Endovenous laser ablation: A comprehensive review

Abstract

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.

Keywords

Chronic venous insufficiency endovenous laser treatment ligation

Historical background

Prior to the late 1990s, the gold standard for the treatment of refluxing truncal veins was stripping and high ligation.¹ While the initial description of great saphenous vein (GSV) ligation dates back to the mid-1500s, this procedure was popularized in the late 1800s after Friedrich Trendelenburg authored a paper describing the technique.¹ Subsequently, American surgeons Mayo, Keller, and Van der Stricht described vein stripping procedures in the early 1900s,^1,2 and various modified and combined surgical techniques ensued. In 1999, endovenous laser ablation for the treatment of superficial venous reflux was approved in the USA, and this has since become a mainstay of treatment for chronic venous insufficiency in the United States and abroad.³

The shift towards endovenous treatments for venous reflux is attributable in part to the decreased morbidity, as well as the increased safety and efficacy of these procedures compared to open surgery, and to the portability of these procedures to the ambulatory setting.⁴ Endothermal ablation techniques, including endovenous laser ablation (EVLA) and radiofrequency ablation (RFA), are now considered the treatment of choice for symptomatic truncal vein reflux.⁵

Clinical evaluation

Risk factors for chronic venous insufficiency are varied and multifactorial, and they include obesity, pregnancy, female gender, and prolonged standing, as examples. Patients will often present to a clinician with significant and even debilitating symptoms; however, cosmetic concerns also factor into the evaluation. When patients present initially for an evaluation of chronic venous insufficiency, in addition to a thorough history and physical exam, photographs may be taken of the various areas of concern to document severity and to serve as a comparison for post-procedural results but are only required for insurance purposes. The Clinical, Etiologic, Anatomic, Pathophysiologic (CEAP) system is widely used to classify the extent of venous disease.^6,7

The gold standard imaging modality for evaluating reflux is duplex ultrasonography. A thorough vascular study with the patient preferably in a standing or dependent position allows for evaluation of reflux or obstruction in the deep, perforator, and superficial veins.^8,9

Both physician and patient scoring systems have been created, which allow for the evaluation of both objective findings and the impact of disease on quality of life. Such scoring systems also allow for the comparison of symptoms pre and post-procedure. The Venous Clinical Severity Score (VCSS) includes not only the physical findings, but also documents the patient’s perception of pain related to the physical findings as well as whether or not compression therapy is currently being used.¹⁰ Additional patient-reported scoring systems have been developed to augment the understanding of the impact to the patient including VEINES-QOL/Sym, the Aberdeen Varicose Vein Questionnaire (AVVQ), and the Varicose Vein Symptom Questionnaire (VVSymQ).^11–13

Endovenous Laser Ablation

The goals of any treatment for varicose veins are to improve the clinical picture, to alleviate symptoms, and to prevent progression of disease, and this is commonly achieved by eliminating or correcting the source of reflux. As stated by the Society of Vascular Surgery and American Venous Forum clinical practice guidelines, the endothermal techniques of EVLA and RFA are considered the standard of care.⁵

EVLA represents a technology with multiple iterations that has evolved over time. Different laser wavelengths generate thermal energy, ultimately causing fibrosis and occlusion of the treated vein.^15,16 The varying wavelengths in the near infra-red spectrum (808, 810, 940, 980, 1064, 1320, 1470, 1510, and 1920nm) can be classified into either hemoglobin-specific laser wavelengths (HSLW) or water-specific laser wavelengths (WSLW). Laser wavelengths ranging from 810 nm to 1064 nm are absorbed by hemoglobin found within the red blood cell, whereas wavelengths of 1320 nm and longer are absorbed by water preferentially found within the vessel wall.¹⁷

Comparisons of the efficacy of treatment using different wavelengths reveal limited differences; however, the use of longer wavelengths, with concomitant lower power settings, may lead to decreased pain and bruising.^16–23 Studies have demonstrated that the WSLW lasers allow for vein obliteration with lower energy settings due the increased specificity for the vein wall.^16,18 In taking the varying wavelengths into account, the treatment safety and efficacy appear to be based on the amount of energy delivered over a defined distance, or the linear endovenous energy density (LEED). LEED is measured using the units of Joules/cm. Initial data on the correlation between laser energy and long-term durability of venous closure were reported in 2004.²⁴ Based on subsequent studies, the appropriate values for safety and efficacy appear to be in the range of 60–80 J/cm, although this number may be as low as 30–50 J/cm for the WSLW lasers.^24–26 Again, the appropriate LEED varies based on the laser wavelength, fiber, and manufacturer.

