Lumbar Epidural Steroid Injection (ESI) ProcedureMay 08, Author: The first documented epidural medication injection, which was performed using the caudal approach see the image below; see also Approaches for Epidural Injections was performed in lesi lumbar epidural steroid injection, when cocaine was injected to treat lumbago and sciatica presumably pain referred from lumbar nerve roots. Injection of corticosteroids into the epidural space for the boldenon und testosteron enantat of lumbar radicular pain was first recorded in Find the Cause, Watch for the Comebacka Critical Images slideshow, to help epodural and manage this common problem. Also, see the Pain Management:
Lumbar Epidural Steroid Injections for Low Back Pain and Sciatica
May 08, Author: The first documented epidural medication injection, which was performed using the caudal approach see the image below; see also Approaches for Epidural Injections was performed in , when cocaine was injected to treat lumbago and sciatica presumably pain referred from lumbar nerve roots. Injection of corticosteroids into the epidural space for the management of lumbar radicular pain was first recorded in Find the Cause, Watch for the Comeback , a Critical Images slideshow, to help diagnose and manage this common problem.
Also, see the Pain Management: ESIs can provide diagnostic and therapeutic benefits. Diagnostically, ESIs may help to identify the epidural space as the potential pain generator, through pain relief after local anesthetic injection to the site of presumed anatomic pathology. In addition, if the patient receives several weeks or more of pain relief, then it may be reasonable to assume that an element of inflammation was involved in his or her pathophysiology.
Since prolonged pain relief is presumed to result from a reduction in an inflammatory process, it is also reasonable to assume that during the period of this analgesia, the afflicted nerve roots were relatively protected from the deleterious effects of inflammation. Chronic inflammation can result in edema, wallerian degeneration, and fibrotic changes to the neural tissues.
Radicular pain often is the result of nerve root inflammation with or without mechanical irritation. Clinical practice and research demonstrate that mechanical compression alone to the nerves causes only motor deficits and altered sensation but does not necessarily cause pain. Inflammation within the epidural space and nerve roots, as can be provoked by a herniated disk, is a significant factor in causing radicular pain. Historical evidence of nerve root inflammation has been demonstrated during surgery in patients with radicular low back pain LBP from lumbar disk herniation.
Animal research in dogs and rats also has revealed severe inflammation locally within the epidural space and nerve root after injection of autologous nuclear material into the epidural space. A high level of phospholipase A2 PLA2 , an enzyme that helps to regulate the initial inflammatory cascade, has been demonstrated in herniated disk material from surgical samples in humans. Leukotriene B4, thromboxane B2, and inflammatory products also have been discovered within herniated human disks after surgery.
Animal models have demonstrated that injection of PLA2 into the epidural space induces local demyelination of nerve roots, with resultant ectopic discharges which is considered the primary pathophysiologic mechanism for sciatica [radicular pain].
The radicular LBP caused by spinal stenosis is probably related to the inhibition of normal nerve root vascular flow with resultant nerve root nutrition, nerve root edema, and nerve root dysfunction.
Chronic nerve root compression can induce axon ischemia, impede venous return, promote plasma protein extravasation, and cause local inflammation. If dorsal root ganglia are chronically compressed and irritated, this theoretically can lead to their sensitization and resultant radicular pain. Similar mechanisms of radicular pain are postulated to occur in the thoracic and cervical spine as well.
Since lumbar radicular pain may originate from inflammation of the epidural space and the nerve root, analgesic effects of corticosteroids most likely are related to the following mechanisms:.
Although the primary indication for epidural steroid injection ESI is radicular pain associated with a herniated nucleus pulposus, a variety of other indications have been reported in the literature. Lumbar, thoracic, and cervical ESIs may be indicated for lumbar radicular pain associated with any of the following conditions:.
In addition, fluoroscopy should not be used in epidural injections for women who are pregnant, to avoid exposing the fetus to ionizing radiation. Caution should be used when performing injections in patients with poorly controlled diabetes, since the corticosteroid may transiently, but significantly, increase blood glucose levels.
Caution should be exercised when performing injections in individuals who have a history of congestive heart failure because of the potential for steroid-induced fluid retention. Although numerous articles have supported the benefit of ESIs for LBP, especially if the pain is caused by radiculopathy, other studies have disputed the efficacy of these procedures.
Unfortunately, most of the earlier studies those that failed to show a benefit from the injection had significant limitations. Aside from using a less-than-desirable research methodology, most of these studies did not use fluoroscopy and radiographic contrast to document accurate placement of the injected substance into the epidural space. Many also failed to demonstrate that injection was performed at a presumed level of pathology, which has been shown to be critical to the success of ESIs.
