Endovenous laser ablation: A comprehensive review

OBJECTIVE

To provide an evidence-based overview of endovenous laser ablation and describe its role as an effective and durable technique for the management of superficial venous insufficiency.

METHODS

The published literature on the treatment of varicose veins using endovenous laser ablation was reviewed. The literature search focused on the history of endovenous laser ablation, its safety and durability, known complications, and differences in outcomes based on the iterations of fiber type and laser wavelength.

RESULTS

Treatment safety and efficacy of endovenous laser ablation appear to be based on the amount of energy administered over a defined distance, or the linear endovenous energy density. The ideal linear endovenous energy density varies with the laser wavelength and fiber-type. Post-operative pain and bruising may be reduced by the use of higher wavelength fibers or the use of radial or jacket-tip fibers as compared to bare-tip fibers. The incidence of endothermal heat-induced thrombosis remains low and has declined with increasing experience. Reports have demonstrated a greater than 90% technical success rate with saphenous endovenous laser ablation, long-term durability of ablation, and commensurate improvement in quality of life.

CONCLUSIONS

Endovenous laser ablation is a safe and durable treatment option for the management of incompetent superficial and perforator veins of the lower extremities. As an endothermal technology, it remains a key component of the standard of care for the treatment of chronic venous insufficiency.

Lidocaine safety after saphenous vein tumescent anesthesia

Objectives

For endovenous thermal ablation of the saphenous veins, tumescent lidocaine anesthesia is often used. Unfortunately, information is sparse on the pharmacokinetics of lidocaine absorption and its maximum safe dose. The aim of this study was to evaluate plasma concentration of lidocaine on 12 lead electrocardiograms (ECGs) and symptoms over time after the administration of tumescent lidocaine during endovenous thermal ablation procedures in healthy volunteers.

Methods

An observational study of symptoms, 12 lead ECGs, and serum lidocaine levels were obtained following the administration of either 15 mg/kg lidocaine or 35 mg/kg lidocaine in the perivenous saphenous space under ultrasound guidance. Blood was drawn at regular intervals in heparinized tubes and spun at 3000 r/min for 10 min. The plasma lidocaine levels were plotted vs. time for statistical comparisons.

Results

With the 35 mg/kg dose, four of 11 participants developed symptoms of lidocaine toxicity at 40 min, which resolved by 180 min. The 35 mg/kg dose resulted in a mean serum lidocaine peak of 2.55 µg/ml at 60 min. The 15 mg/kg dose did not result in any symptoms of lidocaine toxicity, and it resulted in a serum lidocaine plateau of 0.85 µg/ml at 180 min. No significant changes were seen on the 12-lead ECG after the administration of lidocaine at either dose.

Conclusions

The 15 mg/kg total lidocaine dose did not cause symptoms and appears to be a safe lidocaine dosage for tumescent anesthesia for saphenous endovenous thermal ablations. The 35 mg/kg lidocaine dose is associated with lidocaine toxicity. More study on the maximal safe dose of lidocaine for endovenous thermal ablations is needed.

Comparison of endovenous laser treatment and high ligation in treatment of limb varicosity: A meta-analysis

To assess the efficacy and safety of endovenous laser treatment (EVLT) and high ligation (HL) for limb varicosity using meta-analysis. Multiple databases including PubMed, Springer, Excerpta Medica Database, Ovid Technologies, and China Journal Full-text database were searched for relevant studies in English or Chinese, and full-text articles were used to compare EVLT and HL for limb varicosity. Review Manager 5.0 was used to estimate the effects of the results among eligible articles. Forest plots, sensitivity analysis, and bias analysis of the included articles were also conducted. Initial screening yielded 1031 studies, 11 randomised controlled trials involving 1145 limb varicosity patients met the inclusion criteria in this study. The results of the heterogeneity test suggested that intraoperative blood loss mean difference (MD) = -6.31[-9.03, -3.60], P < 0.00001), operative time (MD) = -39.76[-42.27, -37.24], P < 0.00001), rate of complications (odds ratio [OR] = 0.37[0.22, 0.61], P < 0.0001), and recurrence (OR = 0.28[0.16, 0.49], P < 0.0001) were significantly different. Although both EVLT and HL have their own merits and demerits, EVLT is a more effective and safe method to treat limb varicosity.

Initial outcomes of endovenous laser ablation with 1940 nm diode laser in the treatment of incompetent saphenous veins

OBJECTIVES

To investigate the initial outcomes of 1940 nm diode laser in the treatment of incompetent saphenous veins.

METHODS

This was a prospective observational study. We treated 89 patients with 160 incompetent saphenous veins using a 1940 nm diode laser and bare fiber. The laser's power was set to 4.5 W with a mean linear endovenous energy density of 50.4 J/cm.

RESULTS

The one-month closure rate was 100%. The post-procedural pain score at 6 h, 1 day, 10 days, and 1 month was 0.85 ± 1.04, 0.65 ± 1.01, 0.82 ± 1.25, and 0.47 ± 0.82, respectively. Complications encountered included paresthesia (3.8%) and thrombophlebitis (4.4%), whereas no cases of endovenous heat-induced thrombosis were observed.

