A Retrospective Study on Biliary Cooling During Thermal Ablation of Central Liver Tumors in Taiwan

<b>Background:</b> Thermal ablation of centrally located liver tumors carries an increased risk of bile duct injury due to their proximity to the biliary tree. We aim to evaluate whether biliary cooling using a nasobiliary tube can effectively mitigate bile duct injury during the ablation process. <b>Methods:</b> We retrospectively analyzed the data of 322 patients who underwent thermal ablation at Dalin Tzu Chi Hospital from July 2020 to June 2023 and identified those who received prophylactic biliary cooling during thermal ablation for central liver tumors. Data including demographics, tumor characteristics, procedural details, and clinical outcomes were analyzed. <b>Results:</b> Among the 322 patients who underwent thermal ablation, 9 with central liver tumors received prophylactic biliary cooling. The median distance between the tumor and the central bile duct was 1 mm (range: 0-4 mm), the temperature of the cold normal saline was 4 °C, and the mean volume of normal saline infused was 150 mL (range: 100-200 mL). Complete ablation was achieved in all patients in a single session without any biliary injury. One patient developed acute cholangitis after ENBD placement, which resolved with antibiotic therapy. <b>Conclusions:</b> Biliary cooling with 4 °C cold saline through a nasobiliary tube can improve the safety and effectiveness of thermal ablation for central liver tumors.