Effect of caudal epidural steroid or saline injection in chronic lumbar radiculopathy: multicentre, blinded, randomised controlled trial
BMJ 2011; 343 doi: https://doi.org/10.1136/bmj.d5278 (Published 13 September 2011) Cite this as: BMJ 2011;343:d5278
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How much experience do the authors have with sacral epidurals?
There were experienced anesthesiologists performing the procedure I read in the paper. But experienced in what kind of procedures? Did they have adequate experience with sacral epidurals?
And did they have experience with ultrasound?
The only way do to a study like this is to let experienced people do the procedure or even better to use fluoroscopy.
Best Regards,
Kurt Andreassen
Oslo
Competing interests: I have done about 5000 sacral epidurals. It therefore surprises me very much that the authors do not manage to create better results than with placebo doing this study.
Dear Lady, and Sirs:
Indeed most low back pain gets better by itself in 90% of patients without any treatment whatsoever. It has probably been this way for the past 1 million years. Pretty much since we started walking up straight. Many times “treatment” whether non invasive, behavioral, or invasive makes matters worse. Low back, and radiculopathy have numerous well documented etiologies, many with similar overlapping objective and subjective findings. Thus it is very difficult to come up with useful evidence. At the same time, jumping to conclusions can be very counter productive.
At baseline, the patients included in your study have less than 5 pain on a scale VAS 0-10. Personally, I don’t inject patients that don’t have severe pain, as they are likely to get better anyhow. Your study appears to confirm the obvious. I also don’t inject patients that have noticed recent improvement. In fact you had to exclude 23 patients because they improved rapidly, and 17 because they declined.
Your study excludes 328 of 461 patients. Of the exclusion criteria severe pain is the most common one. In my opinion these are the patients that usually respond best. Furthermore, I have many times injected patients with bilateral pain, sever back pain, or pain less than 3 months. Again these 97 patients were excluded in your study. Thus it appears that, you excluded patients that are likely to respond, and included those that were going to get better naturally.
For example, in the study, if a patient had a prior spinal injection they were excluded. Imagine the following scenario: a patient has an acute episode, has partial improvement with the first injection elsewhere, and then is referred to you, this patient is excluded form treatment. Likely, such a patient would have responded positively.
For example, a patient has facet joint pain, disc pain, sacroiliac joint pain, pyriformis pain, etc,. All of these conditions can result in unilateral radicular pain, and would be included in your study. Non of these patients are likely to respond to caudal epidural injection long term.
Your patient referral base is biased. Bias in the patient referral base is created by informing referring surgeons and chiropractors by letter of a trial that is to validate injections.
As far as blinding, I would not want to be on the receiving end of 30 ml’s in the caudal canal, as compared to 2 ml’s subcutaneously. Most of my patients complain quite a bit at 6 ml’s.
Sincerely,
Marc J. Yland, MD
Competing interests: No competing interests
Dear Lady, and Sirs:
Indeed most low back pain gets better by itself in 90% of patients without any treatment whatsoever. It has probably been this way for the past 1 million years. Pretty much since we started walking up straight. Many times “treatment” whether non invasive, behavioral, or invasive makes matters worse. Low back, and radiculopathy have numerous well documented etiologies, many with similar overlapping objective and subjective findings. Thus it is very difficult to come up with useful evidence. At the same time, jumping to conclusions can be very counter productive.
At baseline, the patients included in your study have less than 5 pain on a scale VAS 0-10. Personally, I don’t inject patients that don’t have severe pain, as they are likely to get better anyhow. Your study appears to confirm the obvious. I also don’t inject patients that have noticed recent improvement. In fact you had to exclude 23 patients because they improved rapidly, and 17 because they declined.
Your study excludes 328 of 461 patients. Of the exclusion criteria severe pain is the most common one. In my opinion these are the patients that usually respond best. Furthermore, I have many times injected patients with bilateral pain, sever back pain, or pain less than 3 months. Again these 97 patients were excluded in your study. Thus it appears that, you excluded patients that are likely to respond, and included those that were going to get better naturally.
For example, in the study, if a patient had a prior spinal injection they were excluded. Imagine the following scenario: a patient has an acute episode, has partial improvement with the first injection elsewhere, and then is referred to you, this patient is excluded form treatment. Likely, such a patient would have responded positively.
