Potential for iatrogenic coil embolization of the caudal cerebellar artery during treatment of internal carotid artery bifurcation in two horses with guttural pouch mycosis.

The research article discusses a medical observation on two horses diagnosed with guttural pouch mycosis, a fungal infection. In the process of receiving treatment, the horses exhibited a unique anatomical variation in the internal carotid artery, which led to the discovery of the risk of a brain artery infarction as a potential complication during treatment.

Case Presentation

• The research began with the examination of two horses suffering from chronic nasal discharge secondary to guttural pouch mycosis, an infection in the auditory tube diverticulum caused by fungus.
• On initial endoscopic examination, the researchers found a fungal plaque on the inside (dorsomedial aspect) of the medial compartment of the guttural pouch. This was involving the internal carotid artery (ICA), which is a major blood vessel in the neck that supplies blood to the brain, neck, and face.
• Neither of the horses displayed any signs of hemorrhage or neurological deficits on admission.

Treatment Process and Observations

• A procedure known as transarterial stainless steel coil embolization of the affected ICA was performed. This is a minimally invasive procedure that blocks abnormal blood flow in an artery.
• During this procedure, an atypical branch of the ICA, possibly a bifid ICA, that connected with the caudal cerebellar artery (a brain artery) was identified.
• In both horses, occlusion of the distal (noncardiac side) of the aberrant branch was performed due to potential mycotic (fungal) involvement.
• After the treatment, although the fungal infection was resolved in both horses, one of them developed signs of an ischemic infarction in the caudal cerebellar artery after recovering from anesthesia. However, within two months, these signs had resolved completely.

Conclusions

• The research findings highlight the presence of anatomical variations in the internal carotid artery in the two horses, observed during the guttural pouch mycosis treatment.
• The study also flagged the infarction of the caudal cerebellar artery as a potential complication of the treatment.
• The researchers proposed that the term ‘bifurcation of the ICA’ was a more accurate way of describing the anatomical variation in the horses, as opposed to the previously used term ‘aberrant branching’.
• The findings could be an invaluable resource for clinicians conducting procedures on the head and neck vasculature in horses.