Overview of Interlaminar Epidural Injection
An interlaminar epidural injection is a type of pain relief treatment. In this procedure, a needle is used to inject a combination of numbing medicine (anesthetics) and steroids into the epidural space, which is a fat-filled area between the protective coverings of the spinal cord and the bony vertebrae of the spine. The needle is placed between the small arches of bone (laminae) of two stacked vertebrae.
This treatment is used to relieve radicular pain, which is pain that travels along the nerves from the spine. It can be an option for treating pain in the neck (cervical), chest (thoracic), or lower back (lumbar). The aim of this treatment is to spread the medicine over a larger area compared to another type of epidural injection.
One advantage of interlaminar epidural injections is that they can treat pain in more than one area of the spine at the same time. However, the way the needle is positioned for this type of injection may limit how much of the drug reaches the front part of the spine (ventral spread) compared to other methods, and this could affect its effectiveness depending on the specific type of spine condition being treated.
Anatomy and Physiology of Interlaminar Epidural Injection
The spine, also known as the vertebral column, is made up of different stacked bones called vertebrae. These vertebral bones include seven in the neck (cervical vertebrae), twelve in the upper back (thoracic vertebrae), five in the lower back (lumbar vertebrae), five that are joined together at the base of your spine (sacral vertebrae), and four that are fused together to form the tailbone (coccygeal vertebrae).
Each vertebrae has a specific structure. It has a primary segment called the vertebral body, two parts called pedicles that attach to the back of it, and other structures at the back of the vertebrae. This includes the laminae, which have four joint surfaces on both sides, the transverse processes that extend sideways, and a back extension called the spinous process. Each vertebrae has also two joints called facet joints, which connect it to adjacent vertebrae. The spinal cord, which is the main pathway for information connecting the brain and peripheral nervous system, runs through the spinal canal – a tunnel made by these vertebrae.
Between each vertebrae, there are structures known as intervertebral discs. These discs are like small cushions made of a softer inner part (nucleus pulposus) and a tough outer layer (annulus fibrosus). The soft inner part is made of a semi-fluid substance while the outer layer is made up of densely packed fibers. If a disc herniation happens, meaning the disc becomes damaged and the inner part leaks out, it can create inflammation and possibly irritate the surrounding nerves.
The spinal cord runs from the base of the brain at the C1 vertebra and ends approximately at the top of the lower back region, around the L1-L2 vertebrae. Nerve roots from the spinal cord combine at each level to make spinal nerves that exit through openings in the vertebrae. The nerves that control the lower parts of the body continue past the end of the spinal cord in a structure known as the cauda equina. The spinal cord is protected by three layers of covering tissue, from inner to outer they are called the pia mater, the arachnoid, and the dura mater. The epidural region is the space between the dura mater and the bony structure of the spinal canal, and it contains fatty tissue, lymphatic vessels, and connective tissue.
In some medical procedures like an epidural injection, a needle is passed through a ligament in the spine known as the ligamentum flavum to deliver medication into this epidural space.
Why do People Need Interlaminar Epidural Injection
If you’re experiencing back pain that seems to spread to your arms or legs, you might benefit from something called an epidural injection. This type of pain can usually be traced back to a condition called a herniated disc, where a disc, which serves as a cushion between the bones in your spine, slips out of place.
If the slipped disc is in the neck area, also known as the cervical spine, the pain may spread to your arms. If it’s in the lower back or lumbar spine, you might feel the pain radiating down your legs. Your doctor can confirm if this is the case by doing a few physical tests. For neck pain, there is a test called the Spurling test, and for lower back pain, a test called a straight-leg-raise is performed.
Epidural injections can also help patients who have a condition called spinal stenosis, which is a narrowing of the spaces within your spine. This can cause pressure on the nerves that travel through the spine, leading to pain. However, research is still ongoing to determine the best mixture of medicines for the injection in such cases.
When a Person Should Avoid Interlaminar Epidural Injection
There are certain conditions when having an interlaminar epidural injection, which is a type of pain relief treatment, might not be safe. These conditions include:
If you have an infection in the area where the injection would go in or if you are sick in general, the procedure may not be advised. Having an allergy to the medication in the injection can also make the procedure unsuitable. The procedure could be risky for individuals with bleeding disorders or those taking blood-thinning medications.
