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.
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.
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.
There is a positive association between the BMI (and weight) and transforaminal epidural depth but not with age, sex, and height.
BMI; correlation; depth; transforaminal epidural injection
Prior to performing a cervical interlaminar epidural steroid injection (CIESI), knowledge of the depth from lamina to epidural space may assist in preventing cord injury.
This is a prospective analysis of data including gender, age, weight, height, previous surgery, neck circumference, distances from tip of chin to sternal notch, occiput to C7 vertebral prominence, and ear lobe to tip of shoulder, pain score, angle from C7 vertebral prominence to the back, depth at which the Tuohy needle contacted T1 vertebral lamina and depth at which the epidural space was entered was conducted with 92 subjects, average age (± SD) 41.3 ± 13.2 years underwent fluoroscopically-guided C7-T1 intralaminar epidural steroid injections.
Depth to lamina was the best individual predictor with an r-value of 0.86. Weight, neck circumference, and BMI correlated positively with depth to epidural space with r-values of 0.66, 0.62, and 0.61 respectively. A linear regression model of depth to lamina for predicting depth to epidural space was accurate to within ± 0.5 cm of the actual depth in 69% of subjects. However, when comparing predicted to actual depth to epidural space for individual subjects, the prediction was inaccurate by as much as 1.6 cm deep or 1.7 cm shallow.
While statistically significant correlations do exist between both quantitative external body characteristics and depth to cervical epidural space and T1vertebral lamina to depth of cervical epidural space for fluoroscopically guided interlaminar epidural steroid injections at C7-T1, even the most optimal regression models do not permit clinical confidence in predicted depth to epidural space.
This prospective-controlled observational study looked at well-matched patients with spinal pain and radicular symptoms, caused by lumbar intervertebral disc herniation to compare the short-term clinical outcome of transforaminal and interlaminar epidural steroid injection (ESI) in a resource challenged tertiary institution in Nigeria.
Materials and Methods:
49 patients with radicular symptoms who were matched for age, symptom duration, magnetic resonance imaging findings, and pre-injection revised Oswentry Disability Index (ODI) score and Visual Analogue Scale (VAS) were assigned into ESI technique. The ODI and VAS score were analyzed immediately after an injection and upon follow-up (average 178.5 days), also with the need for repeated injections and surgical interventions over a 1-year follow-up interval.
In the transforaminal group (25 patients), there was a statistically significant improvement in the ODI scores from before the injection (ODI mean 62.4) to immediately after the injection (ODI mean 24.4, P < 0.01), and upon follow-up (ODI mean 20.8, P < 0.01). 9 patients (18.4%) required 1 or 2 repeated injections, 3 (6.1%) patients underwent surgery and 2 (4%) patients lost to follow-up. In the interlaminar group (24 patients), there was a statistically significant improvement in the ODI scores from before the injection (ODI mean 60.7) to immediately after the injection (ODI mean 30.1, P < 0.01), but not upon follow-up (ODI mean 43.2, P = 0.09). 11 (22.4%) patients required 1 or 2 repeated injection, 4 (8%) patients underwent surgery and 3 (6.1%) patients were lost to follow-up. There is an average of 2 fold improvement of transforaminal ESI over interlaminar ESI in a 40 point scale of ODI score on follow-up, which was statistically significant (P < 0.01). The VAS showed similar pattern with the ODI scores in the study.
Transforaminal ESI to treat symptomatic lumbar disc herniation resulted in better short-term pain improvement and fewer long-term surgical interventions compared to interlaminar ESI.
Epidural injections; oswentry disability index; spinal pain
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.
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.
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.
Blunt needle; fluoroscopy; intravascular penetration; radicular pain; transforaminal epidural injection
The purpose of this study was to evaluate the clinical feasibility of an electric nerve stimulator in a lumbar transforaminal epidural block.
Using an electric nerve stimulator, transforaminal epidural blocks were performed in 105 segments of 49 patients who presented with lower back pain with radiating pain to lower extremities. The contrast medium was injected to delineate the nerve root after positioning an insulated needle at the intervertebral foramen under fluoroscopic guidance. Then, the nerve root was electrically stimulated with the insulated needle to confirm whether or not the same radiating pain was evoked.
Of the 105 foraminal segments, the same radiating pain was evoked at 0.5 mAh in 47 segments (44.8%), at 1.0 mAh in 22 (21.0%), at 1.5 mAh in 3 (2.9%), at 2.0 mAh in 15 (14.3%), at 2.5 mAh in 4 (3.8%), and at 3.0 mAh in 5 (4.8%). No response was observed in 9 segments (8.6%). The fluoroscopy revealed successful positioning of the needle in the patients with an evoked radiating pain over 2.0 mAh. The visual analogue scale (VAS) obtained for pain improved from a mean of 7.5 to 2.7 after the block (p = 0.001). In the 9 cases without response to electrical stimulation, the patients showed an improvement on VAS from 7.8 to 3.4 (p= 0.008) also.
