Size and aggregation of corticosteroids used for epidural injections

The noninferiority of the nonparticulate steroid dexamethasone vs the particulate steroids betamethasone and triamcinolone in lumbar transforaminal epidural steroid injections

OBJECTIVE

To assess whether a nonparticulate steroid (dexamethasone, 10 mg) is less clinically effective than the particulate steroids (triamcinolone, 80 mg; betamethasone, 12 mg) in lumbar transforaminal epidural steroid injections (TFESIs) in subjects with radicular pain with or without radiculopathy.

DESIGN

Retrospective observational study with noninferiority analysis of dexamethasone relative to particulate steroids.

SETTING

Single academic radiology pain management practice.

SUBJECTS

Three thousand six hundred forty-five lumbar TFESIs at the L4-5, L5-S1, or S1 neural foramina, performed on 2,634 subjects.

METHODS/OUTCOME MEASURES

Subjects were assessed with a pain numerical rating scale (NRS, 0-10) and Roland-Morris disability questionnaire (R-M) prior to TFESI, and at 2 weeks and 2 months follow-up. For categorical outcomes, successful pain relief was defined as either ≥50% reduction in NRS or pain 0/10; functional success was defined as ≥40% reduction in R-M score. Noninferiority analysis was performed with δ = -10% as the limit of noninferiority. Continuous outcomes (mean NRS, R-M scores) were analyzed for noninferiority with difference bounds of 0.3 for NRS scores and 1.0 for R-M scores.

RESULTS

With categorical outcomes, dexamethasone was demonstrated to be noninferior to the particulate steroids in pain relief and functional improvement at 2 months. Using continuous outcomes, dexamethasone was demonstrated to be superior to the particulate steroids in both pain relief and functional improvement at 2 months.

CONCLUSION

This retrospective observational study reveals no evidence that dexamethasone is less effective than particulate steroids in lumbar TFESIs performed for radicular pain with or without radiculopathy.

Cervical epidural steroid injections for the treatment of cervical spinal (neck) pain

Cervical epidural steroid injections (CESI) are an accepted treatment for neck pain with a radicular component, and may be accomplished by using either transforaminal (CTFESI) or interlaminar (CILESI) approaches. CESIs are routinely performed using real-time fluoroscopic-guidance in conjunction with the injection of water soluble, iodine-based contrast media to enhance visualization of intravascular injections. Digital subtraction angiography (DSA) imaging is an adjuvant to fluoroscopic methods for visualizing blood vessels while performing spinal injections. However, as with any neuraxial procedure, various complications associated with CESIs have been reported. Complications are directly associated with the technical procedures of CESIs. Particulate steroids may have a prolonged duration of action but non-particulate steroids are safer for CESIs. Blunt-beveled needles are less likely than sharp-beveled needles to penetrate blood vessels to cause bleeding complications during CTFESI procedures. Small doses of local anesthetics appear to be safe and assist in identifying intravascular injections previously overlooked by conventional techniques.

Ultrasound-guided selective nerve root block versus fluoroscopy-guided transforaminal block for the treatment of radicular pain in the lower cervical spine: a randomized, blinded, controlled study

OBJECTIVES

To compare the short-term effects and advantages of ultrasound-guided selective nerve root block with fluoroscopy-guided transforaminal epidural block for radicular pain in the lower cervical spine through assessment of pain relief, functional improvement, and safety.

METHODS

A total of 120 patients with radicular pain from cervical spinal stenosis or cervical herniated disc were enrolled. All procedures were performed using a fluoroscopy or ultrasound apparatus. The subjects were randomly assigned to either the fluoroscopy (FL) or ultrasound (US) group. The complication frequencies during the procedures, treatment effects, and functional improvement of the nerve root block were compared at 2 and 12 weeks after the procedures.

RESULTS

Verbal Numeric Pain Scale (VNS) improved 2 weeks and 12 weeks after the injections in both groups. Statistical differences were not observed in VNS, Neck Disability Index (NDI), and effectiveness between the groups. In 21 patients at US, vessels were identified at the anterior aspect of the foramen. Eleven patients had a critical vessel at the posterior aspect of the foramen and five patients had on artery continue medially into the foramen, forming, or joining a segmental feeder artery. In both cases, the vessels might well have been in the pathway of the needle correctly positioned under fluoroscopic guidance. Five cases of intravascular injections were observed only in FL without significant difference between the groups.

