Comparison of methods of thermal ablation and endovenous laser coagulation of lower extremity varicose veins in experiment: energy and temperature characteristics of impact on vein and surrounding tissues, effectiveness and safety

BACKGROUND: Lower extremity varicose vein disease is a common condition among people of working age, leading to serious complications and impairment of quality of life. Modern minimally invasive techniques, such as endovenous laser coagulation (EVLC) and radiofrequency ablation, are effective and safe; however, complications such as thrombosis, heat-induced lesions, recanalization and recurrence are possible. Steam thermal ablation (STA) is a promising technique that minimizes the risk of tissue damage via the use of the energy of condensing steam. AIM: To evaluate comparative characteristics of EVLC and STA in vitro: energy and temperature characteristics of impact on the vein and surrounding tissues, effectiveness and safety. METHODS: Experimental studies were performed on 38 veins removed during phlebectomy. The veins were randomly divided into groups depending on the obliteration method: STA in different modes and EVLC. An Acrovein steam-generating prototype complex (Russia) and a Lakhta Milon diode laser (Russia) were used. A system with continuous liquid circulation was used to simulate physiological conditions. Temperature distribution was modeled in MATLAB R2017b (Mathworks, USA). The technical characteristics of the catheters, including the minimum bending radius, were compared; after the procedure, a histological examination of the veins was performed to assess morphological changes. RESULTS: The maximum catheter temperature during EVLC (1470 nm) was 58 [48–69]°C, during STA in 1 pulse/cm mode — 36 [32–40]°C, STA in 3 pulse/cm mode — 44 [34–54]°C (p 0.05). During STA, after 4 pulses, the temperature reached a maximum of 58 [49–67]°C, further temperature increase was insignificant (p 0.05). The catheter for STA (Acrovein, Russia) withstood a bend of 0.5 mm in diameter, maintaining functionality, whereas the light guide for EVLC (Lakhta-Milon, Russia) fragmented at a radius of 3.0 mm. Modeling confirmed the safety of STA. During EVLC, vein perforation was noted in 57.1% of cases (n = 4; p 0.05), while during STA no perforations occurred. CONCLUSION: The results of the experimental study demonstrated the effectiveness of STA of varicose veins in vitro with a lower incidence of vessel perforation cases compared to EVLC.