The American Society of Intervention Pain Physicians (ASIPP) and the American Society of Regional Anesthesia and Pain Medicine (ASRA) have different advice on whether to stop taking these blood-thinning medications before the procedure. The ASIPP rates different spinal techniques as low, medium, or high risk. Depending on the type and location of the epidural injection, the procedure can fall into different risk categories:
– Medium risk: Lumbar interlaminar (lower back) epidural injections at the L5-S1 vertebrae.
– High risk: Neck (cervical), chest (thoracic), and particular lower back (lumbar) interlaminar epidural injections above the L4-L5 vertebrae.
The decision to continue or cease blood-thinning medications depends on the specific medication in use. Healthcare providers must weigh the benefits and risks of stopping these medications for each patient. More contraindications might occur if a steroid (a type of medication used to reduce inflammation and discomfort) is used in the injection. These include uncontrolled diabetes or blood pressure, or serious heart conditions.
Equipment used for Interlaminar Epidural Injection
An operation, like an appendectomy (removal of the appendix), involves the use of various medical tools. During an open appendectomy, doctors use a sharp surgical knife called a scalpel and a tool known as a forceps, which is essentially a tweezer used for surgical purposes. In addition, there are non-damaging graspers and a tool called as an electrocautery, which applies heat using electric current to seal wounds or cut through tissues. Retractors are tools used to hold open the tissues or organs of the body. Surgeons also use absorbable sutures, these are basically special threads for stitching wounds that will eventually dissolve with healing, and needle drivers, which are devices designed to help with suturing.
For laparoscopic appendectomy, which is a minimally invasive surgery, fewer and smaller incisions are made. The surgery is performed using one laparoscopic monitor. A laparoscope, a tiny camera attached to a light source and cord is inserted into the body. This enables the surgeon to visualize your internal organs on a monitor. They also use a Veress needle or Hasson trocar, both are instruments used to puncture the body and create an entry point for the laparoscope. A carbon dioxide source and tubing for insufflation are used to puff up the body cavity for a better view and space to perform the surgery. A standard laparoscopy instrument tray and an endoscopic retrieval bag is used to hold and remove the appendix. Scalpels, needle drivers, and stitches are also used in this procedure. Additionally, the medical team needed to be prepared for any emergency, hence they had an open major abdominal tray ready for instant conversion to an open appendectomy, if required.
In some operations, there’s the use of a fluoroscopy (C-arm) – it’s like a real-time X-Ray machine that helps the doctor see the patient’s body part in detail. Skin is usually prepped with iodine or chlorhexidine which are substances used to kill germs before the surgery. Sterile drapes are used to cover the rest of the body to prevent infections. A small 25-gauge needle, which is approximately 1 to 1.5 inches long, is used. Touhy or Crawford needle is used to inject medications or to extract fluids from the body. Syringes are used to inject medications like Lidocaine, an anesthetic used to numb the tissue in a specific area, and a type of contrast medium, which helps improve the visibility of certain structures or fluids within your body during an X-ray exam. A special syringe called a Loss of Resistance (LOR) syringe is used to identify when the needle has entered the right area. Doctors also make use of preservative-free 0.9% normal saline, which is a sterile salt water solution, and non-particulate, preservative-free steroid, a medication used to reduce inflammation.
Who is needed to perform Interlaminar Epidural Injection?
A team of healthcare professionals is involved in your medical care. This team includes a doctor, an X-ray technician, a nurse, and a medical assistant or other similar healthcare provider. Everyone has a different role to play in your healthcare journey.
Your doctor oversees your overall care, makes vital decisions about your health, and coordinates with other healthcare team members. The X-ray technician focuses on the operation of X-ray machines and creates images for the doctor to interpret. Nurses provide patient care alongside doctors, offering support and ensuring you’re comfortable. A medical assistant or another type of healthcare provider performs support duties, including administrative tasks, to help smooth the process.
