2.1. Study cohort

The study was approved by the institutional review board of Zhongshan Hospital of Traditional Chinese Medicine Affiliated to Guangzhou University of Traditional Chinese Medicine (approval No. 2024ZSZY-LLK-025) and complied with the Declaration of Helsinki. The requirement for informed consent was waived because the study was retrospective. This retrospective cohort study included all patients in the Chinese National Renal Data System (CNRDS) who underwent maintenance dialysis at our center between 1 January 2010 and 10 October 2023. According to the 2019 KDOQI VA guidelines [2], CVCs can be used for long-term and short-term use. In our study, a TCC was defined as a tunneled cuffed catheter that was a long-term CVC. Our center suggests that patients who (1) have multiple prior failed AV accesses with no available options, (2) are absence of AV access creation options due to a combination of inflow artery and outflow vein problems, (3) have more comorbidities, (4) have a limited life expectancy, or (5) refuse AVF placement should attempt at TCC placement for hemodialysis. The inclusion criterion was judged by a clinician. Patients who (1) lacked baseline data, (2) were followed up for <3 months, or (3) were younger than 70 years were excluded. Full-time staff were responsible for the system information registration and all of the follow-up of the maintenance dialysis patients in our center. Hence, the data of the cohort were relatively complete and reliable.