Ultrasound-guided Versus Fluoroscopy-controlled Lumbar Transforaminal Epidural Injections: A Prospective Randomized Clinical Trial

Radicular Pain Management Using Ultrasound-Guided Versus Fluoroscopy-Guided Epidural Steroid Injections: A Systematic Scoping Review of Comparative Studies

Back pain is the leading cause of disability globally and results in a substantial medical and economic burden. Epidural steroid injections (ESIs) have been widely used as a treatment for back pain with radiculopathy of various etiologies. Ultrasound guidance (UG) for delivering ESIs can reduce costs and facilitate the procedure in resource-limited settings compared to the current standard technique of using fluoroscopic guidance (FG). This scoping review aimed to compare the clinical outcomes between UG and FG ESIs in the treatment of radicular pain. Systematic searches of Embase, Ovid Medline, Scopus, CENTRAL (Cochrane Central Register of Controlled Trials), CDSR (Cochrane Database of Systematic Reviews), and ClinicalTrials.gov were conducted in accordance with PRISMA-ScR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping reviews) guidelines. Randomized controlled trials (RCTs) and comparative observational studies investigating the outcomes between UG and FG ESIs in the treatment of radicular pain were included. The risk of bias for included RCTs was assessed using the Cochrane Collaboration risk-of-bias tool. From 1,659 potentially relevant publications, eight studies (five RCTs and three retrospective comparative studies) were included. Five of the studies were conducted in the Republic of Korea, one in China, one in India, and one in Egypt. All studies reported no significant difference between UG and FG ESIs in success rate, pain index, and postoperative disability (p > 0.05). One study reported increased intravascular injections in the FG group, but this did not reach statistical significance (p > 0.05). One study reported decreased needle-placement time in the UG group (p < 0.001). One study reported decreased total operation time in the UG group (p < 0.05). Overall, treatment outcomes and adverse events profile are comparable between UG and FG ESIs for radicular pain. UG ESIs reduce costs, minimize radiation exposure, facilitate vessel identification, prevent injury, and potentially save intraoperative time while offering the same benefits as FG injections. Future studies should focus on long-term outcomes, cost-effectiveness, and the impact of UG ESIs on patient satisfaction and quality of life.

A novel simplified sonographic approach with fluoroscopy-controlled L5 transforaminal epidural injections in patients with high iliac crest: a retrospective study

BACKGROUND

To explore a novel ultrasound (US) modality for lumbar transforaminal epidural injections (TFEIs) in patients with low back pain (LBP) and L5 radicular pain combined with high iliac crest (HIC).

METHODS

One-hundred and forty-one patients were retrospectively stratified into two groups based on the treatment they received: novel group, receiving US-guided and fluoroscopy (FL)-controlled TFEIs using a sagittal oblique approach between the superior articular process of L5 and S1, and control group, receiving US-guided TFEIs with conventional transverse approach combined with FL confirmation. Accuracy of contrast dispersing into lumbar epidural space was set as the primary endpoint. Radiation dosages, procedure time, numeric rating scale (NRS) scores, Modified Oswestry Disability Questionnaire (MODQ) scores, adverse events, and rescue analgesic requirement were also recorded. The generalized liner mixed model (GLMMs) was employed to compare the repeatedly measured variables between groups, taking individual confounding factors as covariance.

RESULTS

The accuracy of TFEIs was 92.8% and 65.2% in novel and control group, with a significant difference of 26.7% (95% CI: 15.4%, 39.8%) between two modalities (p < 0.001). Significant pain relief was observed in novel group as opposed to control group after one injection. Procedure time in novel group (8.4 ± 1.6 min) was shorter than control group (15.8 ± 3.5 min) (p < 0.001) with less radiation dosage (3047 ± 5670 vs. 8808 ± 1039 μGy/m2, p < 0.001). Significantly, lower incidence of L5 paresthesia occurred in novel group. Statistical differences of NRS scores between the novel and control group were reached at 1 week after procedure (1 (IQR: - 1-3) vs. 3 (IQR: - 1-7), p = 0.006), while not reached at both 1- (1 (IQR: 0-2) vs. 1 (IQR: - 1-3), p = 0.086) or 3-month follow-up (0 (IQR: - 1-1) vs. 1 (IQR: 0-2), p = 0.094). Both groups showed similar functional improvement (F = 0.103, p = 0.749) during follow-up.

