Adverse events associated with fluoroscopically guided lumbosacral transforaminal epidural steroid injections

BACKGROUND CONTEXT

Although the types and incidence of adverse events (AEs) associated with transforaminal epidural steroid injection (TFESI) have been described, no study has used a systematic standardized questionnaire to solicit AEs from patients to capture an accurate range and incidence of complications.

PURPOSE

The aim was to systematically identify the types and incidence of AEs associated with TFESI. Additionally, this study evaluated demographic and clinical factors that may predict a higher risk of an AE.

STUDY DESIGN/SETTING

This was a retrospective cohort study from a multiphysician academic PM&R clinic.

PATIENT SAMPLE

Patients, aged 19 to 89, who underwent a fluoroscopically guided TFESI for lumbosacral radicular pain between 2004 and 2007 were included.

OUTCOME MEASURES

The relationship of AEs with gender, age, trainee presence, steroid type, preprocedure visual analog scale (VAS) pain score, systolic blood pressure, fluoroscopy time, and corticosteroid injectate volume was analyzed.

METHODS

Adverse event data were collected using a survey both immediately and at 24 to 72 hours after TFESI. Statistical analysis was performed using the chi-square, Fisher exact, or Wilcoxon rank sum two-sided tests. Logistic regression analysis was also performed. C.P. is the owner of Rehabilitation Institute of Chicago Physiatric Log & Analysis System computer software.

RESULTS

In 1,295 consecutive patients undergoing 2,025 TFESI procedures, immediate AEs and delayed AEs occurred after 182 (9.2%) and 305 (20.0%) injections, respectively. The most common immediate AEs were: vasovagal reaction (4.2%) and interrupted procedure from intravascular flow (1.7%). Common delayed AEs included: pain exacerbation (5.0%), injection site soreness (3.9%), headache (3.9%), facial flushing/sweating (1.8%), and insomnia (1.6%). Significant associations were identified between AEs and gender, age, preprocedure VAS, steroid type, and fluoroscopy time. Trainee involvement in the procedure did not impact the complication rate.

CONCLUSIONS

Fluoroscopically guided lumbosacral TFESI is associated with a similar rate of minor AEs both immediately and 24 to 72 hours after procedure that are typical of other axial corticosteroid injections. Permanent AEs were not found in this sample. The most common AEs associated with TFESI include vasovagal episodes, procedure interruption from intravascular flow, pain exacerbation, injection site soreness, headache, and insomnia.

Oxidized LDL-bound CD36 recruits an Na⁺/K⁺-ATPase-Lyn complex in macrophages that promotes atherosclerosis

One characteristic of atherosclerosis is the accumulation of lipid-laden macrophage foam cells in the arterial wall. We have previously shown that the binding of oxidized low-density lipoprotein (oxLDL) to the scavenger receptor CD36 activates the kinase Lyn, initiating a cascade that inhibits macrophage migration and is necessary for foam cell generation. We identified the plasma membrane ion transporter Na(+)/K(+)-ATPase as a key component in the macrophage oxLDL-CD36 signaling axis. Using peritoneal macrophages isolated from Atp1a1 heterozygous or Cd36-null mice, we demonstrated that CD36 recruited an Na(+)/K(+)-ATPase-Lyn complex for Lyn activation in response to oxLDL. Macrophages deficient in the α1 Na(+)/K(+)-ATPase catalytic subunit did not respond to activation of CD36, showing attenuated oxLDL uptake and foam cell formation, and oxLDL failed to inhibit migration of these macrophages. Furthermore, Apoe-null mice, which are a model of atherosclerosis, were protected from diet-induced atherosclerosis by global deletion of a single allele encoding the α1 Na(+)/K(+)-ATPase subunit or reconstitution with macrophages that lacked an allele encoding the α1 Na(+)/K(+)-ATPase subunit. These findings identify Na(+)/K(+)-ATPase as a potential target for preventing or treating atherosclerosis.

Elevated Plasma Marinobufagenin, An Endogenous Cardiotonic Steroid, Is Associated With Right Ventricular Dysfunction and Nitrative Stress in Heart Failure

BACKGROUND

Plasma levels of cardiotonic steroids are elevated in volume-expanded states, such as chronic kidney disease, but the role of these natriuretic hormones in subjects with heart failure (HF) is unclear. We sought to determine the prognostic role of the cardiotonic steroids marinobufagenin (MBG) in HF, particularly in relation to long-term outcomes.

