Heat dissipation during endovenous laser treatment of varicose veins – is there a risk of nerve injury?

Abstract

Objective: Endovenous laser therapy (EVLT) is a new minimally invasive treatment for varicose veins employing laser ablation of the long saphenous vein (LSV) under tumescent local anaesthesia. Concerns about thermal injury to perivenous nerves (tibial, peroneal, sural) have prevented its use for saphenopopliteal/short saphenous incompetence. This study assesses heat dissipation around the LSV during EVLT. Methods: In 12 consenting patients undergoing EVLT (Local research ethics committee approved), thermocouples (inserted percutaneously) were positioned (ultrasound control) 3, 5 and 10 mm from the LSV following perivenous injection of tumescent anaesthesia (0.1% lignocaine at room temperature). The 810-nm diode laser delivery system delivered 1-s pulses (12 W power) with 1-s intervals during laser fibre withdrawal at 3 mm/s. Results: The maximum recorded temperatures at 3, 5 and 10 mm were 43.3°C, 42.0°C and 36.0°C, with median temperatures (±interquartile range) of 34.5°C (30.8–40.0), 33.7°C (30.5–39.9) and 31.1°C (30.3–33.3), respectively. Conclusions: Although intravascular laser-tip temperatures of up to 1334°C have been recorded in experimental models of EVLT, these results indicate that heat dissipation into adjacent tissues is minimal. Thus, careful ultrasound-guided injection of adequate volumes of perivenous local anaesthetic and the associated heat-sink effect should allow safe use of EVLT in treating saphenopopliteal/short saphenous incompetence.

Endovenous laser ablation treatment with 980 nm diode laser for saphenous vein insufficiency: 6 months follow up results

“…In all 42 extremities, the etiology was primary and the pathophysiology was related with reflux. Superficial venous insufficiency was found in EVLA treatment of the small saphenous vein may be related with a higher rate of nerve injury because of adjacency to the sural nerve (18). In our study, varying degrees of tenderness and ecchymosis were observed in 34 (81%) extremities at the one-week follow-up vizit.…”

The surgical anatomy of the small saphenous vein and adjacent nerves in relation to endovenous thermal ablation

“…Distance X was used to create the upper lateral landmarks (13,14). Distance Y was used to create the upper medial landmarks (15,16). Distance X ϭ one-third of the distance between landmark 1 and 3.…”

“…Local tumescent anesthesia is known to protect surrounding tissue from high coagulation temperatures. 16 When the distance between the SSV and SN is Ͻ1 mm, the SN runs immediately next to or partly under the SSV. Insertion of tumescent anesthesia exactly between the SSV and the SN might therefore be difficult, if not impossible.…”

Combined endovenous laser therapy and microphlebectomy in the treatment of varicose veins: Efficacy and complications of a large single-center experience

“…Published reports confirm that endovenous laser ablation of an incompetent great saphenous vein (GSV) [1][2][3][4][5][6] or small saphenous vein (SSV) 7,8 is safe 9 and can provide outcomes equal to or better than traditional surgical ligation and stripping. [10][11][12][13] Some practitioners advocate ablating the thigh segment of the GSV and treating the remaining visible varicosities with sclerotherapy during subsequent follow-up visits.…”