only on the rectilinear surfaces of the protruding central section of each sponge, but also on the curved surface of the arcuate recess, the distribution of the heating temperature of the wall of the pulmonary vessel is uneven along its perimeter. As evidence, Fig. 5, which shows the trunk of the pulmonary artery 14 with an outer diameter of 28.3 mm, compressed by a pressure of 0.045 MPa between the fixed 4 and movable 5 sponges of the ablator with straight electrodes with a width (B) = 0.2 mm and a height (H) = 3.0 mm, installed with a constant gap between them along their length (С) = (D) = 0.6 mm, as well as a graph of the temperature distribution (epure) on the surface of the adventitia layer Т _a ( l ), recorded by five thermistors installed on this surface 15 , and temperature diagram on the inner surface of the vessel wall from the side of its intimal layer T _i ( l) , recorded by five thermistors 16 installed inside the vessel. Assuming that the temperature decreases linearly along the thickness of the vessel wall from the surface of the adventitia layer to the inner surface of the vessel wall from the side of its intimal layer, a temperature plot T _lim ( l ) was also constructed at the boundary of the zone of permissible damage to the vessel wall (59% of its thickness) at radio frequency (440 kHz) with an impact energy of 112 J.

On the same fig. 5 also shows a horizontal line corresponding to a wall temperature of the heating vessel 50 ^C. As noted earlier, during the RF-effects increase the wall temperature of the vessel abroad I zone on the inner wall surface of the compressed than 50 ^{° C} is regarded as a situation leading to irreversible thermal damage to the vessel and should not be allowed.

From the analysis of Fig. 5 it follows that the temperature distribution along the contact length of the compressed vessel wall with rectilinear electrodes is uneven. Thus, the maximum temperature at the center and the outside wall is 59 ^{° C,} on the boundary zone of damage tolerance, it decreases to 52 ^{° C} and the inner surface of the vessel wall temperature does not exceed 47 ° ^C but more temperature decreases from the contact center to the peripheral portions of smooth curve (arc), moreover, such a decrease looks like a mirror relative to the center of contact.

In FIG. 5, two vertical lines 1-1 and 2-2 mark the points of contact between the wall of the compressed vessel and the electrodes, in which RF exposure provided the required heating temperatures in the vessel wall in all its layers. From this it becomes obvious that in order to ensure such an optimal RF exposure, it is necessary that the resulting plots be converted into rectangular plots with the temperatures that are reached at the points of contact along lines 1-1 and 2-2.

To do this, the average value of the temperature T _{i cf.} over the contact length ( l _k ) of the electrodes with the vessel was determined. from the side of the intimal layer of the vessel wall according to the formula:

T _{i cf} =[∫T _i (l) dl]/l _k [^OWITH],

where the integration limits are from 0 to the value the contact length of the vessel wall with the electrodes along their length (l _k), and the integral∫T _i (l) dlgraphically represents the area under the curveT _i -l,limited by the size of the contact of the vessel wall with the electrodes along their length (l _k).

Similarly, we calculated the averages over the contact length (l _k) temperature valuesT _{lim cf.} andT _{a cf.} . For the one shown in FIG. 5 examples, these values were:

T _{i cf} = 40.5 ^o C, T _{lim cf.} \u003d 45.0 ^about C and T _{and cf.} = 51.0 ^o C.

Obviously, to ensure optimal RF exposure, it is necessary that, firstly, the temperature T _{lim cf.} was 50 ^{° C} (then correspondingly rises and the temperature T _{a Wed),} and secondly, all three diagrams should be rectangular, i.e. with a uniform distribution of temperatures along the length of the contact of the compressed vessel wall with the electrodes ( l _k ).

During the ablation of pulmonary vessels, it was found that a change in the gap between the electrodes (C) significantly affects the heating temperature of the pulmonary vessel tissue. In FIG. 6 shows graphs of the dependence of the average temperatureT _{lim Wed}. along the contact length (l _k) at the boundary of the zone of permissible damage to the vessel wall, calculated from the average values of the measured temperaturesT _iср. from the side of the intimal layer of the vessel wall, from the average amount of energyN _Wed., supplied from the RF generator to the treated volume of the pulmonary vessel wall, at different values of the gap between the electrodes (C).

