Paranasal sinus surgery is a challenging operation that can encounter complications, such as pneumocephalus, a condition in which air is trapped inside the brain. Veterinarians recently used a computed tomography (CT) scan to decide the best way to treat a Quarter Horse with a benign bone tumor growing in the paranasal sinus. As a result, the horse survived and was able to compete with no reoccurrence reported at the follow-up examination two years later.

Claude A. Ragle, DVM, Dipl. ACVS, APVP, and his colleagues at Washington State University, treated a 2-year-old stallion that was having severe trouble breathing. The X rays showed a bone mass growing inside the sinuses. It was hard to tell how the mass was oriented within the head based on X rays alone.

Bony tumor in horse's sinus

This CT image shows the bone mass completely filling the left sinus and nasal spaces, pushing on the skull, nasal septum, soft palate, and eye.

The veterinarians opted to use a CT scan, which gave a three-dimensional picture to help them map an exact outline of the mass. This also helped them visualize the best approach to remove it, Ragle said. They removed as much of the tumor as was practical--not all of it, because it was part of the bone encasing the brain.

"Complete removal would have risked penetration of the cranial vault, exposing the brain to the sinus cavity and nasal passages," Ragle said. "The more complex an anatomical area the more important the imaging is to making and understanding the diagnosis and achieving a positive outcome.

"CT allows cross-sectional viewing and 3D reconstruction, which is superior to regular X rays. Seeing the problem on cross section provides a clear image of the mass relative to the surrounding structures, which allows detailed pre-surgical planning," he said.

The report, "Pneumocephalus secondary to removal of an osteoma from the paranasal sinuses of a horse," was published in the July 2009 issue of The Journal of the American Veterinary Medical Association. The abstract is available on PubMed.  

About the Author

Marie Rosenthal, MS

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