Dispersal pattern of injectate after lumbar interlaminar epidural spinal injection evaluated with computerized tomography

Dispersal Pattern of Injectate After Cervical Epidural Steroid Injection Evaluated With Magnetic Resonance Imaging

STUDY DESIGN

Prospective, nonrandomized, clinical study.

OBJECTIVE

Epidural steroid injections (ESIs) are an important diagnostic and treatment modality for spine pathology. The success of these injections has been attributed to the anatomic location reached by the injectate. This study evaluates injectate dispersal patterns after cervical interlaminar ESI using magnetic resonance imaging (MRI).

METHODS

Patients between the ages of 18 and 85 years with cervical radiculopathy were identified. After obtaining consent for study participation, a gadolinium-enhanced cervical ESI was administered via an interlaminar approach under fluoroscopic guidance. Study participants underwent a cervical spine MRI within 15 minutes of administering the injection. Craniocaudal dispersal and the presence or absence of circumferential dispersal was assessed.

RESULTS

The injectate dispersed a mean of 8.11 cm in the cranial direction, 6.63 cm in the caudal direction, and 360° circumferentially. No adverse events related to the ESI were reported.

CONCLUSIONS

Fluoroscopy-guided cervical interlaminar ESI resulted in nearly uniform circumferential dispersal within the epidural space with multilevel migration in the cranial and caudal directions. MRI is a safe and accurate tool to evaluate spinal injectate dispersal.

Lumbar Spinal Stenosis Severity by CT or MRI Does Not Predict Response to Epidural Corticosteroid versus Lidocaine Injections

BACKGROUND AND PURPOSE

Epidural steroid injections may offer little-to-no short-term benefit in the overall population of patients with symptomatic spinal stenosis compared with lidocaine alone. We investigated whether imaging could identify subgroups of patients who might benefit most.

MATERIALS AND METHODS

A secondary analysis of the Lumbar Epidural Steroid Injections for Spinal Stenosis prospective, double-blind trial was performed, and patients were randomized to receive an epidural injection of lidocaine with or without corticosteroids. Patients (n = 350) were evaluated for qualitative and quantitative MR imaging or CT measures of lumbar spinal stenosis. The primary clinical end points were the Roland-Morris Disability Questionnaire and the leg pain numeric rating scale at 3 weeks following injection. ANCOVA was used to assess the significance of interaction terms between imaging measures of spinal stenosis and injectate type on clinical improvement.

RESULTS

There was no difference in the improvement of disability or leg pain scores at 3 weeks between patients injected with epidural lidocaine alone compared with corticosteroid and lidocaine when accounting for the primary imaging measures of qualitative spinal stenosis assessment (interaction coefficients for disability score, -0.1; 95% CI, -1.3 to 1.2; P = .90; and for the leg pain score, 0.1; 95% CI, -0.6 to 0.8; P = .81) or the quantitative minimum thecal sac cross-sectional area (interaction coefficients for disability score, 0.01; 95% CI, -0.01 to 0.03; P = .40; and for the leg pain score, 0.01; 95% CI, -0.01 to 0.03; P = .33).

CONCLUSIONS

Imaging measures of spinal stenosis are not associated with differential clinical responses following epidural corticosteroid injection.

Ultrasound-Assisted Lumbar Interlaminar Epidural Dye Injection and Evaluation of Its Distribution by Anatomical Dissection

Background: Epidural steroid injections are frequently used to treat lumbar radicular pain. However, the spread of a solute in the epidural space needs further elucidation. We aimed at assessing the distribution of green dye in the epidural space after lumbar epidural injection on cadavers.

Methods: We performed ultrasound-guided injections of green dye between lumbar vertebrae 4 and 5 in 24 cadavers. The cadavers were randomly divided into group A and B according to the volume of injected dye; 3 ml in group A (n = 13) and 6 ml in group B (n = 11). Accuracy of the needle insertion and patterns and distributions of the spread were compared between the groups. After local dissection, we examined the spread of dye in dorsal and ventral epidural spaces and presented the distribution as whole numbers and quartiles of intervertebral segments. Mann-Whitney U Test was used to compare distribution of dye spread between groups A and B. Wilcoxon Signed-Rank Test was used to compare the spread of dye in cranial and caudal direction within the group. We considered P < 0.05 as significant.

Results: Data were obtained from all 24 cadavers. Median levels of dorsal cranial dye distribution in groups A and B were 2 and 4 (P = 0.02), respectively. In the dorsal caudal−2 and 2, respectively (P = 0.04). In the ventral epidural space cranial dye spread medians were−0 and 2 in groups, respectively (P = 0.04). Ventral caudal spread was 0 and 1, respectively (P = 0.03). We found a significant difference between cranial and caudal dye distribution in group B (P < 0.05). In group A the dye spread was bilateral. In group B cranial and caudal dye spread was observed.

Conclusions: Ventral dye flow was observed in 50% of injections. Bilateral spread of dye occurred in 63%, and more often in group A. Cranial spread was slightly higher than caudal spread in group A despite a smaller injected volume, and significantly higher in group B following a larger volume.

Effectiveness of Bilateral Transforaminal Epidural Steroid Injections in Degenerative Lumbar Spinal Stenosis Patients With Neurogenic Claudication: A Case Series

BACKGROUND

As our population ages, neurogenic claudication (NC) from central canal stenosis of the lumbar spine is becoming an increasingly common condition. Studies have been undertaken to assess the efficacy of caudal, interlaminar, or unilateral transforaminal epidural injections, but bilateral transforaminal epidural injections (BTESIs) have not been evaluated to date.

OBJECTIVE

To assess the therapeutic value and long-term effects of fluoroscope-guided BTESIs in patients with NC from degenerative lumbar spinal stenosis (DLSS) of the central spinal canal.

DESIGN

Case series.

SETTING

Single institution spine clinic.

PATIENTS

Twenty-six adults between the ages of 40 and 90 years with a diagnosis of DLSS and a history of subacute or chronic NC.

METHODS/INTERVENTIONS

Patients meeting inclusion criteria received fluoroscope-guided BTESI of local anesthetic and steroid at the level immediately below the most stenotic level. Patient self-reported pain level, activity level, and overall satisfaction were recorded by telephone interview at 1, 3, and 6 months after injection by an independent observer.

MAIN OUTCOME MEASURES

Pain score and Swiss Spinal Stenosis score at baseline, 1, 3, and 6 months.

RESULTS

Of the 22 participants eligible for analysis, 20, 19, and 18 had follow-up data available at 1, 3, and 6 months, respectively. Reduction in numeric pain scale score of at least 50% was noted in 30% of participants at 1 month, 53% at 3 months, and 44% at 6 months. Swiss Spinal Stenosis subscale scores indicated a significant reduction in the proportion of participants reporting the presence of severe pain in the back, buttocks, and legs (particularly the back or buttocks) at 1, 3, and 6 months of follow-up compared with baseline (P < .05). The proportion of participants reporting severe weakness in the legs or feet also decreased after injection and was statistically significant at 3 months of follow-up (P = .04).

CONCLUSIONS

Fluoroscope-guided BTESI was moderately effective in reducing pain, improving function, and achieving patient satisfaction in patients with NC from DLSS at the central spinal canal in this clinical case series.

LEVEL OF EVIDENCE

IV.