Original Article Ultrasound-Guided Versus C-Arm Fluoroscopy Controlled Radiofrequency Ablation of the Cervical Facets

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1 Egyptian Journal of Neurosurgery Volume 31 / No. 3 / July September Original Article Ultrasound-Guided Versus C-Arm Fluoroscopy Controlled Radiofrequency Ablation of the Cervical Facets 1 Tariq Elemam Awad*, 1 Khalid Elsayed Mohamed and 2 Housseini Abdallah 1 Department of Neurosurgery Faculty of Medicine - Suez Canal University, Ismailia, Egypt 2 Department of Radiology Faculty of Medicine - Suez Canal University, Ismailia, Egypt Received: 22 February 2016 Accepted: 24 December 2016 Key words: Cervical facet, Radiofrequency ablation, Ultrasound, Fluoroscopy 2016 Egyptian Journal of Neurosurgery. All rights reserved ABSTRACT Background: Cervical Facet radiofrequency ablation is indicated for patient with chronic neck pain. It is generally carried out under fluoroscopic guidance. The long term exposure of the surgeon to radiation may cause serious side effects. Ultrasonography-guided facet ablation has recently been attempted. Objective: Our aim is to compare between ultrasonographic and fluoroscopic imaged guided techniques for non-pulsed radiofrequency ablation of the facets of the cervical spine. Patients and Methods: We followed forty patients who had cervical pain due to facet arthropathy. They were diagnosed as having cervical spondylosis and operated from January 2012 to October 2015 in Departments of Neurosurgery and Radiology in Suez Canal University Hospitals. Patients were divided into two groups: Ultrasound group and fluoroscopy group. Results: We studied 123 levels of the cervical facet joint which underwent radiofrequency ablations in forty patients. Sixty three facets were ablated using fluoroscopy, while sixty one facets were ablated under ultrasonographic guidance. The demographic characteristics between the two groups were not sta s cally different. The mean execu on me per facet joint was 14 minutes for fluoroscopic guidance compared to 10 minutes for ultrasonographic guidance. Clinical outcomes in both groups showed no significant difference. Ultrasonographic guidance showed less execution time and no radiation exposure. Conclusion: The ultrasound-guided facet joint ablation in the cervical spine is accurate, feasible, and bears minimal risk. It results in a significant pain reduction, not different from fluoroscopic-guided ablations. Additionally a reduction of execution time, radiation dose and resources is highly evident. INTRODUCTION Chronic cervical pain may be originated from different innervated structures in the cervical region, including zygapophyseal joints, discs, cervical segmental nerve roots, ligaments, and myofascial structures. Cervical facet (zygapophysial) joint pain in patients with chronic neck pain ranges about 55% of all other causes. 1 The most commonly performed interventional spine procedures include epidural steroid injections, facet or zygapophyseal joint-related procedures. The standard of care for most of these procedures includes the use of imaging modalities to increase the precision of spinal injections and reduce the risk of neurovascular complications. These interventional spine procedures are most commonly performed under fluoroscopic guidance and less commonly under computed tomography (CT) or magnetic resonance imaging (MRI). 2 *Corresponding Author: Tariq Elemam Awad, M.D., Ph.D. Department of Neurological Surgery, School of Medicine, Suez Canal University Hospital 4.5 Kilo of the round road, Ismaillia, Egypt Tariqelemam@yahoo.com; Tel: (+2) Ultrasound (US) guidance began to emerge as an imaging technique in interventional spine pain management in 2001 as advances in ultrasound technology allowed significant improvements in resolution to image the spine and neuraxial structures. 3 With the clear evidence of the reliable role of ultrasound guidance in increasing the efficacy and safety of diagnostic and therapeutic peripheral nerve blocks and spinal anesthesia, there has been a growing interest in the use of ultrasound guidance with interventional spinal procedures. 3-6 Although fluoroscopy remains the most frequently used imaging technique employed by interventional spine physicians, reports of the use of ultrasound guidance have begun to emerge PATIENTS AND METHODS This study was designed as a controlled, nonrandomized, prospective, clinical study to compare between ultrasonographic and fluoroscopic imaged guided techniques for non-pulsed radiofrequency ablation of the facets of the cervical spine. All cases were managed in the Departments of Neurosurgery and Radiology, Suez Canal University Hospital. Between January 2012 and October 2015, at Suez Canal area Hospitals (Ismailia, Egypt) a total of forty Egyptian Journal of Neurosurgery 189

