Spider Veins and Varicose Veins: Laser and Sclerotherapy Treatment — Procedure Guide, Recovery & Risks | MyMedicPlus

Spider veins (telangiectasias) and varicose veins are abnormally dilated superficial veins caused by venous insufficiency and reflux due to incompetent venous valves. Spider veins are small, flat, red-blue vessels 0.1–1 mm in diameter. Varicose veins are larger, raised, tortuous vessels over 3 mm diameter. Modern minimally invasive treatments include endovenous laser ablation (EVLA), radiofrequency ablation (RFA), ultrasound-guided foam sclerotherapy (UGFS), liquid sclerotherapy, and ambulatory phlebectomy — all performed as outpatient procedures. The choice depends on vessel size, extent of reflux, and underlying anatomical findings on duplex ultrasound.

Modern treatment has moved from surgical stripping (stripping the long saphenous vein through groin and knee incisions under general anaesthesia) to endovenous thermal ablation as the first-line procedure. Endovenous laser ablation (EVLA) and radiofrequency ablation (RFA/VNUS Closure) use thermal energy delivered inside the vein via a fibre or catheter to damage the vein wall and cause it to collapse and fibrose, eliminating reflux while avoiding external surgical wounds. Both procedures are performed under local tumescent anaesthesia as outpatient treatments, with patients walking immediately after and returning to work the next day. Sclerotherapy uses chemical sclerosants (polidocanol, sodium tetradecyl sulphate) injected directly into veins to cause endothelial damage and fibrosis, eliminating varicose and spider veins without surgery.

Treatment is indicated for symptomatic varicose veins causing aching, heaviness, leg swelling, night cramps, or skin changes (CEAP classification C2–C6), and for varicose veins complicated by bleeding, superficial thrombophlebitis, or venous ulceration. Spider veins causing cosmetic distress or discomfort are treated by sclerotherapy. Duplex ultrasound mapping of the great and small saphenous venous systems identifies the source of truncal reflux before treatment planning. Pregnancy, arterial insufficiency, deep vein thrombosis, and severe coagulation disorders are contraindications to elective treatment. NICE guidance TA2 recommends endovenous ablation as first-line treatment for truncal varicose veins over surgical stripping.

Treatment planning requires a formal duplex ultrasound venous mapping assessment performed by a vascular sonographer, identifying the specific pattern of reflux: great saphenous vein (GSV) reflux at the saphenofemoral junction (SFJ), small saphenous vein (SSV) reflux at the saphenopopliteal junction (SPJ), anterior accessory saphenous vein, or isolated tributary reflux. Treatment is directed at abolishing the source of reflux before treating tributary varicose veins or spider veins. NICE guidance (NG168, 2023) recommends endovenous thermal ablation as first-line treatment for truncal reflux, with foam sclerotherapy as second-line and surgery reserved for cases where neither is suitable.

For varicose veins, great or small saphenous vein reflux is first treated by EVLA or RFA under duplex ultrasound guidance. A laser or radiofrequency catheter is introduced through a small skin nick at the knee under local tumescent anaesthesia (diluted lidocaine infiltrated around the vein to protect surrounding tissue). The catheter is positioned from knee to groin and thermally ablates the vein wall as it is slowly withdrawn. Tributary varicose veins are then removed by ambulatory phlebectomy (micro-hook extraction through 2 mm incisions) or treated with foam sclerotherapy at the same or a subsequent session. Spider veins are treated by injecting liquid sclerosant (polidocanol 0.5–1% or sodium tetradecyl sulfate 0.2–0.5%) with a fine 30G needle. Compression stockings are applied immediately after treatment.

