Interlaminar Epidural Steroid Injection (ILESI) in Castle Rock
What is an Interlaminar Epidural Steroid Injection?
An interlaminar epidural steroid injection (ILESI) delivers anti-inflammatory steroid medication into the epidural space through the back of the spine, between two vertebrae (the laminae). Unlike a transforaminal epidural, which targets a single nerve root, an interlaminar injection spreads more broadly across the epidural space. This makes it useful for conditions that affect multiple nerve roots or both sides of the spine.
When is an Interlaminar Epidural Used Instead of a Transforaminal?
An interlaminar approach is typically preferred when:
Your symptoms are on both sides (bilateral leg pain, bilateral arm pain)
You have spinal stenosis causing compression at multiple levels
Imaging does not show a single nerve root being compressed - the narrowing is more diffuse
Your provider wants broader medication coverage across several nerve roots at once
If your pain clearly follows one nerve (like sciatica down one leg from a specific disc herniation), a transforaminal epidural is usually the better choice because it places the medication more precisely at the site of compression. For broader or bilateral symptoms, interlaminar is often more effective.
What Conditions are Treated with an Interlaminar Epidural?
Lumbar spinal stenosis causing leg pain, heaviness, or numbness with walking
Cervical spinal stenosis with bilateral arm symptoms
Bilateral sciatica or radiculopathy
Diffuse disc bulging affecting multiple levels
Chronic back or neck pain with nerve irritation at several segments
How Should I Prepare?
Let the team know about all medications you are taking, particularly blood thinners and NSAIDs. You may need to stop certain medications temporarily before the procedure. IV sedation is rarely needed. Arrange for a ride home, as temporary numbness or mild weakness can occur. Wear comfortable, loose-fitting clothing.
What Happens During the Procedure?
You will lie face down on a procedure table. The skin is cleaned and numbed with a local anesthetic. Using fluoroscopy (live X-ray), a needle is advanced between two vertebral laminae into the epidural space. Contrast dye is injected to confirm correct positioning and to visualize how the medication will spread. The steroid and anesthetic mixture is then injected. The procedure takes about 2 to 5 minutes.
How Much Does It Hurt?
Most patients tolerate the procedure well. The anticipation is usually worse than the actual injection. A local anesthetic numbs the skin before the epidural needle is placed, and the injection itself causes brief pressure or mild discomfort. Patients typically rate the overall experience between 1 and 4 out of 10.
What Should I Do After the Procedure?
Avoid strenuous activities for 24 hours.
Resume normal activities gradually the following day.
Avoid submerging the injection site in water for two days.
Do not apply heat or ice directly to the site for 48 hours.
Temporary soreness at the injection site and mild numbness in the legs are common and resolve within a few days.
When Will I Feel Better?
Pain relief typically begins within one to two days, with full effects developing over about a week. The local anesthetic may provide immediate temporary relief that wears off in a few hours before the steroid takes effect.
How Long Does the Relief Last?
Results vary, but about 50 to 75% of patients experience at least 50% pain reduction for three months or longer. For patients with stenosis, interlaminar epidurals can help maintain walking ability and delay the need for surgical intervention. If pain returns, the injection can be repeated.
How is This Different from a Caudal Epidural?
Both interlaminar and caudal epidurals deliver medication broadly into the epidural space, but they enter from different locations. An interlaminar epidural enters between the vertebrae at the level being treated. A caudal epidural enters from the base of the spine (the tailbone) and the medication travels upward. Caudal epidurals are sometimes preferred for patients who have had previous lumbar surgery, since scar tissue at the surgical site can make an interlaminar approach more difficult. Dr. Carrera's team selects the approach based on your anatomy and surgical history.
Does Insurance Cover Interlaminar Epidurals?
Yes. Most insurance plans cover interlaminar epidural injections when the patient meets medical criteria, which typically include pain for at least six weeks and failure of conservative treatments. Some plans allow earlier treatment. Prior authorization is usually required, and the team handles this in-house.
Schedule a Consultation
If you have back pain with leg symptoms from spinal stenosis or broad disc disease, an interlaminar epidural may provide the coverage you need. Dr. Carrera's team can evaluate your condition and recommend the best epidural approach.