Indian Journal of Pain

: 2016  |  Volume : 30  |  Issue : 3  |  Page : 158--161

Ultrasound-guided fluoroscopic-verified lumbar transforaminal epidural injection: A clinical evaluation of technique

Dinesh Kumar Sahu, Atul Sharma, Kailash Kothari, Piyush Wani, Chandrakant Patel, Reena Parampill 
 Department of Anaesthesiology and Pain Management, Jagjivan Ram Railway Hospital, Mumbai, Maharashtrac, India

Correspondence Address:
Dinesh Kumar Sahu
F No. 13, Sky Scraper Building, Station Campus, Mumbai Central, Mumbai - 400 008, Maharashtra


Background: Fluoroscope guidance method is the gold standard for performing lumbar transforaminal epidural steroid injections (TFESIs), but it is not devoid of adverse effects such as exposure to radiation and need to wear heavy lead aprons. Ultrasound (US)-guided techniques are being evaluated recently but methodological acceptability and reproducibility remain unknown. So after reviewing literatures, studing the us scan of lumber region, we have performed these injection safely and methodologial manner and describing in this study. Duration of Study: The duration of this study was six months, from May 01, 2016, to November 31, 2016. Study Design: This was a prospective, open-label, clinical, pilot study. Materials and Methods: A total of twenty patients with low back pain and radiculopathy were enrolled in this study. A US-guided novel technique was used to perform TFESI. A needle was placed under the guidance of US, and then verified with fluoroscope for dye spread. Then, predecided mixture of drugs were injected. Patients were monitored for number of attempts for localization of transforaminal space, number of adjustment, time taken for needle insertion in transforaminal space, radiation dosage, if the cortex of bone touched by the needle, and whether any complication occurred. Results: The number of attempts for localization of transforaminal space in 85% was one and two in 15% of the patients, number of adjustment per attempt was 5.3, and the average time taken for TFESI in patients in one-attempt group was 973 ± 93 s and 1506 ± 65 s in two-attempt group. Average exposure time of fluoroscope per person was 17.5 ± 2.5 s only. Bone was contacted in 75% of cases and no complications were noted. Conclusion: Lumbar TFESI can be safely and effectively performed under US guidance but fluoroscopic confirmation is required to rule out intravascular and intrathecal spread of the contrast at this stage. However, US guidance has reduced radiation exposure to significant level in this study.

How to cite this article:
Sahu DK, Sharma A, Kothari K, Wani P, Patel C, Parampill R. Ultrasound-guided fluoroscopic-verified lumbar transforaminal epidural injection: A clinical evaluation of technique.Indian J Pain 2016;30:158-161

How to cite this URL:
Sahu DK, Sharma A, Kothari K, Wani P, Patel C, Parampill R. Ultrasound-guided fluoroscopic-verified lumbar transforaminal epidural injection: A clinical evaluation of technique. Indian J Pain [serial online] 2016 [cited 2020 Nov 25 ];30:158-161
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Full Text


Lower back pain and radiculopathy are very common conditions. In fact, most individuals experience neck and/or low back pain at least once in their life, and with increasing age, a greater number of patients with such symptoms are seen by family physicians and in outpatient clinics. Aside from physical therapy and other rehabilitative methods, transforaminal epidural steroid injection (TFESI) is used to treat lumbar radicular pain and radiculopathy.

The lumbar TFESI is one of the most effective therapies for these diseases and is commonly performed with fluoroscopic (FL) or computed tomography (CT) guidance. Radiologic guidance provides anatomic precision and accuracy, and it is a standard technique by now. [1],[2],[3] However, these techniques are time consuming, and patients and doctors can be at a risk for radiation exposure during the operation. Recently, the reliability of ultrasound (US)-guided injections in the lumbar spine including the lumbar medial branch blocks, intra-articular facet joint injections, selective nerve root block, and central neuraxial blocks has been well received by patients and doctors because of the feasibility, real-time guidance of this procedure, and the lack of radiation exposure. [1],[2],[4],[5],[6],[7],[8]

Hence, we have done a pilot study with US-guided technique in twenty patients after reviewing literatures, and then designed this study to evaluate a new "US-guided and fluoroscopy-verified" lumbar transforaminal epidural injection (TFEI) technique.

