RU2591841C1 - Method for laser obliteration of varicose veins - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to phlebology, and can be used for laser obliteration of varicose veins. An area of varicose vein is influenced by radiation resonant absorbed by water in two-micron spectral range of solid-state laser with semiconductor pumping. Radiation wavelength is 1,912 nm, output power is 1.5-4 W. Radiation is introduced into the vein by means of optic light guide with a titanium tip.

EFFECT: method ensures painless recovery after treatment, as well as eliminates scars and bruises due to action in two-micron spectral range.

1 cl, 9 dwg

Description

The invention relates to the field of laser medical equipment, and in particular to a method for the action of laser radiation with a wavelength of 1912 nm on venous blood and venous wall, and can be used to treat varicose veins.

A known method of laser obliteration of varicose veins using laser radiation of 532 nm and 1064 nm [1].

A number of works are known in which laser laser obliteration uses the radiation of lasers generating at wavelengths of 810 nm and 970 nm and 1470 nm [2, 3].

Known methods of laser obliteration using lasers with wavelengths of 810 nm and 970 nm [4, 5].

A disadvantage of the known methods is the rather high power of the used laser radiation (10-12 W), which can lead to damage to tissues and nerves adjacent to the veins, as well as to relapse of the disease.

The closest in technical essence to the claimed invention is the use of laser radiation of 1.56 microns for laser obliteration of veins. This radiation has a higher coefficient of absorption by water. Radiation with a wavelength of 1.56 μm is absorbed directly by the water contained in the blood and vein wall, and its energy is more effective against thermal damage to the vein wall [6].

The use of 1.56 μm radiation for laser venous obliteration reduces the laser radiation power. However, the used radiation power (12 W) remains quite high.

The technical result is to ensure painless recovery of patients after treatment, reducing treatment time, and also eliminating the occurrence of hemorrhages and bruises after exposure to varicose veins of two-micron laser radiation.

The essence of the invention lies in the fact that the method of laser obliteration of varicose veins is carried out by exposure to laser radiation on the plot of the varicose vein. The vein is exposed to a two-micron radiation of a solid-state pump with a semiconductor pump, which is resonantly absorbed by water, and generates radiation with a wavelength of 1912 nm and an output radiation power of 1.5-4 W, introduced into the vein using an optical fiber with a titanium tip.

In FIG. 1 shows a water absorption spectrum; in FIG. 2 - photographs of a varicose vein in a test tube before exposure to laser radiation (a) and after exposure to laser radiation (b) with a wavelength of 1912 nm; in FIG. 3 - histological section of the vein wall during its varicose transformation (without obliteration); in FIG. 4 - histological section of a vein after laser irradiation of the wall with radiation power of 1.5 W and a retrieval rate of 0.6 mm / s (a) increase × 40, (b) increase × 100; in FIG. 5 - histological section of a vein after laser obliteration when exposed to radiation with a power of 1.5 W and a retrieval rate of 0.3 mm / s (magnification × 40); in FIG. 6 - histological section of a vein after laser obliteration when exposed to radiation with a power of 1.5 W, the extraction speed of 0.3 mm / s, (magnification × 100); in FIG. 7 (a) - a macrodrug of a vein before (1) and after (2) laser coagulation with blood, power 1.5 W, extraction speed 0.5 mm / s, (b) - a microdrug of a vein after laser coagulation (staining - hematoxylin and eosin, St. 40); in FIG. 8 (a) —a vein microdrug before (1) and after (2) laser coagulation with blood, power 2.8 W, extraction rate 0.6 mm / s, (b) —vein microdrug after laser coagulation (staining - hematoxylin and eosin, tv. 40); in FIG. 9 (a) - a macrodrug of a vein before (1) and after (2) laser coagulation with blood, power 4 W, extraction speed 0.8 mm / s, (b) - a microdrug of a vein after laser coagulation (staining - hematoxylin and eosin, Rev. 40).

The method is as follows. For the obliteration of varicose veins, a model of the installation is used, which consists of a solid-state laser with a wavelength of 1912 nm, optical elements that provide input of radiation into the fiber, a fiber with a titanium tip, a special tube holder, inside which there is a vein filled with physiological saline, and devices ( precision motorized table), providing the movement of the optical fiber with a certain speed. A solid-state laser based on a LiYF ₄ : Tm crystal acts as a pump source.