From Figure 6 it is seen that with decreasing gap between the electrodes (C) at the same value of the energy of the vessel wall, the heating temperature increases (see. The vertical line 3-3) and for providing a temperature of 50 ^{° C} at the boundary of the permissible area wall damage vessel needs to consume more energy with increasing gap between the electrodes (see horizontal line 4-4). It follows that, by changing the gap between the electrodes, it is possible to change the heating temperature of the vessel wall along their length.

Based on the results of the ablation procedures performed, it was found that the optimal RF effect on the vessel occurs when, firstly, the temperature T _{lim cf.} equal to 50 ^{+3 o} C, and secondly, this temperature is evenly distributed along the entire length of the contact of the compressed vessel wall with the electrodes ( l _k ).

To fulfill these conditions in the claimed invention, it has been empirically established that the electrodes 11 (Fig.3) on both rectilinear surfaces 12 of the protruding central section 10 of each sponge must be located rectilinearly with a gap between them (C) from 0.5 mm to 0.6 mm , and from the boundaries of the arcuate recess 13 with rectilinear surfaces 12 of the protruding central section of each sponge to its middle, the electrodes must be symmetrically separated along the longitudinal axis Z of the protruding central section to its side faces along a circular arc so that the distance between the vertices of the arcs (D) formed electrodes, is equal to from 1.6 mm to 1.8 mm.

At the same time, the specified values of the gap between the electrodes on the rectilinear surfaces of the protruding central section of each sponge are regulated by the condition of the absence of electrical air breakdown between the opposite polarity electrodes installed on one sponge and the opposite polarity electrodes installed on different sponges. To do this, a certain gap was set between the electrodes, which was filled flush with them with thin plates of insulating material (getinax, fiberglass, etc.), the sponges were brought to the closed position of the device (without placing a pulmonary vessel between them), and a radio frequency (440 kHz) current with voltage varying from 10 V to 100 V. In this case, the energy also changed accordingly - from 60 J to 600 J. Before applying current to the electrodes, the straight surfaces in contact 12 protruding central sections 10 jaws 4 and 5 wiped with a cotton swab moistened with water. After 10–15 s, current was applied to the electrodes. The experiments were carried out in a darkened room so that the arc could be observed in the event of an air breakdown between the electrodes. The air breakdown was also recorded on the screen of a personal computer monitor. Experiments have shown that at maximum power, breakdown is absent at a gap of 0.6 mm, and when operating at operating modes (80 ... 400 J), breakdown is no longer observed at a gap of 0.5 mm.

Example 1 of the invention.

A device for radiofrequency ablation according to the claimed invention with fixed 4 and 5 movable sponges with a pair of electrodes 11 installed on them, the design of which is shown in Fig. 7, and geometric parameters - in position 1 of the table. 2, pulmonary vein ablation procedures were performed on 14 deceased individuals aged 47 to 66 years, with relatively intact pulmonary vein walls.

table 2

Position Geometric parameters of the electrode assembly sponges of the proposed device for ablation, mm A R L V H WITH D one 22 80 28 0.2 3.0 0.5 1.6 2 60 600 70 0.5 2.5 0.6 1.8

Extraction of pulmonary veins was carried out no later than 3 hours after the moment of death. The resulting biological material is placed in a cold solution "Custodiol" and was refrigerated at +5 ^o C, not more than 4 hours before the ablation procedure. Not later than this period, the biological material was delivered to the laboratory for ablation. Four pulmonary veins with an outer diameter of 13.2 mm to 14.4 mm were selected for the ablation procedure. Before radiofrequency exposure, the pulmonary vein was removed from the Custodiol solution and dried with a napkin, after which it 14 was installed in the arcuate recess 13 of the fixed sponge 4. After that, five thermistors were installed inside the vessel at an equal distance from each other, the same five thermistors were located as follows outside the vessel (in Fig. 8, the installation sites of thermistors are marked with dots). Then the movable sponge 5 was brought into contact with the fixed sponge 4 with a pressure of 0.045 MPa, and a radio frequency current of a certain power and duration of exposure was applied to the electrodes 11. At the same time, on the computer monitor, the temperature was recorded from all ten thermistors with simultaneous calculation, using a special computer program, of the temperature averaged over the entire length of the contact of the vessel with the electrodes ( l _c ) on the surface of the adventitia layer T _{a cf} ., the temperature on the inner surface of the vessel wall from its side intimal layer T _{i cf} . and on their basis - the temperature at the border of the zone of permissible damage to the vessel wall (59% of its thickness) T _{lim cf.} At that moment, when the average temperature T _{lim cf} reached 53 ^about C, the device was disconnected from the high-frequency generator.

