Investigation of treatment volume versus circulating blood volume during Rheocarna treatment.

INTRODUCTION: Rheocarna's therapeutic effect is associated with fibrinogen (Fib) and low-density lipoprotein cholesterol (LDL-C) adsorptive removal. This study aimed to retrospectively investigate the association between treatment volume (TV) and circulating blood volume (CBV) and the Fib removal rate (Fib-RR) and LDL-C-RR. METHODS: CBV and TV/CBV, cut-off value (CO value), and area under the receiver operating characteristic (ROC) curve (AUC) were calculated. The Fib-RR and LDL-C-RR at the midterm and end of treatment were compared. The groups were further categorized into three groups with TV/CBV lower than or higher than the CO value at the midterm and end (midterm/end; Group L: lower than/lower than CO; Group L/H: lower than/higher than CO; Group H: higher than/higher than CO), and the Fib-RR and LDL-RR of each group at the midterm and end were compared. RESULTS: ROC analysis revealed a TV of 1.480 times the BV as CO value, which showed a maximum Youden index predicting a Fib-RR of 20% (AUC: 0.828). Among the three groups, Group L and Group L/H demonstrated significantly higher Fib-RR and LDL-C-RR at the end of the study than in the midterm, while Group H exhibited no difference. CONCLUSION: The results reveal that a treatment volume of 1.5 times the circulating blood volume is a sufficient solute removal capacity in the Rheocarna-enabled cases.

Evaluation of the treatment volume and removal rate of Rheocarna: A novel adsorption-type blood purification device for patients with chronic limb-threatening ischemia.

INTRODUCTION: Chronic limb-threatening ischemia (CLTI) is a clinical syndrome defined by peripheral arterial disease (PAD) combined with rest pain, gangrene, or leg ulceration for longer than two weeks resulting in lower extremity amputation. In recent years, low-density lipoprotein apheresis (LDL-A) has been implemented for PAD treatment. However, it has not been possible to ensure insurance coverage for patients with lower LDL levels than 140 mg/dL under cholesterol-lowering drugs. Rheocarna is a novel adsorption-type blood purification device for the treatment of CLTI by adsorbing LDL and fibrinogen (Fib) that is not constrained by hypercholesterolemia and is not amenable to or nonresponsive to revascularization surgery. The only requirements for use are that the blood flow rate increases up to 200 mL/min gradually. METHODS: To evaluate the applicability of this treatment procedure, we compared the removal rates of Fib and LDL following Rheocarna therapy using various blood treatment volumes (6, 10.5, and 19.5 L). RESULTS: Fib and LDL removal rates were about 20% and 15%-25% per treatment, with no significant differences between treatment volumes. Following treatment with Rheocarna, blood pressure tends to decrease at first, which later increases, and the higher the treatment volume, the longer the time of low blood pressure tended to be. CONCLUSION: Although no significant difference was found in the removal rate of Fib and LDL in response to increase volume to 6 L or beyond in this study, the 6 L volume is considered effective enough for the removal of Fib and LDL.