Malignant biliary obstruction is commonly treated with biliary stenting either endoscopically or percutaneously; however, tumor ingrowth might occlude the stent, often leading to recurrent jaundice and repeat interventions. Endobiliary microwave ablation (MWA) is an emerging adjunct intended to devitalize intraductal tumors and potentially prolong stent patency. This review assesses the state of the art of endobiliary ablation for malignant biliary obstruction, focusing on the technique and safety of percutaneous procedures, as well as patient outcomes. It also discusses the use of flexible endobiliary MWA for hilar cholangiocarcinoma. The review covers ablation methods such as radiofrequency and MWA, which can be performed endoscopically or percutaneously. Research indicates that endobiliary thermal ablation is technically feasible and can be safely combined with stenting. Some studies suggest it may prolong stent patency and decrease the necessity for repeat procedures compared with stenting alone. Percutaneous techniques may be particularly helpful in complex hilar cases, allowing accurate energy delivery, protection of secondary bile ducts, and tailored stent placement. New microwave systems can heat tissue more deeply and evenly than radiofrequency ablation, which may improve local tumor control. Endobiliary thermal ablation appears to be a useful supplement to stenting, especially for patients with unresectable hilar cholangiocarcinoma. Flexible percutaneous MWA probes could make this treatment more widely available. Still, more high-quality studies are needed to find optimal ablation settings, identify which patients benefit most, and compare this method with standard stenting.
Hatzidakis et al. (2026) studied this question.