CONCLUSIONS

The novel sonographic technique provided superior accuracy needle placement and better pain-relieving effect through one injection as compared to the routine transverse approach. Consequently, in situations where the HIC imposed limitations for TFEIs performance on L5, the novel technique should be recommended to consider increasing accurate puncture, minimizing radiation exposure, consuming procedure time, and reducing the risk of neuraxial injury.

Ultrasound-Guided Versus Conventional Fluoroscopy-Guided Epidural Injection for Radiculopathy. A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Radiculopathy, a painful condition due to the irritation of a spinal nerve root, is a common neurosurgical presentation. Apart from its conventional treatment with pain killers and surgical management, it can also be managed with epidural steroid injections (ESIs). The objective of this study is to compare ultrasonography (USG) guidance with conventional fluoroscopy (FL) guidance for ESIs to treat radiculopathy.

METHODS

PubMed, Embase, Clinicaltrials.gov, and Cochrane were systematically searched and randomized controlled trials comparing USG with conventional FL for ESIs in the case of radiculopathy were included. Web Revman was used for data analysis.

RESULTS

The Literature search resulted in 640 studies, of which 7 studies were included in this meta-analysis after extensive screening. There was no statistically significant difference in pain reduction between USG and FL groups especially in the case of lumbosacral spinal level at 1 month [mean difference -0.12 (-0.47-0.23)] and at 3 months [mean difference 0.73 (-1.49, 2.96)]. Similarly, functional improvement after ESIs was comparable between the 2 groups. The Risk of inadvertent vascular puncture in USG-guided ESIs was lower as compared to conventional FL-guided ESIs [odds ratio 0.21 (0.07, 0.64)]. Furthermore, the procedure time in the USG group was also significantly lower as compared to FL group.

CONCLUSION

USG-guided ESIs are not only comparable to conventional FL-guided ESIs in terms of pain control and functional improvement, particularly evident at the lumbosacral spinal level, but also have a lower risk of inadvertent vascular puncture.

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.

Comparative efficacy of ultrasound guidance and fluoroscopy or computed tomography guidance in spinal nerve injections: a systematic review and meta-analysis

PURPOSE

Spinal nerve injections have traditionally been performed under fluoroscopic (FL) and computed tomography (CT) guidance. Recently, ultrasound (US)-guided procedures have provided an alternative guidance approach that does not expose the patient and operator to radiation. The aim of this study was to compare the efficacy and safety of US-guided spinal nerve injections compared with FL- or CT-guided spinal nerve injections.

METHODS

MEDLINE, Cochrane Library, EMBASE, international clinical trials registry platform (ICTRP) and ClinicalTrials.gov database searches for inclusion until February 2023 were independently performed by two authors using predefined criteria. Randomized controlled trials (RCTs) were included. Primary outcomes were change in pain score (numeric rating scale or visual analogue scale) and major adverse events. Secondary outcomes were procedure time, change in functional disability score and minor adverse events. Meta-analysis was performed using random-effect model. We evaluated the certainty of evidence based on the Grading of Recommendations, Assessment and Development (GRADE) approach.

RESULTS

Eight RCTs involving 962 patients were included. There might be little to no difference in the mean score of the pain change between the US-guided methods and the FL- or CT-guided injections (standard mean difference -0.06; 95% confidence interval [CI] -0.26 to 0.15). US guidance probably reduced major adverse events (0.7% [3/433] and 6.5% [28/433], respectively), reduced procedure time (mean difference -4.19 min; 95% CI -5.09 to -3.30), and probably reduced minor adverse events (2.1% [9/433] and 4.2% [18/433], respectively) compared with FL or CT guidance. There was probably little to no difference in the change in functional disability score with either method.

CONCLUSION

US-guided spinal nerve injections remained effective and reduced adverse events compared with conventional FL- or CT-guided spinal nerve injections. Further RCTs are required to verify our results.