A nerve stimulator can help to predict the accuracy of needle positioning as a supplemental aid for a successful lumbar transforaminal epidural block. It is sufficient to initiate a proper stimulation amplitude of the nerve at 2 mAh.
Lumbar; Transforaminal epidural block; Electric nerve stimulator
Cervical transforaminal epidural injections (C-TfEI) are commonly performed in patients with cervical radiculopathy/pain. C-TfEIs are typically performed without incident but adverse events can occur. Using CT-fluoroscopy-guided C-TfEI, we commonly observe the vertebral artery in proximity to the target injection site. The purpose of this study was to assess the position of the vertebral artery relative to the typical C-TfEI injection point.
CT-fluoroscopy-guided C-TfEIs were performed at 70 levels in 68 patients with radiculopathy/neck pain (age range 19-83 yrs, mean 50.6 yrs). Degenerative neural foraminal narrowing at each level was characterized (normal-to-mild, moderate, severe). Vertebral artery position was categorized as: anterior (normal), partially covering neural foramen, complete/near-complete covering the neural foramen. Additional measured variables included angle of needle trajectory, foraminal angle, and whether or not needle trajectory intersected with the vertebral artery.
Foraminal vertebral artery covering correlated with severity of foraminal degenerative narrowing (p=0.003). Complete/near-complete covering was seen in: 65% severely narrowed foramina, 30% moderately narrowed foramina and 10% normal/mildly-narrowed foramina. Needle trajectory intersected with the vertebral artery in 30 of 70 injections (46%) by CT-fluoroscopy, frequently associated with shallow (lateral) approaches. Foraminal angle, approximating oblique fluoroscopic technique, suggests needle trajectory intersection with the vertebral artery in 27 of 70 foramina (39%).
Vertebral artery position is commonly displaced into the foramen in patients with advanced cervical degenerative disease. Operator awareness of altered vertebral artery position is important for determination of optimal needle trajectory and tip placement prior to injection in patients undergoing C-TfEI.
cervical spine; cervical radiculopathy; neck pain; cervical transforaminal epidural injection; cervical nerve root block; computed tomography
OBJECTIVES—To investigate the accuracy of placement of epidural injections using the lumbar and caudal approaches. To identify which factors, if any, predicted successful placement.
METHODS—200 consecutive patients referred to a pain clinic for an epidural injection of steroid were randomly allocated to one of two groups. Group L had a lumbar approach to the epidural space and group C a caudal approach to the epidural space. Both groups then had epidurography performed using Omnipaque and an image intensifier to determine the position of the needle.
RESULTS—Body mass index (BMI), grade of operator, and route of injection were predictors of a successful placement. 93% of lumbar and 64% of caudal epidural injections were correctly placed (p< 0.001). 97% of lumbar and 85% of caudal epidural injections clinically thought to be correctly placed were confirmed radiographically. For epidural injections where the clinical impression was "maybe", 91% of lumbar injections, but only 45% of caudal injections were correctly placed. Obesity was associated with a reduced chance of successful placement (odds ratio (OR) 0.34 (95% confidence interval (CI) 0.17 to 0.72) BMI >30 v BMI <30). A more senior grade of operator was associated with a reduced chance of successful placement (OR 0.16 (95% CI 0.03 to 0.89) consultant v other). However, small numbers may have accounted for the latter result.
CONCLUSIONS—The weight of the patient and intended approach need to be considered when deciding the method used to enter the epidural space. In the non-obese patient, lumbar epidural injections can be accurately placed without x ray screening, but caudal epidural injections, to be placed accurately, require x ray screening no matter what the weight of the patient.
We wanted to investigate the relationship between the magnetic resonance (MR) findings and the clinical outcome after treatment with non-surgical transforaminal epidural steroid injections (ESI) for lumbar herniated intervertebral disc (HIVD) patients.
Materials and Methods
Transforaminal ESI were performed in 91 patients (50 males and 41 females, age range: 13-78 yrs) because of lumbosacral HIVD from March 2001 to August 2002. Sixty eight patients whose MRIs and clinical follow-ups were available were included in this study. The medical charts were retrospectively reviewed and the patients were divided into two groups; the successful (responders, n = 41) and unsatisfactory (non-responders, n = 27) outcome groups. A successful outcome required a patient satisfaction score greater than two and a pain reduction score greater than 50%. The MR findings were retrospectively analyzed and compared between the two groups with regard to the type (protrusion, extrusion or sequestration), hydration (the T2 signal intensity), location (central, right/left central, subarticular, foraminal or extraforaminal), and size (volume) of the HIVD, the grade of nerve root compression (grade 1 abutment, 2 displacement and 3 entrapment), and an association with spinal stenosis.
