Unusual internal carotid artery branching that prevented arterial occlusion with a balloon-tipped catheter in a horse.

The research article discusses an unusual case in a horse where a condition called guttural pouch mycosis caused bleeding which could not be treated with the usual procedure of inserting a balloon catheter into the artery, due to an abnormal branching of the artery.

Article Explanation

The research article starts with explaining a case of a mare that presented hemorrhage caused by a condition known as guttural pouch mycosis.

• Guttural pouch mycosis is a condition affecting the guttural pouch, a large air-filled sac located on the cranial aspect of the head in horses, due to a fungal infection.

The conventional treatment for this condition is the insertion of a balloon-tipped catheter into the internal carotid artery.

• A balloon catheter is a type of “soft” surgical instrument used to inflate, or ‘occlude’ (block), the blood vessels to stop bleeding.

Despite being performed under general anesthesia, the mare had copious nosebleeding (epistaxis) following the procedure, leading to a second procedure to identify the site of colonization.

The hemorrhage was confirmed to be from the internal carotid artery. However, during the autopsy, the balloon catheter was found in an abnormal branch that had risen from the internal carotid artery and jointed the basilar artery.

• The basilar artery is a blood vessel that plays a key role in supplying the brain with oxygen-rich blood.

The mycotic plaque (fungal infection) was located on the internal carotid artery. However, it was distal to the origin of the abnormal branch, which means it was away from the center of the body, and therefore, the balloon could not block the retrograde (backward) blood flow through the infected segment.

Due to this complication, the article makes two recommendations for future procedures:

• Additional dissection of the internal carotid artery is encouraged before the insertion of a balloon catheter to identify any abnormal branches that might impact the effectiveness of the procedure.
• Ligation (surgical tying-off) of such abnormal branches should be performed where they bifurcate (split) from the internal carotid artery. This is recommended to prevent unintentional catheterization and to block retrograde flow from the cerebral arterial circle, which could otherwise lead to further complications like brain damage from lack of oxygen supply.