2 consecutive patients were included. The patients were categorized into two groups: Group A: Fluoroscopy is the imaging guidance method (Twenty patients) Group B: Ultrasound is the imaging guidance method (Twenty patients) Patients were selected if they have chronic neck pain with or without radiating pain to the shoulder for at least 3 months. They should have focal tenderness over the cervical facet joints and pain on hyperextension and/or lateral flexion of the cervical spine. Preoperative neuroimaging investigations consisted of x-ray cervical spine (both A-P and lateral views) and magnetic resonance imaging (MRI) of the cervical spine. The following data were collected: patient age, sex, indication for ablation, level of ablation and imaging findings. The feasibility of each modality (fluoroscopy or ultrasound) was evaluated by accurate injection site, execution time, number of trials (another trial was defined as backward movement of the needle followed by advancement of it toward the target point after an improper position of the needle tip) and radiation exposure. For intraoperative assessment, execution time, Accuracy of localization (number of trials to reach the golden standard point which is waist of center of trapezoid process), complications (vertebral artery injury, cervical root injury, cord injury and death) and immediate patient improvement (symptomatic) were assessed. For assessment of therapeutic outcome, the Visual analogue Scale (VAS, 0-10 scale) before the treatment and within one hour & one month after the treatment were assessed. Good therapeutic response was identified when more than 50% reduction in VAS was achieved. Fluoroscopic guided technique: The patient is placed in the prone position with a pad under the upper chest The C-arm is then positioned over the cervical spine in the anteroposterior view. Traditionally, 10-cm Sluijter-Metha cannula (SMK) with 5-mm active tips, ranging from 16 to 22 gauges, is then directed to the center of the waist of the targeted vertebra where the medial branch courses. The lateral view is obtained where the cannula is advanced to position the active tip along the course of the nerve in the center of the trapezoid of the lateral mass. (Figure 1) Testing is then performed with the patient awake, using sensory stimulation at 50 Hz at less than 0.5 V to produce pain or paresthesia in the area involved. Motor stimulation is then performed at 2 Hz, usually at an output three times the necessary sensory stimulation level, to ensure proper placement and to avoid lesioning of spinal motor nerves. The radiofrequency ablative lesion is then applied at a temperature of C for sec. a b Fig. 1a&b: a: A-P view of the cervical spine showing the waist of the lateral mass as a target for cervical medial branch ablation. b: lateral view of the cervical spine showing the center of the trapezoid of the lateral mass as the target for cervical medial branch ablation. Ultrasound guided technique: Ultrasound will be used to define the sonographic target point for radiofrequency cervical medial branch neurotomy using high-resolution ultrasound (12 to 5 MHz). Ultrasound interventions were performed on a standard US device (iu22; Philips Ultrasound, Bothell, 190 Washington), using a 12-5 broadband linear array transducer. The patients were placed in prone position. A sagittal scan is obtained first at the midline to identify the correct cervical level. C1 spine has no or rudimentary spinous process and the first identified bifid spinous process belong to C2. Then after, one can Egyptian Journal of Neurosurgery

3 continue counting caudally. By scanning laterally, one can easily see the lamina and further laterally the facet column will appear in the image as the characteristic saw sign. If in doubt, one can scan even more laterally till the facet joints are no more in the image and then come back medially toward the facet joints. The inferior articular processes of the level above and the superior articular process of the level below appear as a hyperechoic signals and the joint space appears as anechoic gap in between. The needle is then inserted inferior to the caudal end of the transducer and advanced from caudal to cephalad in plane to enter the caudal end of the joint under real-time ultrasonography. The sonographer classified the target as clearly visible, partially visible or not visible. If clearly or partially visible, the RF probe was inserted. Subsequently, the position of the ultrasound-guided needle will be verified using C-arm fluoroscopy. RESULTS We studied 123 levels of the cervical facet joint which underwent radiofrequency ablations in forty patients. Sixty three facets were ablated using fluoroscopy, while sixty one facets were ablated under ultrasound guidance. Age ranged between 27 and 62 years with a mean of 52 years. Female patients were 23/40 representing 56% of patients. A mean number of three facet joints were injected for every patient. The demographic characteristics between the two groups were not statistically different. (Table 1) C5-C6 level and also C6-C7 level were the most frequently levels for ablation representing 64 % of the ablated facet joints. C2-C3 and C7-T1 were the least levels (4% each). (Table 1) Table 1: Patient-related pre-interventional data for both groups Fluoroscopy