What Is A Transforaminal Epidural Steroid Injection?
Epidural Steroid Injection is a procedure where numbing medicine (anesthetic) and anti-inflammatory medicine (steroid) are injected into the epidural space to treat pain caused by irritation of the spinal nerves. A protective covering called the dural sac surrounds the spinal cord. This sac contains spinal fluid that bathes and nourishes the spinal cord. The space between the outer surface of the dural sac and the bones of the spinal column is the epidural space. Nerves that go from the spinal cord, through the spinal column, and to the body pass through the epidural space. Depending on the location of your pain, the epidural steroid injection can be given in the neck (cervical), middle back (thoracic), or lower back (lumbar).
Transforaminal Epidural Steroid Injection
The approach to the epidural space can be thought of in three different ways.
- The Caudal approach accesses the epidural space via an opening near the tailbone.
- The Interlaminar approach axis is the epidural space directly between the spinous processes of the vertebral bones.
- The Transforaminal approach accesses both the epidural space and the nerve roots from the side or through the intervertebral foramen.
The advantages of this approach is that depending on the location of the needle tip placement one can make an excellent diagnostic prediction based on the patient’s response. The Transforaminal epidural steroid injection is especially useful when the patient has had previous surgery making access via the midline Interlaminar approach impossible. It is also especially useful if there is one-sided leg pain or back pain. The procedure is carried out with the patient lying facedown with a supportive pillow under the abdomen. Intravenous access and mild sedation are often performed.
Using a very thin needle, under fluoroscopic guidance, it is directed into the foraminal opening. Confirmation is made by using the x-ray contrast material which can show the outlines of the spinal nerve. The contrast can also flow past the spinal nerve and into the epidural space. This option can be regulated based on the location of the needle tip. After confirming the correct needle tip position, a solution of steroid with or without a local anesthetic and saline is gently injected. After the procedure, a light dressing, Band-Aid is applied to the patient to allow recovery.
Depending on the amount of local anesthetic used, the patient may exhibit immediate pain relief in the area of their previously reported symptoms. When this happens, it can also be a diagnostic injection helping to determine which nerve root is the main culprit, especially if the MRI suggests a compression of more than one nerve root by a herniated disc. Complications from this procedure are usually rare and can be related to any of the common steroid side effects.