There was no significant difference between the responders and non-responders in terms of the type, hydration and size of the HIVD, or an association with spinal stenosis (p> 0.05). However, the location of the HIVD and the grade of nerve root compression were different between the two groups (p< 0.05).
MRI could play an important role in predicting the clinical outcome of non-surgical transforaminal ESI treatment for patients with lumbar HIVD.
Spine, intervertebral disks; Spine, MR
The most common causes of failed back surgery are residual or recurrent herniation, foraminal fibrosis and foraminal stenosis that is ignored, untreated, or undertreated. Residual back ache may also be from facetal causes or denervation and scarring of the paraspinal muscles.1–6 The original surgeon may advise his patient that nothing more can be done on the basis of his opinion that the nerve was visually decompressed by the original surgery, supported by improved post-op imaging and follow-up studies such as EMG and conduction velocity studies. Post-op imaging or electrophysiological assessment may be inadequate to explain all the reasons for residual or recurrent symptoms. Treatment of Failed back surgery by repeat traditional open revision surgery usually incorporates more extensive decompression causing increased instability and back pain, therefore necessitating fusion. The authors, having limited their practice to endoscopic MIS surgery over the last 15-20 years, report on their experience gained during that period to relieve pain by endoscopically visualizing and treating unrecognized causative patho-anatomy in FBSS.7
Thirty consecutive patients with FBSS presenting with back and leg pain that had supporting imaging diagnosis of lateral stenosis and /or residual / recurrent disc herniation, or whose pain complaint was supported by relief from diagnostic and therapeutic injections (Figure 1), were offered percutaneous transforaminal endoscopic discectomy and foraminoplasty over a repeat open procedure. Each patient sought consultation following a transient successful, partially successful or unsuccessful open translaminar surgical treatment for disc herniation or spinal stenosis. Endoscopic foraminoplasty was also performed to either decompress the bony foramen for foraminal stenosis, or foraminoplasty to allow for endoscopic visual examination of the affected traversing and exiting nerve roots in the axilla, also known as the “hidden zone” of Macnab (Figure 2).8, 9 The average follow up time was, average 40 months, minimum 12 months. Outcome data at each visit included Macnab, VAS and ODI.
A diagnostic and therapeutic epidural gram may help identify unrecognized lateral recess stenosis underestimated by MRI. An excellent result from a therapeutic block lends excellent prognosis for a more lasting and “permanent” result from transforaminal endoscopic lateral recess decompression.
Kambin's Triangle provides access to the “hidden zone” of Macnab by foraminoplasty. The foramen and lateral recess is decompressed by removing the ventral aspect and tip of the superior articular process to gain access to the axilla between the traversing and exiting nerve. FBSS contains patho-anatomy in the axilla between the traversing and exiting nerve that hides the pain generators of FBSS.
The average pre-operative VAS improved from 7.2 to 4.0, and ODI 48% to 31%. While temporary dysesthesia occurred in 4 patients in the early post-operative period, all were happy, as all received additional relief of their pre-op symptoms. They were also relieved to be able to avoid “open” decompression or fusion surgery.
Conclusions / Level of Evidence 3
The transforaminal endoscopic approach is effective for FBSS due to residual/recurrent HNP and lateral stenosis. Failed initial index surgery may involve failure to recognize patho-anatomy in the axilla of the foramen housing the traversing and the exiting nerve, including the DRG, which is located cephalad and near the tip of SAP.10 The transforaminal endoscopic approach effectively decompresses the foramen and does not further destabilize the spine needing stabilization.11 It also avoids going through the previous surgical site.
Disc narrowing as a consequence of translaminar discectomy and progressive degenerative narrowing and spondylolisthesis (Figure 3) as a natural history of degenerative disc disease can lead to central and lateral stenosis. The MRI may underestimate the degree of stenosis from a bulging or a foraminal disc protrusion and residual lateral recess stenosis. Pain can be diagnosed and confirmed by evocative discography and by clinical response to transforaminal diagnostic and therapeutic steroid injections.12 Foraminal endoscopic decompression of the lateral recess is a MIS technique that does not “burn bridges” for a more conventional approach and it adds to the surgical armamentarium of FBSS.
Cadaver Illustration of Foraminal Stenosis (courtesy of Wolfgang Rauschning). As the disc narrows, the superior articular process impinges on the exiting nerve and DRG, creating lateral recess stenosis, lumbar spondylosis, and facet arthrosis.
Failed Back Surgery Syndrome(FBSS); Hidden zone; Foraminal decompression; Recurrent herniation; Lateral stenosis; Foraminal osteophyte
Study Design: Retrospective case-control study.
Objective: To compare the effectiveness between caudal and trans-foraminal epidural steroid injections for the treatment of primary lumbar radiculopathy.
Summary of Background Data: Spinal injections with steroids play an important role in non-operative care of lumbar radiculopathy. The trans-foraminal epidural steroid injection (TESI) theoretically has a higher success rate based on targeted delivery to the symptomatic nerve root. To our knowledge, these results have not been compared with other techniques of epidural steroid injection.
