Endovenous laser therapy using image guidance

What is endovenous laser therapy?

Endovenous laser therapy (EVLT) (sometimes called endovenous laser ablation) uses a laser to close some abnormal veins. The laser burns the inner surface of the vein and stops blood flow in that area.

EVLT is done using image guidance by an interventional radiologist.

How endovenous laser therapy is done

The interventional radiologist will insert a special tiny tube, called a catheter, into the affected vein. The interventional radiologist may use an X-ray or ultrasound machine to make sure the catheter is in the correct position inside the vein. Through this catheter, a laser fibre is inserted into the vein. The interventional radiologist then uses the laser to burn the vein. The laser fibre is slowly pulled out, closing the vein and stopping the blood flow through the abnormal vein.

The procedure generally takes two hours.

Endovenous laser therapy

A: Laser fiber is inserted into the abnormal vein. B: Laser is turned on to burn the abnormal vein from the inside while the laser fibre is slowly pulled out. C: The laser closes the vein and stops the blood flow.

Risks of endovenous laser therapy

EVLT is usually a low risk procedure. The risk may increase depending on your child’s condition, age and health.

Potential risks include:

  • bleeding
  • skin burns
  • nerve damage (temporary or permanent)
  • blood clots
  • infection

After EVLT it is normal to experience:

  • bruising
  • local swelling
  • tenderness and pain

Visiting the clinic before the procedure

Your child will visit the Vascular Anomalies Clinic and be seen by an interventional radiologist before the procedure to decide on the best treatment options.

During this clinic visit, your child may:

  • see a physiotherapist and/or occupational therapist
  • get information about pressure garments
  • be sent to have photographs taken
  • have blood work, if needed

Your child may also need to have other tests such as ultrasound, magnetic resonance imaging (MRI) or venography done. This will help the doctor see what your child’s veins look like. After these tests, the doctor can determine if your child is a suitable candidate for EVLT.

If your child is suitable for EVLT, you should expect:

  • A health assessment to make sure your child is healthy and that it is safe to have general anaesthesia and to go ahead with the procedure.
  • An overview of the procedure, and a review of the consent form with an interventional radiologist.

Giving consent before the procedure

Before the procedure, the interventional radiologist will go over how and why the procedure is done, as well as the potential benefits and risks. They will also discuss what will be done to reduce these risks, and will help you weigh any benefits against the risks. It is important that you understand all of these potential risks and benefits of the EVLT and that all of your questions are answered. If you agree to the procedure, you can give consent for treatment by signing the consent form. A parent or legal guardian must sign the consent form for young children. The procedure will not be done unless you give your consent.

Pressure garments/stockings

Parents must obtain their child’s high pressure garment(s) (30-40 mmHg) prior to EVLT. They will be given a prescription for the garment at their visit to the Vascular Anomalies Clinic.

If your child regularly wears a garment in addition to the high pressure garment, please bring both of these with you on the day of your laser treatment.

The interventional radiologist doing the treatment will decide which garment will be applied and when it should be used.

If the garment is to be used, often it is required for the following period:

  • day and night for the first 48 hours
  • then in the daytime only for six weeks

How to prepare your child for the procedure

Before any treatment, it is important to talk to your child about what will happen. When talking to your child, use words they can understand. Let your child know that medicines will be given to make them feel comfortable during the procedure.

Children feel less anxious and scared when they know what to expect. Children also feel less worried when they see their parents are calm and supportive.

If your child becomes ill within two days before the procedure

It is important that your child is healthy on the day of the procedure. If your child starts to feel unwell or has a fever within two days before the EVLT, let your doctor know. Your child may need to be rebooked.

Food, drink, and medicines before the procedure

  • Your child’s stomach must be empty before sedation or general anaesthetic.
  • If your child has special needs during fasting, talk to your doctor to make a plan.
  • Your child can take their regular morning medicine with a sip of water two hours before the procedure.
  • Medicines such as acetylsalicylic acid (ASA), naproxen or ibuprofen, warfarin, or enoxaparin may increase the risk of bleeding. Do not give these to your child before the procedure unless they have been cleared first by their doctor and the interventional radiologist.

Your child will have medicine for pain

Children are given medicine for treatments that may be frightening, uncomfortable, or painful. This includes sedation or general anaesthesia. For EVLT, most children are given a general anaesthetic.

On the day of the endovenous laser therapy

Arrive at the hospital two hours before the planned time of your child’s procedure. Once you are checked in, your child will be dressed in a hospital gown, weighed and assessed by a nurse. You will also have a chance to speak to the interventional radiologist who will be doing the EVLT, and the anesthetist who will be giving your child medication to make them comfortable during the procedure.

You must bring your child’s high pressure garment (30-40 mmHg) with you to the hospital on the day of their procedure. If you do not have these, your child may not have the EVLT done and they may need to be rebooked.

During the endovenous laser therapy, you will be asked to wait in the waiting area.

After the endovenous laser therapy

Once the venous laser treatment is complete, your child will be moved to the recovery area. The interventional radiologist will come and talk to you about the details of the procedure. As soon as your child starts to wake up, a nurse will come and get you.

Going home

In most cases, children go home the same day as the procedure. If your child’s doctor has arranged this, your child will be ready to go home about four hours after the procedure. Your child’s nurse will let you know when they are well enough to go home.


A follow-up visit about three months after the procedure will be arranged. However, if your child has future procedures scheduled to treat vascular malformations (sclerotherapy treatments), a follow-up visit may take place one week prior to the booked sclerotherapy.

For more details on how to care for your child after laser treatment, please see Endovenous laser therapy: Caring for your child at home after the procedure.

Key points

  • EVLT is used to close some abnormal veins.
  • It is usually considered a low-risk procedure.
  • You must bring your child’s high pressure garment with you on the day of the procedure.

Candice Sockett, RN(EC), MN:APN

Michelle Cote BScN, RN

Joao Amaral, MD


At SickKids

At SickKids, the interventional radiologists work in the Department of Diagnostic Imaging – Division of Image Guided Therapy (IGT). You can call the IGT clinic at (416) 813-6054 and speak to the clinic nurse during working hours (8:00 to 15:00) or leave a message with the IGT clinic nurse.

For more information on fasting see Eating and drinking before surgery.

For more information on preparing your child for their procedure see Coming for surgery.