Comparison of 1470 nm and 1940 nm lasers in the treatment of chronic venous insufficiency: differences and similarities

Introduction

Chronic venous insufficiency (CVI) and varicose veins of the lower limbs represent a significant public health concern, affecting a substantial proportion of the adult population. In the past two decades, minimally invasive ablation techniques – such as thermal endovenous ablation – have become the standard for treating superficial vein insufficiency, including the great and small saphenous veins [1]. Endovenous laser ablation (EVLA) using wavelengths between 810 and 980 nm was initially widely adopted, though it was often associated with adverse effects such as pain, bruising, and paresthesia [1]. The introduction of longer wavelengths, particularly 1470 nm, marked a significant advancement due to selective energy absorption by water within the vein wall. This allowed for effective vein closure with reduced linear endovenous energy density (LEED) and minimized perivenous tissue damage [1]. The 1470 nm laser, especially when paired with radial fibers, demonstrated high efficacy in vein closure and a reduced complication profile compared to earlier lasers [1].
A more recent evolution in EVLA technology includes lasers with wavelengths near 1940 nm (e.g., 1920 nm and 1940 nm), which have an even higher water absorption coefficient than the 1470 nm laser [2]. Theoretically, this results in more focused thermal effects within the vein wall at lower power settings, potentially reducing postprocedural pain and inflammatory responses [2]. This development raises the question of whether 1940 nm lasers provide similar long-term closure durability as 1470 nm lasers while improving patient experience. This review aims to compare the two wavelengths with a focus on (1) clinical efficacy (short- and long-term closure rates), (2) patient-reported outcomes (pain, quality of life, return to activity), and (3) vein recanalization over 1–5 years following EVLA.

Methods

This article constitutes a narrative review based on a descriptive synthesis of the most relevant literature regarding endovenous laser ablation using 1470 nm and 1940 nm wavelengths.
A literature review was conducted using PubMed to identify studies evaluating treatment outcomes with 1470 nm and 1940 nm EVLA in patients with chronic venous insufficiency. Publications from the past 10 years were included, encompassing randomized trials, prospective cohort studies, retrospective analyses, and meta-analyses. Studies reporting anatomical vein closure at multiple time points, patient outcomes (pain, satisfaction, quality of life, recovery), and recanalization or reflux recurrence during at least 12 months of follow-up were analyzed. Keywords included “1470 nm,” “1940 nm,” “endovenous laser ablation,” “varicose veins,” and “chronic venous insufficiency.” Relevant findings were synthesized descriptively due to heterogeneity in protocols and follow-up duration, with emphasis on consistent trends and outcomes confirmed across multiple sources.
To enhance the scientific transparency of this review, basic inclusion and exclusion criteria were applied during the literature selection process. Studies were included if they (1) involved patients with chronic venous disease of the lower limbs, (2) reported treatment outcomes using 1470 nm or 1940 nm laser systems, and (3) provided at least 12 months of follow-up data. Publications were excluded if they were not in English, if they were conference abstracts without full data, or if the study population included fewer than 20 patients per group. Given the narrative nature of this review, formal risk of bias tools (e.g., Cochrane RoB) were not applied; however, preference was given to studies with clear methodology, sufficient sample size, and objective outcome measures. Additionally, it should be noted that while the majority of included studies met the aforementioned criteria, not all studies included in this review fulfilled them comprehensively.

Results

Clinical efficacy (vein closure rates)

Both the 1470 nm and 1940 nm lasers provide very high vein closure rates shortly after the procedure. In a randomized trial of over 200 patients, 100% of those treated with the 1940 nm laser and 99% of those treated with 1470 nm achieved successful vein obliteration (confirmed by Doppler ultrasound) at 1 month. These rates persisted at 6 months (100% vs. 99%) [3]. No statistically significant differences were observed [3].
Although this review includes one randomized controlled trial (RCT) that directly compares the 1470 nm and 1940 nm lasers, most of the efficacy data come from separate studies evaluating each wavelength independently. As a result, the comparison is largely indirect, which limits the strength of conclusions regarding their equivalency.
Other studies corroborated near-complete early efficacy: in 7- and 30-day evaluations, the 1940 nm laser achieved approximately 100% closure rates [4], similar to historical data for the 1470 nm laser. One-year closure rates also remained high. In a cohort treated with 1470 nm using a radial fiber, reflux elimination was seen in 99.6% of patients, with only one of ~300 treated limbs showing partial recanalization within 12 months [5]. Comparable outcomes were reported for the 1940 nm laser in a multicenter trial, with a 96.9% closure rate at 12 months and 95.9% at 24 months [6]. A systemic review of the studies concerning lasers >1900 nm (1920/1940 nm) reported closure rates of 96.3% at 12 months and 96.0% at 24 months [6]. Long-term data for the 1470 nm laser also support sustained efficacy. One 10-year follow-up study from Padua showed that 98% of patients remained asymptomatic or significantly improved, with complete recanalization in only one patient [7].
Overall, anatomical durability appears comparable for both wavelengths, especially for the great saphenous vein (GSV). Some variability may exist in more complex cases such as small saphenous vein (SSV) incompetence. In a 10-year follow-up, reintervention rates were 5% for the GSV and 21% for the SSV [7]. Nonetheless, three-year follow-up data for 1940 nm EVLA showed > 90% closure in SSV cases, with asymptomatic recanalizations only [8].