Methods: 93 patients diagnosed with primary lumbar radiculopathy of L4, L5, or SI were recruited for this study: 39 received caudal epidural steroid injections (ESI) and 54 received trans-foraminal epidural steroid injections (TESI). Outcomes scores included the SF-36, Oswestry disability index (ODI) and pain visual analogue scale (VAS), and were recorded at baseline, post-treatment (<6 months), long-term (>1 year). The average follow-up was 2 years, and 16 patients were lost to follow-up. The endpoint “surgical intervention” was a patient-driven decision, and considered failure of treatment. Intent-to-treat analysis, and comparisons included t-test, Chi-square, and Wilcoxon rank-sum test.
Results: Baseline demographics and outcomes scores were comparable for both treatment groups (ESI vs. TESI): (SF-36 PCS (32.3 ± 7.5 vs. 29.5 ± 8.9 respectively; p = 0.173), MCS (41.2 ± 12.7 vs. 41.1 ± 10.9, respectively; p = 0.971), and VAS (7.4 ±2.1 vs. 7.9 ± 1.2, respectively; p = 0.228)). Surgery was indicated for failure of treatment at a similar rate for both groups (41.0% vs. 44.4%, p=0.743). Symptom improvement was comparable between both treatment groups (ESI vs. TESI): SF-36 PCS improved to 42.0±11.8 and 37.7±12.3, respectively; p=0.49; ODI improved from 50.0±21.2 to 15.6±17.9and from 62.1±17.9 to 26.1±20.3, respectively (p=0.407).
Conclusions: The effectiveness of TESI is comparable to that of ESI (approximately 60%) for the treatment of primary lumbar radiculopathy. The increased complexity of TESI is not justified for primary cases, and may have a more specific role in recurrent disease or for diagnostic purposes.
Epidural steroid injections are an accepted procedure for the conservative management of chronic backache caused by lumbar disc pathology. The purpose of this study was to evaluate the epidurographic findings for the midline, transforaminal and parasagittal approaches in lumbar epidural steroid injections, and correlating them with the clinical improvement.
Sixty chronic lower back pain patients with unilateral radiculitis from a herniated/degenerated disc were enrolled. After screening the patients according to the exclusion criteria and randomly allocating them to 3 groups of 20 patients, fluoroscopic contrast enhanced epidural steroids were injected via midline (group 1), transforaminal (group 2) and parasagittal interlaminar (group 3) approaches at the level of the pathology. The fluoroscopic patterns of the three groups were studied and correlated with the clinical improvement measured by the VAS over the next 3 months; any incidences of complications were recorded.
The transforaminal group presented better results in terms of VAS reduction than the midline and parasagittal approach groups (P < 0.05). The epidurography showed a better ventral spread for both the transforaminal (P < 0.001) and the paramedian approaches (P < 0.05), as compared to the midline approach. The nerve root filling was greater in the transforaminal group (P < 0.001) than in the other two groups. The ventral spread of the contrast agent was associated with improvement in the VAS score and this difference was statistically significant in group 1 (P < 0.05), and highly significant in groups 2 and 3 (P < 0.001). In all the groups, any complications observed were transient and minor.
The midline and paramedian approaches are technically easier and statistically comparable, but clinically less efficacious than the transforaminal approach. The incidence of ventral spread and nerve root delineation show a definite correlation with clinical improvement. However, an longer follow-up period is advisable for a better evaluation of the actual outcom.
epidural steroid injection; fluoroscopy; midline interlaminar; parasagittal interlaminar; transforaminal
In the midthoracic region, a fluroscope guided epidural block has been proposed by using a pedicle as a landmark to show the height of the interlaminar space (Nagaro's method). However, clinical implication of this method was not fully evaluated. We studied the clinical usefulness of a fluoroscope guided thoracic epidural block in the midthoracic region.
Twenty four patients were scheduled to receive an epidural block at the T6-7 intervertebral space. The patients were placed in the prone position. The needle entry point was located at the junction between midline of the pedicle paralleled to the midline of the T7 vertebral body (VB) and the lower border of T7 VB on anteroposterior view of the fluoroscope. The needle touched and walked up the lamina, and the interlaminar space (ILS) was sought near the midline of the VB at the height of the pedicle.
The authors could not insert an epidural needle at T6-7 ILS in two patients and it was instead inserted at T5-6 ILS. However, other patients showed easy insertion at T6-7 ILS. The mean inward and upward angulations were 25° and 55° respectively. The mean actual depth and calculated depth from skin to thoracic epidural space were 5.1 cm and 6.1 cm respectively. Significant correlation between actual needle depth and body weight, podendal index (kg/m) or calculated needle depth was noted.
The fluorposcope guided epidural block by Nagaro's method was useful in the midthoracic region. However, further study for the caudal shift of needle entry point may be needed.