STUDY REGISTRATION

Open Science Forum (Available from: https://osf.io/vt92w/ ).

Ultrasound-Guided vs. Fluoroscopy-Guided Interventions for Back Pain Management: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The objective of this study was to compare the outcomes of the ultrasound- and fluoroscopy-guided techniques in the management of back pain. Using PubMed, Scopus, and the Cochrane Library, we searched randomized controlled trials (RCTs) published before May 2023, which reported relevant data on the topic. The effectiveness of the ultrasound-guided (US-guided) and fluoroscopy-guided (FL-guided) approaches for back pain management was compared in terms of postoperative pain intensity, postoperative functional outcomes, and postoperative complications. Subgroup analyses were conducted for different postoperative periods. Eight studies were included in the analysis. There was no significant difference in post-procedural pain relief at one week, two weeks, one month, two months, and three months between the US-guided and FL-guided interventions for back pain management (SMD with 95% CI is -0.01 [-0.11, 0.10]), p = 0.91, I2 = 0%). In terms of the postoperative functional outcomes assessed by the "Oswestry Disability Index" (ODI) functionality score, the model tends to favor the FL-guided injections over the US-guided injections (SMD with 95% CI: 0.13 [-0.00, 0.25], p = 0.05, I2 = 0). Finally, the US-guided and FL-guided injections did not show significantly different results in terms of postoperative complications (RR with 95% CI is 0.99 [0.49, 1.99], p = 0.97, I2 = 0). The subgroup analysis also did not demonstrate differences between the US-guided and FL-guided techniques in the following outcomes: vasovagal reaction, transient headache, and facial flushing. There was no significant difference between the US-guided and FL-guided injections for treating back pain in terms of postoperative pain intensity and complications. Still, the model tends to favor the FL-guided injections over the US-guided injections in terms of functionality.

Ultrasound-guided transforaminal epidural injection with fluoroscopy confirmation for the treatment of unilateral lumbar radiculopathy: A randomized controlled non-inferiority study

BACKGROUND

Ultrasound (US)-guided injections for chronic pain has multiple advantages over traditional radiologic method. The study was performed to exam the clinical outcomes of lumbar transforaminal epidural injection (LTFEI) between US and fluoroscopy (FL) guidance for lumbar radiculopathy (LRP).

METHODS

A total of 164 patients with LRP were randomly assigned into US and FL group to receive LTFEI in a 1:1 ratio. Pain relief and functional disability were assessed by numeric rating scale (NRS) and Modified Oswestry Disability Questionnaire (MODQ) scores before treatment, 1 month and 3 months post-intervention. Contrast spread pattern, fluoroscopic image number and complications were also recorded. The primary outcome was accurate rate of contrast dispersing into lumbar epidural space, and non-inferiority margin was predefined at -15 %.

RESULTS

The accuracy of LTFEI was 90.2 % and 91.5 % in US and FL group, and the lower limit of the 95 %CI of mean difference between two modalities (-4.9 % (95 %CI: -12.8 %, 3.1 %)) was above the non-inferiority margin. Procedure time in US group (531.90 ± 67.12 s) was shorter than FL group (904.20 ± 120.20 s) (p < 0.05), while radiation dosage in the US group was lower than in the FL group (3047.20 ± 569.53 vs. 8807.50 ± 1039.10 μGy m², p < 0.001). Both groups didn't differ in pain reduction (F = 1.050, p = 0.306) and functional improvement (F = 0.103, p = 0.749) during follow-up period. No severe complications occurred in both groups.

CONCLUSIONS

US-guided LTFEI confirmed by FL was not inferior to conventional FL method in terms of accurate rate of lumbar epidural contrast dispersion. Effective pain relief and functional ability improvement were comparable between two modalities, and US technique had advantages of less radiation exposure and possible facilitation of avoiding critical vessels around intervertebral foramen.

