Advanced Pain Management
November 13, 2024
painschooladminChronic posterior neck and upper extremity pain may result from disc herniation, discogenic pain, spondylosis, spinal stenosis, or post cervical surgery syndrome (1). Cervical epidural steroid
injection is a commonly used therapy in patients with cervical disc herniation or spinal stenosis (1-11). If the injectate cannot reach the target lesion due to mechanical compression of structures on the root or epidural/perineural fibrosis, the drugs may be delivered via catheter to the intended location. Heavner et al (12) found that epidural neuroplasty reduces the need for additional treatment. Previous reports showed that epidural neuroplasty using the Racz catheter has a therapeutic effect in some patients with cervical disc herniation and central stenosis who did not respond to fluoroscopically guided epidural injections (13,14). Unsuccessful results of lumbar epidural neuroplasty are associated with previous surgery, spondylolisthesis, or foraminal stenosis in patients with lumbosacral spinal stenosis or disc herniation (15,16). However, to our knowledge, predictive risk factors for poor outcomes have not been clearly investigated for cervical epidural neuroplasty in patients with posterior neck and upper extremity pain, except for the finding that there is no correlation between grade of improvement and grade of cervical central stenosis. The aim of this study was to evaluate clinical outcomes of cervical epidural neuroplasty in patients with posterior neck and upper extremity pain at 12 months and to demonstrate correlations between predictive factors and unsuccessful results of cervical epidural neuroplasty using the Racz catheter.
Methods
The study was approved by the Institutional Review Board of Seoul St. Mary’s Hospital, Catholic University (IRB No. KC11QISI0674), and written informed consent was obtained from all patients.
Participants
The chronic posterior neck and upper extremity pain was diagnosed on the basis of clinical symptoms, neurological examination, and imaging studies including plain radiography, magnetic resonance imaging (MRI), or computed tomography (CT). Patients older than 20 and younger than 80 years who had herniated disc, spinal stenosis, or post cervical surgery syndrome were included in the study. Patients were consecutively included if they had pain lasting more than 3 months, which was decreased by less than 50% by 4 weeks after conservative therapy and cervical epidural steroid injection. Exclusion criteria are as follows: (a) discordance between clinical symptoms and MRI findings, (b) symptoms of myelopathy, (c) facet joint pain, (d) instability, (e) traumatic injuries, (f) bleeding tendency, (g) psychiatric disease, or (h) underlying systemic disease.
Data Collection
We obtained clinical data such as age, gender, duration of symptoms, and history of previous cervical surgery or recommendations for surgery. Radiologic findings from plain radiography and MRI (and CT if required) were collected, including the presence of spinal cord signal change, spondylolisthesis, foraminal stenosis, and ossification of posterior longitudinal ligament (OPLL).
MRI Findings
All patients underwent plain radiography and MRI of the cervical spine. One neuroradiologist blinded to the clinical findings evaluated the radiologic images. According to T2-weighted sagittal MRIs, cervical central stenosis was assessed by the following scale: grade 0, absence of canal stenosis; grade 1, obliteration of more than 50% of subarachnoid space; grade 2, spinal cord deformity; grade 3, spinal cord signal change (17). Spondylolisthesis was defined as a vertebral displacement exceeding 2 mm in either the anterior or posterior direction (18). Presence of foraminal stenosis or OPLL was recorded. With multilevel spinal stenosis, the level with the highest stenosis grade relevant to clinical symptoms was selected for analysis.
Clinical Evaluation
All patients were asked to rate pain, sleep, and disablility using the numeric rating scale (NRS) for total pain (NRS pain), neck pain (NRS neck), arm pain (NRS arm) and sleep disturbance (NRS sleep) as well as the Korean version of neck pain and disability scale (NPDS) (19). The ratings were performed before the procedure, and one month, 3, 6, and 12 months after the procedure on an out-patient basis by an independent assessor. The NRS represented the degree of pain or sleep disturbance with 0 as having no pain or no sleep complaints and with 100 as the worst pain imaginable or the most extreme sleep disturbance. Epidural neuroplasty was defined as successful with a 50% or more reduction from preprocedure NRS pain and with at least a 40% reduction in the NPDS. The changes in medication use were assessed. The daily opioid intake was converted to oral morphine equivalents (20).
