Nonthermal, nontumescent ablation techniques for the treatment of lower extremity superficial venous insufficiency

INTRODUCTION — Nonthermal, nontumescent ablation refers to techniques that cause vein closure using sclerosing agents, glue, or mechanical methods. Because these methods do not involve the use of heat, the likelihood of adjacent nerve injury is reduced, and tumescent anesthetic infiltration is not necessary.

Nonthermal ablation techniques for the treatment of superficial venous insufficiency are reviewed.

Alternative approaches to treatment of superficial venous insufficiency and comparisons of the various techniques are discussed separately.

●(See "Approach to treating symptomatic superficial venous insufficiency".)

●(See "Techniques for endovenous laser ablation for the treatment of lower extremity chronic venous disease".)

●(See "Techniques for radiofrequency ablation for the treatment of lower extremity chronic venous disease".)

●(See "Comparison of methods for endovenous ablation for chronic venous disease".)

VENOUS ANATOMY — The superficial veins of the lower extremity are classified as axial or nonaxial. The axial veins include the great, small, and accessory saphenous veins (figure 1A-B). Other superficial veins, including the intersaphenous veins, lateral veins, and other nonaxial veins, have variable anatomy. (See "Classification of lower extremity chronic venous disorders", section on 'Superficial venous system (As)'.)

The deep veins of the lower extremity are contained within the deep muscle compartments bounded by the muscular fascia (figure 2). (See "Classification of lower extremity chronic venous disorders", section on 'Deep venous system (Ad)'.)

Perforator veins are those veins that traverse the muscular fascia to connect superficial veins with the deep veins. These are located anteriorly, posteriorly, laterally, and medially in both the thigh and calf. (See "Classification of lower extremity chronic venous disorders" and "Classification of lower extremity chronic venous disorders", section on 'Perforator veins (Ap)'.)

INDICATIONS — The decision to offer nonthermal, nontumescent ablation depends upon symptoms, response to conservative therapy, extent of lower extremity disease, and likelihood of providing a durable benefit, either with respect to appearance or improvement in symptoms.

Nonthermal, nontumescent ablation techniques can be used to achieve axial vein closure (eg, great saphenous vein, small saphenous vein) or perforator vein closure for patients with documented reflux (ie, retrograde flow >0.5 seconds in a superficial vein or perforating vein) as a source of symptoms. (See 'Saphenous ablation' below and 'Perforator ablation' below.)

For patients with venous ulceration who are refractory to medical management or have recurrent ulceration, ablation of perforators may help heal ulcers and prevent recurrence. Only pathologic perforator veins should be treated. A pathologic perforator vein is defined as one that demonstrates outward flow (reflux) of greater than 0.5 seconds, has a diameter of greater than 3.5 mm, and is located under an active or healed venous ulceration [1]. This means that perforator veins should only be treated in patients with CEAP classification C5 and C6 disease. There is no benefit for treating incompetent perforator veins in patients with only varicose veins. (See "Overview of lower extremity chronic venous disease", section on 'With perforator reflux'.)

For all patients, it is important to address patient expectations and to discuss potential adverse effects, treatment failure, complications, and alternative treatment methods. Alternatives to nonthermal, nontumescent ablation for superficial venous reflux include no intervention (ie, ongoing conservative management), thermal ablation (ie, radiofrequency laser ablation, endovenous laser ablation), or surgical removal. (See "Techniques for radiofrequency ablation for the treatment of lower extremity chronic venous disease" and "Techniques for endovenous laser ablation for the treatment of lower extremity chronic venous disease" and "Approach to treating symptomatic superficial venous insufficiency", section on 'Surgical options'.)

Contraindications — Sclerosing agents or glue should not be used in patients who have signs of acute venous thrombosis (superficial, deep). While other ablation techniques have been investigated for managing superficial venous thrombosis, the results of these studies cannot be generalized to the use of sclerosing agents or glue.

Pregnant individuals should defer treatment until after delivery.

Specific hypersensitivities or risk for adverse reactions may preclude the use of any particular technique. (See 'Complications' below.)