For example, a patient has facet joint pain, disc pain, sacroiliac joint pain, pyriformis pain, etc,. All of these conditions can result in unilateral radicular pain, and would be included in your study. Non of these patients are likely to respond to caudal epidural injection long term.
Your patient referral base is biased. Bias in the patient referral base is created by informing referring surgeons and chiropractors by letter of a trial that is to validate injections.
As far as blinding, I would not want to be on the receiving end of 30 ml’s in the caudal canal, as compared to 2 ml’s subcutaneously. Most of my patients complain quite a bit at 6 ml’s.
Sincerely,
Marc J. Yland, MD
Competing interests: Practice in Interventional Pain Management
Dear Doctor Trond Iversen,
The dorsal horns are not merely passive transmission stations but
sites at which dynamic activities (inhibition, excitation and modulation)
occur. [18]
Via a series of filters and amplifiers, the nociceptive message is
integrated and analysed in the cerebral cortex, with interconnections with
various areas. [1]
The processing of pain takes place in an integrated matrix throughout
the neuroaxis and occurs on at least three levels, at peripheral, spinal,
and supraspinal sites. [9]
Knowledge of the modalities of pain control is essential to correctly
adapt treatment strategies (drugs, neurostimulation, psycho-behavioural
therapy, etc.).
Dysfunction of pain control systems causes neuropathic pain. [1]
Spinal Cord Stimulation modalities evolved from the gate-control
theory postulating a spinal modulation of noxious inflow. [16] [2] [7]
[11] [12] [15] [17] [20] [22] [23] [24] [25] [26]
It has been demonstrated in multiple studies that dorsal horn
neuronal activity caused by peripheral noxious stimuli could be inhibited
by concomitant stimulation of the dorsal columns. [8]
Pain relief was more prominent at pain ascending through C fibers
than pain ascending through Adelta fibers [21]
Many theories on the mechanism of action of Spinal Cord Stimulation
have been suggested, including activation of gate control mechanisms,
conductance blockade of the spinothalamic tracts, activation of
supraspinal mechanisms, blockade of supraspinal sympathetic mechanisms,
and activation or release of putative neuromodulators. [14]
At present, Spinal Cord Stimulation is a well established form of
treatment for failed back surgery syndrome, complex regional pain
syndromes (CRPS), low back pain with radiculopathy and refractory pain due
to ischemia. [4] [3] [8] [13]
Stimulation produced analgesia can provide a level of analgesia and
efficacy that is unattainable by other treatment modalities. [19]
Spinal Cord Stimulation for the treatment of chronic pain is cost-
effective when used in the context of a pain treatment continuum. [14]
Precise subcutaneous field stimulation is targeted to specific areas
of neuropathic pain. [6]
We aim at attenuation or blockade of pain through intervention at the
periphery, by activation of inhibitory processes that gate pain at the
spinal cord and brain. [9]
Segmental noxious stimulation produces a stronger analgesic effect
than segmental innocuous stimulation. [10]
That is exactly what intradermal sterile water or subcutaneous saline
injections do!
Chloride, used in your subcutaneous "sham" injections, independently
regulates the pain pathway. [5]
In your study there was no valid control group receiving sham
injections.
In the past, other researchers, in similar studies, have also had
difficulties in blinding and comparing with control groups. [4]
Your study simply compared an established therapeutic intervention to
another established therapeutic intervention.
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Competing interests: No competing interests
Dear Sir
Thank you for taking the time to read our article and submit your
comments. Here are our responses to your questions regarding the
interpretation of data.
1.In all our mixed model analyses we adjusted for the baseline
differences between the groups. We absolutely agree that this should be
done irrespective of whether or not the differences at baseline are
statistically significant... in fact, that is the reason why we adjusted
for these differences in our study.
2. The minimal important significant difference (MID)is estimated at
0.081 (SD 0.319) for the EQ-5D.
Szpalski, M. et al. (Eds) Surgery for Low Back Pain. Chap. 6.1.
Springer. 2010.
Walters, S.J. and Brazier, J.E. Comparison of the minimally important
difference for two health state utility measures: EQ-5D and SF-6D. Qual
Life Res. 2005 Aug; 14(6) 1523-32.
