Commonly Used Endovenous Laser Ablation (EVLA) Parameters Do Not Influence Efficacy: Results of a Systematic Review and Meta-Analysis

Abstract

WHAT THIS PAPER ADDSThis study shows that all previously studied parameters of endovenous laser ablation (EVLA; wavelengths, administered energy, and definitions of outcome) have no influence on the EVLA treatment success rate. The overall success rate of EVLA is proven to be high (92%), confirming that EVLA is a highly effective treatment for incompetent great saphenous veins (GSVs), with increasing follow up. In clinical practice, this means that it is likely there will be a good treatment effect after EVLA, regardless of which (clinically studied) parameters are used.Objectives: The objective of this systematic review and meta-analysis was to summarise available randomised controlled trials (RCTs) of EVLA efficacy, and to define the differences in success rate of variations in wavelength, administered energy, outcome definition, and follow up period. Methods: A literature search was conducted in Embase, Medline (Ovid-SP), Cochrane Central Database, and Web of Science from inception to November 2017. RCTs with follow up of more than three months were included. The studied outcome was the proportion of patients with EVLA treatment success, defined as absence of reflux or occlusion of the great saphenous vein (GSV). Pooled proportions of anatomical success were compared. Subgroup and meta-regression analysis included wavelengths (short [810, 940, and 980 nm], long [1470, 1500, and 1920 nm]), amount of energy ( 50 J/cm, > 50 J/cm), follow up ( 1 year, > 1 year), outcome definition (occlusion, no reflux), and quality of the studies (low risk of bias, unclear/high risk of bias). Results: Twenty-eight RCTs, with a total of 2829 GSVs were included. The overall success rate of EVLA was 92% (95% CI 90e94%, I 2 ¼ 68%). In subgroup analysis, no statistically significant differences were found for long or short wavelengths (95% [95% CI 91e97%] vs. 92% [95% CI 89e94%], p ¼ .15), high or low administered energy (93% [95% CI 89e95%] vs. 92% [95% CI 90e94%], p ¼ .99), long or short follow up (89% [95% CI 84e93%] vs. 93% [95% CI 91e95%], p ¼ .13) and outcome definition (occlusion group 94% [95% CI 91e96%] vs. absence of reflux group 91% [95% CI 87e94%], p ¼ .26). Studies with low risk of bias reported a significantly higher success rate than high or unclear risk of bias (93% [95% CI 90e95%] vs. 89% [95% CI 83e93%], p ¼ .04). Conclusions: The overall success rate of EVLA is high (92%), even with increasing follow up. Commonly used parameters of EVLA (wavelength, administered energy, and outcome definition) have no influence on the treatment success rate.

Uso do laser de 1.470 nm para o tratamento de insuficiência venosa superficial

“…Several publications state that it is necessary to apply LEED from 65 to 100 J/cm to achieve adequate occlusion and fibrosis of the vein, with success rates from 90 to 100% at 1 year follow-up. 25 - 28 However, a meta-analysis by Malskat et al 17 showed no significant difference in occlusion rates between groups with LEED > 50 J/cm and ≤ 50 J/cm. This discrepant information is explained by Proebstle et al, 29 who discuss the fluence (J/cm 2 ) administered to the vessel lumen as a factor with potential impact on definition of the quantity of energy administered, taking into consideration the diameter of the vein treated along its entire length.…”

“…Treatment of superficial venous insufficiency with EVLT has been in use for more than 15 years and proven to be an excellent option because of the high rates of safety, efficacy, and patient satisfaction when compared to other surgical techniques. 17 - 19 If we compare it to conventional surgery, EVLT is a less invasive technique that can achieve better esthetic results while maintaining the effectiveness of conventional stripping. 1 , 12 However, it is expensive and, because of this, is not accessible to all patients and is not available on the Brazilian National Health Service (SUS - Sistema Único de Saúde).…”

“…O tratamento da insuficiência venosa superficial com o EVLT tem sido utilizado há mais de 15 anos e mostra-se uma excelente alternativa devido à alta taxa de segurança, efetividade e satisfação dos pacientes quando comparada a outras técnicas cirúrgicas 17 - 19 . Ao confrontarmos com a cirurgia convencional, o EVLT é uma técnica menos invasiva, que consegue melhor resultado estético e mantém a efetividade da abordagem convencional 1 , 12 .…”

“…Diversas literaturas trazem a necessidade da aplicação de uma LEED entre 65 e 100 J/cm para se obter oclusão e fibrose adequada da veia, com taxas de sucesso entre 90 e 100% em um ano de acompanhamento 25 - 28 . Entretanto, a metanálise de Malskat et al 17 mostrou não haver diferença significativa na taxa de oclusão nos grupos com LEED > 50 J/cm e ≤ 50 J/cm. Essa discrepância de informações é justificada por Proebstle et al 29 , que trazem a discussão da fluência (J/cm 2 ) aplicada à luz do vaso como um fator com potencial de impacto na definição da quantidade de energia aplicada, levando em consideração o diâmetro da veia tratada em todo seu trajeto.…”

If it Looks Like a Duck, Swims Like a Duck, and Quacks Like a Duck, Then it Probably is a Duck. What “The Duck Test” Tells us About Systematic Reviews and Meta-Analyses of LEED and Other EVLA Parameters

“…Such is the case, in my view, of the message given in the recent publication "Commonly used EVLA parameters do not influence efficacy e results of a systematic review and metaanalysis." 1 The authors looked at randomised controlled trials of endovenous laser ablation (EVLA) of the great saphenous vein (GSV). Overall, they quoted a 92% success rate e although the trials were heterogeneous and the authors cannot be certain whether "successful ablation" is fibrotic or merely thrombotic with possible future recanalisation.…”