A history of migraine headache and patent foramen ovale are relative contraindications to the use of a foamed sclerosing agent such as physician-compounded foam using room air, due to a risk for microembolism [2-7]. (See 'Sclerotherapy' below.)

NONTHERMAL ABLATION METHODS

Sclerotherapy — Sclerotherapy injects liquid or foam sclerosing agents into a vein, which causes endothelial damage and induces thrombosis. The most common sclerosing agents used in the treatment of chronic venous disease are polidocanol, hypertonic saline, sodium tetradecyl sulfate, and glycerin (table 1). Of these agents, only polidocanol and sodium tetradecyl sulfate have been approved for sclerotherapy by the US Food and Drug Administration. Foam preparations are particularly useful for nonthermal, nontumescent ablation of the axial veins given the overall volume of sclerosant that is needed [8,9]. Sclerosant foam was developed from the detergent sclerosant agents [10].

Foam preparations — Foam preparations are used to treat larger veins (≥6 mm). The foam is necessary to displace the increased volume of blood in these larger veins. For saphenous venous ablation, foam preparations (physician compounded, polidocanol endovenous microfoam [PEM]) have distinct advantages. Compared with liquid agents, the expanded volume of the foam provides more surface contact, a more uniform vessel closure, and requires smaller volumes of sclerosant. The relative effectiveness of foam compared with liquid sclerotherapy for ablation of the great saphenous vein is discussed below. (See 'Foam versus liquid sclerotherapy' below.)

●PEM (ie, Varithena [1% polidocanol]) is a commercial standardized (uniform microbubbles) propriety foam sclerosant that is approved for use in the United States to treat incompetent great saphenous or accessory saphenous veins and visible varicosities of the great saphenous vein system above and below the knee [11]. Phase III trials, including the Efficacy and Safety Study of Polidocanol Injectable Foam for the Treatment of Saphenofemoral Junction Incompetence (VANISH-1 [12]) and Polidocanol Endovenous Microfoam Versus Vehicle for the Treatment of Saphenofemoral Junction Incompetence (VANISH-2 [13]) trials, have confirmed the safety and efficacy of PEM (ie, Varithena) for improving symptoms when used to treat superficial venous incompetence [14]. In an observational study evaluating PEM for the treatment of axial superficial venous reflux (great, small, and anterior accessory saphenous veins), the closure rate was 93 percent at six months [15]. PEM can be used to treat larger varicose veins (≥6 mm) or incompetent perforator veins. In clinical trials, the concentration of polidocanol foam (3 versus 1%) did not appear to significantly alter outcomes for saphenous venous ablation [16-20].

●Foam can also be produced manually (also referred to as physician-compounded foam [PCF]) just prior to injection using the Tessari method (figure 3); however, compared with PEM, the bubbles created with PCF are larger and less stable [21]. Foam prepared by the Tessari technique has a half-life of approximately 90 seconds. Thus, the procedure should be completed within one minute, before the foam degrades. An alternative method consists of a product that dispenses a low-nitrogen gas and sclerosant liquid under pressure to produce a polidocanol foam with appreciably smaller and more consistently sized bubbles compared with a foam/air mixture made by hand [13,22,23]. PCF can be created using polidocanol or sodium tetradecyl sulfate with room air or carbon dioxide (CO₂). PCF is an off-label use of these sclerosants and is associated with a higher incidence of neurologic complications compared with PEM when room air is used. It is believed that the nitrogen content in PCF made with room air is responsible for these neurologic complications because of the relative insolubility of nitrogen in the blood [6,24,25]. Physician-compounded foam made with carbon dioxide is more soluble in blood. Microembolism has not been reported with proprietary microfoam formulations.

Ultrasound guidance — Ultrasound imaging accurately guides delivery of the foam into the intended veins since the sclerosant foam is echogenic due to the gas component. For great saphenous ablation, the foam sclerosant is typically administered through a micropuncture sheath or intravenous catheter placed near the knee, above the proximal calf perforator veins. Foam sclerotherapy is especially useful for very tortuous saphenous veins, as it is the only method of endovenous ablation that does not require catheter placement along the length of the vein. Ablation with a foam sclerosant is also extremely useful for treating recanalized veins or veins with webbing or synechiae in which a catheter would not easily be passed proximally. Larger varicose veins can also be treated in the same session as saphenous ablation.

