Noncontact free fiber ablation of equine progressive ethmoid hematoma

Abstract

The neodymium:yttrium aluminum garnet laser (Nd:YAG) produces an intense amount of irradiation when set at 100 W of total power output. The irradiation is easily transmitted through small quartz glass fibers that can be passed through the biopsy channel of most endoscopes. Noncontact or free fiber applications of lasers employ high-power outputs, whereas contact applications of laser energy are restricted to low-wattage output of the laser. Horses periodically develop a benign lesion referred to as a progressive ethmoid hematoma (PEH) that may fill the paranasal sinuses and can break through the ventral floor into the nasal passage. When this lesion originates from the nasal ethmoid turbinates, it can be removed by transendoscopic Nd:YAG laser photoablation. In the sinus form of PEH, the lesion first requires surgical removal, after which remnants are transendoscopically irradiated using laser technique. At NCSU College of Veterinary Medicine between 1986 and 1996, 41 horses received standing noncontact Nd:YAG laser treatment for PEH. In 70% of the cases, the treatment was successful in removing the entire lesion and/or eliminating any postsurgical remains or recurrences.