Lateral deviation of four types of epidural catheters from the lumbar epidural space into the intervertebral foramen.

BACKGROUND: During epidural anesthesia, the catheter tip occasionally deviates from the epidural space into the intervertebral foramen, resulting in inadequate anesthesia. METHODS: During postoperative plain radiography, iohexol was injected via the epidural catheter to determine its position and to observe the spread of the material. After exclusion of seven patients with catheters that migrated into the subcutaneous area and 25 patients with no evidence of the contrast medium, 415 patients were evaluated. We retrospectively compared patients to determine whether the incidence of deviation into the intervertebral foramen differed between four types of epidural catheters. We also investigated the load applied to the catheter tip using a Shimadzu Autograph AG-X-500 N-111 universal testing machine. RESULTS: Deviation of the epidural catheter into the intervertebral foramen was observed in eight and 33 patients in the Hakko and Perifix Soft tip catheter groups, respectively. The incidence of deviation was higher in the Perifix Soft tip catheter group, and lower in the FlexTip Plus and Perifix FX catheter groups. A rapid increase was observed in the force exerted on the tips of the Hakko and Perifix Soft tip catheters, while the force transmitted to the tips of the FlexTip Plus and Perifix FX catheters gradually increased and then reached a plateau at a low level. CONCLUSIONS: The incidence of deviation was significantly lower with spiral-type catheters than with other types of catheters. This might be attributable to the gradual transmission of a lower level of force to the tip in spiral-type catheters.

Does improvement in epidurography following percutaneous epidural neuroplasty correspond to patient outcome?

OBJECTIVE: The positive effects of percutaneous epidural neuroplasty (PEN) likely result from elimination of fibrous tissue. However, a direct link between epidural adhesions and pain symptoms is debatable. We tested the hypothesis that epidurographic improvements correspond to improved patient outcome. METHODS: In this prospective study, patients with a filling defect on initial epidurography underwent PEN. Two weeks later, contrast agent distribution around the target area was assessed with repeat epidurography. A successful treatment was defined as over a 50% reduction in visual analog scale (VAS) score 2 weeks postprocedure. The demographic data, history of lumbar spine operation, target nerve, diagnosis, VAS scores, degree of epidurographic improvement, and patient satisfaction were compared between the successful treatment group (Group I) and unsuccessful treatment group (Group II). RESULTS: Seventy-nine patients were included. Epidurographic findings improved in 67.1% of patients 2 weeks after the procedure. Following PEN, the mean VAS scores of all patients were significantly decreased at 2 weeks (4.12 ± 2.34), 1 month (3.56 ± 2.30), 3 months (3.84 ± 2.45), and 6 months (4.13 ± 2.71) compared with the initial scores (7.82 ± 1.78). In the comparison between Groups I and II, the rate of epidurographic improvement in Group I was higher than in Group II (P = 0.022). Satisfaction in patients that had epidurographic improvement (median satisfaction: 4) was higher than in patients that did not have epidurographic improvement (median satisfaction: 3; P = 0.003). CONCLUSION: The epidurographic changes following PEN correlate with patient-assessed pain relief and satisfaction.

Why do thoracic epidurals fail? A literature review on thoracic epidural failure and catheter confirmation.

Thoracic epidural anesthesia (TEA) has been the gold standard of perioperative analgesia in various abdominal and thoracic surgeries. However, misplaced or displaced catheters, along with other factors such as technical challenges, equipment failure, and anatomic variation, lead to a high incidence of unsatisfactory analgesia. This article aims to assess the different sources of TEA failure and strategies to validate the location of thoracic epidural catheters. A literature search of PubMed, Medline, Science Direct, and Google Scholar was done. The search results were limited to randomized controlled trials. Literature suggests techniques such as electrophysiological stimulation, epidural waveform monitoring, and x-ray epidurography for identifying thoracic epidural placement, but there is no one particular superior confirmation method; clinicians are advised to select techniques that are practical and suitable for their patients and practice environment to maximize success.

Computed Tomographic Epidurography in Patients with Low Back Pain and Leg Pain: A Single-Center Observational Study.