In FIG. 8 is a distribution chart (diagram) the temperature at the boundary wall of the vessel damage tolerance zone T _lim (l) at the radio frequency (440 kHz) with an impact energy of 80 J, at the pulmonary vein 14 with an outer diameter of 14.4 mm. From FIG. 8 it follows that the distribution of temperature T _lim ( l ) along the contact length ( l _k ) of the vessel with the electrodes 11 is almost uniform. Average of contact length (l _k) temperature value is equal to 50.8 ^{° C,} and its deviation from this value is 1.2 ° ^C / -1.8 ° ^C.

From this it follows that with the above (Fig. 7) design of the sponge electrode assembly with its geometric parameters given here, the temperature values at the thermistor installation sites differed from each other by no more than 6%, while at the border of the zone of permissible damage to the vessel wall (59% of the thickness), the maximum temperature was 52 ^{° C,} which is lower than the allowable value (50 ^{+3 C),} and accordingly, the intimal layer of the vessel is not thermally damaged, which was confirmed by the results of studies with measurement of histological preparations formed necrotic layer pulmonary veins.

Example 2 of the invention.

A device for radiofrequency ablation according to the claimed invention with fixed 4 and 5 movable sponges with a pair of electrodes 11 installed on them, the design of which is shown in Fig. 7, and geometric parameters - in position 2 of the table. 2, pulmonary vein ablation procedures were performed on 14 deceased individuals aged 47 to 66 years, with relatively intact pulmonary vein walls. For the ablation procedure, six trunks of the pulmonary arteries with an outer diameter of 35.4 mm to 36.3 mm were selected. The preparation of biological material for high-frequency ablation, the method of its implementation and the processing of the results obtained were carried out in the same way as described in example 1.

In FIG. 9 is a distribution chart (diagram) the temperature at the boundary wall of the vessel damage tolerance zone T _lim (l) at the radio frequency (440 kHz), the impact of energy equal to 312 J, the pulmonary artery 14 with an outer diameter of 35.8 mm. From FIG. 9 it follows that the temperature distribution T _lim ( l ) along the contact length ( l _k ) of the vessel with the electrodes 11 is almost uniform. Average of contact length (l _k) temperature value is equal to 50.6 ^{° C,} and its deviation from this value is 1.4 ° ^C / -1.6 ° ^C.

From this it follows that with the above design of the sponge electrode assembly with its geometrical parameters given here, the temperature values at the thermistor installation sites differed from each other by no more than 6%, while at the border of the zone of permissible damage to the vessel wall (59% of its thickness ) the maximum temperature was 52 ^o C, which is below the permissible value (50 ^{+3 o} C), and accordingly, the intimal layer of the vessel was not thermally damaged.

To prove this, after radiofrequency exposure to the trunks of the pulmonary arteries, all biological material was fixed in 10% (buffered to pH=7.0) neutral formalin. The volume of the fixing liquid exceeded the volume of the fixed material by more than 10 times. Fixation in formalin was carried out at room temperature for 36 h.

Then from the trunks in their cross section along a circular line passing in the middle of the RF exposure zone, preparations necessary for microscopic examinations were cut out. This made it possible to study different zones of RF exposure of the vessel wall on the same preparation.

