"Fluoroscopically Guided Lumbar Transforaminal Epidural Steroid Injection" - Expert Insights from Dr. Debjyoti Dutta"

Indications for Fluoroscopically Guided Lumbar Transforaminal Epidural Steroid Injections (TFESIs) -

Fluoroscopically guided lumbar transforaminal epidural steroid injections (LTFESIs) are

recommended for addressing lumbar radicular pain that remains unresponsive to conservative treatments like oral medications, activity modification, and physical therapy. They can also be considered earlier in cases where conservative options are contraindicated or not well tolerated. The primary objective of this procedure in cases of disc herniation is to alleviate pain and enhance functionality during the period in which the herniation typically resolves naturally. For conditions like spinal stenosis, characterized by fixed lesions, a short to moderate-term reduction in pain is expected.

• Treatment of lumbar radicular pain is unresponsive to conservative measures.

• Early consideration when conservative treatments are contraindicated or poorly tolerated.

• Alleviation of pain and improvement of function during the natural resorption period of disc herniation.

• Short to moderate-term pain relief in conditions like spinal stenosis with fixed lesions.

Contraindications for Fluoroscopically Guided Lumbar Transforaminal Epidural Steroid Injections:

• Allergy or hypersensitivity to any of the medications used in the injection, such as local anaesthetics or steroids.

• Active infection at the injection site or systemic infection.

• Uncontrolled diabetes or other significant medical conditions may increase the risk of complications.

• Bleeding disorders or the use of anticoagulant medications that cannot be safely discontinued before the procedure.

• Pregnancy.

• Spinal abnormalities or anatomical variations may pose a higher risk of nerve injury or other complications during the injection procedure.

• Patient refusal or inability to cooperate during the procedure.

• Psychological or psychiatric conditions that may interfere with the patient's ability to tolerate the procedure or understand its risks and benefits.

Patient positioning and preparation

The medications are aseptically drawn into three separate and labelled 3–5 mL syringes. One syringe contains iodinated contrast medium, typically Omnipaque 240 or 300, with small bore extension tubing attached and primed. The extension tubing minimizes needle tip movement during syringe exchanges and keeps the physician's hand out of the X-ray beam during live contrast administration. In cases of severe iodinated contrast allergy, gadolinium can be substituted, though it may be less radio-opaque than Omnipaque. However, during live fluoroscopy, the visibility of gadolinium can be enhanced in digital subtraction angiography mode. The main concern with gadolinium is the risk of seizure if inadvertently administered intrathecally.

A second syringe contains 1%-2% lidocaine for local anaesthesia of the skin and subcutaneous tissues. Adding sodium bicarbonate can alleviate the burning sensation upon injection for patient comfort. The third syringe contains a nonparticulate corticosteroid, typically dexamethasone at 10–15 mg or particulate steroids like triamcinolone and methylprednisolone at 80 mg. However, the use of particulate steroids like triamcinolone and methylprednisolone in LTFESIs has the documented risks of embolizing a radicular artery, leading to spinal cord infarction and paralysis. A small volume (0.5–1 mL) of local anaesthetic may be included with the steroid for diagnostic response.

The patient is positioned prone on a radiolucent procedure table with a pillow under the abdomen to flatten the lumbar lordosis. The skin is sterilized using betadine or chlorhexidine, and a sterile drape with an opening in the middle is placed. A C-arm is then positioned over the patient for fluoroscopic visualization.

Steps of The Procedure -

Initial X-Ray and Identification of Area of Interest:

• Take an initial x-ray to identify the area of interest over the desired vertebral level.

• Use a sterile marker, like an 18-G needle, placed on the skin. For transitional lumbosacral anatomy, count down from the T12 ribs for proper level confirmation

C-Arm Positioning and Oblique Angle

1. Square the targeted vertebral endplates with cephalad or caudal tilt on the C-arm.

2. Oblique the C-arm to the side of the pathology to be treated.

3. Adjust the obliquity so that the superior articular process overlies one-third to one-half the width of the vertebral body.

4. Visualize a "Scotty dog" view and centre the targeted level on the screen to avoid parallax error.

Collimate the view to decrease radiation exposure and improve focus on key structures.

1. Anaesthesia and Needle Placement:

• Adjust the skin marker to align directly under the pars interarticularis for the sub-pedicular or supernatural approach. Or

• Adjust the skin marker to align just lateral to the Superior articular process of the

lower vertebra for Kambin’s Triangle Approach.

• Anaesthetize the skin with lidocaine using a 25- or 27-G 1.5-inch needle, ensuring it's in the same oblique plane as the C-arm.

1. Quincke Needle Placement:

• Utilize a 22- or 25-G Quincke needle, typically 9 cm in length.

• Optionally, place a small bend in the tip of the needle opposite the bevel and notch of the hub for precise steering.

• Insert the Quincke needle just deep enough to maintain its angle of entry without falling down.

• Make small adjustments to ensure the needle is parallel to the image intensifier, verified by intermittent X-rays.

• Advance the needle slowly while verifying proper trajectory in a coaxial manner, staying at the most superior aspect of the neuroforamen to avoid contacting the exiting nerve root.

1. Verification and Adjustment:

• Rotate the C-arm to obtain a true anterior-posterior view.

• Advance the needle carefully to the mid-pedicular line, corresponding to the 6 o'clock position on the pedicle. Or Just Lateral to Superior articular Facet For Kambin’s Triangle approach.

• Obtain a lateral view to verify the depth of the needle tip within the neuroforamen.

• Check again with a true anterior-posterior view, remove the stylet, and attach extension tubing primed with contrast.

1. Live Fluoroscopic Injection of Contrast:

• Centre the image on the screen and remove collimation to allow a wide field of view.

• Slowly inject contrast under live fluoroscopy, focusing on ruling out aberrant contrast flow.

• Analyse for arterial uptake, lack of venous, subdural, intrathecal, and superficial soft tissue contrast spread.

• Proper contrast flow should be along the nerve root, its sheath medial to the pedicle, and into the epidural space.

• Adjust the needle and reinject live contrast if improper flow is observed.

• Once proper location is confirmed, slowly inject the final solution with dexamethasone.

1. Completion and post-injection:

• Communicate with the patient to monitor the reproduction of radicular pain during injection.

• If radicular pain is severe and not diminishing, consider the intraneural needle tip and adjust accordingly.

• Upon completion, retract the needle out of the epidural space, restyletted, and removed.

• Optionally, obtain a washout picture to demonstrate the final spread of injectate.

Post Procedure Advice - 

After the procedure, patients are advised to have a band-aid applied to the injection site, which can be safely removed the following day. Discomfort can be managed using ice as needed. It is recommended that patients refrain from driving until the next day as the local anaesthetic on the nerve root may cause temporary weakness. While patients can shower as usual. Normal activities may be resumed as tolerated, allowing patients to gradually return to their daily routines with appropriate caution and attention to their comfort levels.