To ascertain the effects of prolonging flushing intervals (FIs) for Totally Implantable Venous Access Devices (TIVADs) on catheter-related complications in the off-treatment period.A preliminary search of PubMed, EMBASE, Cochrane, Web of Science, Web of Science, Scopus, CNKI, and SinoMed was conducted from inception to 6th June 2023, using the keywords "vascular access devices", "interval", "occlusion", and "complication". Two independent reviewers performed studies screening, quality assessment, and data extraction. The methodological quality of included articles was assessed using the Newcastle-Ottawa Scale (NOS) and Risk of Bias (ROB) tools. Meta-analysis and trial sequential analysis (TSA) was performed to calculate the risk ratios and 95% confidence interval (CI).Eleven studies with 4,924 participants were included. Extending FIs to two or three months increased the risk of catheter occlusion compared to one-month intervals [RR = 1.50 (1.18-1.92), P = 0.001], but this finding was not confirmed by sensitivity analysis and TSA. Extending FIs to three months showed no significant effect on overall complications rates [RR = 1.21 (0.99-1.48), P = 0.49], consistent with sensitivity analysis and TSA results. For other catheter-related complications, the results showed extending the FIs to three months was feasible, but with weak measurements due to insufficient data.Data from the current included studies tended to support the feasibility of extending the flushing interval to every three months, with no expected increase in catheter occlusion or overall catheter complications. However, due to the inherent limitations of the included study, the findings of the current study should be interpreted with caution.© 2024. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.