This study was conducted to analyze the findings and benefits of computed tomography (CT) epidurography in patients with low back and leg pain and compare these findings with those of magnetic resonance imaging (MRI) images. In total, 495 intervertebral discs from 99 patients with low back and leg pain who underwent percutaneous epidural adhesiolysis (epidural neuroplasty or percutaneous adhesiolysis) were examined. The axial views of CT epidurography were classified into six types to examine each intervertebral disc: round type, ellipse type, spike type, Benz mark, incomplete block, complete block, and non-contrast. MRI images were graded from A to D using the Schizas classification. Notably, 176 images were round-type and ellipse-type axial views, and 138 were spike-type and Benz-mark views; Schizas classification Grades A and B were observed in 272 and 47 MRI images, respectively. The incomplete block and complete block axial images did not significantly differ in CT epidurography and Schizas classification Grades C and D. The images showing Benz marks existed only at the L4/5 and L5/S intervertebral levels and only in 14.7% of patients. The ratio of normal shadows differed between MRI images and CT epidurography. Therefore, CT epidurography may enable a detailed evaluation of the epidural space.

A New Role for Epidurography: A Simple Method for Assessing the Adequacy of Decompression during Percutaneous Plasma Disc Decompression.

Percutaneous plasma disc decompression (PPDD) is a minimally invasive treatment for discogenic low back pain and herniated disc-related symptoms. However, there are no known outcome predictive variables during the procedure. The purpose of this study was to evaluate and validate epidurography as an intra-procedure outcome predictor. We retrospectively enrolled 60 consecutive patients who did not respond to conventional treatments. In the next stage of treatment, PPDD was performed, and the epidurography was conducted before and after the PPDD. We analyzed the relationship between epidurographic improvement and the success rate. The Numerical Rating Scale and the Oswestry Disability Index were used to assess pain and functional capacity, respectively, before the procedure and 1 month after the procedure. The pain reduction and the success rate in the epidurographic improvement group were significantly higher than in the epidurographic non-improvement group. Both the Numerical Rating Scale and the Oswestry Disability Index scores were significantly reduced in both groups, but there was no significant difference in Oswestry Disability Index scores. This study's results showed that PPDD is an effective treatment method. We also suggested that epidurography may be a potential outcome predictor for ensuring successful outcomes and determining the endpoint of the procedure.

Mathematical Models for the Skin to Lumbosacral Epidural Distance in Dogs: A Cadaveric Computed-Tomography Study.

This study aimed to validate previously published computed tomography (CT) derived mathematical equations with the true skin to lumbosacral epidural distance (SLED) in dog cadavers. Phase 1: The lumbar region of 11 dog cadavers were scanned in sternal recumbency to determine the effect of cranial, neutral, and caudal pelvic limb positioning on the CT derived lumbosacral epidural distance (CLED). Phase 2: The epidural space was determined using contrast epidurography, and the SLED was analysed against the mathematical equations using a body condition score (BCS) and either the cadaveric occipital-coccygeal length (OCL) (Equation (1): = 7.3 + 0.05*OCL + 16.45*BCS) or the ilium wing distance (IWD) (Equation (2): = 3.5 + 0.56*IWD + 16.6*BCS). There were no differences detected between the pelvic limb positions and the CLED. Both equations demonstrated strong correlations (Equation (1): r = 0.7196; Equation (2): r = 0.7590) with the SLED. The level of agreement was greater for Equation (1) than with Equation (2) (concordance coefficient 0.6061 and 0.3752, respectively). Equation (1) also demonstrated a closer fit to the concordance line compared with Equation (2) (bias correction factor 0.8422 and 0.4960, respectively). Further studies in live anaesthetised dogs will help to determine the usefulness of the pre-procedural knowledge when performing lumbosacral epidurals.

Contribution of Low-Dose Computerized Tomography With Digital Multiplanar Reconstructions in Thoracic Epidurography and Correlation With Sensory Block in Postoperative Analgesia.