Analgesia; Epidural; Fluoroscopy; Thoracic vertebrae
The objectives of this study were to clarify the short-term effects of transforaminal epidural steroid injection (TFESI) for degenerative lumbar scoliosis combined with spinal stenosis (DLSS), and to extrapolate factors relating to the prognosis of treatment.
Thirty-six patients with lumbar radicular pain from DLSS were enrolled. Subjects were randomly assigned to one of two groups (steroid or lidocaine group). We compared the effect of pain suppression at 2, 4 and 12 weeks after the procedure between the two groups. Radiographic analysis included measurement of the Cobb's angle, the upper endplate obliquities of L3 and L4, and maximal lateral olisthy between two adjacent lumbar vertebrae. Sagittal plane measurement included lumbar lordosis, and thoracolumbar kyphosis. Statistical analysis of both radiographic and clinical parameters along with treatment outcome was performed to determine any significant correlations between the two.
There were no significant differences in the demographic data, initial visual analogue scale (VAS) or Oswestry disability index (ODI) between the steroid group (n=17) and the lidocaine group (n=19). Two, 4, and 12 weeks after injection VAS, ODI showed a significantly greater improvement in the steroid group compared to the lidocaine group (p<0.05). The radiographic and clinical parameters were not significantly correlated with treatment outcome.
Our findings suggest that fluoroscopic transforaminal epidural steroid injections appear to be an effective non-surgical treatment option for patients with degenerative lumbar scoliosis combined with spinal stenosis (DLSS) and radicular pain.
Degenerative; Scoliosis; Steroid; Stenosis; Transforaminal
To compare the short-term effect and advantage of transforaminal epidural steroid injection (TFESI) performed using the Kambin's triangle and subpedicular approaches.
Forty-two patients with radicular pain from lumbar spinal stenosis were enrolled. Subjects were randomly assigned to one of two groups. All procedures were performed using C-arm KMC 950. The frequency of complications during the procedure and the effect of TFESI at 2 and 4 weeks after the procedure between the two groups were compared. Short-term outcomes were measured using a visual numeric scale (VNS) and a five-grade scale. Multiple logistic regression analyses were performed to evaluate the relationship between possible outcome predictors (Kambin's triangle or subpedicular approach, age, duration of symptoms and sex) and the therapeutic effect.
VNS was improved 2 weeks after the injection and continued to improve until 4 weeks in both groups. There were no statistical differences in changes of VNS, effectiveness and contrast spread pattern between these two groups. No correlation was found between the other variables tested and therapeutic effect. Spinal nerve pricking occurred in five cases of the subpedicular and in none of the cases of the Kambin's triangle approach (p<0.05).
The Kambin's triangle approach is as efficacious as the subpedicular approach for short-term effect and offers considerable advantages (i.e., less spinal nerve pricking during procedure). The Kambin's triangle approach maybe an alternative method for transforaminal epidural steroid injection in cases where needle tip positioning in the anterior epidural space is difficult.
Kambin's triangle; Lumbar; Transforaminal; Stenosis
Epidural anaesthesia is being increasingly used to provide anaesthesia for surgery on the lower abdomen, perineum and lower extremities. However success of the epidural technique depends upon the correct identification of epidural space.2 We conducted a study to find the distance from skin to the epidural space and its correlation with body mass index, to improve the success rate.
Patient and Methods:
120 adults patients belonging to ASA physical status I and II in the age group of 18-70 years, scheduled for surgery and or pain relief under epidural block, were taken up for the study. 60 patients of either sex were further subdivided into 2 subgroups of 30 patients each having BMI less than 30 or more than 30. The distance from skin to epidural space was measured as the distance between rubber marker and tip of Tuohy's needle.
It was found that with increase in Body mass Index, the distance from skin to the epidural space also increases. The distance from the skin to the epidural space does not depend on the age or the sex of the patients.
We formulated predictive equation of depth of epidural space from skin in relation to BMI based on linear regression analysis as: Depth (mm) = a + b (BMI). Where a = 17.7966 and b = 0.9777.
Epidural space; Body Mass Index
Given the risk of paralysis associated with cervical transforaminal injection, is it time to reconsider transforaminal injections of the lumbar spine? Arguments for discontinuing lumbar injections have been discussed in the anesthesia literature, raising concern about the risks of epidural steroid injections (ESIs).
In a 47-year-old man, paraplegia of the lower extremities developed, specifically conus medullaris syndrome, after he underwent an ESI for recurrent pain. Correct needle placement was verified with epidurography. Immediately after the injection, the patient felt his legs “going dead”; paraplegia of the lower extremities was noted.