Image-guided intratumoral immunotherapy: Developing a clinically practical technology

Immunotherapy has revolutionized the contemporary oncology landscape, with durable responses possible across a range of cancer types. However, the majority of cancer patients do not respond to immunotherapy due to numerous immunosuppressive barriers. Efforts to overcome these barriers and increase systemic immunotherapy efficacy have sparked interest in the local intratumoral delivery of immune stimulants to activate the local immune response and subsequently drive systemic tumor immunity. While clinical evaluation of many therapeutic candidates is ongoing, development is hindered by a lack of imaging confirmation of local delivery, insufficient intratumoral drug distribution, and a need for repeated injections. The use of polymeric drug delivery systems, which have been widely used as platforms for both image guidance and controlled drug release, holds promise for delivery of intratumoral immunoadjuvants and the development of an in situ cancer vaccine for patients with metastatic cancer. In this review, we explore the current state of the field for intratumoral delivery and methods for optimizing controlled drug release, as well as practical considerations for drug delivery design to be optimized for clinical image guided delivery particularly by CT and ultrasound.

Ultrasonographic Imaging Protocol and Sonoanatomy of the Lumbar Spine in Healthy Dogs

Ultrasound is an imaging technique commonly used in veterinary medicine. Ultrasound devices are widely available, their means of examination are relatively short and cheap, and they do not generate ionizing radiation. In addition, ultrasound generally does not need to be performed under general anesthesia. This study was performed on 23 canine cadavers with full clinical histories and with no confirmed pathological changes in the spine region. The imaging modalities were established in dogs in lateral recumbency, with the selected side being the uppermost angle, in a neutral position. All dogs were examined in the transverse and longitudinal planes. Sacral crest, intertransverse ligament, vertebral canal floor, vertebral body, and intervertebral discs were only visible in the longitudinal plane. Vertebral arch, supraspinal ligament, dorsal wall of the vertebral canal and muscles were visualized only in the transverse plane. This article provides a brief and relatively easy-to-perform protocol for ultrasound imaging of the lumbar spine of dogs. In addition, it presents a detailed description of the sonoanatomy of the area under investigation.

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.

Technical Report of Color Doppler Ultrasonography-Assisted Lumbar Spinal Interventions

ABSTRACT

Ultrasonography (US) has recently been used more frequently during interventions involving the lumbar spine. However, physicians who are more familiar with musculoskeletal US targeting muscles, tendons, and nerves may find it challenging to perform US-guided lumbar spine interventions using only bony landmarks. This study described the use of color Doppler US for the visualization of the lumbar spinal blood supply to identify vascular landmarks in addition to bony landmarks and thus more easily and accurately perform lumbar spine interventions.

Ultrasound-guided fluoroscopic-verified trans-foraminal lumbar dorsal root ganglion pulsed radiofrequency modulation for radicular pain relief: clinical and cadaveric evaluation of the technique

Background

Ultrasound-guided lumbar pain interventions were thought to be difficult; the high acoustic impedance of bone hides the underling structures and needle path. Reviewing the sonoanatomy of the lumbar region using different planes and angles made better sonographic guidance for spine injections. The aim of this prospective study is to assess the accuracy and safety of ultrasound (US)-guided lumbar trans-foraminal pulsed radiofrequency of the dorsal root ganglion confirmed by fluoroscopic imaging in management of chronic radicular pain.

Results

Thirty-two patients, with 34 lumbar interventions, were included in the study. Thirty-one interventions out of 34 were performed successfully with overall accuracy of 91.18% and with minimal complications. The successful first trial placement of the cannula was calculated in 44.1% of interventions; multiple trials were needed in 47.1% while incorrect level was encountered in 8.8%. Visual analogue scale of pain and Oswestry Disability Index decreased significantly after intervention up to 3 months compared to the pre-intervention value. The analgesic consumption was reduced by mean of 73.44 ± 31.07% 1 month after intervention.

Conclusions

US-guided fluoroscopic-verified trans-foraminal PR of lumbar DRG is accurate, safe, and effective for CRP.