METHODS AND RESULTS

We first measured plasma MBG levels and performed comprehensive clinical, laboratory, and echocardiographic assessment in 245 patients with HF. All-cause mortality, cardiac transplantation, and HF hospitalization were tracked for 5 years. In our study cohort, median (interquartile range) MBG was 583 (383-812) pM. Higher MBG was associated with higher myeloperoxidase (r=0.42, P<0.0001), B-type natriuretic peptide (r=0.25, P=0.001), and asymmetrical dimethylarginine (r=0.32, P<0.001). Elevated levels of MBG were associated with measures of worse right ventricular function (RV s', r=-0.39, P<0.0001) and predicted increased risk of adverse clinical outcomes (MBG≥574 pmol/L: hazard ratio 1.58 [1.10-2.31], P=0.014) even after adjustment for age, sex, diabetes mellitus, and ischemic pathogenesis. In mice, a left anterior descending coronary artery ligation model of HF lead to increases in MBG, whereas infusion of MBG into mice for 4 weeks lead to significant increases in myeloperoxidase, asymmetrical dimethylarginine, and cardiac fibrosis.

CONCLUSIONS

In the setting of HF, elevated plasma levels of MBG are associated with right ventricular dysfunction and predict worse long-term clinical outcomes in multivariable models adjusting for established clinical and biochemical risk factors. Infusion of MBG seems to directly contribute to increased nitrative stress and cardiac fibrosis.

Does Electrodiagnostic Confirmation of Radiculopathy Predict Pain Reduction after Transforaminal Epidural Steroid Injection? A Multicenter Study

OBJECTIVE

Minimal definitive literature identifies patients with radicular pain who would benefit most from epidural steroid injection (ESI). This study investigated if electromyographic (EMG) confirmation of radiculopathy with active or chronic denervation predicts a positive treatment outcome following ESI.

DESIGN

Longitudinal cohort study of adults who underwent EMG and subsequent transforaminal ESI within 6 months. The proportion of individuals who experienced >50% pain relief and mean change in daily morphine equivalents (DME) were calculated.

RESULTS

170 individuals with respective mean (Standard Deviation) age and duration of symptoms of 55 (15) years and 36 (56) months were included. Mean time to <30 day and >30 day follow-up post-injection were 18 (6) and 99 (130) days, respectively. At >30 day follow-up, a larger proportion of EMG-confirmed individuals (37.7%) reported >50% pain reduction compared to EMG-negative individuals (17.8%) (p=0.03). This was significant for lumbosacral (40% vs. 15%, p=0.01) but not cervical symptoms (p>0.05). Mean decrease in DME at long-term follow-up in EMG-confirmed compared to EMG-negative individuals trended toward significance (-4 vs. -1, p=0.11). There was no significant relationship between myotomal spontaneous activity and pain or opioid use.

CONCLUSIONS

Needle EMG predicts long-term pain reduction from transforaminal ESI in patients with lumbosacral radiculopathy, regardless of the presence of active denervation.

Changes in gait kinematics and lower back muscle activity post-radiofrequency denervation of the zygapophysial joint: a case study

BACKGROUND CONTEXT

Using diagnostic anesthetic blocks, the lumbar zygapophysial (facet) joint has been shown to be the primary cause of pain in approximately 15% of patients with chronic low back pain. Radiofrequency neurotomy (RFN) of the lumbar medial branch innervating the zygapophysial joint has been shown to provide a significant decrease in pain in patients selected by dual comparative anesthetic blocks, but quantitative improvements in mobility have not been fully elucidated. A theoretical concern with RFN is that the multifidus muscle, a stabilizing paraspinal muscle, is also denervated during this procedure, which may have adverse effects on mobility and spine stability.

PURPOSE

The purpose of this study was to examine gait kinematics and muscle activity of the low back during treadmill walking both before and after RFN.

STUDY DESIGN

Case study.

PATIENT SAMPLE

One 33-year-old female, with 15 years of chronic left low back pain and a diagnosis of L4/L5 lumbar zygapophysial joint pain by dual comparative anesthetic blocks was studied.

OUTCOME MEASURES

Self-reported measures of perceived pain and effort; in addition to physiologic measures of heart rate, gait kinematics and surface electromyography (EMG) activity of the multifidus and erector spinae muscles were collected before and after the procedure.

METHODS

The participant walked for 15 consecutive minutes on a treadmill. The first and last 5-minute intervals were at a self-selected pace, and the middle 5-minute interval was at a 50% increase of the self-selected pace. Gait kinematics and lumbar paraspinal surface EMG activity were recorded during the last minute of each walking interval. Heart rate, perceived effort, and perceived pain were also collected at the end of each walking interval. Data were collected both 7 and 1 days before RFN, and on the following days post-RFN: 0, 8, 14, 28, and 58.

RESULTS

Perceived effort did not change despite an increase in treadmill speed and heart rate. Pain decreased by 60% in the first two weeks and by 92% by 4 weeks post-RFN. There were also gradual positive changes in gait kinematics across all post-sessions and an immediate and sustained decrease in surface EMG activity over the left multifidus and erector spinae muscles following RFN.