Ultrasound Male / Female: 9/11 8/12 Age, yrs 54.7 ± ± 6 Pre intervention 7.1 ± ± 1.6 Visual Analog Scale LEVELS Unilateral rhizotomy Bilateral rhizotomy One level rhizotomy Two levels rhizotomy Three levels rhizotomy C2/3 C3/4 C4/5 C5/6 C6/7 C7/Th1 Total Number of all levels Secondary gain issue 5 (16.7 %) 7 (23.3 %) The mean execution time per facet joint was 14 minutes for fluoroscopy guidance compared to 10 minutes for ultrasonographic guidance. The ultrasonographic group showed significant time savings P-value <0.05. (Table 2) Both groups showed a significant benefit from facet ablation both 60 minutes (p<0.05) and one month (p<0.05) after the procedure: 60 minutes postinterventional there was a mean VAS reduction of 70% (one level) and 72% (two levels) in the fluoroscopy group versus 67% (one level) and 69% (two levels) in the ultrasonographic group. One month postinterventional, fluoroscopic guidance showed a mean VAS reduction of 79% (one level) and 80% (two levels) versus 76% (one level) and 78% (two levels) under ultrasonography guidance (Table 2). There were no significant differences between the fluoroscopy and ultrasonography groups (p) after the intervention. (Table 2) Egyptian Journal of Neurosurgery 191

4 Table 2: Patient-related interventional data results for both groups Fluoroscopy group Ultrasound group P - value Time (min) One level Two levels Three levels 14 ± 3 24 ± 2 30 ± 4 10 ± 3 14 ± 3 18 ± 4 <0.05 <0.05 <0.05 VAS reduction (60 min) One level Two levels Three levels VAS reduction (1 month) One level Two level Three levels 70.1 % (± 13.8) 72 % (± 19.7) 65% (± 14.4) 78.6 % (± 14.7) 80.3 % (± 10) 75.3% (± 12.2) 67 % (± 14.0) 69.2 % (± 19.7) 65.3% (± 20.2) 76.3 % (± 14.5) 78.3% (± 40.3) 73.4 % (± 13.7) There were some cases with self-limited symptoms as aggravation of cervical pain or upper limb pain, tingling sensation, and allergic reaction. These symptoms occurred in five cases of fluoroscopy-guided group and four cases in ultrasound -guided group (total 22.5% of cases). There were two cases with superficial infection (5%) that improved within two weeks. one patients (2.5%) developed mild upper limb weakness that improved at 1-month follow-up visit. There was no statistically significant difference in the incidence of complications between the two groups. DISCUSSION Our results showed that pain relief was significant after a 30-minute- and one-month follow-up in both groups with no significant difference between both groups in the good therapeutic response. But the study was limited by that the outcome was only measured by patient satisfaction and that the long-term follow-up was only performed four weeks after the ablation. According to clinical studies evaluating lumbar facet joint and lumbar periradicular injections under ultrasound-guidance and according to anatomical studies in which accuracy of ultrasound-guided cervical facet joint injections has been analyzed, 100% accuracy of the needle placement could be achieved as the procedure mainly relied on the visibility of cervical facet joints. Also the present study showed similar findings An important consideration is that all cervical injection therapies can be technically challenging, as accidental puncture of Para spinal vessels may lead to severe and irreversible spinal complications This is particularly relevant for cervical injections performed under fluoroscopic control, where the needle placement is more or less a blind flight until contrast agent is administered. 23,26 Following current recommendations for cervical spinal injections, the application of contrast agent under real-time digital subtraction fluoroscopy should thus be performed to reduce the risk of unintentional injection in such Paraspinal, e.g. radicular, vessels 23. In the ultrasound technique, the advantage of utilizing a real-time in plane needle access from dorsal is striking: any relevant vessel is so avoided, as based on normal topography none usually crosses the needle pathway. Also, if the target is clearly visible under ultrasound guidance, no further radiographic control and no systemic application of contrast agents or other ionizing modalities are necessarily required. In this context, the use of Duplex-mode US imaging as a further guidance tool is conceivable, but was not used in the present study because of its questionable additional 27, 28 benefit. One important issue of the use of ultrasound as guidance tool for facet joint injection is the absence of radiation exposure for both the patient and the operative team with no side effects from radiation exposure. Although the necessary radiation dose for one single fluoroscopic-guided intervention may be rather low, the cumulative effects have to be taken into account. For such repeated and multilevel injections, which are quite popular, ultrasound guidance would be the 27, 28 recommended procedure. A further benefit of ultrasound guidance is that it helps to minimize the risk of unexpected side effects, as those are often associated to the application of contrast agents required for the positioning control under fluoroscopy- guided procedures. The fact that ultrasound-guided injections can be performed rather easily is mostly based on the direct depiction of the structures of interest, i.e. cervical facet joints, by ultrasound. Thus, with a little exercise, a needle can be advanced to the target structure itself in just a few seconds under safe and real-time controlled conditions. 12,13, Egyptian Journal of Neurosurgery

