New Optimal Needle Entry Angle for Cervical Transforaminal Epidural Steroid Injections: A Retrospective Study

Safety of cervical transforaminal epidural steroid injections

Background

In 2014 the FDA issued a drug safety warning that steroids in the epidural space may result in rare but serious neurological adverse events. The FDA identified 131 cases of neurological adverse events and most complications were related to cervical transforaminal epidural injections (TFESIs). These complications occurred before the standard use of non-particulate steroids. Many still consider cervical TFSEIs to be unsafe.

Objectives

The objective of this study was to evaluate the safety of cervical TFESIs with non-particulate steroids.

Methods

A review was done of all cervical TFESIs from 2004 to 2021 at an academic institution when non-particulate steroids became more commonly used by reviewing CPT code 64479 linked to the performing physician. All treating physicians and department directors were queried about catastrophic complications (stroke, spinal cord injury, death or other). A secondary analysis was done on 200 consecutive cervical TFESIs looking at immediate and delayed side-effects documented by the nurse in recovery, day-after phone calls and clinic follow-up notes.

Results

From 2004 to 2021 the CPT code 64479 was used 6967 times, with 6241 cervical TFESIs and 726 thoracic TFESIs. No catastrophic complications occurred. In the subset analysis of 200 consecutive cervical TFESIs, 7 patients (3.5 %, 95 % CI 1.0-6.0) had a transient increase in pain, 18 (9 %, 95 % CI 5.0-13.0) had no change in pain and 171 (85.5 %, 95 % CI 80.6-90.4) had a decrease in pain. The average pain score among all participants dropped 3.7 (95 % 3.0-4.4) points. A 2-point drop was seen in 75.5 % (95 % CI 69.5-81.5) and a 3-point drop was seen in 62.5 % (95 % CI 59.1-65.9). Five of the seven patients with transient increased pain had an increase of ≥ 3 points on numerical rating scale. There was one of each of the following reported: insomnia, glucose >500, transient thumb numbness with pain, and hypertension. Two cases of headaches were reported.

Conclusion

This study supports the safety of cervical TFESIs with non-particulate steroids as recommended by consensus opinions from medical societies.

Inter-rater reliability of MRI superior articular process angle measurement for use in the modified approach to cervical transforaminal epidural steroid injections

Background

Upper extremity radicular pain is commonly treated with a cervical transforaminal epidural steroid injection (CTFESI). Recently, a new technique, the modified approach CTFESI, has been developed with a theoretical safety advantage to avoid the neurovascular structures. This approach requires an angle measurement of the superior articular process (SAP) on MRI. The inter-rater reliability of this angle measurement among practicing physicians is yet to be investigated.

Objective

The purpose of this study was to determine the inter-rater reliability of SAP angle measurements on MRI.

Methods

Three raters independently measured the SAP angle on 50 cervical MRIs. A two-way, mixed effects, absolute agreement, single rater statistical model was used to determine the intraclass correlation coefficient (ICC) between all three raters, as well as between each pair of raters.

Results

Inter-rater reliability among all raters showed good reliability with an ICC ​= ​0.837709 (95% CI 0.75-0.9, p ​< ​0.001). Similarly, good inter-rater reliability was found between each of the pairs of raters.

Conclusion

This study demonstrates good inter-rater reliability of MRI SAP angle measurement among clinicians for use in the modified CTFESI approach.

Ultrasound-Guided Cervical Intervertebral Disc Injection Without Fluoroscopy

Cervical disc degeneration commonly results in referred neck pain, which is traditionally diagnosed via fluoroscopy-guided provocative discography. Herein, we discuss three cases of neck and shoulder pain treated with cervical intradiscal injections administered under ultrasound (US) guidance. The most painful intervertebral disc was identified using the sonopalpation technique, which involved palpation while visualizing anatomical structures using US. Injectant spread within the intervertebral disc was validated using superb microvascular imaging rather than fluoroscopy. Symptoms significantly improved following blocks at the identified sites, suggesting that US can be used to guide cervical intradiscal injections even in the examination room.

Single center experience on the rate of discontinuation and safety of cervical transforaminal epidural steroid injections using the modified approach in an office setting without sedation

Background

Cervical transforaminal epidural steroid injections (CTFESI) are commonly used in the treatment of upper extremity radicular pain. Recently, a modification of the conventional technique has been developed and validated which has a theoretical safety advantage of less risk of needle contact of the spinal nerve and vertebral artery. The new approach involves a needle trajectory under fluoroscopic guidance which is directly based upon the specific superior articular process angle measurement on MRI.

Objective

The purpose of this study was to evaluate the discontinuation rate of the modified approach CTFESI procedure in a non-sedated patient population. The study was also undertaken to confirm the safety of the procedure in an office-based setting.

Methods

A retrospective review was performed of the authors' (DL, SH) practice to identify all CTFESI using the modified approach, performed between October 2018 through January 2021 through a query of the investigators' (DL and SH) electronic medical record system. Any discontinued CTFESI procedure was identified. The reason for discontinuation was determined through medical record review. In addition, any significant neurologic or cardiovascular event occurring during or immediately following any completed or discontinued CTFESI was identified. Mild vasovagal reaction was not considered a significant complication.

