The Extent of Tissue Damage in the Epidural Space by Ho / YAG Laser During Epiduroscopic Laser Neural Decompression.

BACKGROUND Lasers have recently become very useful for epiduroscopy. As the use of lasers increases, the potential for unwanted complications with direct application of laser energy to nerve tissue has also increased. Even using the lowest laser power to test for nerve stimulation, there are still risks of laser ablation. However, there are no studies investigating tissue damage from laser procedures in the epidural space. OBJECTIVE This is a study on the risks of Ho/YAG laser usage during epiduroscopy. STUDY DESIGN Observatory cadaver study. SETTING Department of anatomy and clinical research institute at the University Hospital. METHODS We used 5 cadavers for this study. After removing the dura and nerve root from the spinal column, laser energy from a Ho/YAG laser was applied directly to the dura and nerve root as well as in the virtual epidural space, which mimicked the conditions of epiduroscopy with the dura folded. Tissue destruction at all laser ablation sites was observed with the naked eye as well as with a microscope. Specimens were collected from each site of laser exposure, fixed in 10% neutral formalin, and dyed with H/E staining. RESULTS Tissue destruction was observed in all laser ablation sites, regardless of the length of exposure and the power of the laser beam. LIMITATIONS A cadaver is not exactly the same as a living human because dura characteristics change and tissue damage can be influenced by dura thickness according to the spinal level. CONCLUSION Even with low power and short duration, a laser can destroy tissue if the laser beam makes direct contact with the tissue.