An initial magnetic resonance imaging study performed after the patient was transferred to the emergency department was unremarkable. However, a later neurosurgical evaluation showed conus medullaris syndrome, and a second magnetic resonance imaging study showed the conus infarct. We conducted a search of the PubMed database of articles from 2002 to 2011 containing the following keywords: complications, lumbar epidural steroid injection(s), cauda equina syndrome, conus medullaris infarction, spinal cord infarction, spinal cord injury, paralysis, paresis, plegia, paresthesia, and anesthesia.
Summarizing this case and 5 similar cases, we weigh the potential benefits and risks of ESI. Although one can safely assume that this severe, devastating complication is rare, we speculate that its true incidence remains unknown, possibly because of medicolegal implications. We believe that the rarity of this complication should not preclude the continued use of transforaminal ESI; rather, it should be emphasized for discussion with patients during the consent process.
Conus medullaris syndrome; Epidural; Injections; Polyradiculopathy; Steroids
Lumbar interlaminar and transforaminal epidural injections are used in the treatment of lumbar radicular pain and other lumbar spinal pain syndromes. Complications from these procedures arise from needle placement and the administration of medication. Potential risks include infection, hematoma, intravascular injection of medication, direct nerve trauma, subdural injection of medication, air embolism, disc entry, urinary retention, radiation exposure, and hypersensitivity reactions. The objective of this article is to review the complications of lumbar interlaminar and transforaminal epidural injections and discuss the potential pitfalls related to these procedures. We performed a comprehensive literature review through a Medline search for relevant case reports, clinical trials, and review articles. Complications from lumbar epidural injections are extremely rare. Most if not all complications can be avoided by careful technique with accurate needle placement, sterile precautions, and a thorough understanding of the relevant anatomy and contrast patterns on fluoroscopic imaging.
Back pain; Spinal injection; Epidural steroid injection; Lumbar interlaminar epidural; Lumbar transforaminal epidural; Complications; Safety; Risk management
To determine the prevalence of anatomic impediments to interlaminar lumbar epidural steroid injection (LESI) in a community-based population.
Cross-sectional observational study.
Older adults (N=333) sampled irrespective of back pain status.
Main Outcome Measures
Computed tomography evaluation of 5 potential anatomic impediments to interlaminar LESI at the L2-S1 spinal levels, including (1) ligamentum flavum (LF) calcification, (2) interspinous ligament (ISL) calcification, (3) spinous process (SP) contact, (4) the absence of epidural fat in the posterior epidural space, and (5) the presence of fat density superficial to the LF in the midsagittal plane. Independent variables included age, sex, body mass index (BMI), and current smoking.
LF and ISL calcifications were prevalent in 3% to 7% and 2% to 3% of spinal levels, respectively, without significant differences by spinal level. SP contact was most common at the L4-5 level (22%). Absence of posterior epidural fat was very common at L5-S1 (65%), but infrequent at other levels. The presence of midline fat density superficial to LF was most common at L5-S1 (55%). The prevalence of LF calcification, ISL calcification, and SP contact increased with age, but the prevalence of absence of posterior epidural fat and the presence of a midline fat density superficial to LF did not. Sex and smoking status were not associated with the prevalence of anatomic impediments, but higher BMI was associated with a lower prevalence of absence of posterior epidural fat.
Anatomic impediments to interlaminar LESI were common in this community-based population, particularly at the L5-S1 spinal level. Because of the high overall prevalence of anatomic impediments, and differences in prevalence by spinal level, knowledge of the distribution and frequency of these impediments may aid in aspects of decision-making for the interventional spine physician.
Injections; epidural; Low back pain; Pathological conditions; anatomical; Rehabilitation; Spine
Serious complications following cervical epidural steroid injection are rare. Subdural injection of local anesthetic and steroid represents a rare but potentially life threatening complication. A patient presented with left sided cervical pain radiating into the left upper extremity with motor deficit. MRI showed absent lordosis with a broad left paramedian disc-osteophyte complex impinging the spinal cord at C5-6. During C5-6 transforaminal epidural steroid injection contrast in AP fluoroscopic view demonstrated a subdural contrast pattern. The needle was withdrawn slightly and repositioned. Normal lateral epidural and nerve root contrast pattern was subsequently obtained and injection followed with immediate improvement in radicular symptoms. There were no postoperative complications on subsequent clinic follow-up. The subdural space is a potential space between the arachnoid and dura mater. As the subdural space is larger in the cervical region, there may be an elevated potential for inadvertent subdural injection. Needle placement in the cervical subdural space during transforaminal injection is uncommon. Failure to identify aberrant needle entry within the cervical subdural space may result in life threatening complications. We recommend initial injection of a limited volume of contrast agent to detect inadvertent subdural space placement.
Transforaminal epidural injection of steroids is used to treat lumbar radicular pain. However, there are only a few well-designed randomized, controlled studies on the effectiveness of steroid injection.