Besides wavelength, fiber type may also play a significant role in post-ablation pain and bruising. Perforation of the vein wall is believed to be a frequent cause of symptoms, and direct contact between the laser fiber and vein wall may increase the likelihood of subsequent perforations.^27,28 Fibers with a coated tip or “jacket-tipped” fiber are designed to decrease direct contact with the vein wall in hopes of minimizing perforations. Radial tip fibers are designed to disperse the emitted energy and be less traumatic to the vessel wall, resulting in fewer perforations and thereby fewer symptoms. As described by Yamamoto and Sakata, radial and 2ring fibers allow for more even distribution of thermal energy across the vessel wall compared to bare-tip fibers, which apply thermal energy heterogeneously, potentially reducing the risk for perforation.²⁷ Kabnick and Sadek demonstrated that radial and jacket-tipped fibers are associated with decreased vein wall perforations and tissue damage in vitro, and this correlates with decreased post-operative pain and bruising as compared to bare-tipped fibers.²⁹ Other authors have corroborated this.^22,23,29 Moreover, it appears that jacket-tipped fibers exert a greater protective effect as compared to the laser wavelength. Even with the use of longer wavelength lasers, post-procedural pain and bruising are decreased with radial tip fibers as compared to bare-tip fibers.³⁰

GSV ablation

EVLA is commonly performed in the ambulatory setting using local anesthesia to treat refluxing truncal veins, the most common being the GSV, but in select instances involving other junctional tributaries including the accessory GSV, circumflex variants, and so on. Using ultrasound guidance and over-the-wire techniques, the GSV is accessed, and the treatment sheath is advanced until the tip is located 2–2.5cm peripheral to the saphenofemoral junction (SFJ). This treatment landmark relative to the SFJ has been reported on most extensively and has been associated with a low risk for endothermal heat-induced thrombosis (EHIT).^31,32 To protect from thermal injury, tumescent anesthetic is administered circumferentially around the GSV.^31,33,34 One technique aims to perform endovenous laser ablation flush at the level of the SFJ using a radial fiber (i.e. laser crossectomy) with the goal of eliminating recurrence from junctional tributaries and of preventing thrombus propagation from an incompetent saphenous vein stump. Spinedi et al. reported a single-center retrospective experience with this technique in 113 patients and demonstrated good technical success with an EHIT rate comparable to traditional EVLA.³⁵ The safety, efficacy, and durability of this technique require additional evaluation.

Once the anesthetic is administered, the laser fiber is pulled back continuously while monitoring the treatment energy readout. As stated previously, the appropriate LEED ranges from 60 to 80 J/cm, but is as low as 30 to 50 J/cm for the newer WSLW lasers.^24–26 Ablation of the superficial vein and absence of deep vein thrombosis are confirmed by completion duplex ultrasonography. Upon completion, a compression wrap may be applied, and the patient is encouraged to ambulate.

SSV ablation

The SSV is accessed in the middle to lower third of the calf, with the same precautions for more peripheral access due to the potential for injury to the sural nerve. The same general sequence of steps is followed as they are for treatment of the GSV.

Unique to the treatment of the SSV, the appropriate distance of treatment from the saphenopopliteal junction (SPJ) varies due to the greater anatomic variability at the SPJ. A distance from which to begin treatment may still follow the general guideline of 2–2.5cm from the SPJ, but some authors advocate remaining superficial to the muscular fascia to avoid the deeper neurovascular structures altogether.³⁶ Guidance by ultrasonography remains key to procedural safety and efficacy, and the remainder of the procedure follows as described above for GSV ablation.

Management of pathologic perforators

Clinical practice guidelines from the Society for Vascular Surgery and the American Venous Forum recommend the treatment of perforating veins when they fulfill the criteria of reflux time greater than 0.5s, diameter greater than 3.5mm, and located near a healed or active venous ulcer, and this comprises the definition of a pathologic perforator.³⁷ Using many of the aforementioned techniques, the pathologic perforator is accessed, the laser fiber introduced and local anesthetic administered. The laser is positioned 1 cm from the deep vein and approximately at the level of the fascia. Energy settings between 5 and 7 W are applied for 10–15 s at the treatment locations, and this is followed by confirmatory ultrasound as is the case with the treatment of truncal reflux. Post-procedural management remains similar.

Follow-up

Standard post-procedural instructions recommend graduated compression therapy for 7–10 days;^38,39 however, recent studies suggest no difference in pain or in quality of life with compression therapy.^40–42 Some physicians advocate that patients undergo repeat duplex ultrasonography at 72 h to two weeks post-procedure to assess for the entity of EHIT,^43,44 although there is little evidence to support imaging at a specific post-procedural time point. There is current debate regarding the clinical significance of EHIT, protocols for screening, and the appropriate treatment thereof.

Long-term outcomes and complications

Starting with the landmark trial by Min et al. in 2003, numerous studies have demonstrated the safety, efficacy, and durability of EVLA for treating superficial venous reflux.^45–47 The International Endovenous Laser Working Group reported long-term durability in 1020 limbs with failure rates of 7.7% at one year, 5.4% at two years, and 0% at three years.⁴⁸ A 2014 Cochrane Review by Nesbitt et al. reported a total of eight studies comparing EVLA versus surgery in the treatment of great saphenous vein reflux.⁴⁹ No significant differences were found between either physician-identified or symptomatic recurrences or recanalization, but neovascularization was found to be lower among the patients treated with EVLA as compared to surgery.