CONCLUSIONS

The US-guided method may facilitate identifying critical vessels at unexpected locations relative to the intervertebral foramen and avoiding injury to such vessels, which is the leading cause of the reported complications from cervical transforaminal injections. On treatment effect, using either method of epidural injections to deliver steroids for cervical radicular pain, secondary to herniated intervertebral disc or foraminal stenosis, significant improvements in function and pain relief were observed in both groups after the intervention. However, significant difference was not observed between the groups. Therefore, the ultrasound-guided method was shown to be as effective as the fluoroscopy-guided method in pain relief and functional improvement, in addition to the absence of radiation and avoiding vessel injury at real-time imaging.

Epidural steroid injections

Epidural steroid injection (ESI) is the most commonly performed intervention in pain clinics across the United States. This article provides an evidence-based review of ESI, including data on efficacy, patient selection, comparison of types, and complications. The data strongly suggest that ESI can provide short-term relief for radicular symptoms but are less compelling for long-term effects or relief of back pain. Although it has been asserted that transforaminal ESIs are more efficacious than interlaminar injections, the evidence supporting this is limited.

An anatomically based approach to intralesional corticosteroid injection for eyelid capillary hemangiomas

BACKGROUND AND OBJECTIVE

To describe a corticosteroid injection technique for eyelid capillary hemangiomas that minimizes the risk of a central retinal artery occlusion and is based on anatomic, physiologic, and pharmacologic rationales.

PATIENTS AND METHODS

In this retrospective, non-comparative, interventional case series, the medical records of 50 eyes of 50 patients over a 10-year period were reviewed for retinal complications associated with the described injection technique.

RESULTS

Ophthalmoscopy showed no retinal complications in the 50 eyes treated with this injection technique.

CONCLUSION

The risk of central retinal artery occlusion from retrograde embolization can be minimized by using an anatomically based injection technique that prevents canalization of an artery and avoids injection pressures exceeding the mean systemic arterial pressure.

Injectable corticosteroid preparations: an embolic risk assessment by static and dynamic microscopic analysis

BACKGROUND AND PURPOSE

Transforaminal CS injections have been associated with severe adverse CNS events, including brain and spinal cord infarction. Our purpose was to describe the static and dynamic microscopic appearances of CS preparations, with an emphasis on their potential to cause adverse central nervous system events by embolic mechanisms during transforaminal injection.

MATERIALS AND METHODS

Pharmaceutical preparations of nondilute injectable CSs were used after appropriate mixing: MPA (40 mg/mL), TA (40 mg/mL), and DSP (8 mg/2 mL). For dynamic imaging, a novel methodology was devised to replicate the flow of crystals within spinal cord arterioles. In addition, CS preparations were mixed with plasma to assess for changes in crystal size, morphology, and tendency to aggregate.

RESULTS

The CS preparations MPA and TA are composed of crystals of varying sizes. MPA crystal size range was 0.4-26 μm (mean, 6.94 μm), TA crystal size range 0.5-110 μm (mean, 17.4 μm), and DSP did not contain any significant crystals or particles. There was no change in the crystal morphology or propensity to aggregate after mixing with local anesthetic. After mixing with plasma, the crystals also were unchanged; however, there was a significant reduction in the size of aggregates. On dynamic imaging, these aggregates were proved to maintain their integrity and to act as potential embolization agents.

CONCLUSIONS

MPA and TA have a substantial risk of causing infarction by embolization if inadvertently injected intra-arterially at the time of TFESI. DSP is completely soluble and microscopically has no potential to obstruct arterioles. When performing cervical TFESI procedures, the administration of insoluble CSs should be avoided.

Inadvertent injection of a cervical radicular artery using an atraumatic pencil-point needle

STUDY DESIGN

Case report and review of the literature.

OBJECTIVE

To report the first case of inadvertent injection of a cervical radicular artery using an atraumatic pencil-point needle.

SUMMARY OF BACKGROUND DATA

Rare complications from cervical transforaminal epidural corticosteroid injection have resulted in infarction of the spinal cord and brain. The most often-hypothesized mechanism is inadvertent intra-arterial injection of particulate corticosteroids with a resulting embolus and infarction.

