Epiduroscopy represents a successful treatment alternative for humans with chronic back pain who are refractory to conventional treatment following unsuccessful decompressive surgery.1–3 The technique can be used to remove adhesions, flush away inflammatory mediators, and inject corticosteroid drugs and local anesthetic within the target area. Epiduroscopy is also useful for identifying the inciting cause of chronic back pain in patients for which standard imaging modalities fail to provide this information. Epiduroscopy is even superior to advanced imaging techniques, including MRI, for identification of the lesions responsible for producing pain in patients for whom MRI fails to reveal any abnormalities.4 Furthermore, information obtained through epiduroscopy can be used to predict outcomes for humans with chronic low back pain after treatment.5,6
In horses, cervical epiduroscopy and myeloscopy are reportedly feasible diagnostic tools.7–9 In 1 study,10 locations of spinal cord compression were incorrectly identified by use of myelography, compared with results of vertebral canal endoscopy.10 Lesion location in that study was confirmed by subsequent histologic evaluation of spinal cord specimens.
Epiduroscopy can also be used as a treatment tool. In humans, epiduroscopic treatments include adhesiolysis, targeted administration of epidural medication, laser ablation, and saline (0.9% NaCl) solution flushing.3,10–13 In dogs, an injection site commonly used for provision of neuroaxial regional anesthesia is the lumbosacral space.14,15 This intervertebral space is considered a safe entry point because the spinal cord ends cranial to L7 in dogs.16 Epiduroscopy would be a less invasive procedure than conventional surgery to provide spinal decompression in dogs with IVDH and could be used as a diagnostic tool for various diseases affecting the epidural space, such as IVDH, spinal neoplasia, nerve root entrapment, foraminal stenosis, tethered spinal cord syndrome, and other compressive diseases of the spinal cord. Additionally, these interventions would cost much less than the surgical approach to IVDH, particularly when postoperative care is considered. Therefore, potential uses of epiduroscopy in veterinary medicine should be further investigated.
The purpose of the study reported here was to evaluate the feasibility of lumbosacral epiduroscopy for safe visualization of the spinal cord (covered by the dura mater), nerve roots, and dorsal and ventral vertebral canals in dogs. We hypothesized that epiduroscopy would allow visualization and examination of the neural structures in the epidural space and that use of a videoscope would provide results superior to those obtained with a fiberscope. We also preliminarily evaluated whether measurements made with the videoscope would agree with those made via manual dissection of the spinal cord.
Intervertebral disk herniation
18-gauge, 8.75-cm Tuohy tip needle, Arrow International, Reading, Pa.
Avanti + introducer, Cordis, Miami, Fla.
BioVision Technologies, Golden, Colo.
Video-ureter-cystoscope (11278V), Karl Storz, Goleta, Calif.
NCSS 2007, NCSS LLC, Kaysville, Utah.
1. Sakai T, Aoki H, Hojo M, et al. Adhesiolysis and targeted steroid/local anesthetic injection during epiduroscopy alleviates pain and reduces sensory nerve dysfunction in patients with chronic sciatica. J Anesth 2008; 22: 242–247.
2. Shutse G, Kurtse G, Grol O, et al. Endoscopic method for the diagnosis and treatment of spinal pain syndromes [in Russian]. Anesteziol Reanimatol 1996; 4: 62–64.
3. Kallewaard JW, Vanelderen P, Richardson J, et al. Epiduroscopy for patients with lumbosacral radicular pain. Pain Pract 2014; 14: 365–377.
4. Vanelderen P, Van Boxem K, Van Zundert J. Epiduroscopy: the missing link connecting diagnosis and treatment? Pain Pract 2012; 12: 499–501.
5. Bosscher HA, Heavner JE. Incidence and severity of epidural fibrosis after back surgery: an endoscopic study. Pain Pract 2010; 10: 18–24.
6. Bosscher HA, Heavner JE. Lumbosacral epiduroscopy findings predict treatment outcome. Pain Pract 2014; 14: 506–514.
7. Prange T, Carr EA, Stick JA, et al. Cervical vertebral canal endoscopy in a horse with cervical vertebral stenotic myelopathy. Equine Vet J 2012; 44: 116–119.
8. Prange T, Derksen FJ, Stick JA, et al. Cervical vertebral canal endoscopy in the horse: intra- and postoperative observations. Equine Vet J 2011; 43: 404–411.
9. Prange T, Derksen FJ, Stick JA, et al. Endoscopic anatomy of the cervical vertebral canal in the horse: a cadaver study. Equine Vet J 2011; 43: 317–323.
10. Lee GW, Jang SJ, Kim JD. The efficacy of epiduroscopic neural decompression with Ho:YAG laser ablation in lumbar spinal stenosis. Eur J Orthop Surg Traumatol 2014; 24 (suppl 1): S231–S237.
12. Jo DH, Kim ED, Oh HJ. The comparison of the result of epiduroscopic laser neural decompression between FBSS or not. Korean J Pain 2014; 27: 63–67.
13. Di Donato A, Fontana C, Pinto R, et al. The effectiveness of endoscopic epidurolysis in treatment of degenerative chronic low back pain: a prospective analysis and follow-up at 48 months. Acta Neurochirurgica 2011;108:S67–S73.
14. Garcia-Pereira FL, Hauptman J, Shih AC, et al. Evaluation of electric neurostimulation to confirm correct placement of lumbosacral epidural injections in dogs. Am J Vet Res 2010; 71: 157–160.
15. Garcia-Pereira FL, Sanders R, Shih AC, et al. Evaluation of electrical nerve stimulation for epidural catheter positioning in the dog. Vet Anaesth Analg 2013; 40: 546–550.
Scoring system used to characterize the ease with which an endoscope could be navigated and used to visualize anatomic structures during epiduroscopy in canine cadavers.
|1 (Excellent)||Easy, with no damage or bleeding and minimal complication||Great visibility, with all structures clearly seen|
|2||Slightly difficult, with minor bleeding or some complication||Good to great visibility, with all or most structures seen but not clearly|
|3||Somewhat more difficult, with prolonged procedure duration or obvious bleeding||Good visibility, with half to two-thirds of structures seen with moderate clarity|
|4||Difficult, prolonged procedure or obvious bleeding and complications||Poor to adequate visibility, with less than half of structures visible and poor clarity|
|5 (Poor)||Very difficult, leading to termination of the procedure||Failure to identify most structures|