Hence, this study aims to assess the effectiveness of steroid injection to treat lumbar radicular pain using a meta-analysis of transforaminal epidural injection therapy for low back and lumbar radicular pain. The comparison was based on the mean difference in the Visual Analogue Score (VAS) and Oswestry Disability Index (ODI) from baseline to the specified followed up.
The available literature of lumbar transforaminal epidural injections in managing low back and radicular pain was reviewed. Data sources included relevant literature of the English language identified through searches of PubMed and EMBASE from 1966 to 2009, and manual searches of the bibliographies of known primary and review articles. Finally, the search included the Current Controlled Trials Register and the Cochrane Database of Controlled Trials.
The initial search identified 126 papers. After screening, five randomised controlled trials (RCTs) were studied for analysis and only three of these had followed-up patients systematically with pain and disability outcome scores to 3 months and of these, only one had follow up to 12 months. A total of 187 patients (‘treatment group’ receiving local anaesthetic/steroid injection) were compared with 181 patients (‘control’ group, receiving local anaesthetic only or saline injection). Improvement in pain (standardised mean difference in VAS 0.2 in favour of ‘treatment’; 95%CI: −0.41 to 0.00, p = 0.05, I squared 0%) but not disability (standardised mean difference in ODI 0; 95%CI: −0.21 to 0.20, p = 0.99, I squared 0%) was observed between ‘treatment’ and ‘control’ groups; these differences were not significant. Additionally, the one study following patients to 12 months did not find any significant difference in VAS and ODI between treatment and control groups.
The current meta-analysis shows that transforaminal epidural steroid injections, when appropriately performed, should result in an improvement in pain, but not disability. The three RCTs that followed patients to 3 months (and the single study to 12 months) have found no benefit by the addition of steroids. The limitations of this study include the paucity of the available literature.
Transforaminal epidural steroids; Radiculopathy; Sciatica; Steroids; Local anaesthetic
Complications following lumbar transforaminal epidural injection are frequently related to inadvertent vascular injection of corticosteroids. Several methods have been proposed to reduce the risk of vascular injection. The generally accepted technique during epidural steroid injection is intermittent fluoroscopy. In fact, this technique may miss vascular uptake due to rapid washout. Because of the fleeting appearance of vascular contrast patterns, live fluoroscopy is recommended during contrast injection. However, when vascular contrast patterns are overlapped by expected epidural patterns, it is hard to distinguish them even on live fluoroscopy.
During 87 lumbar transforaminal epidural injections, dynamic contrast flows were observed under live fluoroscopy with using digital subtraction enhancement. Two dynamic fluoroscopy fluoroscopic images were saved from each injection. These injections were performed by five physicians with experience independently. Accuracy of live fluoroscopy was determined by comparing the interpretation of the digital subtraction fluoroscopic images.
Using digital subtraction guidance with contrast confirmation, the twenty cases of intravascular injection were found (the rate of incidence was 23%). There was no significant difference in incidence of intravascular injections based either on gender or diagnosis. Only five cases of intravascular injections were predicted with either flash or aspiration of blood (sensitivity = 25%). Under live fluoroscopic guidance with contrast confirmation to predict intravascular injection, twelve cases were predicted (sensitivity = 60%).
This finding demonstrate that digital subtraction fluoroscopic imaging is superior to blood aspiration or live fluoroscopy in detecting intravascular injections with lumbar transforaminal epidural injection.
digital subtraction image; epidural injection; fluoroscopy; intravascular injection
Although transforaminal epidural steroid injections under fluoroscopic guidance have become a common mode of treatment of lumbosacral radiculopathy due to herniated disc, the efficacy of steroid with low doses of clonidine has not been compared yet.
Comparison of the analgesic efficacy of methylprednisolone alone and with low doses of clonidine for transforaminal injection in lumbosacral radiculopathy.
A randomized, double-blind trial.
This study was performed at the Pain Clinic under the Department of Anaesthesiology, Jawaharlal Nehru Medical College Hospital, Aligarh Muslim University, Aligarh, India.
One hundred and eighty ASA grade I and II patients aged between 18 and 55 years were allocated into groups I, II and III to receive methylprednisolone 60 mg alone or methylprednisolone 60 mg with or without low doses of clonidine (0.5 mcg/kg or 1 mcg/kg) as transforaminal epidural injection. Pain relief and patient's satisfaction were evaluated with the global pain scale. Follow-up visits were advised at 1, 2, 4, 6 and 12 weeks and then at 6 months after injection. Associated complications were recorded.
Maximum pain relief was observed at 2 weeks after injection in all the three groups, with no difference in complication rate among the three groups. The most common complication observed was paresthesia in the nerve distribution. Greater than 60% improvement in pain scores was seen in 40% of the patients in group I, 50% of the patients in group II and 75% of the patients in group III.
This study is limited by the lack of a placebo group.
Adding 1 mcg/kg clonidine to 60 mg methylprednisolone in transforaminal epidural injections provided better pain relief than 60 mg methylprednisolone with 0.5 mcg/kg clonidine or 60 mg methylprednisolone alone in patients suffering from lumbosacral radiculopathy, with practically no significant side-effects.
