What is chemical sclerotherapy?

Chemical sclerotherapy, also called endovenous chemical ablation, is a minimally invasive, safe and relatively painless treatment for the removal of spider veins, reticular veins and small varicose veins.

It is performed by injecting a solution (usually a saline solution) directly into the vein. The solution irritates the lining of the blood vessel, causing it to collapse and stick together and the blood to clot. Over time, the vessel becomes scar tissue. This procedure has been in use since the 1930s.

Sclerotherapy for spider veins

Sclerotherapy is a simple procedure that can be performed in the aesthetic medicine clinic without anesthesia. It can last from 15 minutes to an hour, depending on how many veins are treated in one session. The number of veins injected in one session depends on the size and location of the veins, as well as the patient’s general medical condition.

During sclerotherapy treatment the physician will sterilize the injection site with alcohol before starting the procedure. While the patient lies on his or her back with the legs slightly elevated, you will inject the chemical directly into the vein with a small needle. These chemicals will close the vein by irritating the cell lining and causing inflammation and scarring of the vein wall.

If multiple veins are being treated, you will inject the larger veins before the smaller ones, from the thigh to the calves and ankles. Veins that are more uncomfortable are usually injected first before veins that are not painful or uncomfortable.

During the injection, you may feel a slight pain or burning. If it hurts a lot, it is important to notify the doctor. Note, however, that acute burning may mean that the solution has leaked from the vein into the surrounding tissue.

Who can be treated with sclerotherapy?

Sclerotherapy may be appropriate for people with varicose veins or spider veins, but it is not for everyone. The specialist is the one who must assess whether or not this treatment can be performed.

It is important to note that people in the following situations cannot undergo sclerotherapy treatment:

  • Active deep venous thrombosis or superficial venous thrombosis (blood clot)
  • Pregnant women or women who have recently given birth (you must wait at least three months after delivery before you can undergo sclerotherapy).
  • Women who are breastfeeding their baby
  • People who are unable to get out of bed.

People who have had a blood clot in the past may be able to undergo sclerotherapy, depending on the cause of the clot and its severity. The physician will be the one to evaluate this circumstance.

In most cases, the physician will not perform sclerotherapy on a vein that may be needed for future bypass surgical procedures, such as the saphenous vein for coronary artery bypass graft surgery (unless that vein can no longer be used).

Medications to avoid before sclerotherapy

Prior to sclerotherapy treatment, the following medications should be avoided:

  • Antibiotics can cause skin staining if taken seven to 10 days before or after sclerotherapy. It is important to ask your doctor and inform him/her about the use of these medications.
  • Aspirin, ibuprofen or other anti-inflammatory drugs for 48 hours before and after sclerotherapy. These medications may interfere with the action of the sclerosing agent or cause you to bleed more.
  • Some corticosteroids, such as prednisone, make the sclerosing agent less effective.

Other guidelines to follow before undergoing sclerotherapy treatment include the following:

  • Do not use lotion on the legs before or after sclerotherapy.
  • Attend treatment wearing shorts.
  • Purchase compression stockings that provide sufficient support for use after treatment.


Commitment to quality

This text on abdominoplasty has been prepared by professional editors. In addition, we have relied on experts in medicine, engineering and aesthetics as a source of information, as well as specific studies to maintain the quality of what we publish.

At Sisneo Bioscience we are committed to publish truthful and contrasted information. And to update or correct it as soon as new knowledge becomes available.

Among others, we have used the following sources:

  • Deanne Leopardi, Ben L. Hoggan, Robert A. Fitridge, Peter W.H. Woodruff y Guy J. Maddern. «Revisión sistemática de los tratamientos de las venas varicosas» en Anales de Cirugía Vascular. vol:23, num:2. 290-303 (Marzo – Abril 2009). doi: 10.1016/j.acvsp.2008.10.024
  • de Ávila Oliveira R, Riera R, Vasconcelos V, Baptista-Silva JC. «Injection sclerotherapy for varicose veins» en Cochrane Database Syst Rev. 2021 Dec 10;12(12):CD001732. doi: 10.1002/14651858.CD001732.pub3.