Transnasal, Endoscopically Guided Skull-Based Surgery by Pharyngotomy for Mass Removal from the Sphenopalatine Sinus in a Horse

• Published in: Veterinary surgery Vol. 45; no. 8; pp. 1108 - 1117
• Main Authors: Radcliffe, Rolfe M., Messiaen, Yasmine, Irby, Nita L., Divers, Thomas J., Dewey, Curtis W., Mitchell, Katharyn J., Schnabel, Lauren V., Bezuidenhout, Abraham J., Scrivani, Peter V., Ducharme, Norm G.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-11-2016
• Subjects: Animals; Chondroma - diagnosis; Chondroma - surgery; Chondroma - veterinary; Endoscopy - veterinary; Horse Diseases - diagnosis; Horse Diseases - surgery; Horses; Male; Pharyngectomy - methods; Pharyngectomy - veterinary; Sinuses; Skull - surgery; Surgical outcomes; Veterinary medicine
• ISSN: 0161-3499; 1532-950X
• DOI: 10.1111/vsu.12573

Objective
To report a transnasal, endoscopically guided ventral surgical approach for accessing the cranial and caudal segments of the sphenopalatine sinus for mass removal in a horse.
Study Design
Case report.
Animal
Adult horse with acute onset blindness referable to a soft tissue mass within the sphenopalatine sinus.
Clinical Report
A 7‐year‐old Warmblood gelding presented with a history of running into a fence and falling. No neurologic signs were identified at initial examination but acute blindness was noted 3 weeks later. On computed tomography (CT) the sphenopalatine sinus was filled with a large homogeneous mass with poor contrast enhancement that extended dorsally with thinning to the dorsal cortex of the sphenoid bone, just rostral to the entrance of the optic canals into the cranial cavity. Surgical access to the sphenopalatine sinus was achieved using a transnasal, endoscopically guided ventral pharyngotomy approach and the mass lesion was removed. A presumptive diagnosis of chondroma was made based on histopathology. The horse recovered well from surgery, and although it has not regained vision as of 6.5 years postoperatively, the disease has not progressed.
Conclusion
Transnasal, endoscopically‐guided ventral surgical access to the sphenopalatine sinus is possible in horses and may improve access in horses with disease extending caudally beyond the palatine portion of the sinus. Use of smaller diameter or specialized instruments, such as various endoscopic bone cutting instruments, and CT image guidance may improve sinus access by this route.