This team of professionals will help ensure you receive the best possible healthcare treatment and support throughout your medical journey.
Preparing for Interlaminar Epidural Injection
Before giving a spinal epidural injection, doctors usually perform a type of scanning called magnetic resonance imaging (MRI). The MRI helps doctors clearly see the spine and any problems that may be present. This is important to plan the best way to perform the procedure. The MRI also helps doctors choose the method that will likely help the patient the most. For instance, if a patient has a certain type of back pain caused by a disc herniation – where a disc in the spine bulges or breaks open – they might get better treatment through a transforaminal epidural injection. On the other hand, if a patient has a mild to moderate narrowing of the spinal canal due to spondylosis – a type of arthritis affecting the spine – an interlaminar approach might work better. Sometimes, doctors also use a test called electromyography (EMG), which measures muscle response, to plan the procedure and predict how well the patient will respond.
How is Interlaminar Epidural Injection performed
If you’re having a procedure to help with back pain, like an epidural steroid injection, you’ll be positioned face-down with supports to help increase the space between the bones in your spine. First, your skin will be cleaned to prevent infection. The doctor will then use a type of X-ray called fluoroscopy to get a clear view of your spine and decide where to place the needle.
The area where the needle will go is numbed with a small needle. Then, a bigger needle is placed into the same spot. This bigger needle goes through the skin, the fatty tissue under the skin, and the muscles next to your spine. It stops when it reaches a tough layer called the ligamentum flavum, which is right before the epidural space (the area around your spinal nerves where the medicine will go).
Then they’ll attach a syringe filled with saline solution to the needle. The needle is then carefully pushed forwards a little bit at a time. When the needle goes into the epidural space, the doctor will be able to tell because the saline in the syringe will be easier to push. It’s essential to control the depth of the needle at this stage because they’ll need to switch syringes.
They will then replace the saline syringe with one that contains a type of dye. They’ll inject a small amount of this dye, and using the fluoroscopy machine, they’ll check to make sure the dye is spreading correctly in the epidural space. If the dye spreads too fast, too slowly, or not at all, they will adjust the placement of the needle.
Once they’ve confirmed that the needle is in the right place, the syringe will be exchanged once more, this time with the medicine. This medicine will be injected into the epidural space to help reduce inflammation and pain. Finally, the needle is removed, a dressing is applied, and you will be monitored for a little while to make sure you’re okay after the procedure.
Possible Complications of Interlaminar Epidural Injection
There can be certain issues that might occur after receiving an injection in the space between the bones of your spine, also known as an interlaminar epidural injection. These complications could be due to the placement of the needle, infection, or the medicines given through the injection. One such issue could be from the needle going too far and possibly causing damage to the bag-like structure that contains the spinal cord or even to the spinal cord itself. This could lead to things like fainting, headaches, hiccups, temporary blindness, feeling sick, vomiting, or feeling dizzy.
There’s also a risk of infection that could lead to conditions such as an abscess (a pocket of pus) in the space around the spine, meningitis (an infection of the protective membranes that surround the brain and spinal cord), or osteomyelitis (a bone infection).
The steroid medicines used in the injection should be in a form that doesn’t produce particles to avoid the risk of blocking blood vessels, which could lead to damage in the spinal cord. These steroids can also cause side effects like high blood sugar, suppression of a part of the brain that controls many of the body’s hormones (called the hypothalamic-pituitary-adrenal axis), damage to bone tissue due to lack of blood flow (avascular necrosis), Cushing syndrome which is a hormonal disorder causing features such as obesity and high blood pressure, and muscle diseases or problems (myopathy).
What Else Should I Know About Interlaminar Epidural Injection?
Interlaminar epidural injections can be a vital non-surgical solution for people experiencing back pain that also affects the limbs. Natural progression of disc herniation (a condition where a disc in the spine bulges or breaks open) shows that marked relief can come about within 4 to 6 months. When carried out properly by a praticed medical professional, these injections pose a fairly low risk and can enhance the quality of life, aid in the return to daily activities, and steer clear of surgical treatment due to possibly temporary disabling conditions.