Ultrasound-Guided Transforaminal Injections of Platelet-Rich Plasma Compared with Steroid in Lumbar Disc Herniation: A Prospective, Randomized, Controlled Study

Transforaminal steroid injection is extensively used as a treatment in cases of herniated disc, but it is associated with complications. In comparison, platelet-rich plasma (PRP) injection has been used in musculoskeletal disorders and could be another option. This study is aimed at comparing the efficacy and safety aspects between ultrasound-guided transforaminal injections of PRP and steroid in patients who suffer from radicular pain due to lumbar disc herniation. In a randomized controlled trial, ultrasound-guided transforaminal injections of either PRP (n = 61) or steroid (n = 63) were administered to a total of 124 patients who suffer from radicular pain due to lumbar disc herniation. Patients were assessed by the visual analogue scale (VAS), pressure pain thresholds (PPTs), Oswestry disability index (ODI), and the physical function (PF) and bodily pain (BP) domains of the 36-item short form health survey (SF-36) before operation and 1 week, 1 month, 3 months, 6 months, and 12 months after operation. The rate and latency of F-wave were obtained before operation and 12 months postoperation. There was no statistical difference in terms of age and sex between both groups. Statistically significant improvements from the patients' data before operation to data obtained 1-month postoperation were observed in VAS, PPTs, ODI, and PF and BP of SF-36 in both groups and kept for 1 year. F-wave rate and latency were improved significantly at 1-year postoperation in both groups. Intergroup differences during follow-ups over a period of 1 year were not found to be significant in all the above assessment between the PRP and steroid groups. No complications were reported. The results showed similar outcome for both transforaminal injections using PRP and steroid in the treatment of lumbar disc herniation, suggesting the possible application of PRP injection as a safer alternative. The trial was registered in the Chinese Clinical Trial Registry (ChiCTR-INR-17011825).

Ultrasound-Guided Lumbar Spine Injection for Axial and Radicular Pain: A Single Institution Early Experience

STUDY DESIGN

Clinical audit via retrospective review of a database.

PURPOSE

To report an early experience using ultrasound-guided lumbar spinal injection for axial and radicular pain in an Asian multiethnic cohort.

OVERVIEW OF LITERATURE

Ultrasound-guided spine injection therapy is a comparatively new technique in the management of axial and radicular pain from degenerative lumbar spinal conditions, which may be a reasonable alternative to conventional fluoroscopic or computed tomography-guided injection.

METHODS

A retrospective review was conducted, involving all patients who underwent ultrasound-guided lumbar spine injection therapy at a single institution over 1 year. Patients were evaluated by two interventionists, who then performed standardized ultrasound-guided lumbar facet joint and pararadicular spinal injections.

RESULTS

There were 42 patients treated at our Sports Medicine Centre; with 27 patients (64.3%) receiving facet joint injections and 18 patients (42.9%) receiving nerve root injections. The majority (90.5%) of patients experienced an improvement of >30% in pain intensity at 3 months post-injection, using the Numerical Rating Scale pain score (p<0.001); with 40 patients (95.2%) reporting a reduction in Oswestry Disability Index score (p<0.001). No complications were reported.

CONCLUSIONS

Our initial experience confirms the safety, feasibility, and effectiveness of ultrasound-guided lumbar spinal injection for the treatment of axial and radicular pain in an Asian multiethnic cohort.

Chinese Association for the Study of Pain: Experts consensus on ultrasound-guided injections for the treatment of spinal pain in China (2020 edition)

Spinal pain (SP) is a common condition that has a major negative impact on a patient’s quality of life. Recent developments in ultrasound-guided injections for the treatment of SP are increasingly being used in clinical practice. This clinical expert consensus describes the purpose, significance, implementation methods, indications, contraindications, and techniques of ultrasound-guided injections. This consensus offers a practical reference point for physicians to implement successfully ultrasound-guided injections in the treatment of chronic SP.