Patient outcomes (pain, satisfaction, recovery)

Patient satisfaction with EVLA is high for both wavelengths, largely due to its minimally invasive nature, absence of surgical incisions, and rapid symptom relief. In the study by von Hodenberg et al., patients treated with 1470 nm EVLA reported no persistent pain or paresthesia at 1-year follow-up; only 2.8% experienced varicose vein recurrence [5].
However, the 1940 nm laser appears to offer superior postprocedural comfort. A randomized trial demonstrated significantly lower pain scores (VAS) at both 7 days and 1 month in the 1940 nm group (p < 0.001) [3]. Another study using lower LEED (~53 J/cm vs. ~80 J/cm for 1470 nm) reported mean pain scores of 1.3 vs. 2.18, respectively [8]. Recovery was also faster with the 1940 nm laser – median return to normal activity was 7 days vs. 11.5 days with 1470 nm [3]. Lower thermal damage due to efficient water absorption resulted in fewer bruises and induration [8], with ecchymosis rates of ~2% for 1940 nm vs. 10-18% for 1470 nm [8].
Quality of life improved significantly after EVLA, regardless of wavelength, as measured by the venous clinical severity score (VCSS) and CEAP classification [6]. Some studies have used CIVIQ to evaluate health-related quality of life, revealing high satisfaction and improved daily functioning with 1470 nm EVLA [5]. In summary, both wavelengths were associated with positive patient experiences, with 1940 nm offering advantages in terms of reduced pain and quicker recovery [3, 8].

Recanalization and long-term outcomes (1-5 years)

Sustained vein closure without reflux recurrence is a key marker of ablation success. Both technologies demonstrate low recanalization rates. In the short term (6-12 months), recurrence is rare – many studies reported no recanalization at all during this period [9]. When recanalization occurs, it is usually early and affects a small subset of patients [6]. One systematic review noted four partial recanalizations within 1 month of 1940 nm EVLA in a single study center [6]. This may reflect inadequate initial closure, possibly due to low LEED. Most patients maintained closure over time. In one-year follow-up, recanalization was detected in 8 of 218 limbs (~3.7%) treated with > 1900 nm lasers [5], and in 5 of 126 procedures (~4%) at 2-3 years [5]. These events were often asymptomatic and found on routine Doppler ultrasound [8].
Long-term outcomes with the 1470 nm laser also remain excellent. In the study by Pavei et al., clinical improvement was maintained in 98% of patients over 10 years, with only one confirmed recanalization [7]. Some patients developed recurrent varicosities due to disease progression or collateral dilation, not necessarily related to the originally treated vein.
Direct long-term head-to-head data comparing 1470 nm and 1940 nm are lacking, but existing results suggest equivalent durability for both technologies [8]. If proper LEED is applied (> 35 J/cm), closure success exceeds 90-95% over 1-5 years. Concerns have been raised that low-power settings (aimed at pain reduction) might risk under-treatment and late failure [2]. However, this has not been borne out in clinical trials, where LEED levels around 40-50 J/cm achieved comparable results [8]. Maintaining a minimum threshold (e.g., > 35 J/cm) is essential for reliable closure.

