Endobiliary radiofrequency ablation for malignant biliary obstruction due to perihilar cholangiocarcinoma (RACCOON): study protocol for a randomised controlled trial

Abstract Background The majority of patients with perihilar cholangiocarcinoma (pCCA) require palliative biliary drainage. While uncovered self-expanding metal stents (uSEMS) are currently the standard of care, they are prone to tumour ingrowth and recurrent biliary obstruction. Endobiliary radiofrequency ablation (eRFA) may prolong stent patency by targeting intraductal growth. However, existing evidence for eRFA for its use specifically in pCCA managed with uSEMS remains limited. Methods The RACCOON-trial is an international, multicentre, randomised controlled, parallel-group, superiority trial. Patients with pathologically proven, inoperable pCCA will be randomised (1:1) to the intervention group (eRFA + uSEMS) or to the control group (uSEMS alone). Key exclusion criteria include active cholangitis, liver abscess at the time of intervention, or a life expectancy < 3 months. Randomisation is stratified by the intention to place one or multiple stents. The primary endpoint is stent patency, defined as the period between uSEMS placement and recurrent biliary obstruction. Secondary endpoints include technical and functional success, procedure time, time to reintervention, and the total number of (non-elective) reinterventions. Additionally, the study will evaluate the need for permanent percutaneous drainage, presumed causes of recurrent obstruction, stent patency following repeated eRFA, and adverse events within 30 days. Long-term outcomes include Quality of Life (QoL), overall survival (from diagnosis and intervention), and healthcare costs. Discussion The RACCOON-trial will evaluate whether adding eRFA to standard uSEMS placement improves stent patency for patients with inoperable pCCA. We hypothesize that eRFA will prolong the time to recurrent biliary obstruction, thereby improving QoL and reducing the burden of reinterventions during the palliative phase. Trial registration NCT05546372, first submitted 25 August 2022