Thermal ablation of varicose veins: procedure and recovery

What is thermal ablation of varicose veins?

Endovenous thermal ablation is a procedure that uses heat to close a superficial vein that is not functioning properly. It is mainly used when the problem affects one of the saphenous veins, which run along the surface of the legs and connect to other smaller venous branches.

Veins contain small valves that help blood flow towards the heart. When these valves no longer close properly, some of the blood flows backwards due to the force of gravity. This phenomenon is known as venous reflux.

The sustained increase in pressure can cause the veins to dilate and become tortuous. It can also cause heaviness, pain, itching, cramps, swelling or a feeling of tiredness. As venous insufficiency progresses, changes in the colour and texture of the skin, persistent inflammation or ulcers may develop.

During ablation, the specialist inserts a catheter into the affected vein and applies thermal energy. The heat causes the vein wall to contract, sealing the vein shut.

Blood is no longer retained in the leg. It is redistributed to other veins that remain functional and to the deep venous system, which carries most of the blood from the lower limbs.

Current guidelines consider endovenous ablation to be the preferred option for many people with symptomatic varicose veins and reflux in a major superficial vein, provided that the anatomy and clinical circumstances allow the procedure to be carried out.

Laser and radiofrequency: two methods of the same treatment

Thermal ablation can be performed using endovenous laser or radiofrequency. Both techniques use heat to seal the vein, although they generate it in different ways.

In laser treatment, a fibre transmits light energy which is converted into heat. In radiofrequency treatment, a catheter heats the vein wall gradually and in a controlled manner.

For the patient undergoing treatment, the process is very similar. In both cases, the device is inserted through a small puncture, its position is checked using ultrasound, and local anaesthetic is administered around the vein before the energy is applied.

It cannot be said that one method is always better than the other. The course of the vein, its proximity to the skin or certain nerves, the technology available and the team’s experience also influence the choice.

In which cases might it be recommended?

Thermal ablation may be considered when an insufficient superficial vein causes symptoms or contributes to a significant venous condition. Patients often seek advice for heaviness, pain, itching, cramps or swelling that worsen after spending many hours on their feet. There may also be a feeling of pressure or tiredness at the end of the day.

In other cases, the reason for assessment is persistent changes in the skin, repeated episodes of inflammation in a superficial vein, bleeding from a varicose vein, or an ulcer related to venous insufficiency.

The presence of visible veins is not sufficient grounds to recommend ablation. Some conspicuous varicose veins originate from small branches that can be treated using other techniques. Conversely, there may be significant reflux in a saphenous vein even if the external varicose veins do not appear particularly large.

Guidelines recommend a vascular assessment when varicose veins cause symptoms, skin changes, superficial venous thrombosis, ulcers or bleeding. In the event of bleeding, the assessment should be carried out as a matter of urgency.

How do you know if it is the right treatment?

The key test is venous Doppler ultrasound, which allows the veins to be visualised and the direction of blood flow to be assessed.

In medical terminology, it may also be referred to as a duplex ultrasound or Doppler ultrasound. The term ‘duplex’ indicates that the test combines imaging of the veins with an analysis of blood flow. In this factsheet, the term ‘venous Doppler ultrasound’ is mainly used, as it is the most recognisable term for someone without a healthcare background in Spain. Spanish medical literature commonly uses the term ‘Doppler ultrasound’.

Ultrasound allows us to check whether the valves are functioning, to locate the point where reflux begins and to trace its path down the leg. It also shows the diameter and depth of the vein and its relationship to the skin, nerves and other structures.

If the course of the vein is very tortuous, the vein lies too close to the surface or there are other anatomical features, it may be preferable to use a different technique.

The specialist also takes into account the severity of symptoms, a history of thrombosis, mobility, associated medical conditions and any medication that may affect the risk of bleeding or clotting.

Therefore, being a candidate for ablation is not simply a matter of ticking off a set list of criteria. It means that, after assessing the cause of the varicose veins and the patient’s personal circumstances, it is considered that the expected benefit may outweigh the risks and that the technique is appropriate for the problem identified.

