Sclerotherapy closes an unwanted vein by injecting a medicine into it rather than removing it. It is the oldest of the modern vein treatments and still the most versatile: the same principle handles a fine spider vein on the ankle and a recurrent branch vein that an earlier operation left behind. What changes between those two jobs is the concentration, the form of the agent and whether ultrasound is used to guide the needle.
In short: a sclerosant is injected so the vein wall reacts, sticks together and is absorbed. Liquid suits fine surface vessels; foam suits larger or deeper veins because it displaces blood and stays in contact with the wall. Treatment is planned after a Doppler ultrasound, because closing branches while a refluxing trunk vein is left open invites recurrence. Several sessions are usual and fading takes weeks.
What sclerotherapy actually does
The injected agent irritates the inner lining of the vein. The wall reacts, the vessel goes into spasm and its walls come into contact; over the following weeks the vein is converted into a thin fibrous cord and absorbed by the body. Nothing is left behind and no incision is made. Because the veins treated this way are superficial ones carrying only a small share of the return flow, closing them does not deprive the leg of circulation — blood simply redirects into healthy deep veins.
This also explains the timing people find surprising: the vein is closed within minutes, but it looks closed only after the body has cleared it, which takes weeks and sometimes a few months.
Liquid, foam, or ultrasound-guided?
Liquid sclerotherapy
A small volume of liquid agent is injected directly into vessels you can see. It is the standard approach for telangiectasias and the fine reticular veins that feed them, where precision matters more than volume.
Foam sclerotherapy
The same agent is mixed with a sterile gas to make a fine foam immediately before use. Foam behaves quite differently from liquid: it displaces the blood inside the vein instead of mixing with it and being diluted. The result is more contact between the drug and the vein wall, for longer, using less active agent — which is why foam is preferred for larger or longer segments.
Ultrasound-guided foam (UGFS)
When the problem vein cannot be seen — a deeper tributary, a recurrent vein beneath scar tissue, a perforating vein — the needle is placed under live ultrasound and the foam is watched as it fills the segment. This is what allows sclerotherapy to deal with veins that would otherwise need an operation, and it is also the safer way to do it, because the spread of the foam is seen rather than assumed.
| Form | How it is given | Typically used for | Practical note |
|---|---|---|---|
| Liquid | Direct injection into visible vessels | Spider veins and fine reticular veins | Highest precision; many small injections per session |
| Foam | Agent foamed with gas just before injection | Larger surface veins, branches, residual veins | Displaces blood, so more drug contact with less agent |
| Ultrasound-guided foam | Needle and foam tracked live on ultrasound | Veins that cannot be seen or felt; recurrent veins | Avoids an operation in selected cases; spread is monitored |
Why the ultrasound comes first
Varicose and spider veins are usually the visible end of a pressure problem higher up. If a valve in a main trunk vein is leaking, blood falls back down the leg and that pressure keeps loading the surface veins. Inject the surface and nothing else, and the veins reappear — not because the injection failed, but because the cause was never treated.
A colour Doppler scan shows whether reflux is present and in which vein. Where it is, the sequence changes: the trunk vein is closed first with laser, radiofrequency or glue, and sclerotherapy is then used to finish the tributaries and any residual veins. That order is the difference between a result that holds and one that does not. The underlying condition is chronic venous insufficiency, and it is managed over years rather than in one appointment.
The session, step by step
- The leg is examined standing so the veins are filled; the pattern is mapped and often marked on the skin.
- You lie down and the skin is cleaned. For UGFS, the probe is positioned and the target segment located.
- A fine needle is placed in the vein and the agent — liquid or freshly made foam — is injected in small amounts along the vessel.
- The treated segment is pressed and the leg is sometimes elevated briefly to help empty it.
- Compression is applied before you stand up, and you walk for a period before leaving.
A session usually runs between twenty and forty-five minutes depending on how much ground is being covered. No general anaesthetic is used and you leave on foot.
Compression and aftercare
- Compression stockings are worn for a period decided at the time; this influences comfort, bruising and the final appearance more than most people expect.
- Walking every day is part of the treatment — it keeps the deep veins flowing and reduces clot risk.
- Avoid for the first days: very hot baths, saunas, sunbeds, intense leg training and long periods standing still.
- Sun protection on treated skin matters while it settles, because fresh treatment sites pigment more readily.
- Flights and long journeys are normally deferred briefly and then taken with compression, hydration and regular walking.