3. We agree that the power calculations show that we have too low
power to give a valid estimate of the between group differences concerning
sick leave. The P value given in our paper is therefore not so
informative. A more valuable presentation of the data could have been to
give the number of patients on sick leave in the three intervention
groups.
4. At the 52 week follow up 1 patient in the caudal epidural steroid
group, 6 patients in the caudal epidural saline group, and 8 patients in
the sham group had undergone back surgery during the previous year. We did
a within group comparison and used the number of patients in each group at
inclusion to give the within group differences with a P value of 0.07. We
agree that the presentation in the paper could have been misleading
because we have given the percentage in each group at the 52 week follow
up with a P value as reported above.
Regards
Trond Iversen
Competing interests: No competing interests
Dear Sirs
Thank you for your considered response to our article. We have a few
comments in reply.
All doctors and physiotherapists involved in the trial received
training to establish common neurological examination techniques and in
this way secure high inter-tester reliability. Examination for low back
pain and radiculopathy resulted in a conclusion regarding which nerve root
was affected. To obtain this precision regarding the nerve root,
information from clinical index tests was combined. In addition to history
and active movements of the lower back we used a straight-leg raising
test, isometric testing for muscle paresis in all muscle groups in the
lower extremity, and testing for sensory deficits and impaired reflexes.
In a forthcoming paper we will present results concerning sensitivity,
specificity and predicted values for these clinical tests as recommended
in your reference 3.
Sensitivity in diagnostic accuracy studies for the clinicial index
tests varied between 0.14 and 0.81. This does not however imply that we
should stop relying on clinical skills but try to develop our competence
further.
The challenge in obtaining correct needle placement can be solved by
using ultrasound in caudal epidural injections. Using contrast
confirmation is not necessary for the caudal root. For the transforaminal
approach fluoroscopy should always be used, but we have not focused on
this technique in our paper.
Regarding your statement 'We wonder how much more significant the
study would have been if the active treatment group were selected properly
and had been offered effective treatment rather than a hit and miss blind
injection', we can advise the following:
All patients in our study experienced improvement in both Oswestry
Disability Index and clinical health, but there were no differences
between the three intervention groups at any point in time during follow
up. The observed changes in the sham group probably reflect the natural
course of the disease. Treating patients with radiculopathy with epidural
steroid injections seems to add nothing to their spontaneous improvement
in function. It is a paradox that when comparing discectomy, fusion and
disc prosthesis with conservative care or spinal injections the results
after up to one year follow up are indistinguishable. The drawback with
these studies is the lack of control groups illustrating the natural
course of the disease. We have tried to include a control group in our
study to compensate for this.
Regards
Trond Iversen
Competing interests: No competing interests
Dear Sirs
Both the paper by Iverson et al and the accompanying editorial by
Cohen on the treatment of chronic lumbar radiculopathy raise important
issues both in terms of patient selection and fluoroscopic guidance for
interventional procedures (1).
In terms of patient selection, the authors rely on 'clinically proved
radiculopathy' as the primary inclusion criterion. In doing so, we assume
that the authors are attempting to replicate what they believe to be
common clinical practice. We know, though, that the clinical diagnosis of
radiculopathy is challenging. Radicular like symptoms and signs may arise
from various spinal and indeed non-spinal structures (2).
A Cochrane review of 'Physical examination for lumbar radiculopathy
due to disc herniation in patients with low-back pain' by Van der Windt et
al (3) tells us that 'when used in isolation, current evidence indicates
poor diagnostic performance of most physical tests used to identify lumbar
disc herniation'. We also know that in asymptomatic individuals, disc
protrusions shown on MRI are common. Westhaupt et al (4), for example,
showed that the prevalence of disc bulges and disc prolapses in
asymptomatic volunteers to be nearly 70%. Disc extrusions were found in
one in five individuals.
Given this challenging situation, where clinical evaluation is far
from reliable and radiological findings are relatively common in
asymptomatic individuals, it is imperative that both are brought together
and correlated. Not doing so presents a very sizeable risk of selecting
patients with a heterogenous group of conditions which might include true
radiculopathy but we have no way of knowing.