Guidelines recommend using ultrasound to confirm the diagnosis, identify reflux and plan treatment.

Should you wear compression stockings first?

Compression stockings can relieve heaviness and swelling, but they do not repair the valves or eliminate reflux in an insufficient vein.

They remain important when a procedure is not indicated, is not desired or must be postponed. They also form part of the treatment for some people with advanced venous disease or ulcers.

However, where reflux has been confirmed, the patient wishes to be treated and the procedure is clinically indicated, it is not always necessary to continue compression therapy for months before considering ablation. US guidelines advise against routinely imposing a preliminary period of compression on all candidates.

Preparation before the procedure

Preparation is usually straightforward, but must be tailored to each individual.

Before the procedure, the patient’s medical history, history of thrombosis or bleeding, allergies and usual medication are reviewed. Anticoagulants, antiplatelet agents and other medicines must not be stopped without medical advice. In some cases, they may be continued; in others, it will be necessary to temporarily adjust the dosage under medical supervision.

When the procedure is carried out under local anaesthesia only, it may not be necessary to arrive on an empty stomach. The instructions change if sedation is planned or if the ablation is combined with other procedures.

The team will advise whether you should wear a compression stocking, what clothing is most comfortable and whether you need to be accompanied. They will also explain when you can drive and what activity is recommended during the first few hours.

How is thermal ablation performed?

Ablation is usually carried out on an outpatient basis, in a room equipped for vascular procedures and under continuous ultrasound guidance.

1. Localisation and access to the vein

Before beginning, the specialist will examine the course of the vein once more. They will then disinfect the skin and make a small puncture.

Through this entry point, they insert a guide wire and, subsequently, the laser or radiofrequency catheter. Ultrasound allows them to check that the device is advancing through the vein and that its tip is positioned at the intended site.

2. Anaesthesia around the vein

Once the catheter is in place, a local anaesthetic solution is injected around the vein. This technique is known medically as tumescent anaesthesia.

As well as reducing discomfort, the solution compresses the vein around the device and creates a protective layer between the heat source and the skin or nearby nerves.

3. Application of energy

Once the catheter is correctly positioned and the area has been anaesthetised, the laser or radiofrequency is activated. The catheter is gradually withdrawn whilst the heat acts on the vein wall, causing it to close.

You may feel pressure, tightness or some brief discomfort, but you should not experience severe pain. If you do, you should let the team know so that they can check the position or apply more anaesthetic.

Once the procedure is complete, the catheter is removed and the entry point is covered. As access is gained via a small puncture, stitches are not usually required.

The patient can usually get up and walk around shortly afterwards.

Do you need to be admitted to hospital or have a general anaesthetic?

Thermal ablation is usually carried out under local anaesthesia and does not require hospital admission. In some centres, light sedation may be used, particularly if several segments are to be treated or if the ablation is combined with other procedures. General anaesthesia is not usually necessary when only endovenous ablation is performed.

The duration depends on the number of veins treated, the length of the insufficient segment, the patient’s anatomy, and whether other treatments are carried out during the same session.

Is it painful?

Most people tolerate the procedure well. The most uncomfortable part is usually the administration of the anaesthetic around the vein, which requires several small punctures.

During the application of the laser or radiofrequency, you may feel pressure or tightness. Afterwards, you may experience tenderness, a sensation of a cord under the skin, or discomfort similar to muscle soreness.

These sensations usually subside gradually. Severe pain, progressive worsening or disproportionate swelling require medical assessment.

What happens to varicose veins that remain visible?

Closing the vein causing the reflux can reduce the pressure on the varicose branches connected to it. Some of these diminish over the following weeks, but others remain visible.

These branches can be treated using sclerotherapy, which involves injecting a substance to seal off the vessel, or by microphlebectomy, which allows specific varicose segments to be removed via very small incisions.

In some people, these treatments are carried out during the same session. In others, the doctor waits to see how the leg progresses after the main vein has been closed off.