A section of varicose vein is placed in a test tube, the lumen of the vein is filled with a solution of sodium chloride (physiological solution). The tube is fixed in a special holder. An optical fiber with a titanium tip is introduced into the lumen of the vein with saline solution, through which a two-micron radiation of a solid-state laser with a wavelength of 1912 nm is introduced. The effect of radiation on a section of the vein is carried out both in the absence of movement of the optical fiber, and when moving the optical fiber inside the vein with certain values of the speed of movement. The use of the phenomenon of resonant absorption of water and heating of blood with the formation of vapor bubbles leads to thermal destruction of the vein wall, thereby ensuring its obliteration.

10 experiments were conducted on an isolated large saphenous vein taken intraoperatively. Laser radiation with a wavelength of 1912 nm was fed to a motorized stage, providing precise movement with a given speed. Using a special holder, a test tube was fixed to the table, into which a 0.9% sodium chloride solution (physiological solution) was poured. An isolated vein 5 cm long was placed in this solution (Fig. 2a). An optical fiber with a titanium tip was inserted inside the vein. After turning on the laser radiation source, the optical fiber was slowly removed from the lumen of the vein, acting at that time on its wall at a speed of 0.6 mm / s (the first series - 5 experiments) and 0.3 mm / s (the second series - 5 experiments) and output power of radiation of 1.5 watts.

The diameter of the vein before and after obliteration and the degree of obliteration of its lumen were visually evaluated. Optical microscopy (magnification × 40, 100) was used to study venous wall edema, thermal damage, intima, muscle membrane, adventitia, wall perforation, and the effect on adjacent perivascular tissues in the area of laser coagulation.

на всем протяжении лазерного воздействия. Пальпаторно вена превращалась из мягкоэластической в плотный тяж (фиг. 2б). При наблюдении с помощью оптического микроскопа (увеличение ×40) без облитерации стенка варикозно измененной подкожной вены представляла утолщенный слой соединительной и мышечной ткани с ровной внутренней оболочкой и единичными колбообразными выпячиваниями (фиг. 3). После лазерной облитерации при наблюдении в оптический микроскоп (увеличение ×40) стенка вены утолщена вследствие отека, имеется разволокнение мышечных волокон с очагами некробиоза (фиг. 4а). Отсутствовали кровоизлияния в окружающей жировой клетчатке и соединительнотканных элементах. В просвете облитированных вен отсутствовали массы облитированного некроза. Адвентиция оставалась без дистрофических изменений. При увеличении ×100 интима неравномерно утолщена с участками ее деструкции (фиг. 4б).In the first series of experiments, after exposure to an output radiation power of 1.5 W and an optical fiber extraction speed of 0.6 mm / s from the lumen of the vein during visual examination, the vein changed its color: from light-shiny to grayish-dull. In this case, an uneven decrease in its diameter by

throughout the laser exposure. Palpation of the vein was transformed from soft-elastic into a dense cord (Fig. 2b). When observed using an optical microscope (magnification × 40) without obliteration, the wall of the varicose saphenous vein represented a thickened layer of connective and muscle tissue with a smooth inner shell and single bulb-like protrusions (Fig. 3). After laser obliteration when observed under an optical microscope (magnification × 40), the vein wall is thickened due to edema, there is a disengagement of muscle fibers with foci of necrobiosis (Fig. 4a). There were no hemorrhages in the surrounding fatty tissue and connective tissue elements. In the lumen of the obliterated veins, there was no mass of obliterated necrosis. Adventitia remained without dystrophic changes. With an increase of × 100, the intima is unevenly thickened with areas of its destruction (Fig. 4b).

In the second series, after laser obliteration with an output power of 1.5 W and an optical fiber extraction speed of 0.3 mm / s from the vein lumen, visual inspection of the vein was a dense strand with a 2/3 reduction in diameter. The diameter of the vein is uneven, there were areas of sharp narrowing (the area of longer contact between the fiber and the vein wall). The color of the vein is gray with areas of darkening. Microscopically, the vein was an abnormal formation (magnification × 40). In the lumen of the vein lay free fragments of its wall. Differentiation and loss of distinction between collagen and muscle fibers were disrupted. There was a burn destruction of not only the walls of the vein, but also of paravasal tissue. Plots of total destruction of the vein wall and its perforation were observed (Fig. 5). With an increase of × 100, it is seen that the vein wall is edematous, differentiation between the inner and outer muscle layers is disturbed. The inner layer (intima) is destroyed with freely lying fragments (Fig. 6).

