Ultrasound-Guided Lumbar Transforaminal Epidural Injection: A Narrative Review

Guidance of Nerve Stimulator and Ultrasound for Transforaminal Epidural Steroid Injection in Lumbosacral Radicular Pain : A Single Institution Experience in Vietnam

OBJECTIVE

This study aimed to evaluate the clinical feasibility of the combination of ultrasound and nerve stimulator guidance in transforaminal epidural steroid injections (TESIs) to manage lumbosacral chronic radicular pain.

METHODS

Using the combination of nerve stimulator and ultrasound guidance, TESIs were performed in 125 segments of 78 patients who presented with chronic lumbar radicular pain. Demographic characteristics and surgical outcomes were recorded on admission, pre-procedural and post-procedural for 1-week, 1-month, 3-month, and 6-month follow-ups. The result was measured using the Numeric rating scale (NRS) and Oswestry disability index (ODI).

RESULTS

Patients who received TESIs showed significant improvements on two evaluation tools (NRS, ODI), compared to that before procedure (p<0.001). No significant complications were observed for 6 months' follow-up.

CONCLUSION

The result suggests that a combination of ultrasound and nerve stimulator guidance in transforaminal epidural injections is safe, reliable and effective for short-term management of lumbar disc herniation. It is a promising technique and has shown good results in providing intermediate pain relief.

Accuracy of Ultrasound-Guided Needle Placement on the L5 Lumbar Nerve Root: A Cadaveric Study

OBJECTIVES

The aims of the study are to analyze and describe the accuracy of an ultrasound-guided approach to target the L5 root in cadaveric specimens and evaluate whether gender differences exist.

DESIGN

A cross-anatomical study on 40 cadaver L5 nerve roots was performed. A needle was introduced until contacting the L5 nerve root using ultrasound guidance. After that, specimens were frozen and studied by a cross-anatomical view to see the needle's path. The angulation, length, distance from the vertebral spine, the relevant ultrasound anatomical references, and the accuracy of the procedure were evaluated.

RESULTS

The needle tip reached the L5 root at a 72.5% rate. The mean angulation degrees of the needle relative to the skin surface were 75.53 ± 10.17 degrees, the length of the needle inserted was 5.83 ± 0.82 cm, and the distance from the vertebral spine to the point of entry of the needle was 5.39 ± 1.44 cm.

CONCLUSIONS

An ultrasound-guided technique can potentially be an accurate technique to perform invasive procedures on the L5 root. There were statistically significant differences between males and females in the length of the needle introduced. If the L5 root is not clearly visualized, ultrasound will not be the technique of choice.

Selective Nerve Root Block in Treatment of Lumbar Radiculopathy: A Narrative Review

Selective Nerve Root Block (SNRB) is a precise local injection technique that can be utilised to target a particular inflamed nerve root causing lumbar radiculopathy for both diagnostic and therapeutic purposes. Usually, for SNRB to be therapeutic, a combination of a local anaesthetic agent and a steroid is injected under imaging guidance, whereas for diagnostic purposes, just the local anaesthetic agent is injected. While the ideal treatment strategy is to relieve the nerve root from its compressing pathology, local injection of steroids targeted at the affected nerve root can also be attempted to reduce inflammation and thus achieve pain relief. Although the general principle for administering an SNRB remains largely the same across the field, there are differences in techniques depending on the region and level of the spine that is targeted. Moreover, drug combinations utilised by clinicians vary based on preference. The proven benefits of SNRBs largely outweigh their risks, and the procedure is deemed safe and well tolerated in a majority of patients. In this narrative, we explore the existing literature and seek to provide a comprehensive understanding of SNRB as a treatment for lumbar radiculopathy, its indications, techniques, outcomes, and complications.

The Role of Power Doppler Ultrasonography in Caudal Epidural Injection

Background and Objectives: Although the ultrasound-guided technique is used in caudal epidural injections, severe complications can happen if ultrasound cannot identify the occurrence of intravascular injection. To determine intraepidural and intravascular injection during caudal epidural injections, we used power Doppler ultrasonography (PDU) when injecting medications into the epidural space. Materials and Methods: This is a retrospective study that enrolled a total of 277 patients with refractory low back pain or degenerative disc from January 2019 to December 2019. The injectate flow of caudal epidural injections was examined with the assistance of PDU and confirmed by fluoroscopy. Four flow patterns were identified by PDU in our study: the “Earthworm sign,” the “Patch sign,” the ”Tubular sign” and the “Absent flow sign.” The accuracy of PDU in identifying intraepidural and intravascular injections was determined by fluoroscopy images recorded during each injection. Results: We evaluated 277 patients (mean age, 68.6 ± 13.2 years; 106 men). The “Patch sign” showed a sensitivity of 88.76% and a specificity of 80% in predicting epidural injection without intravascular injection. The “Earthworm sign” demonstrated a sensitivity of 70% and a specificity of 100% in detecting intravascular injection. The “Tubular sign” showed a specificity of 100% and a sensitivity of 9.4% in predicting successful epidural injection. The absence of a flow signal showed a sensitivity of 1.87% and a specificity of 90% in predicting successful epidural injection. Conclusions: Ultrasound-guided caudal epidural injection can accurately determine intraepidural and intravascular injections with the assistance of PDU and is thus a good alternative technique to fluoroscopy-guided caudal epidural injection.

Ultrasound and nerve stimulator guidance lumbar transforaminal epidural block for the treatment of patients with lumbosacral radicular pain

Transforaminal epidural block (TEB) is a widely accepted technique and minimally invasive procedure for the treatment of lumbosacral radicular pain. This study aimed to evaluate the accuracy, efficacy, and safety of ultrasound and nerve stimulator guidance lumbar transforaminal epidural block (UNTEB) for the patients with unilateral lower lumbar radicular pain. The accuracy of this method was evaluated by fluoroscopy. Using UNTEB via axial and the in-plane approach technique was performed in 42 segments of 25 patients who presented with lumbosacral radicular pain to lower extremities. The contrast medium was injected to evaluate the needle tip at the intervertebral foramen under fluoroscopic guidance. The numerical rating scale was used to assess pain before and after treatment. The success ratio of UNTEB in L3/L4 level was 100%, in L4/L5 was 95.4% and in L5/S1 was 100%. The numerical rating scale (NRS) for lumbosacral radicular pain improved from a mean from 7.8 to 2.8 1 day after procedure (p = 0.01) and from a mean from 7.8 to 2.4 1 week after UNTEB (p = 0.01). None of our subjects experienced any complications during and after the procedure. UNTEB with fluoroscopic validation is an accurate, effective, and safe method for short-term pain relief of the patients with unilateral lumbosacral radicular pain.