Clinical guidelines allow for both simultaneous and deferred treatment of these branches, depending on their size, distribution, symptoms and the plan agreed with the patient.

What results can be expected?

The primary aim is to ensure that the insufficient vein is properly closed off. When the patient is suitably selected and the procedure is carried out correctly, both laser and radiofrequency treatments generally yield favourable anatomical results.

Improvement in symptoms depends on whether they are related to the reflux being treated. Heaviness, pain, pressure or some of the swelling may decrease, but not all leg discomfort has a venous cause. Muscular, joint, neurological or lymphatic problems may also be present. Therefore, a successfully closed vein does not guarantee that all symptoms will disappear.

Improvement is usually gradual. Some people notice changes within the first few weeks. Varicose branches, swelling or skin changes may take longer to improve.

Where venous ulcers are present, ablation may form part of a broader treatment programme that includes compression, dressings and specialist follow-up.

Risks and possible complications

Thermal ablation is less invasive than open surgery, but it is not without risks.

During the first few days, you may experience small bruises, tightness, tenderness or a hardened area along the vein. These symptoms are usually temporary.

A superficial vein may also become inflamed. The area may feel hard, warm, red or painful. Although this is often a localised reaction, it should be assessed if the pain increases or the redness spreads.

Where the vein runs close to a sensory nerve, tingling or numbness may occur. This is usually temporary, but in some cases it may persist.

Skin burns are rare. Ultrasound guidance and anaesthesia applied around the vein help to protect the tissues from the heat.

Another possible complication is that the clot may spread from the treated vein into a deep vein. Deep vein thrombosis may also occur and, much less commonly, a pulmonary embolism.

The risk is not the same for everyone. A history of thrombosis, mobility, the extent of the treatment and other medical conditions can affect it. This is why a pre-treatment assessment is carried out and follow-up is tailored to each individual’s situation.

What is the recovery like?

Most people are able to walk shortly after the procedure. Early mobilisation helps the blood to circulate and is usually preferable to remaining at rest for many hours.

1. During the first few days

It is common to experience tightness, tenderness or small areas of stiffness. You can alternate gentle activity with periods of rest, whilst avoiding remaining immobile for too long.

It is not usually necessary to stay in bed. Walking regularly, within the limits advised by the medical team, is part of the standard recovery process.

2. Returning to work

Returning to work depends on the type of job and any discomfort you may be experiencing.

Someone with a sedentary job may be able to resume their routine sooner than someone who has to spend many hours on their feet, lift heavy loads or engage in physical exertion. For this reason, it is not appropriate to promise that everyone will be able to return to work within 24 or 48 hours.

3. Exercise and daily life

Walking is usually recommended from the outset. Intense exercise, heavy lifting, saunas, prolonged baths or certain sporting activities may need to be restricted temporarily.

Driving may be resumed once you are able to move your leg normally, perform an emergency stop without pain, and are not taking any medication that impairs your reaction time.

If sedation has been administered, you must not drive on the same day.

4. Compression stockings

Compression stockings may help to reduce some initial discomfort, but there is no one-size-fits-all duration of use for all patients.

The duration of use depends on the area treated, whether other procedures have been carried out, any pre-existing oedema and the unit’s protocol. The instructions provided must be followed.

Follow-up and duration of results

A follow-up appointment allows the puncture site to be checked, any discomfort to be assessed, and the progress of the varicose veins and symptoms to be monitored.

In some patients, a Doppler ultrasound scan is carried out to confirm that the vein remains closed and to check for any thrombotic complications. The need for this test and the timing of it may vary depending on individual risk and the patient’s progress.

During the follow-up, a decision is also made as to whether any varicose branches remain that might benefit from sclerotherapy or microphlebectomy.

Although the closure may be maintained for years, venous disease can progress. The appearance of new varicose veins does not necessarily mean that the initial treatment was carried out incorrectly; it may be due to the deterioration of other veins or the opening of new pathways for blood flow.

