Interlaminar epidural steroid injections (fluoroscopic guided)
Presentation
Severe central canal narrowing at L4/5. Radicular symptoms in both legs.
Patient Data
Two-level interlaminar epidural steroid injections (ILESIs) at L3/4 and L5/S1.
The first three images refer to the L3/4 injection. The first image shows the position and trajectory of the 22G Tuohy needle, which in the center of the left para-midline interlaminar space. The second image is the final precontrast needle position, the third after iodinated contrast has been injected, which confirms the needle tip is in the dorsal epidural space.
The fourth and fifth images are from the L5/S1 injection. The fifth is a post-contrast image and shows contrast extending into the dorsal epidural space.
Case Discussion
ILESIs are a method of delivering steroid into the epidural space to surround nerve roots. They are useful when there is multi-level nerve root compression and/or central canal narrowing.
Access is achieved through the interlaminar space and in this case, a para-midline approach was taken at both levels. This will avoid the interspinal ligament and the first ligament encountered is the ligamentum flavum. The same access is used for image-guided lumbar punctures/ myelograms.
Once the ligamentum flavum is reached, a loss of resistance technique was used with saline to reach the epidural space. This was then confirmed with iodinated contrast and then the injectate was subsequently delivered.
The epidural injectate consisted of 40mg triamcinolone (40mg/1mL), 4mL 1% lidocaine and 5mL 0.9% saline.