For endovenous laser ablation (EVLA): duplex-guided puncture of the GSV is performed below the knee; a sheath is advanced to within 2 cm of the saphenofemoral junction; tumescent local anaesthesia (dilute lignocaine with adrenaline, 200–400 mL) is injected peri-venously under ultrasound guidance to compress the vein around the fibre and provide anaesthetic protection to the surrounding tissues; the 1470 nm or 1940 nm laser is activated as the fibre is slowly withdrawn at 1 cm per second (typically 8–10 W continuous or 12–14 J/cm linear endovenous energy density — LEED). For radiofrequency ablation (RFA, VNUS Closure Fast, Medtronic), a 7 cm heating element is activated for 20-second cycles at 120°C as the catheter is withdrawn. Both technologies achieve GSV closure in 93–97% of cases at 5 years.

Endovenous laser ablation and RFA achieve great saphenous vein occlusion in 93–97% of cases at 5 years, with significantly lower recurrence rates than surgical stripping and without the risk of general anaesthesia or surgical scar. Spider vein clearance of 70–90% is achieved with 2–4 sclerotherapy sessions. Symptom relief — pain, heaviness, and leg swelling — improves in over 80% of symptomatic patients. Venous ulcer healing is accelerated by treating underlying reflux, with evidence from the EVRA trial showing faster ulcer healing when early endovenous treatment is performed alongside compression. All procedures are performed as outpatients, allowing immediate return to walking and daily activities.

NICE evidence review (NICE 2023) confirms EVLA and RFA achieve 93–97% great saphenous vein occlusion at 5 years, significantly superior to conventional surgical stripping (80–85% at 5 years). Patient-reported quality of life improvements (Aberdeen Varicose Vein Questionnaire) are clinically meaningful and sustained at 2-year follow-up in the CLASS randomised trial. The absence of a surgical incision and general anaesthesia reduces procedural risk, eliminates in-hospital stay, and allows immediate ambulation.

EVLA and RFA carry risks including bruising along the treated vein (universal, resolves in 2–4 weeks), skin numbness from saphenous nerve proximity (10–15%), thermal skin burns at access sites (less than 1%), and deep vein thrombosis (less than 1% when compression is worn). Sclerotherapy risks include hyperpigmentation at treated sites (15–20%, usually fading over 6–12 months), telangiectatic matting (15%), and skin ulceration from perivascular injection (under 1%). Foam sclerotherapy carries an additional small risk of transient visual disturbances and migraine-like headache from microemboli in patients with patent foramen ovale. All risks are significantly reduced by performing duplex-guided treatment at an accredited vascular centre.

Endovenous heat-induced thrombus (EHIT) — extension of thrombosis from the treated vein into the deep venous system — occurs in approximately 1% of EVLA and RFA procedures. Classification (EHIT class 1–4) guides management: Classes 1–2 are monitored with repeat duplex at 4 weeks; Class 3–4 (thrombus extending more than 50% into the deep vein) require anticoagulation. Nerve injury from heat is the most common complaint — the GSV runs in close proximity to the saphenous nerve below the knee; EVLA should not be performed below the knee in most protocols to avoid this.

Patients walk immediately after EVLA, RFA, or sclerotherapy and are encouraged to remain active. Compression stockings (class 2, 23–32 mmHg) are worn continuously for 1 week then during the day for a further 3 weeks. Strenuous exercise, hot baths, saunas, and prolonged sun exposure are avoided for 2 weeks. Treated areas appear bruised and mildly tender for 1–2 weeks, with cord-like fibrosis along sclerosed veins for 4–6 weeks before reabsorption. Follow-up duplex ultrasound at 4–6 weeks confirms vein closure and excludes DVT. Multiple sessions (2–4) may be required for spider veins and residual tributaries. Annual review is recommended as new varicosities develop with time.

A short walk of 30 minutes immediately after treatment is recommended to reduce EHIT risk. The treated vein is not palpable at 6 weeks as it has fibrosed and been absorbed. Follow-up duplex ultrasound at 6 weeks confirms successful GSV or SSV ablation and excludes EHIT before any sclerotherapy for residual varicose tributaries is performed. Multiple treatment sessions are typically needed: EVLA or RFA of the saphenous trunk in session 1, sclerotherapy of tributaries at 6 weeks, and sclerotherapy of spider veins at 10–12 weeks for a comprehensive result.