CT-guided transforaminal cervical and lumbar epidural injections

Counterpoint: Conventional Fluoroscopy-Guided Selective Cervical Nerve Root Block-A Safe, Effective, and Efficient Modality in the Hands of an Experienced Proceduralist

BACKGROUND AND PURPOSE

The conventional fluoroscopy-guided (CF) selective cervical nerve root block (SCNRB) is being used commonly as a treatment for cervical radicular pain as well as a diagnostic tool. This study aimed to identify any major complications and determine the safety and clinical utility of CF-SCNRB performed in a university hospital and associated outpatient clinics.

MATERIALS AND METHODS

Two-hundred fifty-four conventional fluoroscopy-guided selective cervical nerve root blocks were retrospectively identified from 2011 to 2018 using a radiology report search tool. Each procedure was performed by an experienced neuroradiologist performing spinal injections on a full-time basis in clinical practice. A 10-point pain scale was used for pre- and postprocedural pain-level assessment. Successful conventional, fluoroscopy-guided, selective cervical nerve root block was defined as a patient-reported pain scale reduction of at least 50% and/or alleviation of numbness or paresthesia at ≥2 weeks postinjection. All clinically important immediate and delayed complications were also recorded.

RESULTS

Two-hundred fifty-four conventional fluoroscopy-guided selective cervical nerve root blocks were performed via an anterolateral approach with an average fluoroscopy time of 24.3 seconds for all cases. There were no aborted procedures and no major or permanent complications. There were 14 minor complications; 12 of these were periprocedural and resolved by the 2-week follow-up visit. One-hundred eighty-five patients (75.2%) reported pain improvement of >50% from baseline at 15 minutes postinjection. Overall, 172 patients (67.7%) reported >50% pain scale reduction or alleviation from paresthesia at least 2 weeks postinjection.

CONCLUSIONS

Conventional fluoroscopy-guided selective cervical nerve root block is an efficacious, efficient, and safe outpatient procedure when performed by a skilled and experienced proceduralist.

Spinal Cord Injury by Direct Damage During CT-Guided C7 Transforaminal Epidural Steroid Injection

Cervical transforaminal epidural steroid injection (TFESI) under the guidance of computed tomography (CT) can offer great anatomical resolution and precise needle placement in the axial plane. However, some complications, including blood pressure surge, allergic reactions, vasovagal syncope, and cerebral infarct, have been reported after CT-guided cervical TFESI. We report the first case of iatrogenic spinal cord injury during a CT-guided cervical TFESI. A 67-year-old woman, upon receiving TFESI on Lt. C7, experienced an electrical shock-like sensation throughout the body. The patient complained of weakness in the left upper and lower extremities (manual muscle testing grade: 2-4) and neuropathic pain (numeric rating scale: 9) in the left upper and lower extremities. Cervical magnetic resonance imaging (MRI) performed 9 days after TFESI showed a high T2 signal at the left side of the spinal cord from levels C5 to C7, and an electrophysiological study performed 14 days after TFESI revealed corresponding findings with cervical MRI. Three months after finishing treatment with a high dose of intravenous methylprednisolone, the patient's motor weakness improved, but it did not recover fully.

Safety of CT-guided cervical nerve root corticosteroid injections

INTRODUCTION

Computed tomography-guided cervical nerve root corticosteroid injections are a commonly performed procedure for cervical radiculopathy. There have been major complications such as spinal cord infarction and posterior circulation stroke reported mostly with X-ray fluoroscopic-guided methods, however, there is relatively little data on the safety of newer CT-guided methods. The purpose of this study was to identify any major complications and evaluate the rate of minor complications from CT-guided cervical nerve root corticosteroid injections performed in a tertiary public hospital.

METHODS

Four hundred and three CT-guided cervical nerve root injection procedures were identified over a period from July 2015 to January 2018 using the radiology information system (RIS) and data collected about the technique and any immediate complications. Patient follow-up and delayed complications were then reviewed, either via outpatient clinic records or telephone consultation.

RESULTS

Two hundred and eighty-six procedures were performed by radiology registrars or fellows, and 117 by radiologists, most commonly via an anterolateral approach and injecting 4 mg (in 1 mL) of dexamethasone. Follow-up data were obtained for all 403 procedures and identified 16 minor complications, but no major neurovascular complications.

CONCLUSION

The overall recorded rate of minor complications with CT-guided nerve root injection was 4.0% with no major neurovascular complications, suggesting that CT-guided transforaminal cervical corticosteroid injection is a safe procedure.

Science to Practice: What Causes Arterial Infarction in Transforaminal Epidural Steroid Injections, and Which Steroid Is Safest?

Transforaminal epidural steroid injections (TFESIs) are associated with rare but devastating neurologic complications. Every published case has been associated with a particulate steroid suspension, and the presumed but not proven mechanism is embolization and occlusion of end arterioles. Through an in vivo murine model and in vitro experiments on human red blood cells (RBCs), the study by Laemmel et al (1) in this issue of Radiology elucidates the potential mechanisms for steroid-induced vascular compromise. Unlike dexamethasone (a nonparticulate steroid solution), saline, and the particulate steroid cortivazol, other particulate steroids (prednisolone, methylprednisolone, and triamcinolone) caused often immediate and complete cessation of capillary blood flow, with RBC (not steroid particle) aggregates and alteration of RBC morphologic structure into spiculated RBCs. Thus, the study strengthens evidence in support of the higher safety profile in TFESI for dexamethasone, the nonparticulate and U.S. Food and Drug Administration-recommended steroid of choice, compared with particulate steroids. The results should not be considered proof that cortivazol has not or could not cause neurologic infarction during a TFESI. Rather, experiments such as those by Laemmel et al should foster more research, particularly in the arena of novel therapeutic agents (nonparticulate steroids and nonsteroidal drugs alike).

Safety of CT-Guided Lumbar Nerve Root Infiltrations. Analysis of a Two-Year Period

Selective nerve root infiltrations are frequently performed in patients with lumbar radiculopathy. Computed tomography (CT) is now commonly used for image guidance. Despite the widespread use of CT-guided lumbar nerve root infiltrations few studies have systematically examined the safety of this approach. In a two-year period, 231 lumbar nerve root infiltrations were performed on in-patients and were retrospectively reviewed. No major complications like inflammation (especially spondylodiscitis), large haematomas requiring surgery, severe allergic reactions or spinal ischaemia occurred. In accordance with other published studies, CT-guided lumbar nerve root infiltrations seem to be safe. To minimize the risk of catastrophic neurological complications due to spinal ischaemia, careful needle placement dorsal to the nerve root and the use of a non-particulate corticosteroid, like dexamethasone, are advocated.

Cervical radicular pain: the role of interlaminar and transforaminal epidural injections

Chronic neck pain and cervical radicular pain are relatively common in the adult population. Treatment for chronic radicular pain recalcitrant to conservative management includes surgical management as well as interventional techniques with epidural injections utilizing either an interlaminar approach or transforaminal approach. Although there have been multiple systematic reviews and randomized clinical trials of cervical interlaminar epidural injections, the literature is sparse in reference to cervical transforaminal epidural injections. Overall, there is good evidence for the effectiveness of cervical interlaminar epidural injections in managing cervical disc herniation and fair evidence in managing central spinal stenosis and postsurgery syndrome. The evidence is poor, however, for cervical transforaminal epidural injections. Complications with cervical interlaminar epidural injections are rare, but more commonly occur with transforaminal epidural injections and can be fatal. Emerging concepts in pain include further randomized trials; proper placebo design; focus on control design (either active control or placebo control); and appropriate methodologic quality assessment and evidence synthesis.