Epidural; lumbosacral radiculopathy; sciatica; transforaminal
To compare a newly developed minimally-invasive method for percutaneous transforaminal epidural injection (INJ group) with the existing method for lumbar epidural catheterization (CATH group).
Through anatomical review of experimental rats, the cephalic one fourth of the neural foramen was selected as the target point for drug delivery. After the rats had undergone lumbar epidural catheterization, lidocaine, and 1% methylene blue were injected through the unilateral or bilateral L5/6 neural foramen in the INJ group, and through an epidural catheter in the CATH group. Measurement of body weight and the mechanical allodynia test before and after injection of lidocaine, and fine dissection after injection were performed.
Results of the mechanical allodynia test of 1.0% lidocaine 50 µl injection in the CATH group were statistically similar to those of 0.5% lidocaine 100 µl injection in the INJ group. The results of 2.0% lidocaine 50 µl injection in the CATH group were statistically similar to those of 1.0% lidocaine 100 µl injection in the INJ group. After dissection, only one distal partial spinal nerve was stained by methylene blue 50 µl through the transforaminal pathway. However, the dorsal root ganglion, nerve root, and adjacent hemi-partial spinal cord were stained by methylene blue 100 µl through the transforaminal pathway.
The percutaneous transforaminal epidural injection is practical, easy, and safe, and, in particular, does not cause significant pain compared to the existing lumbar epidural catheterization. We expect this method to be effective in an animal study showing that drug delivery to the spinal epidural space is necessary.
Epidural catheterization; Transforaminal; Animal study; Pain; Lidocaine
To compare the short-term effects and advantages of transforaminal epidural steroid injection (TFESI) performed using the conventional (CL) and posterolateral (PL) approaches.
Fifty patients with lumbar radicular pain from lumbar spinal stenosis and herniated lumbar disc were enrolled. Subjects were randomly assigned to one of two groups (CL or PL group). All procedures were performed using a C-arm (KMC 950, KOMED, Kwangju, Kyunggi, Korea). We compared the frequency of complications during the procedure and the effects of the pain block between the two groups at 2, 4, and 12 weeks after the procedure.
There were no significant differences in the demographic data, initial VNS (Visual numeric scale), or ODI (Oswestry disability index) between the CL group (n=26) and the PL group (n=24). There was no statistically significant difference in the outcome measures (VNS and ODI) between the groups at 2, 4, or 12 weeks. Symptoms of nerve root irritation occurred in 1 case of the CL group and in 7 cases of the PL group (p<0.05). Pricking of spinal nerve during the procedure and transient weakness after the procedure occurred in 6 cases and 3 cases, respectively in the CL group, but did not occur in the PL group.
Our findings suggest that the posterolateral approach represents an alternative TFESI method in cases with difficult needle tip positioning in the anterior epidural space, and could lower the risk of target nerve root irritation and nerve penetration.
Transforaminal; Conventional; Posterolateral; Injection
The present study was undertaken to evaluate the effectiveness of transforaminal epidural steroid injection (TFESI) with using a preganglionic approach for treating lumbar radiculopathy when the nerve root compression was located at the level of the supra-adjacent intervertebral disc.
Materials and Methods
The medical records of the patients who received conventional TFESI at our department from June 2003 to May 2004 were retrospectively reviewed. TFESI was performed in a total of 13 cases at the level of the exiting nerve root, in which the nerve root compression was at the level of the supra-adjacent intervertebral disc (the conventional TFESI group). Since June 2004, we have performed TFESI with using a preganglionic approach at the level of the supra-adjacent intervertebral disc (for example, at the neural foramen of L4-5 for the L5 nerve root) if the nerve root compression was at the level of the supra-adjacent intervertebral disc. Using the inclusion criteria described above, 20 of these patients were also consecutively enrolled in our study (the preganglionic TFESI group). The treatment outcome was assessed using a 5-point patient satisfaction scale and by using a VAS (visual assessment scale). A successful outcome required a patient satisfaction scale score of 3 (very good) or 4 (excellent), and a reduction on the VAS score of > 50% two weeks after performing TFESI. Logistic regression analysis was also performed.
Of the 13 patients in the conventional TFESI group, nine showed satisfactory improvement two weeks after TFESI (69.2%). However, in the preganglionic TFESI group, 18 of the 20 patients (90%) showed satisfactory improvement. The difference between the two approaches in terms of TFESI effectiveness was of borderline significance (p = 0.056; odds ratio: 10.483).
We conclude that preganglionic TFESI has the better therapeutic effect on radiculopathy caused by nerve root compression at the level of the supra-adjacent disc than does conventional TFESI, and the diffence between the two treatments had borderline statistical significance.
Spine, interventional procedure; Spine, therapeutic radiology