Ultrasound-Guided Lumbar Transforaminal Epidural Injection: A Narrative Review

Transforaminal epidural steroid injection is often administered to patients with radiculopathy under fluoroscopic guidance, although it has disadvantages of radiation hazards and requirement of a special area to perform the block. To avoid these disadvantages, ultrasound-guided transforaminal injection (USTFI) has recently been described and is continually developed. This review article describes the indexed articles published on USTFI and ultrasound-guided selective nerve block (SNRB) to evaluate current evidence on best approach to perform the block. Through literature search, eight articles and one case report on USTFI and five articles on ultrasound-guided SNRB were found. Most of the studies have utilized parasagittal orientation of curvilinear probe to perform the block. Nevertheless, with the present literature, it is difficult to come to any conclusion. Further studies with larger sample size and description of dye spread patterns are recommended to come to a more definite conclusion.

Ultrasound-Guided Lumbar Transforaminal Epidural Injections; A Single Center Fluoroscopic Validation Study

Objective

To investigate the success rate (technical precision) of ultrasound-guided lumbar transforaminal epidural steroid injection, which was validated by conventional fluoroscopic technique.

Methods

A total of 20 patients with unilateral single-level lumbar foraminal disc protrusion causing radiculopathy were enrolled. Using transforming route, the needle location was determined by an axial (transvers) view of the ultrasound with fluoroscopic confirmation. We determined the needle placement accuracy of ultrasound- guided lumbar transforaminal injections approach.

Results

The accuracy of ultrasound-guided interventions was 90% as confirmed by fluoroscopy. There were 2 failed cases at the L4-L5 level in the US-guided. The success rate in L5-S1 level was 100%, in L4-L5 level was 80% and in L3-L4 level was 100%. No complications were noted.

Conclusion

Ultrasound-guided lumbar transforaminal epidural injections are accurate and feasible in clinical setting with an accuracy of 90% and no complications.

Ultrasound- versus fluoroscopy-guided injections in the lower back for the management of pain: a systematic review

PURPOSE

Ultrasound-guided spinal injections are less common than fluoroscopy-guided injections. Although unable to penetrate bones, ultrasound guidance has a number of advantages including convenience and reduced exposure to ionizing radiation. However, it is not known how ultrasound-guided injections compare to fluoroscopy-guided injections in the management of lower back pain. Our objective is to systematically review the literature comparing ultrasound-guided injections to fluoroscopy-guided injections for the management of lower back pain.

METHODS

Medline, Cochrane CENTRAL Register of Controlled Trials, Embase, and NHSEED were searched from 2007 to September 26, 2017. Inclusion criteria included (1) randomized controlled trial design, (2) compared ultrasound-guided and fluoroscopy-guided injections for lower back pain, (3) dose and volume of medications injected were identical between trial arms, and (4) reported original data.

RESULTS

One hundred one unique records were identified, and 21 studies were considered for full-text inclusion. Nine studies formed the final data set. Studies comparing ultrasound- and fluoroscopy-guided injections for lower back pain management reported no difference in pain relief, procedure time, number of needle passes, changes in disability indices, complications or adverse events, post-procedure opioid consumption, or patient satisfaction.

CONCLUSION

Fluoroscopic guidance of injections for the management of lower back pain is similar in efficacy to ultrasound guidance. The exact role of ultrasound guidance needs to be further studied, especially for nerve root injections, where safety is the major concern.

KEY POINTS

• There were no differences in pain relief, procedure time, number of needle passes, changes in disability indices, complications or adverse events, post-procedure opioid consumption, or patient satisfaction between ultrasound- and fluoroscopy-guided injections for the management of lower back pain. • Given the lack of evidence to demonstrate superior efficacy and the added harms with fluoroscopic guidance, ultrasound guidance may be the preferred method of guidance for injections to manage lower back pain in appropriate patients. Further study is required to understand the exact role of ultrasound in image-guided injections.

