Endoscopy is a minimally invasive percutaneous examination technique that can be used for colorauthentic visualization of the epidural space located inside the vertebral canal.1 The epidural space is a potential space that surrounds the spinal cord between the dura mater and the endosteum, which covers the inside of the bony structure of the vertebral canal.2
In the human medical literature, visualization of the spinal cord by use of a rigid endoscope was first reported by Burman3 in the 1930s, who examined human cadavers and named the procedure myeloscopy. In 1938, myeloscopy was first performed in living humans4 from which a detailed description of the anatomic structures of the epidural space was obtained. The technical development of fiber optics represented important progress in endoscopic procedures1,5 and was important for clinical application of endoscopy of the epidural space in human patients.6–12 Since 1996, such epiduroscopy has been used for the diagnosis and treatment of disease in humans.5,10
Current indications for epiduroscopy in human medicine are differential diagnosis of chronic low-back pain and removal of foreign bodies and neoplastic lesions.1,5 Pathologic changes, such as adhesions, fibrosis, and lumbar spinal stenosis as well as nerve root compression, can be diagnosed on the basis of epiduroscopic findings.1,13
In veterinary medicine, epiduroscopy has not been used for diagnostic or therapeutic purposes in living animals, to our knowledge. Epiduroscopy has been performed in cadavers of rabbits under experimental conditions6; the procedure has also been performed in dog cadavers with the objective of describing anatomic features and technical details.14 The purpose of the study reported here was to develop a suitable epiduroscopic technique for use in standing cattle and describe the endoscopically visible anatomic structures of the epidural space in the sacrococcygeal area.
Gräub AG, Bern, Switzerland.
Portex Tuohy needle 18G, Portex Inc, Keene, NH.
Iff I, Mosing M, Lechner T, et al. The use of an acoustic device to identify the extradural space in standing horses (abstr), in Proceedings. Am Vet Anesth Cong 2007;41.
Graseby 3300, Graseby Medical Ltd, Watford, Hertfordshire, England.
Xylanaest purum 2%, Gebro Pharma, Fieberbrunn, Austria.
Karl STORZ, Tuttlingen, Germany.
Einführbesteck 9F, Smiths Medical Deutschland GmbH, Kirchesoon, Germany.
Millex filter unit (25 mm), Millipore, Vienna, Austria.
Kochsalz Braun 0.9%, B. Braun Melsungen AG, Melsungen, Germany.
Berg R. Rücken, Dorsum. In: Berg R, ed. Angewandte und topographische Anatomie der Haustiere. 4th ed. Stuttgart, Germany: Gustav Fischer Verlag Jena, 1995;340–344.
Pool JL. Direct visualization of dorsal nerve roots of the cauda equina by means of a myeloscope. Arch Neurol Psychiatry 1938;39:1308–1312.
Heavner JE, Chokhavatia S, Kizelshteyn G. Percutaneous evaluation of the epidural and subarachnoid space with the flexible fiberscope. Reg Anesth 1991;15:85.
Shimoji K, Fukuda S, Fujioka H, et al. Development of fine fiberscopes for subarachnoid and epidural spaces. J Jpn Soc Clin Anesth 1988;8:215–220.
Shimoji K, Fujioka H, Onodera M, et al. Observation of spinal canal and cisternae with the newly developed small-diameter, flexible fiberscopes. Anesthesiology 1991;75:341–344.
Saberski LR, Kitahata L. Persistent radiculopathy diagnosed and treated with epidural endoscopy. J Anesth 1996;10:292–295.
Schütze G, Kurtze H. Percutaneous investigation of the epidural space using a flexible endoscope: a contribution to epiduroscopy. Reg Anesth 1993;18:24.
Schütze G, Kurtze H. Direct observation of the epidural space with a flexible catheter-secured epiduroscopic unit. Reg Anesth 1994;19:85–89.
Saberski LR, Kitahata L. Direct visualization of the lumbosacral epidural space through the sacral hiatus. Anesth Analg 1995;80:839–840.
Lorinson D, Kogler J, Grösslinger K. Perkutane Epiduroskopie beim Hund: anatomische und technische Grundlagen. Vet Med Austria 2006;93:278–282.
Ferguson JD, Galligan DT, Thomsen N. Principle descriptors of body condition score in Holstein cows. J Dairy Sci 1994;77:2695–2703.
Lechner TJ, van Wijk MG, Maas AJ, et al. Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space. Anesth Analg 2003;96:1183–1187.
Seldinger SI. Catheter replacement of the needle in percutaneous arteriography; a new technique. Acta Radiol 1953;39:368–376.
Higgs ZC, Macafee DA, Braithwaite BD, et al. The Seldinger technique: 50 years on. Lancet 2005;366:1407–1409.
Skarda RT. Local and regional anestehtic techniques: ruminants and swine. In: Thurmon JC, Tranquilli WJ, Benson GJ, eds. Lumb & Jones' veterinary anesthesia. 3rd ed. Baltimore: The Williams & Wilkins Co, 1996;479–514.
Magda II. Örtliche Betäubung durch intravertebrale Injektion der Anästhetika (Spinalanästhesie). In: Magda II, ed. Lokalanästhesie. Stuttgart, Germany: Gustav Fischer Verlag Jena, 1966;223–254.
Blomberg RG, Olsson SS. The lumbar epidural space in patients examined with epiduroscopy. Anesth Analg 1989;68:157–160.
Igarashi T, Hirabayashi Y, Shimizu R, et al. The epidural structure changes during deep breathing. Can J Anaesth 1999;46:850–855.
Holmström B, Rawal N, Axelsson K, et al. Risk of catheter migration during combined spinal epidural block: percutaneous epiduroscopy study. Anesth Analg 1995;80:747–753.
Gill JB, Heavner E. Visual impairment following epidural fluid injections and epiduroscopy: a review. Pain Med 2005;6:367–374.
Geurts JW, Kallewaard JW, Richardson J, et al. Targeted methylprednisolone acetate/hyaluronidase/clonidine injection after diagnostic epiduroscopy for chronic sciatica: a prospective, 1-year follow-up study. Reg Anesth Pain Med 2002;27:343–352.
Lee I, Soehartono RH, Yamagishi N, et al. Distribution of new methylene blue injected into the dorsolumbar epidural space in cows. Vet Anaesth Analg 2001;28:140–145.
Lee I, Yamagishi N, Oboshi K, et al. Multivariate regression analysis of epidural pressure in cattle. Am J Vet Res 2002;63:954–957.
Lee I, Yamagishi N, Oboshi K, et al. Effect of epidural fat on xylazine-induced dosolumbar epidural analgesia in cattle. Vet J 2003;165:330–332.
Lee I, Yamagishi N, Oboshi K, et al. Eliminating the effect of epidural fat during dorsolumbar epidural analgesia in cattle. Vet Anaesth Analg 2004;31:86–89.
Lee I, Yamagishi N, Oboshi K, et al. Practical tips for modified dorsolumbar epidural anesthesia in cattle. J Vet Sci 2006;7:69–72.
King FG, Baxter AD, Mathieson G. Tissue reaction of morphine applied to the epidural space of dogs. Can Anaesth Soc J 1984;31:268–271.
Kytta J, Rosenberg PH, Wahlstroem TR. Effects of continuous epidural administration of bupivacaine through a catheter in pigs. Eur J Anaesthesiol 1986;3:473–480.
Kitamura A, Sakamoto A, Aoki S, et al. Epiduroscopic changes in patients undergoing single and repeated epidural injections. Anesth Analg 1996;82:88–90.