CONCLUSIONS

The results of this pilot study are the first to show quantitative positive changes in gait and muscle activity post-RFN, suggesting that the relationship between this procedure and mobility warrant further investigation.

Morphologic changes in the lumbar spine after lumbar medial branch radiofrequency neurotomy: a quantitative radiological study

BACKGROUND CONTEXT

Medial branch radiofrequency neurotomy (RFN) is a common treatment for zygapophyseal joint pain. The lumbar medial branch innervates these joints and adjacent structures. The impact of the intended neurotomy on these structures remains unclear. No studies have yet verified quantitatively the effect of medial branch RFN on intervertebral discs, facet joints, and multifidus cross-sectional area.

PURPOSE

The aim of this study was to determine, using objective radiographic measures, whether there is a quantitative difference in the lumbar multifidus muscle cross-sectional area, facet joint degeneration, or intervertebral disc degeneration after segmental medial branch RFN.

STUDY DESIGN/SETTING

This is a retrospective single-cohort study performed at a university spine center.

PATIENT SAMPLE

The patient sample consisted of 27 patients treated with lumbar medial branch RFN, with pre- and posttreatment magnetic resonance images available for analysis.

OUTCOME MEASURE

The primary study outcome measure was interval change in fat-subtracted multifidus cross-sectional area, and intervertebral disc and zygapophyseal joint degeneration grade.

METHODS

In this retrospective study, segmental levels unaffected by RFN treatment were used as controls to compare against levels affected by treatment.

RESULTS

Levels affected by RFN demonstrated a significantly greater amount of disc degeneration compared with unaffected levels (14.9% vs. 4.6%; p=.0489). There was no statistical difference in the multifidus cross-sectional area or rates of deterioration in the zygapophyseal joints observed.

CONCLUSIONS

The full impact of RFN on multifidus function, morphology, and segmental anatomy is unknown. This retrospective study indicates that measurable changes in segmental morphology may occur after lumbar medial branch RFN. These findings require validation in a prospective, controlled study.

Epidural Steroid Injections are Safe and Effective: Multisociety Letter in Support of the Safety and Effectiveness of Epidural Steroid Injections

BACKGROUND

In April 2014, the Food and Drug Administration (FDA) issued a Drug Safety Communication requesting that corticosteroid labeling include warnings that injection of corticosteroids into the epidural space of the spine may result in rare but serious adverse events, including loss of vision, stroke, paralysis, and death.

RESULTS

The International Spine Intervention Society spearheaded a collaboration of more than a dozen other medical societies in submitting the letter below to the FDA on November 7, 2014. We are publishing the letter to ensure that the readership of Pain Medicine is aware of the multisociety support for the safety and effectiveness of these procedures. A special note of thanks to all of the societies who signed on in support of the message.

Concordant pain provocation during transforaminal epidural steroid injection for lumbosacral radiculopathy: effect on pain outcome and predictive factors

BACKGROUND

Anecdotal report suggests that provocation of pain during epidural steroid injection (ESI) that is concordant with typical radicular symptoms predicts pain outcome following injection. However, limited evidence exists that substantiates this theory. Additionally, there is a paucity of literature investigating factors associated with the provocation of pain during ESI.

OBJECTIVES

The goal of this study was to determine whether provocation of concordant radicular pain during transforaminal ESI predicts pain relief immediately after injection and at short-term follow-up. Demographic, radiologic, and procedural factors associated with the pain provocation and pain outcomes at immediate and short-term follow-up were also investigated.

STUDY DESIGN

Longitudinal cohort study.

SETTING

Urban academic outpatient interventional spine clinics.

METHODS

Adults who underwent a fluoroscopically guided transforaminal ESI without sedation between January 1, 2006, and October 29, 2007, for the treatment of lumbosacral radicular pain were included in this study. The relationships between provocation of concordant pain, immediate post-injection, and follow-up visual analogue scale (VAS) pain scores, as well as with demographic, radiologic, and procedural factors were determined using chi-square/Fisher's exact tests for categorical variables and t-tests or ANOVA for numerical variables.

RESULTS

One thousand twenty one patients, 42.4% (433) male/57.6% (588) female, with a mean (SD) age of 54.1 (16.7) years were included in the study. Concordant pain provocation did not predict the magnitude of pain reduction (P = 0.9255) or the frequency of achieving > 50% pain relief (P = 0.7449) at short-term follow-up. Radiologic evidence of foraminal stenosis or nerve root impingement (P < 0.0001) and the lack of a medial-superior contrast flow pattern (P = 0.0199) were associated with a greater frequency of pain provocation during transforaminal ESI.

LIMITATIONS

This study is primarily limited by possible selection bias given that patients who did not follow-up in the clinic could not be studied, and an incomplete follow-up rate (66%). Conclusions regarding subacute and long-term pain outcomes cannot be determined from this study as only short-term data were available.