These methodologic problems most likely were the major factors that led to the mixed assessment of ESIs. As with other medical procedures, the efficacy of the ESIs is related to many factors. Aside from the clinician's experience and training, other factors that play an important role include patient selection, symptom duration, underlying pathophysiology, ESI approach, the use of fluoroscopy and contrast enhancement, and the vocational status, as well as the socioeconomic and psychological circumstances, associated with the individual patient.
Patients with symptoms of shorter duration have more sustained relief than those with chronic pain. Patients with chronic back pain generally have better response if they develop an acute radiculopathy. In a cross-sectional study design at a university spine center, 76 patients with sciatica were followed for a mean of days after receiving transforaminal ESIs. Patient response to ESIs is also related to underlying pathophysiology. In general, acute radicular pain from lumbar disk herniation responds more favorably than does radicular pain from lumbar spinal stenosis.
Patients with radicular pain after lumbar spine surgery frequently receive less benefit from ESIs unless the radicular pain is from a recurrent herniated nucleus pulposus. Still, ESIs are often helpful for radicular pain from stenosis. The following research demonstrated the efficacy of lumbar transforaminal epidural injections see Approaches for Epidural Injections in patients with persistent sciatica from lumbar disk herniation or spinal stenosis:.
A systematic review included 15 fluoroscopically guided randomized trials and 11 nonrandomized studies. The efficacy is good for radiculitis secondary to disk herniation with local anesthetics and steroids and fair with local anesthetic only, whereas it is fair for radiculitis secondary to spinal stenosis with local anesthetic and steroids and fair for axial pain without disk herniation with local anesthetic with or without steroids.
A prospective study demonstrated that as compared with conventional lumbar interlaminar epidural injections, the lateral parasagittal interlaminar epidural approach has higher rate of contrast spread into the anterior epidural space. A maximum of 3 injections were performed with day intervals between injections, if necessary. Follow up was 6 months post injection. The results demonstrated that PIL approach has better ventral epidural spread in contrast At the end of 6 months, the PIL group had a significantly higher percentage of pain relief in the visual analogue scale PIL 13 [ It is important to know that at least 3 cases of lumbar paraplegia have been reported, and each developed after interlaminar lumbar epidural steroid injections.
In fact, the anatomical studies have demonstrated that after the radicular medullary arteries enter the neuroforamen in the anterior aspect of exiting nerve root and dorsal root ganglion, they often travel a distance superiorly and laterally in the lateral epidural space to join the anterior spinal artery supplying the anterior two thirds of the spinal cord.
It is conceivable that the epidural needle in the interlaminar lumbar epidural steroid injection will very likely encounter the radicular medullar artery in the lateral aspect of the epidural space or midline posterior epidural space. As the paraplegia after interlaminar lumbar ESIs is often underreported, the exact frequency of this event cannot be determinted.
It is clear that in light of the anatomical positions of these radicular medullary arteries inside the spinal canal as described above, neither midline nor parasagittal interlaminar lumbar ESIs are completely risk free with respect to vascular injury and paraplegia. The alternative approach using the Kambin triangle may be the better choice see below for description.
More evidence favors the use of transforaminal ESIs in the lumbar spine compared with the cervical spine. Although the interlaminar approach see Approaches for Epidural Injections may allow the injectate to flow to the site of pathology by migrating around the thecal sac and into the ventral epidural space, the transforaminal route is presumably more reliable for delivering the steroid to the affected area in cases of disk herniation in which the disk comes into contact with the nerve root.
Rhee and colleagues found a difference in patients undergoing interlaminar and transforaminal ESI. Recently, a randomized, prospective, blinded, and controlled trial on the 38 patients with lumbar subacute radicular pain was conducted. The study demonstrated that while both groups improved, the transforaminal ESIs provided better pain relief in up to 16 days post injections compared with the interlaminar group. However, a separate randomized and prospective research study enrolled 32 patients in each group with chronic lumbar radiculopathy and 6 months follow up; the study again revealed the improvement in pain and disability in both groups.
However, no significant differences were noted in pain reduction and the Oswestry disability scale between the transforaminal and interlaminar groups at the end of 6 months. The above discrepancy of efficacy may be due to the lower response to epidural steroid injections in general because of the chronicity of the radiculopathy; alternatively, it may reflect the differences of timing in follow up between the 2 studies. It is generally agreed that ESIs offer short-term several months pain relief.