5 According to the analysis on increasing numbers and costs of spinal injection therapies, published by Carrino et al 29, the overall cost-effectiveness of cervical instillations must be evaluated as well. Ultrasoundguided facet joint ablations may be performed very efficiently under bed-side conditions, e.g. in outpatients. This saves time and resources, as ultrasound is comparatively inexpensive and broadly available, and does not imply any therapeutic compromises for the patient, as accuracy is obviously sufficient for the purpose described here. 13 The ultrasound-guided facet joint ablation in the cervical spine is accurate, feasible, and bears minimal risk. However, as with any form of intervention needing practice for good results, a specific and mandatory learning curve to achieve good visualization and guidance of the needle has to be taken into account with ultrasound guidance. Upcoming research is supposed to evaluate this and the value of the ultrasound -guided procedures during daily routine work. CONCLUSION The ultrasound-guided facet joint ablation in the cervical spine is accurate, feasible, and bears minimal risk. It results in a significant pain reduction, not different from fluoroscopic-guided ablations. Additionally a reduction of time, radiation dose and resources is highly evident. Declaration The author(s) declare no conflict of interest or any financial support and confirm the approval of the submitted article by the concerned ethical committee. REFERENCES 1. Eichenberger U, Greher M, Curatolo M: Ultrasound in interventional pain management. Tech Reg Anesth Pain Manag 8:171 8, Manchikanti L: Utilization of interventional techniques in managing chronic pain in the medicare population: analysis of growth patterns from 2000 to Pain Physician 15: E969 82, Yun DH: Efficacy of ultrasonography-guided injections in patients with facet syndrome of the low lumbar spine. Ann Rehabil Med 36:66-71, Grau T: The lumbar epidural space in pregnancy: visualization by ultrasonography. Br J Anaesth 86: , Curatolo M, Eichenberger U: Ultrasound in interventional pain management. Eur J Pain 2 Suppl:78 83, Hotta K: Ultrasound-guided epidural block. Masui 57:556 63, Lew HL: Introduction to musculoskeletal diagnostic ultra-sound: examination of the upper limb. Am J Phys Med Rehabil 86:310 21, Smith J, Finnoff JT: Diagnostic and interventional musculoskeletal ultrasound: part 1. Fundamentals. PM & R 1:64 75, Deimel G, Jelsing E, Hall M: Musculoskeletal ultrasound in physical medicine and rehabilitation. Curr Phys Med Rehabil Rep 1:38 47, Klocke R, Jenkinson T, Glew D: Sonographically guided caudal epidural steroid injections. J Ultrasound Med 22: , Pekkafahli MZ: Sacroiliac joint injections performed with sonographic guidance. J Ultrasound Med 22:553 9, Galiano K, Obwegeser AA, Bale R, et al: Ultrasound guided and CT-navigation-assisted periradicular and facet joint injections in the lumbar and cervical spine: a new teaching tool to recognize the sonoanatomic pattern. Reg Anesth Pain Med 32: , Galiano K, Obwegeser AA, Bodner G, et al: Ultrasound guided facet joint injections in the middle to lower cervical spine: a CT-controlled sonoanatomic study. Clin J Pain 22: , Galiano K, Obwegeser AA, Bodner G, et al: Ultrasound guidance for facet joint injections in the lumbar spine: a computed tomography-controlled feasibility study. Anesth Analg 101: , Galiano K, Obwegeser AA, Bodner G, et al: Ultrasound guided periradicular injections in the middle to lower cervical spine: an imaging study of a new approach. Reg Anesth Pain Med 30: , Galiano K, Obwegeser AA, Bodner G, et al: Real time sonographic imaging for periradicular injections in the lumbar spine: a sonographic anatomic study of a new technique. J Ultrasound Med 24: 33-38, Loizides A, Gruber H, Peer S, Brenner E, Galiano K, Obernauer J: A new simplified sonographic approach for Para radicular injections in the lumbar spine: a CT-controlled cadaver study. AJNR Am J Neuroradiol 32: , Loizides A, Peer S, Plaikner M, et al. Ultrasoundguided injections in the lumbar spine. Med Ultrason 13:54-58, Loizides A, Obernauer J, Peer S, Bale R, Galiano K, Gruber H: Ultrasound-guided injections in the middle and lower cervical spine. Med Ultrason 14: , Baker R, Dreyfuss P, Mercer S, Bogduk N: Cervical transforaminal injection of corticosteroids into a radicular artery: a possible mechanism for spinal cord injury. Pain 103: , Benny B, Azari P, Briones D: Complications of cervical transforaminal epidural steroid injections. Am J Phys Med Rehabil 89: , 2010 Egyptian Journal of Neurosurgery 193

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