Myeloscopy, or the direct visualization of the spinal canal and its contents, was first reported in 1931 from the pioneering work of Michael Burman . With each decade since then, myeloscopists and epiduroscopists have attempted to develop a means of visualization that would be easy and safe to apply to medical practice. Unfortunately, until the recent advent of both flexible fiberoptic light sources and optics  this could not be achieved. The recent work of Heavner et al.  and Schutze and Kurtze  indicated that the lumbar epidural space can be accessed with fiberoptic systems. However, the angle of entry into the lumbar epidural and the intrathecal spaces made steering difficult. Steering is thought to be a required feature to make this technology clinically useful. Described in this report is passage of a fiberoptic system from the sacral hiatus into a saline-expanded lumbar epidural space. Most importantly, the straight entry allowed for easier maneuvering of the fiberoptic scope and laid the foundation for future fiberoptic guided procedures.
A 30-yr-old man was disabled from work because of 10 mo of persistent right-sided lumbar radiculopathy. The prescribed physiotherapy had caused excessive pain and noncompliance. The patient required 6-10 Percocets Registered Trademark (DuPont Pharmaceuticals Caribe Inc., Wilmington, DE; oxycodone and acetaminophen) per day with fair relief. Physical examination was positive for sciatic tension without additional evidence of sensory, motor, or reflex abnormality. A magnetic resonance imaging scan showed evidence of a bulging disk at right L2-3 without root impingement. Neuroconductive studies showed a slow conduction velocity for the right L-5 root. The patient was thought to be a good candidate for a therapeutic steroid epidural injection for the persistent radiculopathy. After informed consent and institutional approval a fiberoptic-directed epidural steroid injection was planned.
With the patient in the prone position, his sacral area was prepared and draped as a sterile field. The epidural space was entered through the sacral hiatus with a 17-gauge Tuohy needle. A 0.9-mm guidewire was inserted through the needle and advanced with fluoroscopic guidance to the level of suspected pathology. A 2-mm times 17.8-cm vein dilator catheter was then advanced over the guide wire. Once the catheter was advanced to the tip of the guide wire, the wire was removed. An adaptor with a one-way valve and sidearm was then attached to the proximal end of the catheter. The sidearm was connected to a syringe containing the normal saline flush. The 0.8-mm, specially designed, fiberoptic scope was then introduced into the catheter through the valve Figure 1 and advanced until the tip was positioned at the distal end of the catheter as determined by the video image. The video camera was then attached. Gentle irrigation with normal saline distended the epidural space, especially at the catheter tip. The catheter and fiberoptic were advanced cephalad, caudad, and rotated clockwise and counterclockwise. The right L-5 root was clearly visualized Figure 2 and Figure 3. It was encased with both a fibrinous and a cottony material. The cottony material was moved aside with a gentle stream of normal saline. Behind it, an area of erythema extended lateral to the right L-5 root. This could have represented an inflammatory response from antecedent trauma. This finding could explain why the pain syndrome was out of proportion to the conventional radiographic findings. Triamcinalone 80 mg in 10 mL of normal saline was injected onto the root and contiguous structures. The device was removed atraumatically.
The patient had significant postprocedural discomfort at the catheter insertion site described as a sharp pain made worse with activity. This diminished over 3 days and was treated effectively with 6-8 percocets per day. However, there was an immediate decrease in the sciatic tension signs and radicular pain. The patient was tapered off opioid medication and rehabilitation was continued. The patient remained symptom-free for 6 mo. At that time his pain returned, but examination showed the symptoms to be myofascial and not radiculopathic.
This case report indicates that the epidural space can be accessed safely with flexible fiberoptic catheters via the sacral hiatus with subsequent three-dimensional color visualization of the contents. In addition, with gentle rotatory movements, the catheter can be steered toward structures of interest. The technique allowed for examination of a specific nerve root, its pathology, and proper treatment with the injection of a steroid preparation onto the root. Further study is needed to determine the safety of the saline expansion of the epidural space and the introduction of the fiberoptic system through the sacral hiatus, as well as whether these techniques hold any advantage over currently practiced techniques. Lastly, epiduroscopy may not be limited to just the role of directed injection of epidural steroids. It may prove useful for the diagnosis of various conditions, such as inflammations, adhesions, hematoma, abscess, and tumor. There is also the potential of performing closed procedures, such as the removal of extradural scar, drainage of cysts, biopsies, and retrieval of foreign bodies. The disadvantage of the epiduroscopy is the localized regional discomfort at the site of the instrumentation immediately after the procedure. However, as the technology advances, so will the ability to provide new, safe, and effective therapies.
1. Burman MS. Myeloscopy or the direct visualization of the spinal cord. J Bone Joint Surg 1931;13:695-6.
2. Shimoji K, Fujioka H, Onodera M, et al. Observation of spinal canal and cisternae with the newly developed small diameter, flexible fiberscopes. Anesthesiology 1991;75:341-4.
3. Heavner J, Cholkhavatia S, Kizelshteyn G. Percutaneous evaluation of the epidural and subarachnoid space with the flexible fiberscope. Reg Anesth 1991;15(Suppl):85.
4. Schutze G, Kurtze H. Direct observation of the epidural space with a flexible catheter-secured epiduroscopic unit. Reg Anesth 1994;19:85-9.