Transforaminal epidural steroid injections, in particular, may require more guidance from imaging as the doctor performs the procedure, as the needle must be inserted into empty space to the side of the spinal column. However, this approach is regarded as being comparable to the specificity needed for the interlaminar approach. Transforaminal injections may also be associated with reduced risks of dural damage. Some research even indicates that this approach may be superior in cases of spinal pain associated with neuropathy in comparison to the caudal or interlaminar approach.
With a transforaminal epidural steroid injection (ESI), often referred to as a 'nerve block', the needle is placed alongside the nerve as it exits the spine, and medication is placed into the 'nerve sleeve'. The medication then travels up the sleeve and into the epidural space from the side. This allows for a more concentrated delivery of steroid into one affected area (usually one segment and one side). Transforaminal ESIs can also be modified slightly to allow for more specific coverage of a single nerve and can provide diagnostic benefit, in addition to improved pain and function.