Discussion

Available data indicate that both the 1470 nm and 1940 nm lasers provide high efficacy in treating superficial venous insufficiency. The introduction of the 1470 nm laser revolutionized endovascular varicose vein treatment, significantly reducing pain and complications compared to earlier wavelengths, while maintaining nearly 100% closure rates [5]. The 1940 nm laser represents a logical progression of this technological development.
The similarities between the two methods are striking: no clinical trials have reported inferior anatomical outcomes with 1940 nm compared to 1470 nm in large saphenous trunks. On the contrary, short-term closure rates are equivalent [3], and two-year patency rates remain comparable at 95-97% [6].
The advantages of 1940 nm become more evident in patient tolerance. Due to its unique absorption characteristics – greater affinity for water – the 1940 nm wavelength delivers more localized thermal energy closer to the fiber tip, reducing heat diffusion to surrounding tissues [2]. This enables effective ablation at lower power and total energy levels. In practice, 1940 nm EVLA typically uses 4-6 W and LEED of 40–60 J/cm, while classical 1470 nm protocols require 8–12 W and LEED of 60-100 J/cm [8]. This lower energy delivery reduces thermal injury and inflammation, leading to fewer bruises, swelling, and pain [8]. Faster recovery with 1940 nm is especially valuable for working-age patients, shortening convalescence by several days [3].
Importantly, quality of life improves significantly after successful ablation regardless of the laser used. Both methods eliminate reflux, alleviating symptoms such as swelling, pain, and leg heaviness, while improving cosmetic appearance. Comparative studies confirm similar improvements in VCSS and CEAP scores after both 1470 nm and 1940 nm treatments [6].
The long-term durability of 1940 nm laser outcomes appears comparable to those of 1470 nm, although the longest available follow-up for 1940 nm is only 3-4 years. While early results for the 1940 nm laser are promising, its equivalence to the 1470 nm wavelength beyond 5 years has not yet been conclusively demonstrated.
Nevertheless, no significant increase in recurrence has been observed. In fact, some series show promising data. For example, no reinterventions were needed in a 3-year 1940 nm cohort, compared to 21% reintervention in historical 1470 nm SSV patients [8]. This difference likely reflects anatomical challenges rather than wavelength alone.
Technical factors play a crucial role in preventing recanalization. These include appropriate energy adjustment to vein diameter, precise fiber positioning (especially near vein junctions), and even fiber withdrawal under ultrasound guidance [8]. It has been suggested that to ensure long-term efficacy, the 1940 nm laser should not operate at excessively low settings, even if it reduces pain. A LEED of at least 35-40 J/cm is recommended [4].
This ensures sufficient thermal injury to the intima and media. Whiteley notes that overly reducing power to eliminate pain might lead to suboptimal vein wall damage and increase late recanalization risk [2]. This is a practical concern – clinicians using newer wavelengths must balance patient comfort with procedural efficacy. Fortunately, current evidence suggests that both goals can be achieved simultaneously: patients report less discomfort, while closure success remains high, as long as energy parameters are appropriately maintained [6].
Another point worth discussing is the potential for specific indications of 1940 nm EVLA. Due to its more superficial heat distribution, it may offer benefits when treating thin-walled or superficial veins – such as perforators or small tributaries. In vitro studies show that at very low power, 1470 nm generates a broader heat spread than 1940 nm, which might increase the risk of collateral tissue damage in delicate vessels [10]. However, at standard power levels (6-10 W) used in GSV ablation, heat profiles between 1470 nm and 1940 nm converge [10]. Thus, in large-diameter veins, physical differences between lasers have limited clinical impact – both achieve similar closure rates.
Safety profiles are also comparable. Serious complications (e.g., deep vein thrombosis, skin burns, nerve injuries) are rare with either wavelength [8]. No differences have been noted in rates of deep vein thrombosis or endovenous heat-induced thrombosis (EHIT) extending to deep veins – both occur in < 2% of cases [8]. Minor complications such as transient paresthesia or phlebitis are similarly uncommon (< 3%) and usually resolve spontaneously within weeks or months [6].
Limitations of the current data include relatively short follow-up in most 1940 nm studies (< 5 years) and a limited number of head-to-head comparisons – only one RCT with 6-month follow-up has been published to date [3]. Many conclusions derive from juxtaposing separate studies for 1470 nm and 1940 nm, which may differ in populations or protocols. Nonetheless, the consistency of trends (high efficacy for both, less pain with 1940 nm, no difference in durability) suggests robustness.
Further research is needed, especially long-term randomized trials (≥ 5 years), to confirm the equivalence or superiority of 1940 nm in maintaining vein closure. Future investigations should also assess cost-effectiveness – for instance, whether the potentially higher upfront cost of 1940 nm systems is offset by faster return to work and lower use of analgesics. Technological innovations in fiber design (e.g., dual-ring radial fibers [7]) may further enhance outcomes and influence wavelength preference.

Conclusions

The 1470 nm diode laser has established itself as a safe and effective method for treating superficial venous insufficiency, providing near-complete closure rates and long-term symptom resolution. The newer 1940 nm laser represents a viable alternative with comparable clinical efficacy – achieving anatomical closure in ~95-100% of cases over 2–3 years – and is expected to perform similarly in longer-term observations.
Moreover, the 1940 nm wavelength is associated with better procedural tolerance, including reduced postoperative pain, faster return to activity, and fewer local adverse effects (bruising, induration, swelling). Low recanalization rates (< 5%) for both technologies support their durability, provided ablation parameters (power and LEED) are appropriately maintained. No significant differences have been reported in reflux recurrence rates between 1940 nm and 1470 nm [8].
While the 1470 nm laser has been evaluated in multiple studies with long-term follow-up of up to 10 years, the available data for 1940 nm EVLA extend only to 3-4 years. This should be considered a significant limitation when interpreting long-term equivalency, and further longitudinal research is necessary to validate the durability of the 1940 nm technology.
Therefore, the choice of wavelength may depend on operator experience and patient preference – 1940 nm may be particularly beneficial for those sensitive to pain or requiring shorter recovery. Both methods fulfill the criteria of modern varicose vein therapy: they are minimally invasive, safe, and highly effective. Though still relatively new, the 1940 nm laser has already proven its clinical parity with 1470 nm in chronic venous insufficiency, while offering superior patient comfort. Continued studies and long-term follow-up will help define its role within treatment algorithms, but currently both wavelengths represent excellent therapeutic options.

Disclosures

1. Institutional review board statement: Not applicable.
2. Financial support and sponsorship: None.
3. Conflicts of interest: None.

References