Mechanochemical ablation — Endovenous mechanochemical ablation (MOCA; ie, ClariVein) uses an agitating wire to cause venospasm and mild injury to the endothelial lining of the vein while simultaneously injecting a sclerosing agent. Either polidocanol or sodium tetradecyl sulfate can be used. Venospasm increases the contact time between the sclerosant and the endothelium, which augments closure. MOCA is applicable to virtually all veins that are straight enough to allow catheter placement but is particularly useful for very superficial veins and those below the knee since there is no chance of nerve injury (unlike thermal ablation) and there is no residual foreign body (unlike glue). When MOCA is used to treat the saphenous veins, venous cannulation is at the knee or ankle; the wire is activated 2 cm from the saphenofemoral junction [26,27].

Compared with endovenous ablation methods, MOCA is associated with lower initial closure rates, but among the endovenous and other ablation therapies is associated with the least amount of pain [28-31]. In the MARADONA trial, which randomly assigned 213 patients to MOCA or radiofrequency ablation (RFA), while pain scores were lower, hyperpigmentation occurred more often with MOCA (7 versus 2 patients) [29]. Clinical success at one and two years were similar despite more recanalizations with MOCA. In the Laser Ablation versus Mechanical Ablation trial, which randomly assigned 150 patients to MOCA or EVLA, duplex-derived anatomic occlusion rates were lower for MOCA at one year (53/69 [77 percent] versus 63/69 [91 percent]), but the improvement in the venous severity score and quality-of-life scores were similar [28]. 

MOCA has also been validated as safe and painless for the treatment of small saphenous vein incompetence. In one review, occlusion rates were 92.6 percent at one year with no sural nerve injuries or other major complications [32].

Cyanoacrylate adhesive closure — Cyanoacrylate adhesive closure (CAC) is a catheter-directed procedure that seals the saphenous vein without the use of tumescent anesthesia. CAC was initially described for the treatment of saphenous insufficiency in 2013 [33]. An adhesive sealing system (ie, VenaSeal) was later approved for use in the United States in 2015 [34]. The procedure is performed in a manner like RFA and endovenous laser ablation, but without the need for tumescent anesthesia. Closure rates for CAC are high without use of postprocedure compression, which is unique to this nonthermal method of ablation [35-37].

To perform CAC, the catheter is positioned in the saphenous vein 5 cm from the saphenofemoral junction, and the proximal great saphenous vein is compressed with the ultrasound probe to prevent migration of the glue into the deep veins [33,38-40]. An aliquot of cyanoacrylate adhesive is injected into the vein, the catheter is pulled back, and pressure is held. This process is repeated until the entire vein is occluded from 5 cm distal to the saphenofemoral junction to the distal point of reflux. The total volume of adhesive delivered is generally less than 1.5 mL.

In the European Multicenter Cohort Study on Cyanoacrylate Embolization (eSCOPE), great saphenous ablation was performed in 70 patients [36,37]. Closure rates by life table analysis at 6-, 12-, 24-, and 36-month follow-up were 91.4, 90, 88.5, and 88.5 percent, respectively. Through 36 months, the reduction in venous clinical severity score from 4.3 at baseline to 0.9 was significant.

In randomized trials comparing adhesive ablation with radiofrequency venous ablation, outcomes were similar, and in one trial, longer-term (60 month) occlusion rates were improved for CAC compared with RFA [41]. The VenaSeal Sapheon Closure System Pivotal Study (VeClose) randomly assigned 220 patients with symptomatic great saphenous vein incompetence to a proprietary CAC system or RFA [41]. The early closure rate at three months was 99 percent for CAC and 96 percent for RFA demonstrating noninferiority, which persisted at 24 months and 60 months follow-up [42,43]. The feasibility of CAC for perforator veins was investigated in a separate study; there were no serious complications [44].

