CT-guided transforaminal epidural steroid injection for discogenic lumbar radiculopathy: influence of contrast dispersion and radiologist’s experience on clinical outcome

Abstract

Objective To investigate the impact of contrast dispersion pattern/location during lumbar CT-guided transforaminal epidural steroid injection (TFESI) and experience of the performing radiologist on therapeutic outcome. Materials and methods In this single-center retrospective cohort study, two observers analyzed contrast dispersion during CT-guided TFESI of 204 patients (age 61.1 ± 14 years) with discogenic unilateral single-level L4 or L5 radiculopathy. The contrast dispersion pattern was classified as “focal,” “linear,” or “tram-track”; the location was divided into “extraforaminal,” “foraminal,” or “recessal.” Pain was assessed before and 4 weeks after treatment using a numerical rating scale (0, no pain; 10, intolerable pain). Additionally, the patient global impression of change (PGIC) was assessed. The TFESI was performed by musculoskeletal radiologists (experience range: first year of musculoskeletal fellowship training to 19 years). Contrast pattern/location and radiologist’s experience were compared between “good responder” (≥ 50% pain reduction) and “poor responder” (< 50%). A p-value < 0.05 was considered to be statistically significant. Results Overall, CT-guided TFESI resulted in a substantial pain reduction in 46.6% of patients with discogenic radiculopathy. The contrast dispersion pattern and location had no effect on pain relief (p = 0.75 and p = 0.09) and PGIC (p = 0.70 and p = 0.21) 4 weeks after TFESI. Additionally, the experience of the radiologist had no influence on pain reduction (p = 0.92) or PGIC (p = 0.75). Regarding pre-interventional imaging findings, both the location and grading of nerve compression had no effect on pain relief (p = 0.91 and p = 0.85) and PGIC (p = 0.18 and p = 0.31). Conclusion Our results indicate that neither contrast agent dispersion/location nor the experience of the radiologist allows predicting the therapeutic outcome 4 weeks after the procedure.

Predictive value of immediate pain relief after lumbar transforaminal epidural injection with local anesthetics and steroids for single level radiculopathy

“…Each procedure was performed by a fellowship-trained musculoskeletal radiologist. To ensure consistency and reproducibility, a standardized injection protocol was used [7]:…”

“…with 8 years of experience in musculoskeletal imaging) analyzing CT-fluoroscopy images of the lumbar steroid injection. According to the description by Germann et al, the contrast location during CT-TFESI was either extraforaminal, foraminal, or recessal, whereas dispersion pattern was classified as either focal non-linear, linear, or tram-track pattern along the targeted nerve root [7].…”

“…al.) [18] reduction, two groups were formed based on the pain score reduction 4 weeks after TFESI in relation to the preprocedural pain score (NRS 0 ): (1) "good responder" with at least 50% reduction in NRS score and ( 2) "poor responder" with below 50% reduction in NRS score 4 weeks after the peri-radicular injection [7,8,20].…”

“…Schematic illustration (left column) and equivalent sagittal T2-weighted MR images at the level of the neuroforamen (right column), depicting the grade of nerve root (arrows) compression. Grade 0, "normal": perineural fat preserved; Grade 1, "mild stenosis": perineural fat obliteration in transverse or vertical direction; Grade 2, "moderate stenosis": perineural fat obliteration in four directions without morphologic change; Grade 3, "severe stenosis": nerve root collapse/morphologic change ( adapted from Lee et al) [19] back pain and radiating leg pain after the TFESI [7,15,21,22]. The possible answers included (1) "much worse," (2) "worse," (3) slightly worse," (4) "no change," (5) "slightly better," (6) "better," and ( 7) "much better.…”

“…The most frequent location of lumbar disc herniations are levels L4-5 and L5-S1, whereas the upper lumbar levels are far less commonly affected [4]. It has been shown that image-guided therapeutic injections with steroids are a viable, safe, and effective treatment in patients with lumbar radiculopathy [5][6][7][8][9]. Hence, it is not surprising that the number of these injections has increased over the last few decades, and most likely will continue to do so in the future [10][11][12][13].…”