In our experience, performing epidural injections on the strength of
a clinical evaluation alone is not common clinical practice. With the
advent of precision diagnosis and treatment techniques it is important
that an accurate diagnosis is made before embarking upon any form of
spinal intervention - particularly when the intervention has known risks.
Establishing the site of the pathology helps to target the procedures
appropriately rather than injecting at relatively remote sites.
A further major drawback of the Iverson study is that fluoroscopy and
contrast injection was not used to confirm that correct placement of the
epidural needle had taken place meaning that there could not be
confirmation that that the injected drug had reached the target site.
Fluoroscopic guidance and contrast confirmation is the gold standard
for caudal epidural injections as the epidural space can be difficult to
enter. The Faculty of Pain Medicine of the Royal College of Anaesthetists
has updated its "Recommendations for good practice in the use of epidural
injection for the management of pain of spinal origin in adults" in 2011
(5). The guidelines states that "Further decisions about management are
often determined by the outcome of an epidural injection so it is
important to confirm the accurate placement of the epidural needle and the
spread of the injectate. It is recommended that normally, epidural
injection for patients with pain of spinal origin should be performed
under fluoroscopic guidance. Studies indicate that in a significant number
of patients the needle may not be correctly sited if epidural injection is
performed without fluoroscopy. A non-ionic water soluble contrast medium
should be injected to confirm correct needle placement before injecting
any medication into the epidural space". We would recommend this to
anyone performing epidural
injection.(http://www.rcoa.ac.uk/docs/EpiduralInjections.pdf)
Manchikanti and colleagues have evaluated the accuracy of needle
placement and flow patterns of fluoroscopically guided caudal epidural
injections. They found that with injection of 10 mL of contrast, filling
was noted up to S1 in 70% of the patients, followed by L5 nerve root
filling in only 12% of the patients. Intravenous placement of the needle
was noted in 14% of the patients with positive flashback and aspiration in
50% of the patients (6).
The editorial by Cohen rightly concludes "Fluoroscopy should always
be used to ensure proper needle placement and indeed go on to say that
transforaminal approach seems to provide better relief than the caudal or
conventional interlaminar method".
The editorial makes a very misleading statement that "after around 35
studies have failed to provide a definitive answer regarding the efficacy
of epidural steroid injections, it is unlikely that future trials will do
so". The editorial fails to mention that most of these studies referred
to were substandard and did not use fluoroscopic guidance and/or contrast
injection, which can make a big difference to correct placement of the
drug and its effects. It also appears as though the author has
inappropriately combined the different routes of epidural access (caudal,
lumbar inter-laminar and transforaminal epidural). In contrast the two
studies where fluoroscopic guided caudal epidural steroid placement
occurred have shown positive results (7,8)
If epidural procedures are performed incorrectly it is very likely
that more patients will progress to surgery which will be a great
disservice to our patients. Despite the substandard technique used in
this this study, significantly fewer patients had surgery as indicated in
the BMJ Rapid Response of Tarjei entitled "Absence of evidence is still
not evidence of absence," Tarjei suggests a significant surgery sparing
effect with a recalculated p value of 0.038. We wonder how much more
significant the study would have been if the active treatment group were
selected properly and had been offered effective treatment rather than a
hit and miss blind injection.
In areas of medicine where the existing evidence is conflicting, a
single well conducted randomised trial can make all the difference in
interpreting the truth. This poorly conceived trial tells us simply that
low dose steroid in high volumes administered without appropriate imaging
guidance does not seem to help a heterogenous population of back and leg
pain sufferers who have no diagnosis.
1. Iverson T, et al. Effect of caudal epidural steroid or saline
injection in chronic lumbar radiculopathy: multicentre, blinded,
randomised controlled trial. BMJ 2011; 343: 573-574
2. Nath S, et al. Percutaneous Lumbar Zygapophysial (Facet) Joint
Neurotomy Using Radiofrequency Current, in theManagement of Chronic Low
Back Pain: A Randomized Double-Blind Trial. Spine 2008; 33 (12) 1291-1297
3. van der Windt DA, Simons E, Riphagen II, Ammendolia C, Verhagen AP,
Laslett M, Devill? W, Deyo RA, Bouter LM, de Vet HC, Aertgeerts B.
