Convection-enhanced high-flux hemodialysis.
Internal filtration contributes to convective clearance in high-flux hemodialysis but its contribution is limited by low pressure gradients. Therefore, a modification using a conventional dialyzer was conceived to enhance internal filtration and backfiltration (BF) rates. The modified dialyzer includes two longitudinal independent regions for blood flow, which were created by redesigning dialyzer caps. Blood pressures remained higher than dialysate pressures in one region and lower in the other region, allowing continuous internal filtration and BF in these respective regions. Modified and conventional dialyzers were compared in terms of pressure gradients and solute clearances. Thus, our experiments involved two groups: the modified dialyzer group and the conventional dialyzer group. A renal failure model was established using a dog weighing 25-30 kg by renal artery and vein ligation. With the exception of the dialyzers, experimental conditions were identical in the two groups. The pressure gradients between blood and dialysate were much higher for the modified dialyzer than for the conventional dialyzer. No significant differences were observed with respect to small solute clearances between the two groups, but mid-range solute clearances were significantly higher in the modified group. More optimization is required before the devised unit can be used clinically. However, the devised unit offers a straightforward means of regulating internal filtration and BF rates.
Lee
Kyungsoo
K
Interdisciplinary Program in Biomedical Engineering, Seoul National University, Seoul, Korea.
Jeong
Jae Hoon
JH
Mun
Cho Hae
CH
Lee
Sa Ram
SR
Yoo
Kyu Jae
KJ
Park
Yong Woo
YW
Won
Yong Soon
YS
Min
Byoung Goo
BG
D018481:Convection; D003404:Creatinine / Q000097:blood; D004867:Equipment Design; D006400:Hematocrit; D017583:Hemodiafiltration / Q000295:instrumentation* / Q000379:methods; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007444:Inulin / Q000097:blood; D011312:Pressure; D014805:Vitamin B 12 / Q000097:blood
D006454:Hemoglobins; D007444:Inulin; D003404:Creatinine; D014805:Vitamin B 12