What is normal afterwards — and what is not
| What you may notice | Is it expected? | What is usually done |
|---|---|---|
| Raised, red, itchy lines over treated veins for a few days | Expected | Settles on its own; antihistamine occasionally helps |
| Bruising at injection points | Expected | Fades over one to two weeks |
| Brown staining along the treated vein | Common | Usually fades over months; sun protection helps |
| A crop of fine new red vessels nearby (matting) | Occasional | Often settles; may be treated at a later session |
| A firm tender lump of trapped blood in a treated vein | Occasional | Released with a needle at review, which speeds fading |
| Brief visual disturbance or migraine-like aura after foam | Uncommon | Settles within minutes; report it, as it changes future planning |
| Calf pain with swelling and warmth, breathlessness, chest pain | Not expected | Urgent assessment — see the warning below |
Seek urgent medical care if you develop calf pain with swelling and warmth, sudden breathlessness or chest pain after treatment — these can indicate a clot in the deep veins or lungs. Get prompt review for spreading redness with fever, for skin that blisters or breaks down at an injection site, or for any difficulty breathing or widespread rash shortly after an injection. Tell your doctor beforehand if you have had migraine with aura or a known hole between the heart chambers, as this affects whether foam is the right choice for you.
Sessions, timing and what the result looks like
- More than one session is normal; the number tracks the extent of the area, not the success of the first treatment.
- Sessions are spaced several weeks apart so the previous one can be judged before the next is planned.
- Veins fade gradually; the area frequently looks worse for the first week or two before it improves.
- Substantial improvement is a realistic aim; clearing every last vessel is not something that can be promised in advance.
- New veins can appear over the years because the underlying tendency remains — treatable, and not a failure of what was done before.
Where sclerotherapy sits among the other options
Sclerotherapy is rarely a competitor to the catheter-based treatments; it is their partner. Trunk veins with reflux are closed with endovenous laser, radiofrequency or adhesive, and sclerotherapy then clears the tributaries, residual segments and cosmetic vessels that those catheters cannot reach. For an overview of how the closed techniques compare, see non-surgical varicose vein treatment, and for the condition as a whole, varicose veins treatment.
Why Choose Turkey (Istanbul)?
- Over 30 years of experience in cardiovascular and vascular surgery with Prof. Dr. Yusuf Kalko.
- Modern minimally invasive and hybrid techniques.
- English- and Arabic-speaking support for international patients.
- Easy access to Istanbul from the Gulf, Europe and beyond.
- Remote assessment before travel, then treatment and appointment planning.
How to Start From Abroad (Remote Consultation)
You can send your medical reports and scan images via WhatsApp for an initial assessment before traveling. We then plan your treatment and appointment in Istanbul, Turkey, and support international patients at every step.
To assess your veins and plan treatment in Istanbul (Beylikdüzü) and plan suitable treatment, contact us on WhatsApp.
Related Pages
Foam is usually used for branches and recurrences after the source has been closed — by heat or by adhesive.
Frequently Asked Questions
How many sessions will I need?
Usually more than one, spaced several weeks apart. The number depends on how extensive the veins are and their calibre, not on how well the first session worked — each is assessed once the previous one has had time to fade.
Is sclerotherapy painful?
Discomfort is usually minor: a brief stinging or hot cramping sensation as each injection goes in, lasting seconds. No anaesthetic is normally needed, and the legs may ache mildly for a day or two afterwards.
Is sclerotherapy safe?
It has been used for decades and serious complications are uncommon, but it is a medical procedure rather than a cosmetic service. The important safeguards are an ultrasound beforehand, an accurate record of your medical history and medicines, correct compression afterwards and knowing which symptoms to report.
What is the difference between foam and liquid?
Liquid is injected directly into vessels you can see and is used for fine spider and reticular veins. Foam is made by mixing the agent with gas immediately before use; it pushes blood out of the vein so the drug stays in contact with the wall, which makes it suitable for larger or deeper segments.
Why has the treated area turned brown?
That is hyperpigmentation — iron pigment released as the vein is reabsorbed. It is common rather than a complication and usually fades over a period of months. Keeping the area out of the sun while it settles makes a visible difference.
Do I have to wear compression stockings afterwards?
Compression is a standard part of the treatment and affects both comfort and the final appearance; the duration is set individually. If you have reduced arterial circulation in the legs this is checked first, because compression is not suitable for everyone.
When can I fly after sclerotherapy?
Flights are normally postponed for a short period after treatment, then taken with compression stockings, good hydration and regular walking during the flight. Confirm the interval before booking, as it depends on how much was treated.
Do you treat international patients?
Yes. International and Gulf patients are seen in Istanbul with English- and Arabic-speaking support, and an initial remote assessment can be made from your reports and scan images before you travel.