Paranasal sinus cysts in the horse: Complications related to their presence and surgical treatment in 37 cases.

The research article presents a detailed analysis of the complications and outcomes linked to the presence and surgical treatment of Paranasal Sinus Cysts (PSC) in horses. The study was conducted retrospectively across different centers and sheds light on the relationship between a horse’s age and the severity of PSC complications.

Research Objective and Methodology

• The primary objective of the research was to assess the clinical signs, related morbidities, and outcomes of horses treated for PSC.
• The researchers used a retrospective multicentre case series method for the study. This involved analysing previous case records and conducting telephone follow-up surveys.

Data and Findings

• The study involved 37 horses aged 1-24 years who showed signs of nasal discharge, facial swelling, and epiphora (tear spillage).
• Through radiography and computed tomography, the researchers could identify the changes induced by the cyst, such as tissue destruction, nerve damage causing headshaking, and in one case, unilateral blindness.
• Cysts also caused radiographic changes to the nearby dental apices in 10 horses.
• Horses above 10 years showed more of the mentioned associated problems.
• Post-operation complications included surgical site infection, nasofrontal suture periostitis (inflammation of the tissue on the suture of nose and forehead), and sequestration (death of tissue) after PSC removal via osteotomy (bone cutting).
• The long-term response to treatment was tracked for 28 horses. Of these, 78.6% were fully cured, 14.3% partially cured, and 7.1% showed no response to treatment. In nearly 19% of the horses, there was a recurrence of the cyst post-operation.

Limitations and Conclusion

• The study, being a retrospective multicentre case series conducted over an extended period, had certain limitations. These limitations could lead to inconsistencies in data recording and non-reporting of some findings.
• Nonetheless, the study determined that the diagnosis and treatment of sinus cysts are generally straightforward and carry a good prognosis. However, complications arising from expansive cyst growth – which could cause pressure-induced changes to facial bones, cheek teeth and nerves – drastically affect the prospects for a complete recovery, especially in the case of long-standing issues in older horses. Such complications appear to be due to a combination of prolonged infection period and the rigidity of the bones in older horses.
• Finally, the study discovered that cyst recurrence after treatment can happen in up to approximately a fifth of the cases.