Clinical Application of an Augmented Reality Navigation System for Transforaminal Epidural Injection: A Randomized Controlled Trial

Objectives: Augmented reality (AR) navigation systems are emerging to simplify and enhance the precision of medical procedures. Lumbosacral transforaminal epidural injection is a commonly performed procedure for the treatment and diagnosis of radiculopathy. Accurate needle placement while avoiding critical structures remains a challenge. For this purpose, we conducted a randomized controlled trial for our augmented reality navigation system. Methods: This randomized controlled study involved 28 patients, split between a traditional C-arm guided group (control) and an AR navigation guided group (AR-NAVI), to compare procedure efficiency and radiation exposure. The AR-NAVI group used a real-time tracking system displaying spinal structure and needle position on an AR head-mounted display. The procedural time and C-arm usage (radiation exposure) were measured. Results: All patients underwent successful procedures without complications. The AR-NAVI group demonstrated significantly reduced times and C-arm usage for needle entry to the target point (58.57 ± 33.31 vs. 124.91 ± 41.14, p < 0.001 and 3.79 ± 1.97 vs. 8.86 ± 3.94, p < 0.001). Conclusions: The use of the AR navigation system significantly improved procedure efficiency and safety by reducing time and radiation exposure, suggesting a promising direction for future enhancements and validation.

Role of paraspinal mapping before transforaminal epidural injections for lumbar radiculopathy

Objectives

This study aims to investigate whether electromyography (EMG) including paraspinal mapping (PM) and specific clinical findings before the injection have a predictive role on the results in patients undergoing unilateral transforaminal epidural steroid injection (TFESI).

Patients and methods

In this prospective study, a total of 46 patients (19 males, 17 females; mean age: 44.0±10.8 years; range, 23 to 60 years) with unilateral L5 root compression confirmed by physical examination, EMG and lumbar MRI between March 2013 and January 2014 were included. The patients underwent L5 TFESI. After the injection, they were examined at 1 h, three weeks, and three months.

Results

The clinical findings and presence of acute involvement on EMG were not predictive for TFESI results; however, the patients with lower scores for the L5 segment in PM benefited more from the injection, compared to patients with higher scores for the L5 segment in PM.

Conclusion

In patients with very clearly defined L5 radiculopathy, PM EMG can give us an idea about the effectiveness of L5 TFESI.

A blunt needle (Epimed(®)) does not eliminate the risk of vascular penetration during transforaminal epidural injection

Background:

Transforaminal epidural injection of local anesthetics and corticosteroids is a common practice in patients with radicular pain. However, serious morbidity has also been reported, which can be attributed to an arterial or venous injection of the medication especially particulate glucocorticoid preparations. Using a blunt needle in contrast to sharp needle has been suggested to reduce this risk in a study on animals.

Case Description:

We present a 59-year-old female with L5 lumbar radicular symptoms and left L5-S1 foraminal narrowing who underwent transforaminal epidural injection with fluoroscopic guidance using a 22-gauge blunt curved needle (Epimed^®, Johnstown, NY). Intravascular needle placement was detected during real-time contrast injection under live fluoroscopy after a negative aspiration and local anesthetic test dose. The needle was slightly withdrawn and correct distribution of the contrast was confirmed along the target nerve root and into the epidural space.

Conclusion:

This case report discusses vascular penetration utilizing an Epimed^® blunt needle to perform transforaminal injections in a clinical setting. This topic was previously discussed in earlier animal studies. We also reemphasize that neither negative aspiration or local anesthetic test doses are reliable techniques to ensure the safety of transforaminal epidural injections.

Perineural hematoma following lumbar transforaminal steroid injection causing acute-on-chronic lumbar radiculopathy: a case report

INTRODUCTION

Transforaminal epidural steroid injections (TFESI) are commonly performed for the treatment of lumbar herniated nucleus pulposus and lumbosacral radiculopathy. Although rare, documented complications including spinal cord infarction, paraparesis, epidural abscess, paraplegia, and epidural hematoma have been reported. Here, we present a case of perineural hematoma affecting the L4 nerve root resulting in progressive acute-on-chronic lumbar radiculopathy following TFESI.

CASE REPORT

A 72-year-old female presented with 3 months of low back and right anterior thigh pain. She subsequently underwent right L3 and L4 TFESI for physical examination findings concordant with radiographic right foraminal stenosis at L3-4 and L4-5 with L3-4 spondylolisthesis. Over the following week, the patient reported progressive right lower extremity weakness, worsening sensory loss, and ambulatory dysfunction. Examination revealed mild L3/4 myotomal weakness, sensory changes, and areflexia at the right patella. A gadolinium-enhanced MRI was ordered, which showed focal abnormal signal with involvement of the right L4-L5 neuroforamina and extending slightly far laterally, consistent with a small hematoma, affecting the L4 nerve root. Within 2 months, her strength and reflexes normalized and sensory loss diminished following medical management.

DISCUSSION

Although extremely rare, perineural or foraminal hematomas may occur as a serious complication of TFESI, even in the setting of a standardized procedure. Hematoma may cause worsening of symptoms in the acute and subacute phase following TFESI. Further investigation into the etiologies of such injuries is warranted and must be added to the considerations of pain physicians performing these procedures.

Analysis of influencing factors to depth of epidural space for lumbar transforaminal epidural block in korean

Background

Transforaminal epidural steroid injection is one of the effective treatments in managing radicular pain. There have been some prospective studies on the depth to the epidural space with the transforaminal approach. However, there have been no studies about the depth in Asians, especially Koreans. This study was carried out in order to evaluate the depth to the epidural space and the oblique angle and factors that influence the depth to the epidural space during lumbar transforaminal epidural injection.

Methods

A total of 248 patients undergoing fluoroscopically guided transforaminal epidural steroid injections were evaluated. At the L3-4, L4-5, L5-S1, and S1 levels, we measured the oblique angle and depth to the epidural space.

Results

Needle depth was positively associated with body mass index (correlation coefficient 0.52, P = 0.004). The median depths (in centimeters) to the epidural space were 6.13 cm, 6.42 cm, and 7.13 cm for 50-60 kg, 60-70 kg, and 70-80 kg groups, respectively, at L5-S1. Age and height were not significantly associated with the needle depth.

Conclusions

There is a positive association between the BMI (and weight) and transforaminal epidural depth but not with age, sex, and height.