Application of Preoperative Transarterial Chemoembolization Before Hilar Liver Tumour Resection in a Dog

Hilar hepatocellular tumours in dogs pose a significant surgical challenge due to their proximity to major hepatic vessels. Preoperative reduction of tumour volume and vascular involvement may enhance surgical feasibility and improve outcomes.

To describe the use of transarterial chemoembolization (TACE) as a neoadjuvant strategy for downsizing hilar hepatocellular masses in dogs, thereby enabling safe and effective surgical resection.

A 12-year-old spayed female Beagle presented with a 5.1 cm × 8.1 cm × 8.9 cm hepatic mass in the left medial lobe, with suspected invasion into the left lateral lobe at the hilus. Conventional TACE was performed using idarubicin-loaded ethiodized oil emulsions and gelatin sponge particles. Four weeks after TACE, computed tomography was performed to assess the tumour response, followed by surgical resection 2 weeks later.

The dog experienced mild abdominal discomfort and transient liver enzyme elevation following TACE, consistent with post-embolization syndrome. Tumour volume decreased by 38%, providing adequate space for vascular dissection and enabling successful resection with clear surgical margins. The dog recovered without major complications, remained recurrence-free 22 months postoperatively, and was still alive at the time of manuscript submission. Cytology confirmed a hepatocellular origin, although histopathology was non-diagnostic due to diffuse necrosis.

Preoperative TACE may be an effective neoadjuvant therapy for reducing tumour size and facilitating surgical access in dogs with large liver tumours. This approach may present a viable option for dogs with hepatocellular tumours initially considered difficult to resect due to vascular involvement.