METHODS

Retrospective review of a patient's history and fluoroscopic imaging.

RESULTS

A 30-year-old man with a diagnosed cervical radiculopathy underwent a right C6-C7 transforaminal epidural corticosteroid injection, using a 25-gauge 3.5-inch Whitacre spinal needle. Simultaneous epidural and radicular artery spread were observed under live fluoroscopy. The patient suffered no complications from the procedure.

CONCLUSION

This case demonstrates that the use of pencil-point (Whitacre) needles does not eliminate the risk of inadvertent arterial injection during cervical transforaminal epidurals. Further investigation is required to determine whether the incidence of inadvertent vascular injection is reduced with pencil-point needles compared with sharp-beveled needles.

Comparison of the effectiveness of lumbar transforaminal epidural injection with particulate and nonparticulate corticosteroids in lumbar radiating pain

OBJECTIVE

Lumbar transforaminal epidural steroid injections are procedures often utilized in the treatment of low back pain associated with radicular pain. Particulate steroids have been known to play a role in embolism. It is, unknown whether nonparticulate steroids are as effective as particulate steroids. To investigate the effect of an epidural steroid injection on back pain, we conducted a randomized, controlled trial comparing nonparticulate steroid with particulate steroid to treat lumbar disc herniation.

DESIGN

One hundred-six patients were randomized to receive lumbar transforaminal epidural steroid injections (N = 53) with either dexamethasone 7.5 mg, or with triamcinolone acetate 40 mg (N = 53). Measurement were taken before treatment and one month after treatment using a visual analog scale, short McGill pain questionnaire, and revised Oswertry Back Disability Index.

RESULTS

There was a statistically significant difference in the visual analog score between those treated with dexamethasone and those given triamcinolone. The two groups did not differ significantly on the McGill Pain Questionnaire, or the Oswestry Disability Index before and after treatment.

CONCLUSION

In this study, dexamethasone and triamcinolone treatments were shown to have different effects on low back pain with sciatica, with triamcinolone being more effective than dexamethsone in lumbar radiculopathy.

Pharmaceuticals used in image-guided spine interventions

As image-guided (nonvascular) spine interventions have become progressively more common in the interventional radiologic community, there is a growing need for physician expertise regarding the materials and pharmaceuticals that are used for these procedures. This article is intended to provide information to address these needs.

Lumbar epidural steroid injections: indications, contraindications, risks, and benefits

The clinical use of lumbar epidural steroid injections has increased dramatically. Although there are certainly beneficial effects to using epidural steroid injections in a treatment regimen for lumbar radicular pain, there is a lack of well designed, placebo-controlled studies to define conclusively specific indications and techniques for different spinal diagnoses. This article reviews the pathophysiology of lumbar radiculopathy and the use of epidural steroid injections as one treatment option, as well as describes their risks and benefits. Based on current literature, we offer an evidence-based perspective regarding rational use of lumbar epidural steroid injections for certain indications and treatment goals.

Paraplegia following image-guided transforaminal lumbar spine epidural steroid injection: two case reports

OBJECTIVE

To present two case reports of a rare but devastating injury after image-guided, lumbar transforaminal injection of steroids, and to explore features in common with previously reported cases.

BACKGROUND

Image (fluoroscopic and computed tomography [CT])-guided, lumbar transforaminal injections of corticosteroids have been adopted as a treatment for radicular pain. Complications associated with these procedures are rare, but can be severe.

CASE REPORTS

An 83-year-old woman underwent a fluoroscopically guided, left L3-L4, transforaminal injection of betamethasone (Celestone Soluspan). A 79-year-old man underwent a CT-guided, right L3-L4, transforaminal injection of methylprednisolone (DepoMedrol). Both patients developed bilateral lower extremity paralysis, with neurogenic bowel and bladder, immediately after the procedures. Magnetic resonance imaging scans were consistent with spinal cord infarction. There was no evidence of intraspinal mass or hematoma.