Roopram et al. compared 175 patients who were treated either with surgery (33%) or endovenous laser ablation (67%) for the treatment of small saphenous vein reflux.⁵⁰ At one week following treatment, EVLA patients reported greater pain scores compared to surgery; however, at two weeks post-treatment, surgical patients reported greater complications related to nerve injury (31% vs. 17%). Additionally, 10% of surgically treated patients developed surgical site infections, whereas there were no infections noted in patients treated with EVLA. Quality of life scores were not significantly different. The 2008 randomized controlled trial by Darwood et al. likewise demonstrated similar improvement in quality of life assessments (AVVQ) at three months between surgery and EVLA at two different power levels.⁵¹ Fewer patients randomized to the surgical group had returned to work at one week post-procedure, but there were no differences in pain scores between the groups.⁵¹ In 2014, Brittenden et al. reported comparisons between EVLA, surgery, and foam sclerotherapy in a randomized controlled trial involving 798 patients. They found no significant difference in the AVVQ score between the surgery and EVLA groups. Clinical outcomes at both six weeks and six months were not significantly different.⁵² At five years follow-up, whereby 75% of patients had completed questionnaires, AVVQ scores were low for both surgery and laser ablation.⁵³ The cost-effectiveness of treatment using EVLA has also come up, albeit in a more limited fashion. Interestingly, the same authors found that cost-effectiveness was most favorable for laser ablation. Other authors have corroborated these results based on thresholds of willingness to pay per quality adjusted life year.^54,55

With regards to durability, studies have consistently reported >90% success rates for EVLA, but follow-up between studies has been variable, ranging from several months to several years.^56–58 Similar results have been re-affirmed by more recent studies, including that by Aurshina et al. which reported failure rates of 0.8% for ablation of both GSV and SSV using either RFA or EVLA, and after an average follow-up period of 12 months, recanalization rates were 7.7% for the GSV and 8.5% for the SSV.⁵⁹ Likewise, the Varico 2 study demonstrated an ablation rate of 96.7% after 90 months for GSV ablation using EVLA with a radial tip fiber with concomitant improvements in quality of life scores (VCSS and AVVQ) at both six weeks and 60 months.⁶⁰

Furthering the evaluation of recurrence rates, a 2018 review and meta-analysis by Kheirelseid et al. identified nine randomized controlled trials, including 2185 legs, 1352 of which were followed up for five years, comparing RFA, EVLA, and ultrasound-guided foam sclerotherapy to conventional surgery.¹⁴ Recurrence rates in treated GSVs between surgery and EVLA were not significantly different (33.3% vs. 36.6%). By comparison, perforator ablation rates are significantly lower as compared to saphenous ablation rates, ranging from 59-90%.⁶¹ The SeCure trial demonstrated ablation rates of 75.%, 70.3%, 62.1%, 68.8%, and 71.3% at 1, 3, 6, 9, and 12 months, respectively, and statistically significant improvement in patient-reported quality of life scores were observed at all time points.⁶² Additionally, the proportion of patients with active ulcers improved over the course of the study, supporting the role for ablation of pathologic perforators independent of saphenous ablation.⁶²

Complications related to EVLA include vessel perforation, phlebitis, deep vein thrombosis (DVT), infection, skin pigmentation, neovascularization, paresthesias, skin burns, nerve injury, and pulmonary embolism.^63–66 The incidence of these reported complications varies widely in the literature (skin burns 0–9%, phlebitis 0–22%, and paresthesias 0–22%), though they are collectively rare.^63,64 In a 2018 systematic review and meta-analysis, Healy et al. reviewed the most serious complications of EVLA, reporting 48 DVTs in 15,676 patients (0.31%), 302 cases of EHIT amount 10,325 patients (2.92%), and three cases of PE in 8223 patients (0.04%).⁶⁶ The most common complications reported are superficial thrombophlebitis, nerve injury, and EHITs, and most cases of reported nerve injury are transient in nature.^63–66

Conclusion

EVLA is proven to be a safe, effective, and durable treatment option for symptomatic incompetent superficial and perforator veins of the lower extremities. EVLA can be performed in the ambulatory setting with decreased pain, morbidity, and recovery time, and recurrence rates and overall quality of life are improved with treatment. As an endothermal technique, EVLA represents the standard of care for treating lower extremity superficial venous reflux.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Ethical approval

As no human subjects were involved, this research did not require ethical approval.

Guarantor

KAT.

Contributorship

MS, LK contributed to the design and concept of the paper; KT was involved in data collection and literature review; KT took part in the creation of the manuscript: MS and LK were involved in the critical review and revision of the manuscript. All authors approved the version being submitted.

ORCID iD

Katherine A Teter

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