SAPHENOUS ABLATION — Venous reflux in axial veins can be treated using a variety of techniques. For the great saphenous vein, thermal ablation (eg, endovenous laser ablation [EVLA], radiofrequency ablation [RFA]), mechanochemical ablation (MOCA), and glue are all associated with higher rates of vein closure (immediate and long term) compared with liquid or foam sclerotherapy [45-56]. The rationale used for selecting foam sclerotherapy to treat the great saphenous vein is based on similar long-term, patient-derived clinical outcome measures in the available trials, rather than strictly on rates of vein occlusion [57,58]. In addition, foam sclerotherapy is easily repeated. The approach to treating superficial venous insufficiency is discussed in more detail separately. Treatment of other axial veins (small saphenous, accessory saphenous) follows similar principles [59]. (See "Approach to treating symptomatic superficial venous insufficiency" and "Comparison of methods for endovenous ablation for chronic venous disease", section on 'Vein closure'.)

Foam versus liquid sclerotherapy — When sclerotherapy is selected to treat the great saphenous vein, we suggest foam rather than liquid sclerotherapy. In randomized trials, foam sclerotherapy was more successful initially at eliminating saphenous reflux compared with liquid sclerotherapy [16-18,50,60-66]. In a meta-analysis of seven trials using polidocanol for a variety of clinical situations, efficacy was significantly improved for foam compared with liquid formulations (odds ratio 5.64, 95% CI 3.83-8.10) [67]. These results were similar to an earlier meta-analysis of three trials limited to saphenous vein ablation in which the efficacy of foam compared with liquid was 76.8 versus 39.5 percent, respectively [62]. For the small saphenous vein, closure rates of 91 to 94 percent at 12 months follow-up have been reported for foam sclerotherapy [59,68,69].

Foam sclerotherapy is also associated with lower rates of recanalization compared with liquid sclerotherapy in the longer term [61,65]. In trial that randomized 95 patients, elimination of great saphenous reflux occurred in 85 percent of patients with foam sclerotherapy compared with 35 percent with liquid sclerotherapy [65]. The success rates at two years were 53 percent in the foam group and 12 percent in the liquid group. The significantly improved closure rates for foam sclerotherapy and the practical issues discussed above (see 'Sclerotherapy' above) favor the use of foam for saphenous ablation and outweigh the potential for complications associated with its use (local, systemic), which are overall uncommon. (See 'Complications' below.)

Recurrence rates — Vein recurrence rates following saphenous vein sclerotherapy are related to saphenous recanalization [61,70,71]. In a trial that randomly assigned 500 patients with great saphenous reflux (580 legs) to RFA, EVLA, ultrasound-guided foam sclerotherapy (UGFS), or surgery (high ligation and stripping) [45], the recurrence rate at five-year follow-up was significantly higher for foam sclerotherapy compared with RFA or EVLA (5.8 and 6.8 percent versus 31.5 percent). A later systematic review identified a median recurrence rate of 8.1 percent in 69 studies of foam sclerotherapy [64]. While a single session of UGFS is moderately successful for treating the saphenous veins, higher long-term success rates may be seen with additional vein treatment sessions [72-75]. In one review, 90 percent of great saphenous veins were free of recanalization with two sessions over a mean 39 months of follow-up [73].

For either liquid or foam sclerotherapy, symptoms often do not necessarily correlate with vein recurrence or recanalization. Duplex ultrasound can show procedural failure, yet some of these patients may still have clinical improvement that is maintained long-term [57,58]. Anatomic failure is a useful term to distinguish these patients from those with clinical failure (ie, recurrent clinical symptoms and/or varicose veins). Anatomic failure is classified as type I, II, or III, depending on the timing of failure and etiology (table 2) [76]. In one prospective trial, saphenous vein recanalization occurred in 27 and 64 percent of patients treated at one and five years, respectively [58]. However, 70 percent of patients did not have worsened clinical symptoms. Repeat UGFS was needed to manage symptoms in only 16.5 percent of patients between one and two years and fewer than 10 percent in subsequent years (up to five years).