Image Guidance Technologies for Interventional Pain Procedures: Ultrasound, Fluoroscopy, and CT

Chronic pain is a common medical condition. Patients who suffer uncontrolled chronic pain may require interventions including spinal injections and various nerve blocks. Interventional procedures have evolved and improved over time since epidural injection was first introduced for low back pain and sciatica in 1901. One of the major contributors in the improvement of these interventions is the advancement of imaging guidance technologies. The utilization of image guidance has dramatically improved the accuracy and safety of these interventions. The first image guidance technology adopted by pain specialists was fluoroscopy. This was followed by CT and ultrasound. Fluoroscopy can be used to visualize bony structures of the spine. It is still the most commonly used guidance technology in spinal injections. In the recent years, ultrasound guidance has been increasingly adopted by interventionists to perform various injections. Because its ability to visualize soft tissue, vessels, and nerves, this guidance technology appears to be a better option than fluoroscopy for interventions including SGB and celiac plexus blocks, when visualization of the vessels may prevent intravascular injection. The current evidence indicates the efficacies of these interventions are similar between ultrasound guidance and fluoroscopy guidance for SGB and celiac plexus blocks. For facet injections and interlaminar epidural steroid injections, it is important to visualize bony structures in order to perform these procedures accurately and safely. It is worth noting that facet joint injections can be done under ultrasound guidance with equivalent efficacy to fluoroscopic guidance. However, obese patients may present challenge for ultrasound guidance due to its poor visualization of deep anatomical structures. Regarding transforaminal epidural steroid injections, there are limited evidence to support that ultrasound guidance technology has equivalent efficacy and less complications comparing to fluoroscopy. However, further studies are required to prove the efficacy of ultrasound-guided transforaminal epidural injections. SI joint is unique due to its multiplanar orientation, irregular joint gap, partial ankylosis, and thick dorsal and interosseous ligament. Therefore, it can be difficult to access the joint space with fluoroscopic guidance and ultrasound guidance. CT scan, with its cross-sectional images, can identify posterior joint gap, is most likely the best guidance technology for this intervention. Intercostal nerves lie in the subcostal grove close to the plural space. Significant risk of pneumothorax is associated with intercostal blocks. Ultrasound can provide visualization of ribs and pleura. Therefore, it may improve the accuracy of the injection and reduce the risk of pneumothorax. At present time, most pain specialists are familiar with fluoroscopic guidance techniques, and fluoroscopic machines are readily available in the pain clinics. In the contrast, CT guidance can only be performed in specially equipped facilities. Ultrasound machine is generally portable and inexpensive in comparison to CT scanner and fluoroscopic machine. As pain specialists continue to improve their patient care, ultrasound and CT guidance will undoubtedly be incorporated more into the pain management practice. This review is based on a paucity of clinical evidence to compare these guidance technologies; clearly, more clinical studies is needed to further elucidate the pro and cons of each guidance method for various pain management interventions.

Automatic Localization of the Needle Target for Ultrasound-Guided Epidural Injections

Accurate identification of the needle target is crucial for effective epidural anesthesia. Currently, epidural needle placement is administered by a manual technique, relying on the sense of feel, which has a significant failure rate. Moreover, misleading the needle may lead to inadequate anesthesia, post dural puncture headaches, and other potential complications. Ultrasound offers guidance to the physician for identification of the needle target, but accurate interpretation and localization remain challenges. A hybrid machine learning system is proposed to automatically localize the needle target for epidural needle placement in ultrasound images of the spine. In particular, a deep network architecture along with a feature augmentation technique is proposed for automatic identification of the anatomical landmarks of the epidural space in ultrasound images. Experimental results of the target localization on planes of 3-D as well as 2-D images have been compared against an expert sonographer. When compared with the expert annotations, the average lateral and vertical errors on the planes of 3-D test data were 1 and 0.4 mm, respectively. On 2-D test data set, an average lateral error of 1.7 mm and vertical error of 0.8 mm were acquired.

Visualization of Needle-Tip Localization by Ultrasound Guidance with Contrast Bubble in Lumbar Selective Nerve Root Block: Clinical Pilot Study

BACKGROUND

Epidural steroid injection for low back and leg pain has been shown to result in a positive clinical outcome. Lumbosacral selective nerve root block (SNRB) via a transforaminal approach is commonly performed under fluoroscopic guidance. However, ultrasound guidance is an alternative to overcome the radiologic disadvantages. This study examined the accuracy of needle-tip localization under ultrasound guidance with a contrast bubble, compared with fluoroscopic guidance.