Results

A total of 973 CTFESI procedures were performed using the modified approach during the study period. Twelve procedures, 1.2% (95% CI 0.7-2.1%) were discontinued. Nine were aborted due to vascular flow not resolved with needle repositioning. Only three, 0.3% (95% CI 0.1-0.9) were aborted due to patient intolerance. There were zero significant neurologic or cardiovascular complications.

Conclusion

The performance of the modified approach CTFESI appears to be well tolerated with a very low rate, 0.3%, of discontinuation due to intolerance in non-sedated patients. The zero incidence of neurologic or cardiovascular complication contributes to the current literature on the safety of this procedure.

Modification of the Cervical Transforaminal Epidural Steroid Injection Technique Based Upon the Anatomic Angle of the Superior Articular Process on MRI

Objective

A modification of the conventional technique for cervical transforaminal epidural steroid injection (CTFESI) has been developed. This technique may, theoretically, decrease the likelihood of the needle encountering the vertebral artery and spinal nerve. The approach uses angle measurements of the superior articular process ventral surface from the patient’s axial MRI as a guide for fluoroscopic set-up and needle trajectory. This report aims to compare contrast flow patterns of the modified approach with those of the conventional technique.

Design

Retrospective chart review and prospective blinded analysis of contrast flow patterns. Setting. Outpatient interventional physiatry practice.

Methods

A retrospective blinded qualitative review of fluoroscopic images was performed to compare contrast flow patterns of CTFESIs performed using the modified approach with those using the conventional technique. A detailed description of the modified approach is provided in this report.

Results

Ninety-seven CTFESI procedures were used for flow analysis. The modified approach resulted in a statistically significant greater percentage of injections with epidural flow: 69% [95% CI = 57–82%] modified approach vs. 42% [95% CI = 28–56%] conventional approach. The modified technique also showed a statistically significant higher percent of injections categorized as having an ideal flow pattern, that of predominate epidural and/or intraforaminal flow: 65% [95% CI = 52–78%] vs. 27% [95% CI = 14–40%].

Conclusions

A modification of the conventional CTFESI technique, developed for the purpose of improved safety, may provide superior contrast flow patterns when compared to the conventional approach.

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.

Neck movement during cervical transforaminal epidural injections and the position of the vertebral artery: an anatomical study

Background

Cervical transforaminal epidural steroid injections (CTFESIs) are sometimes performed in patients with cervical radiculopathy secondary to nerve-root compression. Neck movements for patient positioning may include rotation, flexion, and extension. As physicians performing such procedures do not move the neck for fear of injuring the vertebral artery, we performed fluoroscopy and cadaveric dissection to analyze any movement of the vertebral artery during head movement and its relation to the foramina in the setting of CTFESI.

Purpose

To determine cervical rotational positioning for optimized vertebral artery location in the setting of cervical transforaminal epidural steroid injections.

Material and Methods

Four sides from two Caucasian whole cadavers (all fresh-frozen) were used. Using a guide wire and digital subtraction fluoroscopy, we evaluated the vertebral artery mimicking a CTFESI, then we removed the transverse processes and evaluated the vertebral artery by direct observation.

Results

After performing such maneuvers, no displacement of the vertebral artery was seen throughout its course from the C6 to the C2 intervertebral foramina. To our knowledge, this is the first anatomical observation of its kind that evaluates the position of the vertebral artery inside the foramina during movement of the neck.

Conclusion

Special caution should be given to the medial border of the intervertebral foramina when adjusting the target site and needle penetration for the injection. This is especially true for C6-C4 levels, whereas for the remaining upper vertebrae, the attention should be focused on the anterior aspect of the foramen. Since our study was centered on the vertebral artery, we do not discard the need for contrast injection and real-time digital subtraction fluoroscopy while performing the transforaminal epidural injection in order to prevent other vascular injuries.

Needle Entry Angle to Prevent Carotid Sheath Injury for Fluoroscopy-Guided Cervical Transforaminal Epidural Steroid Injection

OBJECTIVE

To suggest rotation angles of fluoroscopy that can bypass the carotid sheath according to vertebral levels for cervical transforaminal epidural steroid injection (TFESI).

METHODS

Patients who underwent cervical spine magnetic resonance imaging (MRI) from January 2009 to October 2017 were analyzed. In axial sections of cervical spine MRI, three angles to the vertical line (α, angle not to insult carotid sheath; β, angle for the conventional TFESI; γ, angle not to penetrate carotid artery) were measured.

RESULTS

Alpha (α) angles tended to increase for upper cervical levels (53.3° in C6-7, 65.2° in C5-6, 75.3° in C4-5, 82.3° in C3-4). Beta (β) angles for conventional TFESI showed a constant value of 45° to 47° (47.5° in C6-7, 47.4° in C5-6, 45.7° in C4-5, 45.0° in C3-4). Gamma (γ) angles increased at higher cervical levels as did α angles (25.2° in C6-7, 33.6° in C5-6, 43.0° in C4-5, 56.2° in C3-4).

CONCLUSION

The risk of causing injury by penetrating major vessels in the carotid sheath tends to increase at upper cervical levels. Therefore, prior to cervical TFESI, measuring the angle is necessary to avoid carotid vessels in the axial section of CT or MRI, thus contributing to a safer procedure.