Physical examination for lumbar radiculopathy due to disc herniation in
patients with low-back pain. Cochrane Database Syst Rev. 2010 Feb
17;(2):CD007431.
4. Weishaupt D, Zanetti M, Hodler J, Boos N. MR imaging of the lumbar
spine: prevalence of intervertebral disk extrusion and sequestration,
nerve root compression, end plate abnormalities, and osteoarthritis of the
facet joints in asymptomatic volunteers. Radiology. 1998 Dec;209(3):661-6.
5. Faculty of Pain Medicine of the Royal Collage of Anaesthetists.
Recommendations for good practice in the use of epidural injection for the
management of pain of spinal origin in adults. 2011.
(http://www.rcoa.ac.uk/docs/EpiduralInjections.pdf)
6. Manchikanti L, Cash KA, Pampati V, McManus CD, Damron KS. Evaluation of
fluoroscopically guided caudal epidural injections. Pain Physician. 2004
Jan;7(1):81-92.
7. Manchikanti L, et al. Premilinary results of randomized, equivalence
trail of fluoroscopic caudal epidural injections in managing chronic low
back pain: Part 2. Disc herniation and radiculitis. Pain Physician 2008;
11: 802-815.
8. Dashfield AK, et al. Comparision of caudal epidural with targeted
steroid placement during spinal endoscopy for chronic sciatica: A
prospective, randomized, double blind trial. British Journal of
Anaesthesia 2005; 94: 514-519
Competing interests:
Dr S Gupta: Chair of the Interventional Pain Medicine Special Interest Group (IPM SIG) of the British Pain Society (BPS); Member of the guidelines development group "Recommendations for good practice in the use of epidural injection for the management of pain of spinal origin in adults" (2011).
Dr Stephen Ward: Secretary, IPM SIG of the BPS; Member of the Board of the Faculty of pain medicine of the RCoA, Perform caudal Epidural injections for radiculopathy in both my NHS and private practices.
Dr Rajesh Munglani: Officer of the IPM SIG of the BPS and secretary of the medicolegal SIG, and an elected member on the council of the BPS
Dr Manohar Sharma: Treasurer of the IPM SIG of the BPS.
All authors practice Pain Medicine
Competing interests: No competing interests
Dear Sirs
Thank you for your questions which we will respond to below.
The MRI imaging was used to exclude patients with large disc
herniations, spinal stenosis and other non-disc related causes of back
pain. The inclusion criteria was clinically proven radiculopathy. It is a
well known fact that there is no necessary correspondance between MRI
findings and clincial signs of radiculopathy. There are many false
positive MRIs. It is necessary to improve the clinical skills of GPs and
specialists when examining patients with low back pain and sciatica. We
should not base our treatment options only on MRI findings.
In randomised controlled trials with strict exclusion/inclusion
criteria it is not uncommon to have lower sample size than expected. In
our study we included 25% of patients referred. This is in accordance with
the inclusion rate in the UK study by Arden et al. 'A multicentre
randomized controlled trial of epidural corticosteroid injections for
sciatica: the WEST study.' Rheumatology 2005;44:1399-1406.
Many patients with low back pain and sciatica experience a rapid
spontaneous improvement. This is regarded as part of the natural course of
the disease. We did not include patients with improvement in symptoms in
the last 14 days before the first injection. The 116 included patients
were highly selected based on clinical examination, and they all had
significant radicular symptoms.
The conclusions in our study are based on effect estimates in a
highly homogeneous patient group (all patients having radiculopathy).
Regards
Trond Iversen
Competing interests: No competing interests
Dear Sirs
Thank you for your response to our article. We hope the following
explanations will be useful.
In 2007 a report from the Therapeutics and Technology Assessment
Subcommittee of the American Academy of Neurology (Armon, C. et al.
Assessment: Use of epidural steroid injections to treat radicular
lumbosacral pain. Neurology 2007;68:723-729) it is concluded that
"epidural steroid injections for lumbosacral radicular pain have no impact
on average impairment of function, on need for surgery, or on long term
pain relief beyond 3 months, and their use for the indications are not
recommended." Our study agrees with this statement.
