Percutaneous transcatheter closure of an aorto-cardiac fistula in a six-year-old Warmblood mare with atrial fibrillation.

This study focuses on the treatment of a rare aorto-cardiac fistula in a six-year-old horse with heart issues; the initial transcatheter closure was successful but the device became dislodged, leading to a deterioration in the horse’s health and eventual euthanization.

Background of the Study

• The research was prompted by the rare case of a six-year-old French Warmblood mare diagnosed with an aorto-cardiac fistula. The horse had notable symptoms including atrial fibrillation, decreased performance, ventral oedema, pulsation in the arteries, and unusual jugular venous pulse.
• An aorto-cardiac fistula is a rare abnormal connection that formed between the right aortic sinus of Valsalva and the right atrium in this horse, which likely triggered the atrial fibrillation.
• The horse’s condition was a result of a volume overload in the right side of its heart caused by abnormal blood flow from the left to the right side, medically known as a left-to-right shunt.

Procedure and Find Results

• In a bid to treat the condition, the researchers carried out a percutaneous transcatheter closure of the fistula. This is a minimally invasive surgical procedure aimed at blocking the abnormal connection, and it was performed under general anesthesia through a transarterial approach.
• The operation initially appeared successful, as signs of heart failure improved instantly. This suggested that the closure of the fistula had potentially rectified the heart’s pumping efficiency.
• However, six days post the procedure, the device used for the surgery dislodged, which caused the horse’s condition to quickly deteriorate.

Second Attempt and Concluding Observations

• The team attempted a second closure, this time using a transvenous approach while the horse was standing. Unfortunately, this attempt was not successful.
• The ongoing deteriorating health of the horse led to the decision to euthanize it.
• The researchers discussed the procedural aspects of the case and highlighted several potential risk factors for device dislodgement in this kind of operation in horses. While the initial results seemed promising, the prevention of such complications like device dislodgement remains a paramount concern to ensure the long-term success of this type of treatment.