Abstract: Objective  To systematically evaluate the efficacy and safety of expanded hemodialysis (HDx) in hemodialysis (HD) patients.  Methods  Pubmed, Embase, Cochrane Library, Web of science, CNKI, Wanfang and VIP databases were searched from the establishment of the database to September 2022 for clinical and prospective studies on HDx intervention in HD patients. The quality of the included literature was evaluated according to the risk bias assessment of the Cochrane Collaboration Network. Meta-analysis was performed using RevMan5.3 software.  Results Twenty trials including 846 HD patients were enrolled for the analyses. They were divided into HDx group, HD group and hemodiafiltration (HDF) group. The Kt/V value in HDx group was significantly higher than that in HD group (MD=0.052, 95% CI: 0.012～0.092, P=0.012), but there was no significant difference between HDx group and HDF group (MD=-0.012, 95% CI: -0.118～0.094, P=0.828). The clearance rate of β2 microglobulin (β2-MG) in HDx group was significantly higher than that in HD group (MD=6.542, 95% CI: 3.411～9.672, P< 0.001), and was lower than that in HDF group (MD=-3.733, 95% CI: -5.262～-2.203, P<0.001). The clearance of human immunoglobulin κ free light chain (κFLC) and human immunoglobulin λ free light chain (λFLC) in HDx group was significantly higher than that in HD group (κFLC: MD=15.793, 95% CI: 9.912～21.647, P<0.001; λFLC: MD=22.412, 95% CI: 18.282～26.542, P<0.001), but was similar to that in HDF group (κFLC: MD=-2.224, 95% CI: -5.408～0.961, P=0.171; λFLC: MD=0.417, 95% CI: -7.945～8.779, P=0.922). Serum albumin (ALB) loss in HDx group was higher than that in HD group, and there was no difference between HDX group and HDF group (HD: MD=2.010, 95%  CI: 1.327～2.692, P＜0.001;  HDF:MD=0.050,  95% CI: -1.626~1.726, P=0.953). The incidence of adverse events showed no significant difference between the HDx group and both the HD and HDF groups (HD: MD=0.624, 95% CI: 0.365～1.066, P=0.084; HDF:MD=0.860, 95% CI: 0.726～1.020, P=0. 141).  Conclusion  HDx increased the clearance of medium and large molecular weight uremia toxins, and is preferable for patients with unsatisfactory vascular access.

Key words: Expanded hemodialysis, Hemodialysis, Hemodialysis filtration, End-stage renal disease, Medium interception membrane