 Materials and Methods

After obtaining approval from the Institutional Research and Ethical Committee of the hospital, twenty adult patients posted for elective lumbar TFESI receiving epidural block were enrolled in the study. Patients fulfilling the inclusion and exclusion criteria were approached.

Inclusion criteria

Age of 40-65 years of either sexBody mass index (BMI) of 18-30The American Society of Anesthesiology I-IIIClinical finding of back pain with or without radiculopathy correlating with magnetic resonance imaging (MRI) finding of prolapsed intervertebral disc.

Exclusion criteria

Infection at the site of injectionPatient refusalSignificant coagulopathiesHistory of allergy to local anesthetic agentsPrevious spine surgery or spine deformity.

All patients were evaluated, enrolled, and the level of the TFESI was selected by a single physician, who is an experienced pain medicine practitioner, on the basis of the history, and examination findings correlated with MRI images. Patients were included in the study after taking written informed consent and explaining the procedure in their own language. Demographic data, BMI as well as visual analog score (VAS) regarding low back pain and block level were recorded.

In operation theater, patients were placed in the prone position on procedure table. A pillow was placed under the abdomen to alleviate lumbar lordosis. A portable US machine (Titan® , SonoSite Inc., Bothell, US) with a curve probe (2-5 MHz frequency) was used for the procedure. Following the sterile technique, the US transducer was covered in sterile wrapping and sterile US gel was spread on the patient's sterilized skin. A midline sagittal scan starting from the sacrum above the spinous processes and then a parasagittal scan along the laminas were obtained to identify spinal levels [Figure 1]a and b. After identification of the fifth lumbar spinous process, the desired spinal level for the injection was marked by cephalad counting of the spinous process starting from L5. A second scan was performed in the transverse axial plane. The sonogram reflected the spinous process, lamina, facet joint, and transverse process which is also called flying bat sign [9] [Figure 2]a and b. The ipsilateral facet joint is identified just cranial to the junction of transverse process and superior articular process. The needle entry point was assigned and marked on the patient's skin. Injection lidocaine 1% 2-3cc given to numb skin and superficial plane. Then, a 23-G, 90 mm needle was inserted approximately 45° into the skin and advanced through the in-plane approach, which enables real-time visualization of the entire path of the needle. The needle tip was advanced until it reaches the target point, i.e., lateral side of the facet joint [Figure 3]a and b. After touching the lateral facet, the needle is withdrawn by 2-3 mm. The needle bevel is turned toward the facet and the needle is maneuvered 5-8 mm anterior to facet to place the needle tip in the foramen. Before progressing the needle, the patients were asked to be alert and to report immediately if they experience any shooting pain or tingling in the leg, and stop the progression of the needle if patient experiences severe shooting pain (touching the nerve). Withdraw the needle by 2-3 mm and check if the pain/tingling disappears. Once satisfactory position of the needle is achieved under US, FL image is taken to confirm the needle tip placement and contrast spread. Minor adjustments to position the needle tip were done if required at this stage.{Figure 1}{Figure 2}{Figure 3}

One milliliter of iohexol 300 mg/ml (contrast) was then injected under FL guidance. This is done to ensure that there is no intravascular or intrathecal spread [Figure 4]a and b.{Figure 4}

If the facet joints and transverse process will not be visualized or there is a problem in real-time visualization of the entire path of the needle (especially in obese patients), we will abort US-guided procedures and the patient will be defined as a failure case. If the needle will diverge from the target position, it will be defined as a failed attempt and a reposition will be done under fluoroscope guidance.


Patients were monitored for number of attempts for localization of transforaminal space, number of adjustments, time taken for needle insertion in transforaminal space, and radiation exposure (in seconds), if the cortex of the bone was touched by the needle. Any complication such as intravascular, intraneural, or subarachnoid injection was also looked for.

In addition, the ultrasound visibility score (UVS) of nine neuraxial structures (lamina, ligamentum flavum, interlaminar space, epidural space, posterior dura, intrathecal space, cauda equine, pulsations of the cauda equine, and anterior dura-posterior longitudinal ligament complex) was noted in a scale of 0-3 (0-not visible; 1-hardly visible; 2-well visible; and 3-very well visible, maximum score possible = 27), [2],[10] and the total UVS was determined for every patient. The US visibility of the neuraxial structures was judged to have been good, if the mean total UVS was >18, average if the score was 9-18, and poor if the score was <9.

