Table 1 Eligibility criteria in Relay-HC trial

Inclusion criteria

 1. Age > 18 years old and ≤ 80 years old

 2. Diagnosis of hilar cholangiocarcinoma by preoperative imaging and laboratory examination; confirmed as biliary malignant tumor by intraoperative frozen and postoperative pathology; evaluated as resectable by preoperative imaging

 3. Preoperative CT/MRI shows no obvious lymph node metastasis of groups 9, 14 and 16

 4. Child-Turcotte-Pugh A–B grade of liver function

 5. Residual liver volume > 30%

 6. ASA grade 1–3

 7. The patient has self-care ability, understands and voluntarily signs the written informed consent, and is able to complete the follow-up plan

 8. Female patients of gestational age must be excluded from pregnancy

 9. The patient has signed the written informed consent form before the screening test

Exclusion criteria

 1. Tumor R1 resection

 2. The patient has obvious heart, lung, brain, or kidney dysfunction that affects the treatment of cholangiocarcinoma

 3. The patient has a history of other malignancies

 4. Child-Turcotte-Pugh C grade of liver function

 5. ASA grade 4–6

 6. Females who are pregnant or breastfeeding

 7. Patients who are not suitable for the study as determined by the researcher