In response to your specific points:
1. It is a well known fact that many patients with an MRI-identified
herniated disc are asymptomatic. Also, many patients without MRI-
identified nerve root compression can present with clinical signs of
radiculopathy. For these people, mechanical compression on the nerve root
is not needed to provoke a clinical sign of radiculopathy. Inflammation in
the nerve root may be a likely cause of the observed clinical symptoms.
2. Patients with large disc herniation (>50% spinal canal
diameter) were excluded from the study and referred to a spinal surgeon.
Patients in this group are more likely to be operated on and less likely
to experience the effects of a steroid injection due to the significant
mechanical compression to the nerve root and the dura mater.
3. The evidence for a difference in effect due to injection technique
to the epidural space is conflicting. We have not focused on this in our
study. Transforaminal injections seem to have a better effect than the
caudal epidural approach but there are so far no convincing randomised
controlled trials to confirm this.
4. With a volume of 30ml as in our study the medication reached up to
level L2. We agree that with a high saline volume the concentration of
steroid was lowered, but based on the results of other studies a higher
concentration of steroid would not have influenced the results.
5. The main purpose in our study was to investigate the effect of the
steroid triamcinolone acetonide.
6. We used ultrasound guidance to improve the precision of the needle
placement. Our experience with fluoroscopy and contrast guidance do not
indicate that the injectate exits via the sacral foramina without reaching
higher levels than L5/S1.
In our study the main purpose was to investigate the effect of the
steroid in patients with clinical signs of radiculopathy.
In our opinion, the study design was comparable with clinical
practice with a focus on selecting patients with radiculopathy suitable
for treatment with caudal epidural steroid injection.
Regards
Trond Iversen
Competing interests: No competing interests
Re: Effect of caudal epidural steroid or saline injection in chronic lumbar radiculopathy: multicentre, blinded, randomised controlled trial
Dear Editors,
As we all know, lumbar canal stenosis is a fairly common problem. Management still remains quite challenging, with surgical decompression/ debridement / fusions/foraminotomy/ laminotomy, etc, being resorted to when NSAIDs, physical therapy and tractions, chiropractic manipulations, epidural steroid injections, acupunctures, etc stop being efficacious anymore. Lumbar canal stenosis is known to keep worsening usually with time, and even can lead to debilitating cauda equina syndrome.
Despite all its improvements and the advent of minimally invasive techniques, many patients continue to have reservations and apprehensions regarding surgery. In order to quantify this problem, we would like to mention out here what we have read somewhere, that an estimated 400,000 Americans suffer from leg pain and/or low back pain from lumbar spinal stenosis. This is a huge number for a single country.
In this context, we would now like to inform you BMJ, and the world thereby, that accidentally we have developed a non-invasive and a painless technique for managing lumbar stenosis. Once this information of a new and innovative non-invasive technique was somehow inadvertently got leaked out, we could not hold back, or deny the patients who thereafter came seeking our help from distant places for their problem of lumbar stenosis. We have tried extending this help totally free of cost to all these patients.
Our prime author, here, was the first patient, who found relief accidentally. He had been having claudications and foot drop as well, for which he had to stop and rest. He had this problem for over two to three decades and much before he had turned 50 years of age. He is 52 ½ years old now. Retrospectively, we suspect that he did have a narrow lumbar canal, possibly by birth. His father had similar problems, and they too were managed as promptly by this same technique. This non-invasive technique, which we would like to be called hereafter as “AGRA TECHNIQUE” for lumbar stenosis, requires no needles, no anaesthesia, no hospitalization, and is over in less than two hours in most cases, and the relief is also as prompt.
This technique may not be helpful in 100 % cases, but we believe that this “AGRA TECHNIQUE” could be very useful for early cases. But then it would require further refinement, so as to become more precise, totally safe even in a novice’s hands, more acceptable, etc. We could do just this much at our own, without any help or encouragement from any quarters. We do believe that vast number of patients around the world can be helped promptly and possibly for lasting intervals, by this innovative AGRA TECHNIQUE, which surely needs much more collaborative research for enhancing refinement, precision, safety, and for prolonging relief, and for increasing success rates. This technique could be used as an alternative for those patients who are not prepared for undergoing surgery, or are unfit to be undertaken for surgery for presence of other co-morbidity which might place added risk for surgery or anaesthesia.
Best regards.
Competing interests: This technique was an accidental development.