Varicose Vein Sclerotherapy

There are many ways to treat varicose veins including sclerotherapy (injections), endovenous laser, Clarivein, Venaseal (glue), surgery, and phlebectomy. This page covers sclerotherapy.

To view some photos of varicose vein treatments see the Ultrasound Guided Sclerotherapy page.

Questions and Answers


What are varicose veins?

See the Vein Basics page.

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What is sclerotherapy?

Sclerotherapy is a treatment for abnormal veins that involves the injection of various chemicals directly into veins. The injection injures the veins. The veins usually shrink or die. Your body breaks down dead veins.

Sclerotherapy is by far the most common treatment for abnormal veins.

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What is foam sclerotherapy?

One of the substances that can be injected is a synthetic soap. Being a soap, it can be whipped into foam prior to injection.

(Some people think that we are blocking off the vein by injecting stuff like the foam you use for insulation. This is not the case. We inject foam that looks a lot like shaving cream from an aerosol can. It doesn’t solidify. It turns back into liquid and washes away.)

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What are the advantages of foam over liquid sclerotherapy?

The most important difference is potency. Foam is about four times stronger than liquid. This increased potency comes from three factors: 

1) Liquid sclerosants are diluted by the blood as they are injected. Foam displaces blood so there is far less dilution.
2) Foam achieves much more complete surface contact. Every square millimeter of the lining of the vein is touched by the foam. Liquid can swirl around and miss parts of the vein.
3) Foam stays put for a while and has more time to do its damage. Liquid is washed away very quickly.
The next advantage of foam is that it is easy to see on ultrasound. While it is being injected, we can watch it with ultrasound to make sure that it is going where we want it to go and staying out of veins we don’t want it in.
The third advantage is that foam can cover large distances. Liquid sclerosants need to be injected every five centimeters or so along a vein. Through a single injection site, foam can be injected to fill a vein 30 centimeters and longer.


What kinds of veins can be treated?

Foam sclerotherapy is used to treat varicose veins. Small spider veins do not require foam; liquid is actually preferable for these little veins.

Any varicose vein can  be treated including veins that are to deep to see at the surface.

There is no upper limit in the size of the vein for the use of foam sclerotherapy. Even the largest of veins can be treated (although the success rate drops as veins get larger). Until about 2002, the only option for treating these large veins was surgery. Modern techniques (foam sclerotherapy and endovenous laser) make surgery unnecessary in almost all cases. 

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What are the alternatives to foam sclerotherapy?

Prior to the introduction of foam sclerotherapy, surgery (ligation and stripping) was the only option for the treatment of large veins like the greater saphenous vein.  
Laser surgery (endovenous laser ablation [EVLA]) became available about the same time as foam. This is a minor surgical procedure that is done in the doctor's office. Under local anesthetic a thin laser fiber is fed up the vein and a laser beam is applied to the inside of the vein to cause a heat injury. This technique has a very high success rate. Like foam sclerotherapy, EVLA makes surgery unnecessary in the vast majority of cases. But its use is limited to straight veins. Twisty varicose veins are not appropriate for EVLA, because the laser fiber won't get around corners. 
Phlebectomy is a minor surgical procedure that is useful for veins that are very close to the surface. It is done in the office under local anesthetic. We offer phlebectomy in combination with EVLA or Clarivein.
Surgery (ligation and stripping) was delisted by OHIP in 2012. OHIP only covers it for pateints with varicose ulcers or other complications. Surgery requires a general anesthetic, causes considerable pain and work loss, leaves scars, and has a recurrence rate of 20-40%. 
Venaseal is a technique in which cyanoacrylate glue is used to close large veins. We do not offer Venaseal.
Clarivein is a treatment which combines sclerotherapy with a spinning wire that scratches the inside of the vein. We offer Clarivein.

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What are the risks of foam sclerotherapy?

Bruising around the injection sites is normal following sclerotherapy. These bruises resolve within ten days. 

Inflammation around the injection site and along the course of the vein can occur, and it may be extremely tender. This is not very common (less than 5%). Ice, elevation, and ibuprofen may be used. It will resolve in 3 days to 3 weeks.
Scabs form on the inside of the injured veins following every treatment. These scabs may be felt as lumps under the skin. Your body will break them down slowly (weeks to months). As these scabs are broken down by the body, they release byproducts that are irritating and pigmented. These substances may cause mild tenderness and staining of the skin. Large vessels with large scabs in them will cause persistent tenderness and staining for a few months.

Allergic reactions can occur to the injected agents. The risk is so small that no one can put a number to it. Severe allergic reactions carry a risk of one in millions.

Extremely rarely, blood clots can form in the deep vessels of the legs. These clots may break loose and travel to the lungs. This can be fatal (about 1/10,000). Let's put that into perspective. Your annual risk of dying in a car crash is about 1 in 6,500. Your risk of dying in an accident in your own home is 1 in 7,000 per year.

At York Vein Clinic we evaluate your risk for blood clots before you are treated. If you have other factors (age, obesity, previous clots, etc) that add significantly to your blood clot risk, you will be given blood thinners during your treatments. This substantially reduces your clotting risk . 

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How many treatments will be required?

There is no simple answer to this. It depends on the extent of the vein problem.

Most people need one to three treatments for each leg that is involved.

Very large veins might require a second treatment several months later. We follow you with ultrasound examinations to see if this becomes necessary.



At what intervals are treatments provided?

Treatments are usually spaced at weekly intervals.

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What should I do to prepare for treatment?

Do not shave your legs the day of treatment. Tiny nicks will sting when we use antiseptic.

Do not apply lotion or cream to your legs. We put pressure bandages over the treated veins, and the tape will not stick.
Bring a pair of loose shorts to allow us access to your veins and give you some dignity. Bring long pants or a long skirt to wear afterwards to cover the bandages.
Bring your support hose to wear after treatment. In most cases, we will measure you for support hose, and it will be here for you at your first treatment visit. You are under no obligation to purchase support hose from us, but we save you the trouble of going out and getting it.
Eat well before you come to avoid hypoglycemia and fainting.
Drink lots of fluids before your treatment to fill up your veins and to prevent fainting. 
Avoid exercise (even walking) prior to treatment. This may drain your veins and make injections more difficult. It is preferable to stand for a prolonged time to fill your veins.

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What should I expect following treatment?

A compression bandage will be applied that needs to stay in place for 4 hours. It should be kept dry. 

You will wear your support hose overnight on the first night.

You will be required to wear support hose during the daytime for two weeks. 

The injected vein will be a bit sore for a few days. Advil or Tylenol are adequate to help with this. The veins will be tender to touch for a few weeks.


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How painful is it?

Except for the insertion of the needle, this is usually a painless procedure. Occasionally you will feel some discomfort when the vein goes into spasm almost immediately following the injection. This can be quite intense, but it only lasts a few minutes. Vein spasm always happens, but most of the time you don't feel it.

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Do I really need to wear support hose?

When large veins are treated, support hose is required. It is an important part of the treatment. Use of support hose decreases the rate of complications (lumps and blood clots).

When spider veins are treated, support hose is not required, but it is strongly recommended to help reduce bruising and pigmentation.

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What is your cancellation policy?

We appreciate two business days notice for cancellation of your consultation or treatment. If sufficient notice is not received, you may be billed a minimum of $100 up to a maximum of the value of the service that was to be provided.  

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