As a result of the experiments, it was found that radiation with a wavelength of 1912 nm, acting on the wall of the vein, causes its damage. At values of the output laser radiation power of 1.5 W with a wavelength of 1912 nm and the speed of the optical fiber (0.3-0.6 mm / s), obliteration of the varicose vein is achieved.

The following are the experimental results when using radiation with a wavelength of 1912 nm for endovasal laser coagulation of segments of varicose veins that were placed in a test tube with blood.

With vein coagulation parameters in a test tube with blood P - 1.5 W, V - 0.5 mm / s, t - 55 sec, shrinkage of the vein diameter by 24 ± 3% was obtained (Fig. 7a). Histological examination showed a decrease in the lumen of the vein, swelling of the vein wall, areas of destruction of intimacy. The differentiation of the muscle layers into the external and internal and the differentiation between collagen and muscle fibers was preserved. There were no masses of coagulated necrosis in the lumen of the coagulated vein, single free fragments of intima were determined (Fig. 7b, color — hematoxylin and eosin, SW 40).

At P - 2.8 W, V - 0.6 mm / sec, t - 47 sec, the shrinkage of the vein diameter by 45 ± 3% was obtained (Fig. 8a). Histological examination showed edema of all layers of the vein wall. Intima was damaged with carbonation sites. In the lumen of the vein, free fragments of the inner membrane were determined. There was a destruction of the inner layer of muscles with areas of air spaces (Fig. 8b, color - hematoxylin and eosin, uv. 40).

At P - 4 W, V - 0.8 mm / s, t - 35 s, the vein diameter shrinkage was obtained by 42 ± 3% (Fig. 9a). Histological examination showed a decrease in the lumen of the vein, edema of all layers of its wall and pronounced vacuolization. Intima is presented as a charred layer. The differentiation of the muscle layers into external and internal, the differentiation between collagen and muscle fibers, was not determined. Fragments of coagulation necrosis were determined in the lumen of a coagulated vein. Advent is fragmented, dystrophically altered (Fig. 9b, color - hematoxylin and eosin, uv. 40).

An increase in coagulation rate to 0.8 mm / s also ensured vein shrinkage up to 45 ± 2%. A further increase in speed to 1 mm / s led to shrinkage of the vein by 40 ± 3%.

Compared with the known solution, the proposed method allows for painless recovery of patients after treatment, reduces the duration of treatment, and eliminates the occurrence of hemorrhages and bruises after exposure to varicose veins of two-micron laser radiation with a wavelength of 1912 nm, resonantly absorbed by water at an output radiation power of 1.5 -4 watts

Information sources

1. Navarro L, Navarro N, Salat CB, Gomez JF, Min RJ (2002) Endovascular laser device and treatment of varicose veins. US 6,398,777 B1; patent filed in 1999, granted in 2002.

2. Proebstle T.M. et al. Endovenous treatment of the greater saphenous vein with a 940-nm diode laser: thrombotic occlusion after endoluminal thermal damage by laser-generated steam bubbles. J. Vase Surg 2002; 35; four; 729-736.

3. Amzayyb M. et al. Carbonized blood deposited on fibers during 810, 940 and 1,470 nm endovenous laser ablation: thickness and absoption by optical coherence tomography. Laser Med Sci 2010; 25: 3: 439-447.

4. Endovenous Laser Treatment of Incompetent Below-Knee Great Saphenous Veins Original Research Article Journal of Vascular and Interventional Radiology, Volume 18, Issue 12, December 2007, Pages 1495-1499.

5. Randomized Controlled Trial Comparing Sapheno-Femoral Ligation and Stripping of the Great Saphenous Vein with Endovenous Laser Ablation (980 nm) Using Local Tumescent Anaesthesia: One Year Results Original Research Article European Journal of Vascular and Endovascular Surgery, Volume 40, Issue 5, November 2010, Pages 649-656.

6. Sokolova A.L., Lyadova K.V., Lutsenko M.M., Lavrenko S.V., Lyubimova A.A., Verbitskaya G.O., Minaeva V.P. The use of laser radiation of 1.56 microns for endovasal obliteration of veins in the treatment of varicose veins.

Claims (1)

A method for laser obliteration of varicose veins by applying laser radiation to a portion of a varicose vein, characterized in that the vein is exposed to a two-micron radiation resonantly absorbed water by a semiconductor-pumped solid-state laser generating radiation with a wavelength of 1912 nm and an output radiation power of 1.5-4 W inserted into a vein using an optical fiber with a titanium tip.

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