BACKGROUND: The level of sensory block in postoperative epidural analgesia has been correlated with conventional contrast epidurography in only one study, while low-dose CT scan epidurography with multiplanar reconstruction may be a better tool for this purpose. OBJECTIVES: The primary objective of this study was to evaluate, by CT imaging and digital multiplanar reconstruction, the spread and distribution of contrast medium injected into the epidural space through a catheter inserted in a low thoracic position for postoperative analgesia. MATERIALS AND METHODS: Ten patients undergoing major abdominal cancer surgery with effective epidural analgesia were prospectively included at postoperative day three. Two consecutive boluses of 5 mL of a mixture of ropivacaine and contrast medium were injected at 15 minutes intervals into the epidural space. Multislice low-dose CT scan epidurography and an assessment of the sensory block were performed before and after injection of the second bolus. The primary objective was to assess the contribution of CT scan epidurography to predict a correlation between the level of sensory block and the spread of the contrast medium in the epidural space; the secondary objective was to determine the agreement between the two methods. RESULTS: The spread of contrast material and the clinical sensory block significantly increased after the second injection (32%; P < 0.05). However, no highly significant correlation was observed between the two methods. A gap of two spinal segments of CT opacification was observed in two patients and was confirmed by clinical assessment. CONCLUSIONS: CT epidurography is not closely correlated with a clinical assessment of epidural block; thus, a clinical assessment of the sensory block is mandatory. The use of opioid analgesia in combination with local anesthetics may compensate for the lack of efficacy of local anesthetics alone.

Analysis of thoracic epidurography and correlating factors affecting the extent of contrast medium spread.

BACKGROUND: Thoracic epidural anesthesia is frequently used to maintain intraoperative and postoperative analgesia. Frequently, 3 ml of local anesthetic is used as a test dose, or for intermittent epidural injection. We assessed the extent of the spread of 3 ml of contrast medium in the thoracic epidural space and attempted to identify any correlating factors affecting the epidurography. METHODS: A total of 70 patients were enrolled in the study, and thoracic epidural catheterizations were performed under fluoroscopic guidance. Using 3 ml of contrast medium, epidurography was evaluated to confirm the number of spinal segments covered by the contrast medium. Correlation analysis was performed between patient characteristics (sex, age, body mass index, weight, height, and location of catheter tip) and the extent of the contrast spread. RESULTS: The mean number of vertebral segments evaluated by contrast medium was 7.9 ± 2.2 using 3 ml of contrast medium. The contrast spread in the cranial direction showed more extensive distribution than that in the caudal direction, with statistical significance (P < 0.01). Patient height demonstrated a negative correlation with the extent of distribution of contrast medium (r = -0.311, P < 0.05). CONCLUSIONS: Thoracic epidurography using 3 ml of contrast medium results in coverage of a mean of 7.9 ± 2.2 spinal segments, with more extensive cranial spread, and patient height showed a weak negative correlation with the distribution of contrast medium.

3D-CT Epidurography Can Detect Cerebrospinal-Fluid Leakage in a Patient with Spontaneous Intracranial Hypotension: A Case Report.

Spontaneous intracranial hypotension presents with many symptoms including orthostatic headache, dizziness, and nausea due to cerebrospinal-fluid (CSF) leakage from the spinal dural sac. Although CSF leakage can be estimated by radioisotope (RI) cisternography or computed tomography/magnetic resonance imaging myelography, it is not easy to detect the leakage point using these modalities. Here, we describe a patient with spontaneous intracranial hypotension in whom three-dimensional computed tomography (3D-CT) performed just after an epidural blood patch (EBP) containing contrast medium detected leakage point. The contrast medium injected into the epidural space at the L3/4 level migrated into the intradural space at the lower cervical spine level. RI cisternography performed before EBP did not show the CSF leakage point or any intracranial extension of the tracer. The rostral extension of the RI may be blocked by the collapse of the CSF space due to a large amount of CSF leakage, and due to the compression of the intradural CSF space by epidural CSF. 3D-CT epidurography may be useful to detect the fistula of a CSF leakage even in patients where other modalities including MRI, CT, or RI cisternography cannot specify the leakage point.

Some epidurographic explanations for incomplete epidural analgesia coverage in the absence of a catheter.

