Laser coagulation of varicose veins

Messages about the first applications of lasers in phlebology date back to 1981 . Anderson RR, Parrish JA, using a dye laser with a wavelength of 577 nm, caused damage to the microvasculature of the skin. The technology was based on the effect of selective absorption by various components of tissue of laser energy of a certain wavelength , which led to their selective destruction.

In the 90s of the XX century, with the advent of new semiconductor structures, it became possible to produce compact lasers, with a long service life at low cost. In 1998-1999, the first reports of Boné C. appeared on the clinical intravascular use of a diode laser (810 nm) for EVLO with VRVNA. The method is called EVLT ( en: Endovenous laser treatment ).

In 2001, Navarro L., Min RJ, Boné C. summarized and published their data on the intravascular insertion of a laser waveguide to deliver laser radiation energy to an FEM. The authors used a diode laser with a wavelength of 810 nm from the American Society of Phlebologists.

In 2002, Chang CJ, Chua JJ published the results of the use from January 1996 to January 2000 of an Nd: YAG laser with a wavelength of 1.064 nm for EVLO of the saphenous vein (BPV). During the study, 252 EVL BPV was performed in 149 patients.

In 2002, the EVLO BPV method was patented by V. Meloni et al.

In 2003, the results of the application of a new technology in the presence of blood reflux through the small saphenous vein (MPV) were published (Proebstle TM, Gül D., Kargl A., Knop J., 2003). The mechanism of thrombotic occlusion after thermal exposure to laser radiation was described in 2002 by Proebstle TM et al.

Since the advent of EVLO, there has been a tendency to increase the power of energy supplied to the vessel. Early work was carried out at 10-15 watts. After the work of Proebstle TM et al, which showed a direct relationship between the volume of vapor bubbles formed and the laser radiation energy, there were reports of EVLO results with high power indices, sometimes reaching 30–40 W. (Proebstle TM, 2005).

In Russia, EVLO technology enjoys growing interest both among surgeons and their patients. The number of publications on this topic is growing. The first monographs and teaching aids were published.

Despite the accumulated experience, EVLO technology is still far from its perfection today. The search goes in two directions: firstly, in the further standardization of its technique, the refinement of indications and contraindications based on the increasingly published long-term results. Secondly, there are still disputes around the optimal wavelength of the laser used for EVLO, and everything is not yet clear in this matter.

The EVLO principle is based on the thermal effect of laser radiation energy on the inner surface of a vein. However, as established ^{[ streamlined expression ]} numerous experimental and clinical studies, the laser beam acts on the vessel wall indirectly. The maximum absorption of laser energy 1040 nm falls on the blood contained in the vessel. Under the influence of a light pulse in the blood, vapor bubbles form. Thermal effects on the vein wall occur due to its contact with these vesicles. In this case, direct damage to the endothelium and coagulation of proteins in the subendothelial layers occur.

It is the destruction of endothelium that is of paramount importance in the outcome of treatment. In the case of preservation of islands of viable endotheliocytes, the latter can become a source of regeneration with the subsequent occurrence of blood flow and the development of recanalization. In order for endothelium destruction to be complete with EVLO, it is necessary to create a sufficient laser energy density in the lumen of the vessel. Thermal damage to the inner wall of the vessel, in this case, should lead to its "carbonization". The black color of carbonized intimacy begins to absorb laser energy as intensely as possible and to warm up even more. However, with a more intense or prolonged exposure, the vein wall may perforate. The latest generation of EVLO lasers has a wavelength of 1.47 microns. At this wavelength, laser radiation is more absorbed by the water of the blood and venous wall. A direct effect on the venous wall can reduce the radiation power, the formation of coal on the fiber and the heating of its radiating surface. There is less likelihood of perforation of the vein wall and pain in the postoperative period. This wavelength is suitable for the largest venous trunks with a diameter of more than 10 mm. The use of new radial fibers increases the area of ​​laser radiation and reduces the heating of the tip of the fiber. A circular spot of radiation reduces the risk of complications and acts mainly on the venous wall. Pain after EVLO by such fibers is minimal.

