Radiographic, computed tomographic and surgical anatomy of the equine sphenopalatine sinus in normal and diseased horses.
Authors: Tucker R, Windley Z E, Abernethy A D, Witte T H, Fiske-Jackson A R, Turner S, Smith L J, Perkins J D
Journal: Equine veterinary journal
Summary
# Sphenopalatine Sinus Disease: Imaging and Surgical Anatomy in the Horse The sphenopalatine sinus remains poorly characterised in equine literature, yet disease affecting this structure can present with dramatic clinical signs including exophthalmos, blindness, epistaxis and unilateral nasal discharge. Tucker and colleagues examined cadaveric specimens using radiography, CT and sinoscopy before conducting a retrospective review of 14 clinical cases diagnosed between 2004 and 2014, establishing clear anatomical landmarks and practical imaging protocols for practitioners. Plain radiography proved inadequate for visualising sinus borders, whilst CT reliably demonstrated anatomy despite variable morphology between individuals; the palatine portion of the sphenopalatine sinus was consistently accessible via sinoscopy in normal cadavers, though the sphenoidal portion could only be reached in 6 of 10 specimens. Disease aetiologies in clinical cases included neoplasia (7 cases), progressive ethmoidal haematoma (4), sinus cysts (2) and empyema (1), with CT evidence of bone loss and neoplastic diagnoses associated with poorer long-term survival (8 of 14 horses alive at one year). Practitioners encountering horses with unilateral nasal or orbital signs should consider sphenopalatine sinus pathology as a differential diagnosis, utilising CT for initial assessment followed by sinoscopy for definitive diagnosis and therapeutic intervention where anatomical access permits.
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Practical Takeaways
- •Consider sphenopalatine sinus disease in differential diagnoses for unilateral epistaxis, nasal discharge, exophthalmos, or blindness, though it remains rare
- •Request CT imaging rather than radiographs when sphenopalatine sinus pathology is suspected—it provides diagnostic information and reveals anatomical variation critical for surgical planning
- •Standing sinoscopic examination and biopsy of the palatine portion of the sphenopalatine sinus can be performed for diagnosis and treatment, though access to the sphenoidal portion is surgically limited
Key Findings
- •CT imaging provided superior anatomical information compared to plain radiographs for evaluating sphenopalatine sinus structure and pathology
- •The palatine portion of the sphenopalatine sinus was consistently accessible via sinoscopy in cadavers (10/10), while sphenoidal access was limited (6/10)
- •Among 14 clinical cases, neoplasia (7 cases) and progressive ethmoidal haematoma (4 cases) were the most common diagnoses
- •Eight of 14 horses (57%) survived to 1 year post-diagnosis, with worse outcomes associated with CT evidence of bone loss and neoplastic disease