CONCLUSIONS

Provocation of concordant radicular pain does not predict pain relief at short-term follow-up after a transforaminal ESI. Foraminal stenosis, nerve root impingement, and lack of a medial-superior contrast flow pattern are associated with pain during the transforaminal ESI. Thus, clinicians should be aware of these radiologic and procedural risk factors for inciting pain during transforaminal ESI.

Gut microbiota-dependent trimethylamine N-oxide (TMAO) pathway contributes to both development of renal insufficiency and mortality risk in chronic kidney disease

RATIONALE

Trimethylamine-N-oxide (TMAO), a gut microbial-dependent metabolite of dietary choline, phosphatidylcholine (lecithin), and l-carnitine, is elevated in chronic kidney diseases (CKD) and associated with coronary artery disease pathogenesis.

OBJECTIVE

To both investigate the clinical prognostic value of TMAO in subjects with versus without CKD, and test the hypothesis that TMAO plays a direct contributory role in the development and progression of renal dysfunction.

METHODS AND RESULTS

We first examined the relationship between fasting plasma TMAO and all-cause mortality over 5-year follow-up in 521 stable subjects with CKD (estimated glomerular filtration rate, <60 mL/min per 1.73 m(2)). Median TMAO level among CKD subjects was 7.9 μmol/L (interquartile range, 5.2-12.4 μmol/L), which was markedly higher (P<0.001) than in non-CKD subjects (n=3166). Within CKD subjects, higher (fourth versus first quartile) plasma TMAO level was associated with a 2.8-fold increased mortality risk. After adjustments for traditional risk factors, high-sensitivity C-reactive protein, estimated glomerular filtration rate, elevated TMAO levels remained predictive of 5-year mortality risk (hazard ratio, 1.93; 95% confidence interval, 1.13-3.29; P<0.05). TMAO provided significant incremental prognostic value (net reclassification index, 17.26%; P<0.001 and differences in area under receiver operator characteristic curve, 63.26% versus 65.95%; P=0.036). Among non-CKD subjects, elevated TMAO levels portend poorer prognosis within cohorts of high and low cystatin C. In animal models, elevated dietary choline or TMAO directly led to progressive renal tubulointerstitial fibrosis and dysfunction.

CONCLUSIONS

Plasma TMAO levels are both elevated in patients with CKD and portend poorer long-term survival. Chronic dietary exposures that increase TMAO directly contributes to progressive renal fibrosis and dysfunction in animal models.

A quantitative study of intervertebral disc morphologic changes following plasma-mediated percutaneous discectomy

OBJECTIVE

To quantitatively evaluate interval magnetic resonance imaging (MRI) changes in disc morphology following plasma-mediated percutaneous discectomy.

DESIGN/SETTING

A retrospective comparison of pretreatment and posttreatment MRIs at a single university spine clinic.

SUBJECTS

From a group of 60 consecutively treated patients, 15 met the study inclusion and exclusion criteria. All had either failed treatment or had other clinical reasons for a posttreatment MRI.

METHODS

Two independent physicians electronically measured disc protrusion size and disc height at the treatment discs and adjacent discs on pre- and posttreatment MRI scans. Additionally, images were compared for gross anatomic changes including disc degeneration by Pfirrman classification, new disc herniations, high intensity zone (HIZ), vertebral endplate changes, post-contrast enhancement, and changes in segmental alignment. Pearson r correlation was used to determine interobserver reliability between the two physicians' MRI measurements. Paired t-tests were calculated for comparisons of pre- and posttreatment MRI measurements, and an ANOVA was performed for comparison of pre- to posttreatment changes in disc height measurements at treatment levels relative to adjacent levels.

RESULTS

Correlation was high for measurement of disc height change (r = 0.89; P < 0.0001) and good for anteroposterior protrusion size change (r = 0.51; P = 0.0512). Disc height at treated discs demonstrated a small but statistically significant mean interval reduction of 0.48 mm (P = 0.0018). This remained significant when compared with the adjacent control discs (P < 0.0001). Pretreatment mean disc protrusion size (4.74 mm; range 3.75-6.55 mm) did not differ significantly (P = 0.1145) from posttreatment protrusion size (4.42 mm; range 2.55-7.95 mm). Gross anatomic changes at treatment levels included reduced disc protrusion size (N = 6), enlarged protrusion (N = 3), resolution of HIZ (N = 3), and improvement in endplate signal changes (N = 1). Also, 11/15 posttreatment MRIs included post-contrast images that showed epidural fibrosis (N = 1), rim enhancement (N = 2), and enhancement of the posterior annulus (N = 4).

CONCLUSIONS

Based on MRI examinations, subtle anatomic changes may occur following plasma-mediated percutaneous discectomy. Further study is required to determine the clinical relevance of these changes.