After EVLA, the burn-induced alteration processes continue to form necrosis in the vein wall until the end of the first week. In addition to intimacy, other layers of the venous wall can also be involved in this process. With insufficient heat exposure, thrombophlebitis with subfebrile condition , soreness and hyperemia along the coagulated vein can occur on days 4–8. This, as a rule, does not occur if the thermal effect was adequate. Further, the described processes are replaced by the organization process. In this case, the thrombus obstructing the lumen of the vein is replaced by connective tissue. After a year, with a correctly performed EVLO, the vein acquires the appearance of a connective tissue cord.

Indications

• The estuarine extension of BPV is not more than 10 mm. It is possible to “close” the wider veins in the lumen with the help of EVLO, however, the procedures for performing the procedure in these cases still remain non-standardized, and the results are often unsatisfactory.
• A small number of varicose dilated tributaries. With a pronounced varicose transformation of a large number of saphenous veins, the volume of operation can so increase that the injury received by the patient due to stripping of the BPV (MPV) becomes already insignificant.
• The smooth course of the barrel BPV (MPV). There are situations in which the main trunk makes a bend that cannot be passed endovasally by either a guide, a probe, or a catheter. In this situation, you can enter two fibers below and above the bend. However, during preoperative angioscanning, you should evaluate the situation and weigh the pros and cons of EVLO in this case.
• Trophic disorders of the lower leg . This indication should be highlighted especially for a separate manipulation - endovasal laser obliteration of perforating veins (EVLOPV). This method of eliminating horizontal reflux in its reliability is practically not inferior to open dressing and endoscopic dissection, comparing favorably with them by low invasiveness and the possibility of repeated repetition. EVLOPV can be performed in combination with almost all types of surgical elimination of reflux by BPV and MPV.

General contraindications

• Established thrombophilia . Since the EVLO method involves the formation of a thrombus in the immediate vicinity of the lumen of the femoral or popliteal vein and activation of the blood coagulation system, such patients are at risk of thrombotic process in deep veins and pulmonary embolism (PE).
• Chronic lower limb ischemia (HINK). Since one of the stages of EVLO technology is mandatory compression in the postoperative period, it can significantly aggravate existing ischemia in patients with HINK.
• Concomitant pathology requiring priority treatment. There is no doubt that the presence of a patient that is not associated with varicose veins of the lower extremities (VRVNA) of the disease, requiring immediate treatment, allows you to postpone the planned intervention for VRVNA.
• The inability to create adequate compression after the intervention in obese patients is a relative contraindication for EVLO. The presence of significant fat deposits on the hips, giving them a conical shape, makes it impossible to wear either compression hosiery or elastic bandages so as to maintain the necessary level of pressure on the thigh. This also includes the patient’s refusal (explicit or not) to wear compression hosiery.
• The inability to activate the patient after the intervention. The best way to prevent postoperative thromboembolic complications is early activation of the patient. Ideally, EVLO technology requires that the patient himself get up from the operating table and walk for a certain time after the intervention. In patients who, for various reasons, cannot be activated early, it is safer to perform stripping from this point of view.

Local contraindications

• Significant expansion of the BPV trunk. In the literature, you can find instructions for performing this intervention with a vein diameter of up to 18 mm inclusive.
• The presence of foci of inflammation in the intervention zone. Small-sized foci of inflammatory diseases of the skin and subcutaneous fat under the influence of operational stress can provoke the development of wound infection .

As a rule, this technique does not require special preparation of the patient. The patient needs to undergo standard screening for hospitalization. Before the intervention, it is necessary to shave the limb.

The marking on the patient’s skin is carried out under ultrasound control immediately before the intervention. Initially, the lower limit of reflux is determined by BPV (MPV). As a rule, this boundary is located at the confluence of a large tributary. A mark is placed at this point. The second mark is placed 3-4 cm distal to the first, at this point a puncture of the vein will be performed. Then, along the BPV (MPV), all the places where the tributaries flow in are marked — this is done in order to withstand the longer exposure of laser radiation in these places and to “close” the mouths of the tributaries. Further, all varicose inflows are marked, regardless of the way in which they will be removed.