STUDY OBJECTIVE: To determine the impact of the plica mediana dorsalis (PMD) on injected contrast media spread in the epidural space. DESIGN: Prospective interventional study. SETTING: Academic medical center. PATIENTS: 30 chronic pain patients ranging in age from 37 to 71 years, undergoing epidural steroid injection. INTERVENTIONS AND MEASUREMENTS: Epidurograms were evaluated for the 1) presence or absence of a PMD and 2) bilateral differential density and the extent of contrast spread on either side of the midline, horizontally and vertically. RESULTS: The PMD (defined as midline radiolucency in epidurograms) was observed in (80%) 24/30 patients based on the epidurograms that were evaluated. Denser contrast spread on one side was found in (79%) 19/24 patients who had the PMD and in (33%) 2/6 patients who did not have the PMD (P = 0.03). Horizontal and vertical asymmetrical spread of the contrast was observed in (67%) 16 of 24 patients with the PMD and in (50%) 3 of 6 of patients without the PMD in each direction independently. CONCLUSION: The difference in density of contrast spread on either side of the midline carries important clinical implications in understanding the pathogenesis of inadequate epidural analgesia and/or unilateral excessive motor weakness or numbness.

The Correlation between Caudal Epidurogram and Low Back Pain.

BACKGROUND: The common causes of lower back pain with or without leg pain includes disk disease and spinal stenosis. A definitive diagnosis is usually made by means of magnetic resonance imaging (MRI), but treatment is often difficult because the MRI findings are not consistent with the symptoms of the patient in many cases. The objective of this study was to observe the correlation between the patterns of epidurography performed in patients having lower back pain with or without leg pain and the position or severity of the pain as subjectively described by the patients. METHODS: The subjects of this study were 69 outpatients with lower back pain with or without leg pain who visited our clinic and complained of predominant pain on one side. We performed caudal epidural block using an image intensifier. A mixture of the therapeutic drug and the contrast agent (10 ml) was injected to observe the contrast flow pattern. The patients who complained of predominant pain on one side were divided into the left side group and the right side group. A judgment of inconsistency was made if the contrast agent flowed to the side of the pain, while a judgment of consistency was made if the contrast agent flowed to the opposite side of the pain. The degree of the drug distribution was evaluated by counting the number of cells to which the contrast agent's flowed for evaluating the correlation between the contrasted cell and the severity of pain (one group ≤ VAS 7, the other group ≥ VAS 8) the degree of the contrast agent's contrast was evaluated by dividing and counting an image into 15 cells (the left, right, and middle sections at each level of L4, L5, S1, S2, and S3). RESULTS: Thirty out of the 69 patients who had laterality in pain, that is, those who complained of predominant pain on one side, showed that the laterality of the pain and the contrast agent flow was consistent, while 39 patients showed that the laterality was inconsistent (P: 0.137). The evaluation of the correlation between the pain and the contrast agent flow showed that the mean number of contrasted cells was 9.0 ± 2.2 for the 46 patients in the group with a VAS of 7 or lower and 6.5 ± 2.0 for the 23 patients in the group with a VAS of 8 or higher, indicating that the former group showed a significantly greater number of contrasted cells (P < 0.001). CONCLUSIONS: This study, conducted with patients having lower back pain with or without leg pain, showed that the contrast flow pattern of caudal epidurography had a significant correlation with the severity of the pain but not with the laterality of the pain.

Cervical brachalgia: Assessment by cervical CT epidurography post transforaminal injection.

Adjunct cervical CT epidurography (CCTE) can be used to image impingement in patients with cervical brachalgia undergoing fluoroscopic-guided cervical transforaminal injection (TFI) of steroid/local anaesthetic where magnetic resonance imaging (MRI) is contraindicated. CCTE images of the 9 patients on whom the authors performed CCTE post TFI over 6 years from 1998 to 2003 were retrospectively reviewed. CCTE is able to provide good images of the cervical spinal canal and its contents. CCTE may be an alternative imaging method for impingement in patients with cervical brachalgia contraindicated for MRI.