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Transforaminal Epidural Steroid Injections


The terms used for different types of injections may be confusing. This fact sheet provides basic information about epidural steroid injection (ESI), an outpatient procedure sometimes done to help treat or diagnose problems related to the spine. It also covers "transforaminal ESI," a type of ESI in which medicine is given into a very specific area.

Your doctor will provide you with more detailed information if an ESI is being recommended for you.

Spine Anatomy

Vertebrae: Your spine is made of ring-shaped bones called vertebrae.

Spinal column: The "rings" at the center of each vertebrae line up to form a column in your back (the spinal column).

Spinal cord: The spinal cord extends from the base of the brain and ends at the upper lumbar spine, continuing further down as a large bundle of nerves through the lower the spinal column.

Dura mater: A membrane called the dura mater covers and protects the spinal cord.

Epidural space: There is a small space surrounding the dura mater called the epidural space.

Nerve roots: Branches of nerves from the spinal column (nerve roots) pass through the spinal canal and extend into the back, arms, and legs. If something is irritating the nerve roots (such as an abnormality in one of the vertebrae or discs), pain can be felt in the back and all along the nerve.

What is ESI?

ESI is an outpatient procedure in which the doctor injects a steroid (an anti-inflammatory medicine) into a very precise area of the epidural space, using X-ray guidance (fluoroscopy).

What are the benefits?

Reduces inflammation. The medicine is used to reduce any inflammation that may be present in a spinal nerve root.

Relieves pain. ESI relieves pain in the arms and legs caused by an irritated nerve root.

Helps determine cause of symptoms. ESI is useful in both the diagnosis and treatment of certain spine conditions. By placing the medicine in a precise area and monitoring the patient's response, valuable information is gained about what nerves may or may not be involved in causing the symptoms and how to target appropriate treatment.

What are the advantages of transforaminal ESI?

May increase success in reducing pain. The main advantage of transforaminal ESI is that the doctor can deliver the medicine into the neural foramen that contains the actual nerve root in question, which can increase the likelihood of success in reducing the patient's pain.

Helps ensure focus on the correct nerves. Another advantage is that the doctor can inject lidocaine - a numbing medicine - which works immediately (but temporarily) to numb the nerve root. If the numbing medicine immediately relieves the patient's pain, the physician then knows that the correct area has been reached. This can help ensure that steroid injections or surgery that will be done are focusing on the correct nerves.

What are some considerations?

Spine injections should only be done by doctors with special training. Before the ESI procedure, the doctor will get detailed pictures of the spine using MRI or CT scan, which will help determine the best approach.

What happens during the procedure?

  1. The patient lies face down on a table.
  2. Numbing medicine is injected into the back.
  3. Contrast dye is injected into the area so that the structures will be visible on X-ray.
  4. Using X-ray guidance, the doctor then places the steroid medication into the precise area believed to be causing the problem.

The procedure takes about 15 minutes. The patient is then observed for 20-30 minutes before going home. The arms or legs can be weak for a brief time after the procedure because of the numbing medicine, so patients are asked not to drive themselves home and to take care when moving about for the rest of the day.

Patients may have slight discomfort for a few days after the procedure, before they begin to feel the benefits of pain relief.

Does ESI work? For how long?

Provides pain relief for many. Many patients who undergo ESI have a significant decrease in arm or leg pain.

Usually lasts about 6-12 weeks. It can take a few days for the effects to be known. If the pain gets better, the effects usually last about 6-12 weeks.

If needed, the procedure can be repeated. Patients who do get better may not get complete relief of their pain. A realistic goal is to achieve a major reduction in the level of pain.

Common Misconceptions about ESI

Frequency of the procedure. Many people think that ESI must be done three times in order to work, or that three times is the maximum number of treatments that can be given. Both are incorrect. Some patients get relief after one or two treatments, others need more. Your doctor can give you more information on how many treatments you may need.

An epidural - like in childbirth? No. An epidural steroid injection is not the same thing as epidural anesthesia used in labor and delivery, or for certain surgeries. 

Number of "sticks." People who may have had epidural anesthesia - for childbirth or for a surgical procedure - may be concerned about the discomfort associated with multiple needle sticks to the back. Unlike epidural anesthesia, ESI is done under X-ray guidance. This means the doctor can see exactly where to place the injection, eliminating the need for multiple sticks. Headaches, and other complications sometimes seen with epidural anesthesia, are rare following ESI using a transforaminal approach.

Your doctor can answer your questions about epidural steroid injections as well as any other questions you have about your spine health. Please be sure to discuss all your questions and concerns.

Contact Information

Spine Center
Beth Israel Deaconess Medical Center
Shapiro Clinical Center, Second Floor
330 Brookline Avenue
Boston, MA 02215
617-754-9000
spinecenter@bidmc.harvard.edu

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