CONCLUSION

These cases consolidate a pattern emerging in the literature. Distal cord and conus injury can occur following transforaminal injections at lumbar levels, whether injection is on the left or right. This conforms with the probability of radicular-medullary arteries forming an arteria radicularis magna at lumbar levels. All cases used particulate corticosteroids, which promotes embolization in a radicular artery as the likely mechanism of injury. The risk of this complication can be reduced, and potentially eliminated, by the utilization of particulate free steroids, testing for intra-arterial injection with digital subtraction angiography, and a preliminary injection of local anesthetic.

Injectable corticosteroid and local anesthetic preparations: a review for radiologists

Corticosteroids and local anesthetics are some of the most commonly administered medications in radiology departments. These medications have marked variability in their formulations, which may increase their adverse event profile for specific procedures. In particular, certain corticosteroid preparations are associated with adverse central nervous system (CNS) sequelae. This is most likely due to distal embolization by particulate formulations. Nonparticulate steroid formulations are not associated with such events. Local anesthetics have severe CNS and cardiac adverse effects if injected intravascularly and have recently been associated with intraarticular chondrolysis if used in large doses. This review discusses these medications with particular emphasis on their established and postulated adverse effects. The administering radiologist should be aware of these potential effects and how best to reduce their occurrence.

Complications of transforaminal cervical epidural steroid injections

STUDY DESIGN

A comprehensive literature review.

OBJECTIVES

To review and critically evaluate the past literature focusing on incidence and clinical presentation of complications associated with transforaminal cervical epidural steroid injection (TFCESI) and techniques employed to avoid them. The overall goal is to guide the direction of future research and improve clinical care by increasing awareness of complications and measures that may be undertaken to increase safety.

SUMMARY OF BACKGROUND DATA

TFCESI is a component in the diagnosis and management of cervical radicular syndromes in patients who have failed conservative management. There has been much discussion and also controversy in the recent literature. Considerable attention has been paid to reports of catastrophic complications and proposed measures to avoid them.

METHODS

Medical databases were searched for studies of TFCESI. The bibliographies of these articles were then searched as well. Thoracic and lumbar articles were discarded as were any non-transforaminal cervical procedures or those that did not involve injection into the epidural space. Particular attention was paid to serious neurologic sequelae after TFCESI and its mechanism, as well as techniques being employed to avoid complications.

RESULTS

There are a limited number of studies looking at complications of TFCESI. One retrospective study reported an overall rate of complications of 1.64%. There are reports of serious neurologic sequelae in the literature including brain and spinal cord infarction due to embolic phenomenon of particulate steroids. Cadaveric dissection revealed ascending and deep cervical arterial branches entering the external opening of the posterior intervertebral foramen, the classic target site for TFCESI. Measures to avoid complications mentioned in the literature include the use of nonparticulate steroids, test dose of local anesthetic before injection of steroids, live fluoroscopy, digital subtraction, no to light sedation, use of true lateral view to supplement frontal and oblique views in fluoroscopy, use of blunt needles, and computed tomography guidance.

CONCLUSION

The literature reveals a number of rare, potentially catastrophic neurologic sequelae including brain and spinal cord infarction. Most of these are thought to be due to intravascular uptake of particulate steroids. The true overall incidence remains obscure due to the lack of blinded controlled studies. Injectionists, referring physicians, and patients should be aware of the nature and potential consequences of these complications. Additionally, it is imperative for injectionists to standardize techniques to minimize complications, especially by using a test dose of local anesthetic before injection of preferably nonparticulate corticosteroid.

Complications and pitfalls of lumbar interlaminar and transforaminal epidural injections

Lumbar interlaminar and transforaminal epidural injections are used in the treatment of lumbar radicular pain and other lumbar spinal pain syndromes. Complications from these procedures arise from needle placement and the administration of medication. Potential risks include infection, hematoma, intravascular injection of medication, direct nerve trauma, subdural injection of medication, air embolism, disc entry, urinary retention, radiation exposure, and hypersensitivity reactions. The objective of this article is to review the complications of lumbar interlaminar and transforaminal epidural injections and discuss the potential pitfalls related to these procedures. We performed a comprehensive literature review through a Medline search for relevant case reports, clinical trials, and review articles. Complications from lumbar epidural injections are extremely rare. Most if not all complications can be avoided by careful technique with accurate needle placement, sterile precautions, and a thorough understanding of the relevant anatomy and contrast patterns on fluoroscopic imaging.