The EVLO methodology consists of five sequentially performed steps:

Step 1. Puncture of the main saphenous vein and conducting the fiber.

Step 2. Positioning the working part of the fiber.

Step 3. Creation of tumescent anesthesia.

Step 4. Carrying out endovasal laser obliteration.

Step 5. Applying a compression brace .

Immediately after putting on the compression hosiery, the patient is recommended to walk for about 40 minutes. Continuous (round-the-clock) compression is 5 days. In the future, the patient wears compression hosiery only in the daytime. The total duration of wearing compression hosiery is 2 months. The first inspection is carried out for 2-3 days. In this case, ultrasound angioscanning is necessarily performed with an assessment of the state of safeno-femoral (popliteal) anastomosis. The thrombus transition to the femoral (popliteal) vein should be excluded. The status of the EVL-venous trunk is also evaluated. Make sure that EVLO has been successful and there is no blood flow in the vein.

Like any surgical intervention, EVLO has its own postoperative period. The normal manifestations of the postoperative period should include:

• Quite rarely, mainly in patients with a low pain threshold, soreness in the operated limb is noted on the first day after EVLO. It must be remembered that often such a pain syndrome is associated not with an operating injury, but with an improperly applied compression bandage, which can greatly compress the limb.
• The appearance of bruising along the coagulated vein. The reason for the appearance of bruising lies both in the perforations of the vein during EVLO and in excessively performed tumescent anesthesia, when the “creeping” infiltrate under pressure tears up the subcutaneous tissue.
• The feeling of a “chord" along the thigh (with EVLO BPV). With full extension of the limb in the knee joint, the patient feels tension at the location of the BPV, which prevents the limb from unbending to the end. As a rule, this sensation disappears in up to 1.5 months.
• Short-term rise in temperature to subfebrile digits after EVLO. This rise is due to the pyrogenic effect of protein degradation products formed after EVLO. If necessary, it is stopped by taking non-steroidal anti-inflammatory drugs (NSAIDs).
• In approximately 20% of patients, pulling sensations along the coagulated vein may appear 4-6 days after EVLO. Unpleasant sensations are stopped by taking NSAIDs.

• Anderson RR, Parrish JA Selective photothermolysis: precise microsurgery by selective absorption of pulsed radiation. Science. 1983 Apr 29; 220 (4596): 524-7.
• Navarro L, Min RJ, Boné C. Endovenous laser: a new minimally invasive method of treatment for varicose veins — preliminary observations using an 810 nm diode laser. Dermatol Surg. 2001 Feb; 27 (2): 117-22.
• Chang CJ, Chua JJ. Endovenous laser photocoagulation (EVLP) for varicose veins. Lasers Surg Med. 2002; 31 (4): 257-62.
• Proebstle TM, Moehler T, Gül D, Herdemann S. Endovenous treatment of the great saphenous vein using a 1,320 nm Nd: YAG laser causes fewer side effects than using a 940 nm diode laser. Dermatol Surg. 2005 Dec; 31 (12): 1678-83.
• Sokolov A. L., Lyadov K. V., Stoyko Yu. M. Endovenous laser coagulation in the treatment of varicose veins. - M .: Medical practice, 2007 .-- ISBN 978-5-98803-082-9 .
• Stoyko Yu.M., Batrashov V.A., Mazayshvili K.V., Sergeev O.G. Endovasal laser obliteration of saphenous veins: step by step // Uchebno-metodich. manual ed. Acad. Yu. L. Shevchenko. M., 2010 .-- 32 p.
• Shevchenko Yu. L., Stoyko Yu. M., Mazayshvili K.V. Laser surgery of varicose veins. - M .: Borges, 2010 .-- ISBN 978-5-9902607-1-9 .

• Phlebological center of the Federal State Institution of the National Medical and Surgical Center named after N.I. Pirogova of Roszdrav
• Association of Phlebologists of RUSSIA
• Site of the Innovative Vascular Center