Chronic venous disorder (CVD), including primary varicose veins (VV) of the lower limbs and progressive forms with chronic venous insufficiency (CVI), is an important medical and social problem due to its high prevalence in the population and its significant burden on healthcare systems. According to general data, up to 19% of the population has primary varicose veins, and up to 13.5% has signs of CVI. At present, the main approach to surgical treatment of VVs is the elimination of pathological reflux, for which minimally invasive endovascular techniques are recommended. The latter, including endovascular laser treatment (EVLT), is noninferior to open surgery in technical efficiency but is associated with a lower risk of postoperative complications. Among all adverse events after EVLT, the most important one is venous thromboembolism (VTE), including endovenous heat-induced thrombosis (EHIT). The incidence of EHIT may depend on the position of the laser fiber relative to the sapheno-femoral junction (SFJ).
Recurrent varicose veins, occurring in 10-62% of patients, are the leading consequence of varicose vein surgery in long-term follow-up. The causes of recurrence depend on the type of primary intervention, with recanalization and reflux recurrence at the SFJ after EVLT being the most common.
In order to reduce the risk of varicose veins recurrence, it was proposed to perform a "laser crossectomy" (flush or zero ablation), which suggests laser fiber position just near the wall of the femoral vein without a traditional 1-2 cm distance from the junction. It is aimed at eliminating the ostia of all adjacent tributaries, including the anterior accessory saphenous vein (AASV), as in a traditional open surgery. To date, the limited evidence of laser crossectomy demonstrates its relative safety and technical feasibility in 57-100%, as well as a contradictory effect on the recurrence rate, including reflux on AASV.
At the same time, the vast majority of studies on laser crossectomy have been conducted at 1.5 μm (1470-1550 nm). The further development of technology has led to devices producing a wavelength of about 2 μm, which exhibit more selective absorption by water in blood and venous walls, allowing a similar depth of wall injury with lower power. First studies on its use show a high occlusion rate of up to 99%, low postoperative pain levels, and a reduced frequency of EHIT (predominantly class 1). Since EHIT of class 1 (superficial vein occlusion up to the level of the deep vein wall) aligns with the intention to perform a laser crossectomy, the use of 2 μm wavelength compared to 1,5 μm can be associated with both improved safety in terms of reducing EHIT of classes 2-4, and lower efficiency due to preservation of a stump with tributaries. Moreover, the technically successful laser crossectomy, despite the reduced risk of reflux recurrence at the SFJ, cannot guarantee the absence of reflux recurrence through other mechanisms. Thus, the question of choosing an optimal wavelength for performing a laser crossectomy, as well as its influence on further progression of GSV reflux, remains open.