Foam sclerotherapy technique — To treat reflux of the great saphenous vein, foam sclerotherapy is performed using ultrasound guidance (ie, UGFS). The saphenous vein is cannulated in the mid- to distal thigh with the needle or sheath directed cephalad. Manual compression is used just caudal to the access site to prevent the foam from traveling into the distal saphenous vein. The extremity is elevated, and sclerosant foam is injected until the foam can be seen approaching the saphenofemoral junction on ultrasound. When the foam is 5 cm from the saphenofemoral junction, the vein is compressed proximally with the ultrasound probe, and the distal pressure is released. Continued injection will fill the tributary varicosities and the great saphenous vein distal to the cannulation site. To help prevent deep vein thrombosis, the patient is often asked to perform a series of dorsiflexion maneuvers following the injection to clear any foam that may have entered the deep venous system.

In a study that evaluated a small number of patients for whom UGFS was performed in combination with compression of the saphenofemoral junction, this practice reduced but did not completely prevent migration of the foam [77]. Some postulate that release of compression could promote microembolization.

PERFORATOR ABLATION — The presence of reflux in perforator veins following saphenous ablation is a known risk factor for vein recurrence and venous ulcer nonhealing or recurrence [78,79]. The ideal technique for perforator ablation has not been established. Some clinicians prefer to use a liquid sclerosant, while others use foam because it does not flow as readily, it can be more easily seen on ultrasound, and it may be better directed into tributary veins associated with an ulcer bed, potentially minimizing entry into the deep venous system [80-82]. Injection of the sclerosant at the level of a refluxing perforator vein can be used to ablate the perforator or to treat associated interconnected superficial veins (Fegan technique) [83]. This technique has been used with good long-term results and without significant complications but requires an experienced practitioner [84].

Sclerotherapy of perforator veins is associated with fewer complications compared with surgical management of perforators (ie, subfascial endoscopic perforator surgery [SEPS]) and is clinically appealing for this indication; however, there are few studies. Ultrasound-guided sclerotherapy of perforator veins does appear to reduce the severity of symptoms and signs as determined by venous clinical severity scores. Following a single treatment, closure following ultrasound-guided sclerotherapy of perforators occurs in about two-thirds. In one trial, ulcer healing was ultimately observed in 32 of 37 limbs treated by ultrasound-guided perforator sclerotherapy [80]. This group of patients did not have concomitant axial venous reflux. Approximately 75 percent of perforator veins remained closed up to five years following treatment. Clinical improvement was sustained at a mean follow-up of 20.1 months.

Following ultrasound-guided sclerotherapy of perforator veins, duplex ultrasound should be performed at three to six weeks to identify recurrent perforator veins that can lead to venous ulcer recurrence. In one study, complete closure of all incompetent perforator veins was the only predictor of ulcer healing [85].

POSTPROCEDURE CARE AND FOLLOW-UP — With sclerotherapy, there is a risk of deep vein thrombosis, and duplex ultrasound 48 hours postprocedure is often obtained [86]. (See 'Venous thromboembolism' below.)

When foam sclerotherapy is performed, the patient should be instructed to call their clinician if they experience unusual coughing or visual, sensory, or motor disturbances, particularly if a physician-compounded foam has been used. (See 'Foam preparations' above and 'Visual and other neurologic disturbances' below.)

Following nonthermal saphenous ablation using sclerotherapy, there is no consensus or high-quality evidence to direct the type and duration of postoperative compression [16,87]. We advise our patients to wear compression stockings continuously for 48 hours after treatment, after which time they may be worn during the day (off at night and to bathe) for the next two weeks. Most trials have evaluated compression bandaging schemes for liquid injection sclerotherapy, but it appears that short-term compression therapy for foam sclerotherapy is also favored [88,89]. One trial randomly assigned 128 patients to 24 hours of compression bandaging followed by antiembolism stockings or to five days of bandaging [88]. No significant differences were found in phlebitis scores or pain scores at two-week follow-up. At six weeks, vein occlusion rates, skin changes, and venous severity measures were also similar. Another trial randomly assigned 60 patients undergoing foam sclerotherapy of the saphenous vein to compression stockings or no compression [90]. Vein closure rates, side effects, and patient satisfaction between the groups at 14 days and one-month follow-up were similar.

For cyanoacrylate adhesive closure, postprocedure compression may not be necessary, though is used by some clinicians to decrease the rate of phlebitis. In two trials, compression was not used, and closure rates were high [35-37].

