Procedure
Vein treatment
Two different diseases get called vein trouble: veins that leak, and veins that block. They are treated in almost opposite ways, so the first job is knowing which one you have.
The Distinction
Leaking and blocked are not the same problem
Both are common, both cause a swollen aching leg, and they are routinely confused. What separates them is how they start.
Veins that leak — reflux
Veins in the leg carry blood upward against gravity, and one-way valves inside them stop it falling back. When those valves fail, blood pools instead of returning, and the pressure shows as aching, heaviness, swelling by the end of the day, visible varicose veins, skin changes at the ankle, and in advanced disease an ulcer that will not heal. This is chronic venous insufficiency, and it develops over years.
Veins that block — clot
A deep vein thrombosis is a clot inside one of the deep veins of the leg or pelvis. It presents suddenly rather than gradually: swelling, pain, and tightness over hours to days. It is treated urgently, primarily with anticoagulation, and it is an entirely different problem from a leaking valve even though both are called vein disease.
Venous Insufficiency
Treating a vein that leaks
The failing vein is closed and the leg reroutes around it. This is the great majority of vein work.
Venous ablation — closing the failed vein
A thin catheter is passed into the failing vein under ultrasound guidance and heat is applied along its length, sealing it closed. Blood immediately reroutes through healthy veins, of which the leg has many. Current guidelines from the Society for Vascular Surgery, the American Venous Forum, and the American Vein and Lymphatic Society make thermal ablation the first-line treatment for axial vein reflux, reserving surgical stripping for cases where an endovenous approach is not feasible.
Sclerotherapy — the smaller vessels
Smaller varicose veins and surface veins are treated by injecting a solution that irritates the lining so the vein collapses and is gradually absorbed. It is often used alongside ablation rather than instead of it: ablation deals with the failing trunk, sclerotherapy with the tributaries and cosmetic branches fed by it.
What comes first, either way
Neither treatment is the first step. Compression, elevation, and exercise are, and a duplex ultrasound comes before any decision — it maps which veins are refluxing and how badly, which is what determines whether a procedure will help at all. Treating a visible vein without knowing what feeds it is how varicose veins come back.
≈95%
Vein closure rate after thermal ablation
18.7%
Five-year recurrence after radiofrequency ablation — 34.6% after surgical stripping
First-line
Thermal ablation for axial reflux in the 2023 SVS, AVF, and AVLS guidelines
Figures are from published systematic review and guideline data, not from this center.
Deep Vein Thrombosis
Treating a vein that blocks
Most deep vein thrombosis is treated with blood thinners and nothing else. Removing a clot is for a narrow group, and the evidence for it is narrower than it is often described as being.
- 01
Anticoagulation is the treatment for most DVT
Blood thinners stop a clot extending and let the body break it down. For most deep vein thrombosis that is the whole treatment, and no procedure is needed or helpful.
- 02
Why anyone considers removing it
Roughly half of patients with a proximal DVT develop post-thrombotic syndrome within two years despite anticoagulation — persistent swelling, aching, skin change, sometimes ulceration, caused by the damage the clot leaves in the vein and its valves. Removing a large clot early is an attempt to prevent that damage rather than to treat the clot itself.
- 03
What the trials actually showed
ATTRACT, the randomised trial of pharmacomechanical clot removal, did not reduce how often post-thrombotic syndrome occurred. It did reduce how severe it was, and the benefit was clearest in patients whose clot involved the iliac and femoral veins. That is a narrower result than the procedure is sometimes described as having, and it is why selection matters so much.
- 04
So who is it for
Broadly: a large clot in the iliac or femoral vein, symptoms that began recently rather than weeks ago, one limb affected, a substantial symptom burden, and no reason the patient cannot tolerate the procedure. Outside that profile, anticoagulation and compression remain the better course.
A new, painful, swollen leg needs assessing the same day, not at a scheduled appointment. Contact your physician or go to an emergency department — a deep vein thrombosis can send clot to the lungs, and that is an emergency.
The Visit
What the day looks like
Ablation and sclerotherapy are done under local anaesthetic, and you walk out afterwards. Walking is part of the treatment.
- 1
Mapping first
A duplex ultrasound of the leg identifies which veins are refluxing, over what length, and how severely. Nothing is scheduled before that scan, because it is what decides whether a procedure is indicated and which vein to treat.
- 2
Before you come in
Eat normally unless told otherwise — ablation and sclerotherapy are usually done under local anaesthetic rather than sedation. Wear or bring loose clothing, and expect to be asked to walk immediately afterwards.
- 3
The procedure
The leg is cleaned and numbed, and the catheter is placed into the vein through a needle puncture under ultrasound guidance. Local anaesthetic is infiltrated along the vein, both for comfort and to protect surrounding tissue, and the vein is then sealed. Most treatments take under an hour.
- 4
Afterwards
You walk out. Compression stockings are worn for a defined period, walking is encouraged from the same day, and strenuous exercise and long flights are restricted briefly. Bruising and tightness along the treated vein are expected for a couple of weeks.
- 5
Follow-up
A repeat ultrasound confirms the vein has closed and checks that no clot has extended into the deep system. Tributaries that remain symptomatic are treated afterwards with sclerotherapy, which is why treatment is sometimes staged rather than done all at once.
Arterial disease in the leg causes a different symptom — cramping brought on by walking and relieved by rest, rather than aching that builds through the day. If that is the pattern, see coronary and peripheral intervention instead.
Risks
What can go wrong, and how likely it is
Vein treatment is well tolerated. The first entry is the one that matters most, and the last is the one patients are most surprised by.
Clot extending into the deep veins
The most serious complication of treating a superficial vein is clot propagating into the deep system, which then needs anticoagulation. It is uncommon, and it is what the follow-up ultrasound is looking for.
Nerve irritation
Sensory nerves run alongside the veins being treated, particularly below the knee. Numbness or tingling over a patch of skin can follow and usually settles over weeks to months, occasionally longer.
Bruising, tightness, and skin discolouration
Expected rather than exceptional. A treated vein becomes a firm, tender cord for a few weeks. Sclerotherapy can leave brown staining along the treated vein that fades over months, and occasionally does not fully.
Skin injury or ulceration at an injection site
Uncommon with sclerotherapy, and more likely if the solution escapes the vein. It is a reason the injections are done under direct vision or ultrasound rather than blind.
Recurrence
Vein disease is a tendency rather than an event. Published five-year recurrence after radiofrequency ablation is around 19%, and higher after some alternatives. Compression and activity after treatment genuinely affect that, which is why they are not optional advice.
Bleeding, and the risks of clot removal
Where a clot is being removed rather than a vein closed, the risks are those of a larger procedure — bleeding, vessel injury, and the risks of any clot-dissolving drug used alongside it. These are discussed specifically, and they are part of why the selection criteria above are narrow.
Sources
Questions about your procedure?
Our team will confirm your date, walk you through preparation, and answer questions about insurance, sedation, and recovery.