Statistical analysis

All data obtained were entered into MS Excel to generate descriptive statistics. Data analysis was done with the help of proper statistical software. Quantitative data were presented with the help of mean, standard deviation, median, and percentages.


The number of attempts for localization of transforaminal space in 85% of the patients was one and two in 15% of the patients, number of adjustments per attempt was 5.3, average time taken for TFESI in patients in one-attempt group was 973 ± 93 s and 1506 ± 65 s in two-attempt group. The average exposure time of fluoroscope per person was 17.5 ± 2.5 s. Bony cortex was contacted in 75% of cases and no complications were noted. The UVS was 2.7 per case with no visibility of pulsations of the cauda equina in any case, probably due to adult patients in the study.


In this study, we could localize transforaminal space in all the cases and maximum two attempts were required to successfully perform TFEI. Gofeld M et al. [8] observed the procedural accuracy of ultrasound-guided lumbar transforaminal injections and proposed anatomically sound approach. Fluoroscopic validation was performed. Of the 50 planned injections, 46 procedures were performed. L5/S1 foraminal access was impossible in 4 cases (8%). Fluoroscopy confirmed the correct foraminal placement in all 46 injections (100%). The contrast-spread pattern was intraforaminal in 42 cases (91.3%) and extraforaminal (nerve root) in 4 cases (8.7%). In 3 cases, intravascular injection was detected (6.5%). Kim et al. [11] showed successful positioning of the needles in 86 out of 96 Selective lumbar nerve root blocks (89.5%). They failed in 1 case for the L2 nerve root; 2 for L3; 3 for L4; and 4 for L5. The failed needles were positioned at wrong leveled segments in 4 cases and inappropriate place in 6 cases. We have also successfully placed needle in all the cases.

The time taken for doing US guided in our study was appropriate (max mean time 1506 + 65 sec) and fluoroscope exposure time was also very less (17.5 + 2.5 sec). We could contact the bone in 75% percentage of cases it may improve further. The Dye spread could not be identified properly under US guidance in this study but with further practice [1] it may be possible. Loizides et al. [12] concluded that the accuracy of US-guided interventions was 90%. The mean time to final needle placement in the US group was 4.0 ± 1.8 minutes, and in the CT group, 7.6 ± 2.1 minutes. Yang et al. [13] evaluated the accuracy, effect on pain relief and safety of US-guided lumbar TFEI. A total of 80 patients with low back pain and radicular pain were enrolled. The FL-guided approaches were performed under standardized procedures using the C-arm, whereas the US-guided injections were performed with an US device with a linear probe and were verified by Fluoroscopy. The success ratio of the US-guided interventions was 85%. The operation time in the US group (518 ± 103 s) was shorter than the FL group (929 ± 228 s) (P < 0.05). In addition, the radiation dosage in the US group (2640 ± 906 uGy m 2 ) was lower than in the FL group (8992 ± 2132 uGy m 2 ). There was no significant difference in pain relief between the US and FL groups. No serious complication was observed in any of the patients in either group. In our study mean time was longer (973 ± 93 sec ), probably because physician had two years of experience in spine US while physician with several months of experience in musculoskeletal US perfomed procedure in the study done by Yang et al. [13]

In our study all the patient has VAS less than 3 on 7 th post procedure day and no inadvertent injection like intravascular, intraneural or subarachnoid injection were noticed. Kim et al. [11] observed VAS was improved from 7.6 ± 0.6 to 3.5 ± 1.3 after the procedure.

The US visibility of neuraxial structures as per UVS was good in 11 (55%), average in 7 (35%), and poor in 2 (10%) patients in our study. Advancement and improvement in US machine will make them able to visualize small vessels better, and three-dimensional US imaging will give more accuracy to the procedure.


Lumbar TFESI can be safely and effectively performed under US guidance but FL confirmation is required at this stage. Further studies and better US technology are required to eliminate fluoroscope dependence; however, US guidance has reduced radiation exposure to a significant level in this study.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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