COMPLICATIONS — Symptomatic venous thromboembolism (deep vein thrombosis, pulmonary embolism) is overall uncommon [64,91-95]. However, endovenous foam or endovenous glue-induced thrombosis (EGIT) analogous to endovenous heat-induced thrombosis [EHIT] for thermal ablation techniques has been reported. Other complications include anaphylaxis and microembolic events as evidenced by coughing, migraine-like headache, visual disturbance, paresthesia, or stroke [3]. An unusual complication of inadvertent saphenous vein stripping has been reported in association with mechanochemical ablation, wherein the rotating wire was caught on a valve leaflet [96].

Venous thromboembolism — With foam sclerotherapy of the great saphenous vein, maneuvers such as elevation of the treated limb and compression at the groin are performed to limit the foam from entering the deep veins; however, some invariably does enter the systemic circulation. A systematic review of foam sclerotherapy reported rates of deep venous thrombosis occurring in 0.02 to 5.7 percent [64]. Venous thrombosis has also been reported in the popliteal vein following foam sclerotherapy of the small saphenous vein [68,69], and following perforator ablation [81,85]. The diagnosis and treatment for deep venous thrombosis in this setting follows standard protocols. (See "Clinical presentation and diagnosis of the nonpregnant adult with suspected deep vein thrombosis of the lower extremity".)

The incidence of deep vein thrombosis for foam sclerotherapy may be increased compared with thermal and other nonthermal, nontumescent ablation techniques. In the VANISH-2 trial, the incidence of deep vein thrombosis was 10 percent [13,14]. However, 9 of 24 of the events were considered extension of thrombus from the treated vein (ie, endovenous foam-induced thrombosis). In a separate trial, 10 patients developed deep vein thrombosis; all were asymptomatic and detected on routine follow-up ultrasound [91].

Endovenous glue-induced thrombosis — EGIT (extension of thrombus into a deep vein) can occur with cyanoacrylate adhesive closure (CAC), analogous to EHIT occurring with thermal ablation techniques. Like EHIT, most EGIT have no associated significant symptoms and either regress or do not change [97-100].

In a review of 191 patients undergoing CAC, EGIT developed in 11 patients (5.8 percent) [97]. A grading scheme was suggested. EGIT grade I occurred in seven (63.6 percent) and grade II in four (36.4 percent) patients. Only a preoperative saphenous vein diameter of <5 mm increased the risk of EGIT.

Visual and other neurologic disturbances — Visual or neurologic disturbance is uncommon during or following liquid or foam sclerotherapy. In a systematic review, the incidence of visual disturbance following sclerotherapy ranged from 0.09 to 2 percent [101]. The disturbance is usually transient; permanent deficits are rare [2,3,64,102]. Symptoms include transient visual disturbance (ie, scotoma), migraine-like headache, and neurologic deficits. These appear to be more common with foam compared with liquid sclerotherapy and likely related to physician-compounded microfoam using room air [6,24,25,101,103,104]. (See 'Sclerotherapy' above.)

During foam sclerotherapy of the great saphenous vein, microbubbles can be detected in the right heart and pulmonary circulation in patients with a patent foramen ovale (PFO) and in the left heart as well [6,105]. Coughing following foam sclerotherapy has been attributed to air microembolization into the pulmonary circulation. In a prospective study of 33 patients, cardiac echo was performed during foam sclerotherapy, with cardiac microemboli detected in every patient studied. Microemboli were also seen in the left ventricle of five patients, and each was subsequently found to have a PFO; however, none of these patients experienced neurologic symptoms [6]. Given the significant prevalence (25 to 30 percent) of PFO in the general population, it is apparent that the incidence of significant neurologic sequelae following foam sclerotherapy is low. Nevertheless, caution needs to be exercised when performing foam sclerotherapy in any patient known to have a PFO. Patients who develop neurologic symptoms following foam sclerotherapy should be referred for further cardiac evaluation and are advised to avoid future sclerotherapy. (See "Patent foramen ovale" and "Atrial septal abnormalities (PFO, ASD, and ASA) and risk of cerebral emboli in adults".)