To identify signs of radiofrequency ablation in the wall of the pulmonary artery, light microscopy was used using hematoxylin and eosin staining, which makes it possible to better visualize typical general pathological processes in tissues subjected to such treatment. At the same time, through the entire wall of the vessel in the area of radiofrequency exposure, starting from the side of the adventitia and to the intimal layer, the vastness of the zones of deep disorganization of the connective tissue in the form of thinning, rarefaction of elastic fibers was assessed, which indicate the disappearance of tight associative bonds in the intercellular stroma of the vessel wall. Areas of karyorrhexis and karyolysis of fibroblasts and smooth myocytes, as well as areas of fibrinoid necrosis with foci of metachromasia, were detected in this zone, which indicates the irreversibility of damage to the tissues of the pulmonary artery wall in the affected area.

When studying histological preparations, first of all, the same nature and degree of thermal damage was noted in different zones of the vessel wall, namely, in the zones adjacent to the marginal sections of the previously compressed vessel wall, and in the central zone of the vessel wall. This indicates the correctness of those technical solutions that were included in the design of the electrode device for ablation of pulmonary vessels according to the claimed invention.

As an example, in FIG. 10 shows a photograph of the microstructure of the area of the drug obtained from the trunk of the pulmonary artery with an internal diameter of 35.8 mm, subjected to RF exposure at an energy of 312 J.

From the analysis of figure 10 it follows that the wall of the pulmonary artery has a clearly observed area (zone 2) of irreversible thermal damage (irreversible thermocoagulation) with a depth of approximately 07 mm. In the rest of the vessel wall (zone 1), including the intimal layer, remained intact. With even greater magnification, it was possible to observe in the adventitial layer of the vessel, which falls into the area of irreversible thermal damage (zone 2), sympathetic nerve trunks with organic damage, dysfunction of the nerve fiber membrane and its internal structures, which, as is known, leads to impaired conduction signals.

Based on the foregoing, it can be noted that the claimed technical result has been achieved, because The device for radiofrequency ablation of pulmonary vessels according to the claimed invention really provides an irreversible thermal effect on its wall, uniform along the perimeter of the pulmonary vessel, without disturbing the structure and functions of the intimal layer, and thus effectively provides denervation of the pulmonary vessels.

Claims (1)

A device for radiofrequency ablation of pulmonary vessels, containing two branches, one of which is fixedly installed in the body-handle of the device, and the other with the possibility of parallel translational movement relative to the fixed branch to form sponges perpendicularly located at the ends of the branches, designed to place a portion of the pulmonary vessel between them, open or closed position of the device, each of the surfaces of the jaws facing each other is made with a central section protruding in height along the entire length of the jaws, on the surface of which an electrode of rectangular cross section is placed flush along it, connected to a source of radio frequency current, characterized in that in in the middle of the protruding central section on the surface intended for placing a pulmonary vessel on each sponge, an arcuate notch is made on the entire width of the protruding central section in the sponge section with a length (A) from 22 mm to 60 mm, with a radius of arcs and a circle (R) from 80 mm to 600 mm, selected from the condition of placing a section of a pulmonary vessel in the recess in the closed position of the device for the procedure of radiofrequency ablation, while flush with the surface of the central protruding section of each of the jaws, a second electrode of rectangular cross section is installed, isolated from of the first electrode, both electrodes are placed on a sponge section with a length (L) from 28 mm to 70 mm, each electrode has a width (B) from 0.2 mm to 0.5 mm, a height (H) from 2.5 mm to 3, 0 mm, and on the rectilinear surfaces of the protruding central section of each sponge, the electrodes are located along the surfaces parallel to each other and with a gap (C) between them from 0.5 mm to 0.6 mm, and from the boundaries of the arcuate recess with the rectilinear surfaces of the protruding central section of each sponge electrodes are symmetrically and arcuately separated relative to the longitudinal axis of the protruding central section to its side faces with the formation of a gap (D) between the tops of the arcs, arr electrodes, equal to from 1.6 mm to 1.8 mm, while the connection of the electrodes to the source of radio frequency current and between themselves is made with the possibility of providing opposite polarity on the two electrodes of each sponge when they are activated, and unipolar electrodes on opposite sponges are located on their protruding central sections mirror each other.

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