Successful minimally invasive simple hepatic cyst ablation via ethanol sclerotherapy in a cat.

Case summary: A 12-year-old neutered male domestic shorthair cat was evaluated at the Michigan State University Veterinary Medical Center (MSU-VMC) for an abdominal cyst that was initially noted on ultrasound 1 year prior by the referring veterinarian. The cystic mass was causing clinical signs, including vomiting, diarrhea, hyporexia and abdominal pain. Cyst drainage had originally been performed every few months, but by referral, the required frequency of drainage had increased to every 2 weeks for a total of eight drainage events; therefore, a more definitive curative option was sought. CT evaluation revealed a large simple hepatic cyst - largest diameter 7.2 cm - likely associated with the right medial liver lobe. Minimally invasive ethanol sclerotherapy was performed. A locking-loop catheter was placed percutaneously and transhepatically into the cyst using ultrasound guidance. The cyst was drained, and contrast injected under fluoroscopic guidance to ensure no communication between the cyst and liver. Sclerotherapy was performed using a volume of 99.5% ethanol calculated from the volume of cyst fluid removed. The patient was discharged on the same day and had complete resolution of clinical signs. At a 6-month follow-up, the cyst had decreased in volume by an estimated 95%. The patient remains asymptomatic more than 1 year postoperatively. Relevance and novel information: To our knowledge, this is the first report of a feline hepatic cyst treated via percutaneous transhepatic ethanol ablation. Minimally invasive simple hepatic cyst ablation is a viable treatment option in cats that could avoid the need for a more invasive surgical intervention.