Because visual and neurologic disturbances have been reported with nonfoamed (ie, liquid) sclerosant solutions and have occurred in the absence of a PFO, an alternative theory proposes that visual and neurologic symptoms related to sclerotherapy are due to the release of endothelin, a potent vasoconstrictor. One group reported increased concentrations of endothelin in the blood following injection with various sclerosing agents, first in an animal model and then in humans [106,107].

Hypersensitivity and anaphylaxis — Cyanoacrylate adhesive remains within the vein permanently and constitutes a foreign body. There is a high cross-reactivity with adhesive allergies. One study noted an incidence of 6 percent of patients will have a type IV hypersensitivity reaction or intolerance of the glue [108,109]. Skin testing may be indicated for patients with a tape or adhesive allergy or prior adverse reactions to acrylic nail or faux eyelash applications to ensure safe use of cyanoacrylate. In clinical practice, when a reaction does occur, it typically requires a short course of steroids and is not insignificant. In very rare cases, excision of the previously treated vein was needed.

Anaphylaxis can occur with any of the sclerosing agents except hypertonic saline. A test dose of the sclerosing agent is recommended (table 1). (See "Anaphylaxis: Emergency treatment".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Chronic venous disorders".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topic (see "Patient education: Vein ablation (The Basics)")

SUMMARY AND RECOMMENDATIONS

●Nonthermal, nontumescent ablation – Nonthermal, nontumescent ablation refers to techniques that effect closure of the axial veins or perforator veins using sclerosing agents, glue, or mechanical methods, rather than thermal energy. These methods do not require the use of tumescent anesthetic infiltration.

•Sclerotherapy injects a sclerosing agent (table 1) formulated as a liquid or foam (physician compounded or proprietary) into the vein, which causes endothelial damage and induces thrombosis. For the treatment of larger veins (≥6 mm), foam is useful to displace the increased volume of blood. Ultrasound is used to guide administration. (See 'Sclerotherapy' above.)

•Mechanochemical ablation uses a wire to irritate the endothelium of the vein wall while simultaneously injecting a sclerosing agent. (See 'Mechanochemical ablation' above.)

•Cyanoacrylate adhesive closure (CAC) introduces glue into the vein to effect closure without the need for postprocedure compression. (See 'Cyanoacrylate adhesive closure' above.)

●Indications and contraindications – Nonthermal, nontumescent ablation techniques can be used to achieve axial vein closure (eg, great saphenous vein, small saphenous vein) or perforator vein closure for patients with documented reflux (ie, retrograde flow >0.5 seconds in a superficial vein or perforating vein) as a source of symptoms, or for venous ulceration. Nonthermal ablation should not be used in patients who have signs of acute venous thrombosis (superficial, deep) or during pregnancy. Specific hypersensitivities or risk for adverse reactions may preclude the use of any particular technique. (See 'Indications' above and 'Contraindications' above and 'Complications' above.)

●Saphenous ablation – When sclerotherapy is selected to treat the axial veins (eg, great, small, anterior saphenous veins (figure 1A-B)), we suggest using ultrasound-guided foam sclerotherapy, rather than liquid sclerotherapy (Grade 2B). Foam sclerotherapy has higher initial success rates compared with liquid sclerotherapy. While closure rates for sclerotherapy are generally lower overall compared with other ablation thermal or surgical ablation methods, the occurrence of symptoms does not necessarily correlate with vein recurrence or recanalization. (See 'Saphenous ablation' above.)

●Perforator ablation – Reflux in perforator veins following saphenous ablation is a known risk factor for vein recurrence and venous ulcer nonhealing or recurrence. The ideal technique for nonthermal perforator ablation has not been established. Repeated treatments are often required. (See 'Perforator ablation' above.)

●Postprocedure compression – Postprocedure compression is generally advocated following sclerotherapy but is not required following CAC. (See 'Postprocedure care and follow-up' above.)

●Complications – Complications associated with nonthermal ablation techniques include deep vein thrombosis (any method), endovenous glue-induced thrombosis (for CAC), hypersensitivity (CAC), anaphylaxis (sclerotherapy), and microembolic events predominantly with physician-compounded foam using room air for sclerotherapy. (See 'Complications' above.)