Epidural steroid injections have been used throughout the 20th century. The first use of an epidural injection was by Cathelin in 1901. Reports of the effectiveness of lumbar epidural steroid injections (LESI) have ranged from 18% to 90%. The efficacy has been reported in a large number of uncontrolled studies. While some have recommended the use of LESIs for radicular pain, others have found the data insufficient to support their use. The practice of LESIs has been considered controversial until more recent reviews and studies have shown their efficacy.
The rationale is to deliver corticosteroid close to the site of pathology, presumably onto a nerve root. This is to deliver a higher concentration of medication over an inflamed nerve root than is possible when a steroid is given orally or by intramuscular injection.
There have been impressive studies showing the superior results obtained by using the transforaminal injection technique with fluoroscopic guidance. Published reports of 6 studies (n=20 to 332) have shown pain relief to be 55-75%. All patients were refractory to conservative care and many had interlaminar epidural steroid injections. Follow up was greater than 1 year and one study up to 10 years. These studies have shown that transforaminal steroids are the only form of treatment that has been found to provide complete relief of pain in patients for whom surgery was the only known option.
At Advanced Pain Treatment Centers(APT), it is the philosophy to perform transforaminal steroid injections in order to best treat radicular pain. A smaller amount of steroid is used since it is placed accurately on the target site. Therefore, there are lower risks of side effects from the steroid. There is no wondering if the medication was deposited on the correct nerve root since the contrast medium clearly outlines the nerve requiring the treatment. Previously reported were the issue of "blind" epidurals and the possibility of up to 40% of injections not in the epidural space. Although, transforaminal ESIs are considered to be in their clinical infancy, impressive studies have been published. It is rapidly emerging as the procedure of choice for radicular pain. It is the practice of many interventional pain specialists and APTC to only perform this type of block for radicular pain.