Interventional procedure overview of endoscopic bipolar radiofrequency ablation for malignant biliary obstruction

Outcome measures

The main outcomes included clinical success, stent patency, OS, quality of life and adverse events. Some of the measures used are detailed in the following paragraphs.

Clinical success, representing the symptomatic control, was defined as a decrease in total bilirubin level by less than 25% of the initial value, to the upper normal limit (Kang 2021a), or to less than 34.2 micromol/l, without moderate or severe post-procedural cholangitis and necessity for additional endoscopic or percutaneous interventions (Xia 2021).

Stent patency was defined as normal laboratory findings and without evidence of cholestasis in diagnostic imaging or non-occluded stent without intervention. Its duration was the time from the index procedure to stent occlusion needing revision of biliary drainage, or death. If the index procedure was done bilaterally with 2 stents at the same time, at least 1 stent occlusion was considered as event for calculating stent patency.

OS was defined from enrolment or the first RFA, to death or the end of the study.

Quality of life was not measured using a conventional tool but instead using KPS; the lower the Karnofsky score, the worse the likelihood of survival. KPS is designed to measure physical functional performance from a clinician perspective rather than quality of life from a person's perspective.