Radiographic, computed tomographic and surgical anatomy of the equine sphenopalatine sinus in normal and diseased horses.

The study provides insight into the anatomy and different disorders affecting the sphenopalatine sinus in horses. Detailed exploration of imaging anatomy, surgical anatomy and potential diseases was executed using computed tomography (CT) and surgical observations. This formed a basis for diagnosing, treating, and predicting outcomes of clinical cases concerning the equine sphenopalatine sinus.

Methodology

• The researchers used the sphenopalatine sinuses of 10 normal cadaver heads for the study. These were examined with digital radiography, CT scan and sinoscopic examination before anatomical sectioning.
• The anatomy of the sphenopalatine sinus was described based on these observations and compared among cadaver specimens across different imaging modalities.
• The medical records from January 2004 to 2014, of cases diagnosed with sphenopalatine sinus disease, were also reviewed to provide a wider context to the research.

Results

• The results affirmed the variability of the anatomy in the sphenopalatine sinus.
• CT scans provided more useful anatomical information than plain radiographs, where the borders of the sphenopalatine sinus could not be identified.
• Enabling access to different parts of the sphenopalatine sinus was important for making accurate observations. The palatine portion of the sinus was consistently accessible sinoscopically while the access to the sphenoidal portion was only possible in 60% of the cadaver heads.
• The study also identified 14 cases of sphenopalatine sinus disease, with diagnoses including neoplasia, progressive ethmoidal haematoma, sinus cyst, and empyema. The presenting clinical signs varied, encompassing exophthalmos, blindness, unilateral epistaxis or unilateral nasal discharge.

Conclusions and Recommendations

• Interestingly, while CT scans provided crucial diagnostic information, they were unable to differentiate the nature of soft tissue masses.
• Surgical access was often limited to the sphenoidal portion, while standing sinoscopic access to the palatine portion was more promising. This could be used for evaluation, biopsy and resection of any abnormal tissues.
• The outcomes were also examined with only 8 of the 14 horses alive after one year, with the worse outcomes associated with CT evidence of bone loss and a diagnosis of neoplasia.
• The study concluded that sphenopalatine sinus disease, although rare, should still be considered a potential cause of the clinical symptoms seen in horses. Therefore, knowledge of the anatomical variation of this sinus is crucial for interpreting CT scans and a combination of CT scan and sinoscopy offers the best approach for diagnosis and treatment of diseases associated with sphenopalatine sinus.