Epidural Neuroplasty
Patients were prepared and draped in a sterile manner in a prone position. After skin infiltration with 1%
lidocaine, a 18-gauge 3½-inch epidural needle (RX epidural needle, Coudé; Epimed International, Johnstown, NY) was inserted and pointed caudally at the level of T1-T2 interspace toward the midline under fluoroscopy. Once the placement of needle tip in the epidural space was confirmed by loss-of-resistance, the tip was rotated cephalad. This technique has been improved with the
advent of the RX-2 Coudé needle, which has a second stylet that protrudes slightly beyound the tip of the needle to prevent dural cutting (21). Then, an epidural catheter (VERSA-KATH, Epimed International, Johnstown, NY) was advanced through the needle and maneuvered into the target lesion, as determined by MRI findings. Given the epidurogram with 0.5 – 1 mL of contrast media and without intravascular or subarachnoid filling, 1,500 units of hyaluronidase in 2 mL preservative-free normal saline was injected via epidural catheter. Subsequently, 2 mL mixture of 0.125% bupivacaine and 5 mg of triamcinolone was injected. In cervical epidural injections, there is a hazard of loculation which usually causes pain involving the spinal cord from compression of the blood supply. That can be relieved by flexion rotation – chin to shoulder bilaterally until lateral transforaminal run off is facilitated (14,21). Loculation is also recognized from development of peri venous counter spread which is a recognized warning sign (22). At 30 minutes after the procedure, 2 mL of 10% sodium chloride solution was infused over 30 minutes under monitoring to verify neurologic intactness. On the following day, 30 minutes after administration of 2 mL of 0.125% bupivacaine, 2 mL of 10% sodium chloride solution was infused again. After this last treatment, the catheter was removed. Heavner et al (12) performed the procedure with a 3-day protocol, and Manchikanti et al (23,24) modified the protocol from a 3-day procedure to a one-day procedure. However, our center selected a 2-day treatment regimen. Patients were asked to perform neural flossing exercises to break up weakened scar tissue and to prevent further scar tissue development (21) and were seen for follow-up one month after the procedure.
Statistical Analysis
Given the multiple comparisons, a P level was adjusted (0.05/4 = 0.0125). Wilcoxon signed rank test was used for comparing average NRS, NPDS, and daily opioid intake at the preprocedure against one month, 3, 6, and 12 months after the procedure. The correlation between unsuccessful results of cervical epidural neuroplasty and predictive factors such as gender, age, duration of symptoms, presence of spinal cord signal change, previous surgery, sponodylolisthesis, OPLL, or foraminal stenosis was analyzed by forward stepwise method in logistic regression analysis. Statistical analysis was performed using the SPSS version 18 (SPSS, Inc., Chicago, IL). A P value < 0.05 was considered statistically significant.
Results
Of the 196 patients assessed for eligibility, 27 patients met exclusion criteria and 6 patients, including one death due to cancer, were lost to follow-up after the procedure. The remaining 169 patients (95 women, 74 men) with a mean age of 51.7 ± 10.5 years excluding 27 patients were included in analysis. Of these, the average duration of symptoms was 51.5 ± 54.7 months. One-hundred-eighteen patients had spinal stenosis, 32 patients had herniated disc, and, 19 patients had post cervical surgery syndrome. Forty-six patients (27.2%) was recommended an operation for pain relief at other hospitals. Cervical canals on MRI were assessed as grade 1, grade 2, and grade 3 stenosis in 81, 77, and 11 patients, respectively. Spondylolisthesis, foraminal stenosis, and OPLL were present in 23, 88, and 11 patients, respectively (Table 1). Successful outcomes (at least 50% reduction in NRS for pain and 40% reduction in the NPDS) were observed in 108 patients (63.9%) at one month following the procedure, in 109 patients (64.5%) at 3 months, in 96 patients (56.8%) at 6 months, and in 89 patients (52.7%) at 12 months (Fig. 1). Three patients underwent surgery due to severe pain during the follow-up period. There was no adverse event except for transient local pain associated with the procedure. Of 46 patients who had received a recommendation for surgery, successful outcomes were obtained for 27 patients (58.7%) at one month after the procedure, in 26 patients (56.5%) at 3 months, in 21 patients (45.7%) at 6 months, and in 20 patients (43.5%) at 12 months. At preprocedure, there were no significant differences in gender ratio, age, duration of symptoms, opioid intake, NRS pain, NRS neck, NRS arm, NRS sleep, and NPDS between patients with and without successful outcomes. NRS pain, NRS neck, NRS arm, NRS and NPDS were significantly decreased at one month, 3, 6, and 12 months as compared to those at preprocedure (P < 0.001; Table 2). Daily opioid intake was reduced at one, 3, 6, and 12 month follow-up periods compared to baseline (P < 0.001; Table 3). Table 4 lists variables that were significantly associated with unsuccessful epidural neuroplasty in log regression analysis. There were no correlation with gender, age, duration of symptoms, presence of spinal cord signal change, foraminal stenosis, or cervical stenosis grade (Table).
