What are Side Effects and Complications of Sclerotherapy?

side effects complications

What are Side Effects and Complications of Sclerotherapy?

Medically Reviewed by Mohsen Talani, MD on November 27, 2023 | Written by CBAM Author

side effects complications

There are different ways to treat varicose veins, but treating varicose veins by sclerotherapy is one of the least dangerous and easiest ways to treat this disease, and specifically spider varicose veins. Sclerotherapy is a treatment method in which the doctor injects medicine into blood vessels or lymphatic vessels, and by doing so, causes the unwanted vessels to shrink. This method is usually used to treat varicose veins or spider veins. Sclerotherapy is not an invasive surgery and only requires several injections. This therapeutic procedure can be used to treat disorders of blood and lymphatic vessels that cause improper formation of vessels.

The most common sclerotherapy complications are: bruising, redness and pain in the injection area. In about a third of people, a number of small branches of blood vessels develop around the vein where the injection was made. These veins usually disappear by themselves.

Sclerotherapy complications

Sclerotherapy is a safe treatment method. This treatment is less invasive than high-risk surgical options because it does not require anesthesia. Research has shown that this treatment eliminates spider veins 75 to 90 percent of the time, but it usually takes a few treatments. If sclerotherapy does not destroy the veins, other treatments such as surgery should be used.

Some of the complications of Sclerotherapy that worth mentioning are:

Darkness of the skin at the sclerotherapy site

After sclerotherapy, a dark area may appear at the injection site, which is actually a kind of body reaction to the injected substance. Darkness of the skin is seen in 9-30% of the people who are injected to some degree. In the case of brunettes and people with dark hair, skin darkening is usually seen more. The color change is not related to skin melanin and is more related to hemosiderin and it takes between 6-12 months to disappear completely.

Stiffness and darkness of the vein path

Inside the path of the vein, patient may feel stiffness and darkness, which is more a sign of the effectiveness of sclerotherapy than a complication. Usually, in the supplementary sessions, this stiffness and lump-like state inside the vein will be removed.

Visual impairment

Visual impairment may occur immediately after sclerotherapy, in which case sclerotherapy should not be performed again.

Formation of new capillary network

Sometimes, the body starts to create a capillary network around the injection site in a defensive reaction against the loss of blood vessels. Usually, if this complication is reported, sclerotherapy is no longer performed and alternative methods such as superficial varicose laser are used to treat spider veins.


Bruising and redness of the skin

Bruising and swelling at the injection site are normal and disappear within one to several weeks after the injection. Usually, the results of each injection session can be evaluated after 3 weeks, and the effect of the sclerosing substance becomes fully visible gradually and within a few weeks. The occurrence of itching and burning at the injection site is one of the complications that may occur in the first days after the injection. Redness, skin sensitivity and hives may occur after sclerotherapy.

Rare but dangerous complications in sclerotherapy

Complications that are rarely reported but are dangerous. Among them is anaphylactic shock, which includes respiratory sensitivity with symptoms such as shortness of breath and cough, and occurs in less than 0.6% of treated people. Venous thrombosis, stroke, tissue necrosis and nerve damage are other rare side effects of this treatment method.

In general, this method is one of the safe and most uncomplicated methods in the treatment of spider veins.

Sclerotherapy aftercare

Sclerotherapy is a fast non-invasive treatment method which doesn’t need anesthesia and patient can return to normal life routine the day after the treatment. These are the aftercares that you should tell your patients to follow:

  • Walk and be more active.
  • Heavy exercise is not allowed for 3 days.
  • Varicose stockings or medical bandages are necessary for a few days after the injection of varicose veins.
  • Drink more fluids.
  • If you want to have a long trip on the day of sclerotherapy, you should inform the varicose vein specialist.
  • Six hours after sclerotherapy, you can take a short lukewarm shower.

Sclerotherapy injection

First, a duplex ultrasound scan should be performed to map the surface path, hole location and deep veins. Those that are more than 5 mm in diameter and have known reflux are more suitable for treatment. Sclerotherapy of larger superficial veins and venipuncture are usually performed with ultrasound (echo) guidance.

In most cases of sclerotherapy, a saline solution is injected directly into the vein using fine needles. Patient may feel discomfort and mild cramping for one to two minutes at this stage, especially when the injection is done in larger veins and these veins are permanently closed. The vein has turned into a dead tissue that is eventually discarded from the body. The sclerotherapy process takes 15 to 30 minutes. The number of injected vessels in one session depends on the size and location of these vessels and the general condition of the patient.

After injecting the solution, the patient feels a slight burning sensation, but this burning sensation lasts only a few seconds. Most people are able to tolerate this method of treatment, and it does not require any kind of anesthesia. Most patients who have used this method believe that, contrary to their expectations, sclerotherapy does not cause so much pain.

What is sclerotherapy

Varicose veins are a venous disease in which the blood does not move properly in the veins (arteries) on the way back to the heart, and returns to the opposite direction, causing the vein to swell, twist and bruise. This problem is mostly seen in the lower torso and legs. The superficial type and close to the skin, which is like spider webs, is called spider varicose.

In the sclerotherapy method, a solution (sclerosant substance) is injected directly into the vein. A strong solution is injected directly into the vein and causes its wall to swell. After a few weeks to a few months, this vein disappears. Larger varicose veins may also be treated with sclerotherapy. Sclerotherapy effectively treats varicose and spider veins. This method is usually considered as a treatment method for small varicose veins.

If you want to add Sclerotherapy treatment to your practice, CBAM Sclerotherapy Certificate Course is the best option to start. Physicians, nurse practitioners, registered nurses, dentists, and international medical doctors and nurses are able to take this course. In CBAM Sclerotherapy Certificate Course you will learn anatomy and physiology of the lower extremity veins, patient evaluation: therapeutic vs cosmetic indications, Sclerosants and their dilutions, Injection techniques and Complications and their managements. There is going to be a live demo on patients at the end of the course.

Learn more about CBAM Sclerotherapy Certificate Course here.