No difference was noted in primary or secondary outcome measures at 4 years between the groups. There was a cross-over of patients who first underwent ESIs and then diskectomy.
For those who underwent an initial trial of ESIs, the delay in surgical decompression was not found to be detrimental to neurologic recovery at time of follow-up. No randomized, controlled trials have been performed to date on the efficacy of ESIs for the cervical spine and treatment of upper limb radicular pain.
A prospective study by Rowlingson and Kirschenbaum described significant reduction in upper limb pain after cervical ESIs, and other studies retrospective and prospective identified radicular pain relief via interlaminar and transforaminal approaches. Given the similar mechanisms of radicular pain postulated for the lumbar and cervical regions, compelling evidence regarding the efficacy of lumbar ESIs might be applicable to treatment of upper lumbar interlaminar ESIs.
A systematic review included fluoroscopically guided 15 randomized trials and 11 nonrandomized studies. The evidence is good for radiculitis secondary to disk herniation with local anesthetics and steroids and fair with local anesthetic only, whereas it is fair for radiculitis secondary to spinal stenosis with local anesthetic and steroids and fair for axial pain without disk herniation with local anesthetic with or without steroids.
In terms of potential efficacy, transforaminal cervical ESIs are preferred over the interlaminar approach by several authors, because the transforaminal cervical injections allow for the delivery of higher concentrations of medications to isolated nerve roots and neuroforamina where stenosis may be present.
A systematic review of cervical interlaminar epidural injections concluded that such injections are effective for relief of cervical radicular pain in the upper limbs; the report strongly recommended the procedure. However, there were no randomized trials identified in this review. Therefore, it is recommended that ESIs be performed under fluoroscopic guidance and with radiographic contrast documenting appropriate placement in order to improve the safety, accuracy, and potential efficacy of ESIs.
Fluoroscopy in conjunction with contrast is used to improve efficacy and minimize potential complications. Furman and coauthors discovered that for lumbar spine ESIs, using flash or positive blood aspirate to predict intravascular injections was Again, a visible flash of blood in the needle hub or positive aspiration of blood demonstrated similar specificity and sensitivity to the lumbar injection study.
In a prospective study involving patients who underwent single-level lumbar transforaminal epidural injection, simultaneous epidural and vascular injection was found to be 8.
Therefore, live fluoroscopy is recommended during contrast injection for confirmation of lumbosacral transforaminal epidural injections.
When performed by a skilled, experienced clinician in an appropriate setting and with carefully selected patients, the chance of significant complication from ESIs is remote. Nonetheless, similar to regional analgesia procedures, there are risks associated with ESIs.
The more common risks from lumbar epidural injections are as follows:. Cervical ESIs carry similar risks, with the apparent caveat that any damage to the spinal cord at the level of the cervical spine often results in greater impairment than damage at the lumbar levels and may precipitate respiratory arrest at higher cervical levels.
There is the risk of spinal cord trauma if the operator performs direct injection into the spinal cord via an interlaminar approach, a risk that is essentially absent at the lower lumbar spine, since the spinal cord terminates at the level of L2. Cord trauma can also result from compression of the spinal cord from an epidural abscess or an epidural hematoma.
Despite these risks, most agree that complications are minimal when ESIs are performed by a physician with the proper equipment, training, and technique. An anatomic study of 95 cervical intervertebral neuroforamina in 10 embalmed cadavers was conducted. Twenty-one arterial branches were found in the posterior aspect of neuroforamina.
Seven of them were potential radicular or segmental medullary vessels to the spinal cord. There were variable anastomoses between vertebral arteries and cervical arteries. The study demonstrated that the critical arteries are found in the posterior aspect of the intervertebral neuroforamina and that they may be vulnerable to injection or injury during transforaminal ESI.
Therefore, aside from the use of live-time fluoroscopy with contrast injection during the cervical transforaminal ESIs to visualize and avoid intravascular injections, the use of smaller-particulate corticosteroid preparations was also recommended to further reduce the risk of central nervous system infarct. Digital subtraction angiography DSA has demonstrated the ability to be able to pick up more venous flow and nonvisible arterial flow during cervical transforaminal ESIs.
Using smaller-particulate corticosteroid such as dexamethasone may reduce the probability of vascular embolism in case of inadvertent intraarterial needle placement during ESIs. A randomized study comparing the effectiveness of dexamethasone and triamcinolone used in cervical transforaminal epidural injection found that at 4 weeks postinjection, both groups exhibited statistically and clinically significant improvement. Although the dexamethasone was slight less effective than triamcinolone, the difference was neither statistically nor clinically significant.