Occlusion of the internal carotid artery by means of microcoils for preventing epistaxis caused by guttural pouch mycosis in horses.

This study evaluates a method of stopping nosebleeds in horses, caused by a fungus infection in their guttural pouch, by blocking the internal carotid artery with tiny platinum coils.

Research Background

• Guttural pouch mycosis in horses is a fungal infection that often results in severe nosebleeds, also known as epistaxis. It can be fatal if not treated.
• The researchers focused on the internal carotid artery, a major blood vessel supplying blood to the brain. They hypothesized that blocking it might stop the bleeding caused by the fungal infection.

Research Procedure

• The study involved nine healthy Thoroughbred horses. They used an arteriotomy method (surgical opening of an artery) for the blockade.
• Horses had their internal carotid artery ligated or tied off at its root, and an arteriotomy was performed distally to the ligature, where the microcoil was then inserted about 13 cm down from the artery origin.
• The effectiveness of the blockade was determined visually and via angiography (an imaging technique that visualizes blood vessels).
• Six horses were examined before and after the operation for possible complications, while one horse was analyzed after 30 days for any artery thrombus (blood clot) formation.
• In the remaining three horses, the blood flow of the right internal carotid artery was monitored before and after the blockade of the left internal carotid artery.

Findings

• They discovered that one or two microcoils halted blood flow within minutes, with no other noticeable abnormal findings clinically.
• The examination 30 days later showed thrombosis in the blocked segment of artery in one horse, but no other abnormalities were found.
• They observed that the blood flow in the right internal carotid artery increased by approximately 28-58% after the occlusion of the left one, suggesting compensatory mechanisms at play.

Conclusion

• This study concluded that the use of microcoils to occlude the internal carotid artery creates an effective thrombosis, thus potentially treating epistaxis caused by guttural pouch mycosis.
• Based on this study’s findings and its application to two clinical cases, this approach appears not only effective, but also safe for use in horses.