Differences between thermal ablation and sclerotherapy

Thermal ablation uses heat to close the vein. Sclerotherapy involves injecting a liquid or foam substance that causes a controlled reaction in the vessel wall.

Sclerotherapy is particularly useful for treating varicose branches, residual veins, certain cases of recurrence and smaller-calibre vessels. It can also be used on a saphenous vein when thermal ablation is not suitable.

For many people with confirmed reflux in a main superficial vein, NICE recommends offering thermal ablation first where possible. If this is not suitable, ultrasound-guided foam sclerotherapy is considered, followed by surgery.

This does not mean that one technique is better in all circumstances. Each responds to different venous patterns and, at times, they are used in a complementary manner.

Other alternatives

Where thermal ablation is not indicated, non-thermal techniques, sclerotherapy, microphlebectomy or conventional surgery may be considered.

Some procedures close off the vein using a medical adhesive or a combination of mechanical and chemical action. As they do not use heat, they can avoid the need for anaesthesia around the vein, although they have their own indications, limitations and risks.

Surgery remains an option when the course of the vein prevents the insertion of a catheter or when no suitable endovenous technique is available.

The choice should not be viewed as a competition between technologies. The aim is to select the treatment that best addresses the cause of the reflux, the anatomy and the clinical needs of each individual.

Situations requiring special consideration

During pregnancy, varicose vein procedures are usually postponed except in exceptional circumstances. Conservative measures are typically used, and venous circulation is reassessed after childbirth.

Patients taking anticoagulants or antiplatelet agents require individualised planning. These medicines must not be discontinued without medical supervision.

A history of thrombosis does not automatically rule out ablation either. However, it requires careful assessment of the deep venous system and the risk of further complications.

Where venous ulcers are present, ablation can be incorporated into a treatment plan that includes compression, specialist wound care and clinical follow-up.

When to seek advice after treatment

Minor bruising, tightness and moderate tenderness may be part of the recovery process. These symptoms should gradually subside.

You should contact the medical team if the pain increases rather than improves, the redness spreads, you develop a fever, your leg swells more than expected, or there is discharge from the puncture site.

Seek urgent medical attention if you experience:

• Sudden difficulty breathing.

• Chest pain.

• Coughing up blood.

• Sudden and severe swelling of one leg.

• Severe pain in the calf accompanied by swelling.

• Fainting or severe dizziness.

• Bleeding that does not stop when direct pressure is applied.

Which specialists are involved

The assessment is usually led by a specialist in angiology and vascular surgery or by a professional with specific training in venous disease and endovenous procedures.

A Doppler ultrasound may be carried out by the specialist themselves or by a vascular diagnostic unit. It should not be viewed as a stand-alone test, but rather as an essential part of the assessment and treatment planning. Vascular nursing staff are involved in preparation, aftercare, compression therapy and health education.

In people with ulcers or advanced venous disease, wound care units, dermatology departments or other specialists may also be involved.

Frequently Asked Questions

Is the treated vein necessary for blood to circulate?

When a vein has significant reflux, it is no longer contributing effectively to venous return. When it is closed off, the blood is redistributed through other veins that are functioning correctly. Before treatment, the deep venous system is checked to ensure it is patent.

Can more than one vein be treated in the same session?

In some cases, yes. The decision depends on the extent of the disease, its expected duration, the anatomy involved and the individual’s risk.

Does it leave scars?

Ablation is carried out via a small puncture. If microphlebectomies are also performed, small incisions may be made, which usually leave only faint marks.

Is laser treatment or radiofrequency better?

Both techniques can achieve an effective seal. The choice depends on the patient’s anatomy, the device and the team’s experience, not just the name of the technology.

When can you go back to work?

It depends on the type of work, the area treated and the level of discomfort. Many people resume light activity quite soon, but there is no set timeframe that applies to everyone.

Can varicose veins come back?

The treated vein may remain closed, but new varicose veins may appear in other segments or the vein may partially reopen. Venous disease may progress over time.