CONCLUSION

The 1940 nm laser and bare fiber at 50.4 J/cm showed satisfactory initial outcomes with less pain and fewer complications, in the treatment of incompetent saphenous veins.

Secondary ablation of saphenous veins: The reasons and the ratios

OBJECTIVE

To assess recurrence of saphenous veins and their tributaries following endovenous laser ablation (EVLA) and define primary or secondary ablation ratios as a result of misinterpretation, new incompetency formation, and re-canalization.

METHODS

The EVLA procedure was applied for vein insufficiency to 50 symptomatic patients (range, 22-78 years; mean age 45 ± 14 years; gender, 18 [36%] men, and 32 [64%] women). Before and after the procedure, a total of 80 legs were prospectively evaluated for recanalization of the great and small saphenous vein, anterolateral, posteromedial, intersaphenous thigh, and the calf veins by Doppler ultrasonography. EVLA was performed on the saphenous veins along with their tributaries, and was defined as the primary ablation. EVLA and alcohol ablation after the first procedure was defined as the secondary ablation. We evaluated the veins according to re-canalization and secondary ablation, and also measured the primary and secondary ablation ratios.

RESULTS

Seventy-three (97.0%) VSM and 39 (95.0%) VSP were treated with primary ablation and 2(3.0%) VSM and 2 (5.0%) VSP were treated with secondary ablation because of newly developed incompetency. In addition, 15 (71.0%) saphenous tributaries were treated with primary and 6 (29.0%) with secondary ablation. After primary or secondary ablation, 9 (12.0%) misinterpretation or new incompetency formation was found during a one-year follow-up. Seven (9.0%) VSM were re-canalized at the mean length of 46 ± 15 cm (range 32-65 cm) in one year. The laser energy in the re-canalized VSM was 78 ± 25 joules/cm (range 61-83) and all were retreated with laser or foam sclerotherapy.

CONCLUSIONS

VSM re-canalization and new vessel incompetency formation are reasons for secondary ablation, which is not a rare condition. Follow-up examinations and anatomical mapping are crucial for detecting new vessel formation or miss-interpretation after sclerotherapy or EVLA treatment.

Histological difference between pulsed wave laser and continuous wave laser in endovenous laser ablation

BACKGROUND

Endovenous laser ablation to saphenous veins has been popular as a minimally invasive treatment for chronic venous insufficiency. However, adverse effects after endovenous laser ablation using continuous wave laser still remain. Pulsed wave with enough short pulse duration and sufficiently long thermal relaxation time may avoid the excess energy delivery, which leads to the perforation of the vein wall.

METHOD

(1) Free radiation: Laser is radiated in blood for 10 s. (2) Endovenous laser ablation: Veins were filled with blood and placed in saline. Endovenous laser ablations were performed.

RESULTS

(1) There were clots on the fiber tips with continuous wave laser while no clots with pulsed wave laser. (2) In 980-nm continuous wave, four of 15 specimens had ulcers and 11 of 15 had perforation. In 1470-nm continuous wave with 120 J/cm of linear endovenous energy density, two of three presented ulcers and one of three showed perforation. In 1470-nm continuous wave with 60 J/cm of linear endovenous energy density, two of four had ulcers and two of four had perforation. In 1320-nm pulsed wave, there were neither ulcers nor perforation in the specimens.

CONCLUSIONS

While endovenous laser ablation using continuous wave results in perforation in many cases, pulsed wave does not lead to perforation.

Thrombus formation using endovenous lasers: an in vitro experiment

OBJECTIVES

The purpose of these experiments was to simulate thrombus formation during endovenous laser closure by measuring coagulum formation of in vitro laser exposures in porcine blood and investigate the role of procedures and equipment in thrombus formation.

METHODS

Continuous wave 810, 940, 980, 1310 and 1470 nm lasers and microsecond pulsed wave 1064 nm Nd:YAG (neodymium-doped yttrium aluminium garnet), 1320 nm Nd:YAG and 2100 nm THC:YAG (thulium holmium chromium-doped yttrium aluminium garnet) lasers were tested with standard fibres with diameters of 365, 550 and 600 μm as well as two prototype modified tip fibres.

RESULTS

The results show that pulsed lasers with high-peak power densities form less coagulum. Fibre specifications were found not to influence coagulum formation, and prototype modified tip fibres designed to prevent contact between the fibre tip and the vein wall did not eliminate coagulum formation.

CONCLUSION

Microsecond-pulsed wave lasers with high-peak power densities may be a better choice to minimize soft thrombus formation during endovenous laser ablation treatments.

Transient thrombocytosis after endovenous laser treatment for primary varicose vein of the lower extremity

We presented a case of a completely occluded great saphenous vein and transient thrombocytosis following endovenous laser treatment (EVLT) for primary varicose veins of the lower extremity. A 54-year-old man with a left saphenous varicose vein underwent EVLT surgery. Twelve-watt laser irradiation was delivered over the length of 33 cm of the saphenous vein. The cumulative exposure was 1042 J. Nine days after treatment, the platelet count increased up to 610 ⋅ 10(3) /mm(3) and returned to normal after 2 months. A complete occlusion of the great saphenous vein commonly occurs after EVLT, but no case of transient thrombocytosis has been reported.