OBJECTIVE

The primary objectives were to envisage the needle-tip localization with an air bubble by ultrasound and also to determine the accuracy of needle-tip location in transforaminal lumbar SNRB for low back and leg pain patients who were not surgical candidates.

METHODS

A prospective study of 30 SNRBs was conducted. An air bubble was produced and was used to envisage the needle-tip location under ultrasound guidance. Finally, the needle tip was confirmed by fluoroscopy. The accuracy of needle-tip location was statistically analyzed.

RESULTS

Twenty-four SNRBs were performed at L4-5 and 6 SNRBs at L3-4. The accuracy of needle-tip localization was 80%.

CONCLUSION

In order to avoid radiation exposure during the SNRB procedure, ultrasound guidance might be an alternative. Despite being accepted practice, there is a steep learning curve involved in the use of ultrasound guidance for lumbar SNRB, and proper training is crucial. A contrast bubble is a prospective enhancement for better visualization of ultrasound guidance.

Ultrasound for Lumbar Spinal Procedures

Ultrasonography has become an increasingly valuable and promising tool for performing image-guided spine interventions. The increase in the use of ultrasound utilization has led to more studies evaluating ultrasound-guided interventional spine procedures in comparison to fluoroscopy and computed tomography. Several studies have investigated the use of ultrasound for lumbosacral pain management procedures with favorable outcomes.

Ultrasonography-Guided Lumbar Periradicular Injections for Unilateral Radicular Pain

Objective. The aim of this study was to compare the accuracy and efficacy of sonographically guided lumbar periradicular injections through in-plane or out-of-plane approach techniques for patients with unilateral lower lumbar radicular pain. The feasibility and accuracy of these techniques were studied by means of computed tomography (CT). Methods. A total of 46 patients with chronic unilateral lumbar radicular pain were recruited and randomly assigned to either the in-plane or out-of-plane injection group. A mixture of 3 mL 1% lidocaine and 7 mg betamethasone was injected. The visual analog scale (VAS) was used to assess pain before and after treatment. Results. The pain intensity, as measured by VAS, significantly decreased in both in-plane and out-of-plane injection groups. Conclusions. The sonographically guided periradicular injections are feasible and effective in treating lumbar unilateral radicular pain.

Ultrasound indications for chronic pain management: an update on the most recent evidence

PURPOSE OF REVIEW

The ability of ultrasound to provide detailed anatomic visualization while avoiding radiation exposure continues to make it an appealing tool for many practitioners of chronic pain management. This review will present the most recent evidence regarding the use of ultrasound-guidance for the performance of interventional procedures in the treatment of chronic pain.

RECENT FINDINGS

For a variety of different procedures, studies continue to compare ultrasound-guided techniques to commonly used fluoroscopic or landmark-based techniques. Small, randomized controlled trials are beginning to demonstrate that ultrasound-guided approaches to interventional pain procedures can be as well tolerated and effective as the traditionally used techniques, while providing some potential advantages in terms of decreased radiation exposure, avoidance of vascular structures, and in some cases, improved efficiency and decreased rates of adverse effects.

SUMMARY

Despite continued interest in ultrasound-guided techniques for chronic pain management procedures, the evidence is still limited mainly to small, randomized trials and case series. For some procedures, such as stellate ganglion block and peripheral joint injections, recent evidence appears to be tilting in favor of ultrasound-guidance as the preferred technique, though fluoroscopy continues to be a much more reliable method for detection of intravascular uptake of injectate.

Ultrasound-guided interventional procedures for chronic pain management

Ultrasonography has multiple advantages over traditional radiologic imaging modalities when used for interventional procedures. It allows improved visualization of the anatomy while avoiding ionizing radiation and risks associated with contrast use. It has proved superiority at accuracy of delivery and procedural effectiveness over blind procedures when used in association with interventional pain procedures. Although limited in its ability to see through bony structures, ultrasound has utility in visualizing soft tissues and vascular structures in anatomic regions of interest resulting in increased use for posterior neuraxial, periaxial, peripheral nerve and joint-related structures. Current evidence for use in these settings is presented here. In some cases, optimal utility may be improved by combining ultrasonography with other imaging modalities.