title: MedTech Mag-Lev, single-use, extracorporeal magnetically levitated centrifugal blood pump for mid-term circulatory support.
abstract: Short- to mid-term extracorporeal ventricular assist devices (VADs) are recommended for critical cardiogenic shock patients. We have designed a preclinical, single-use MedTech Mag-Lev VAD for one-month extracorporeal use. The impeller-rotor of the pump was suspended by a two degree-of-freedom active magnetic bearing in a 300 μm fluid gap, where the computational fluid dynamics analysis predicted a secondary flow of about 400-500 ml/min at a pump speed of 1800-2200 rpm. Three eddy current sensors were employed to implement noise- and drift-free magnetic levitation. The pump components were injection molded using polycarbonate for smooth surfaces as well as improved reproducibility, followed by coating with a biocompatible 2-methacryloyl-oxyethyl phosphorylcholine polymer. Chronic animal experiments were performed in nine calves. Three of the nine calves were excluded from analysis for problems with the circuit. Five of the six (83.3%) completed the 60 day duration of the study, while one prematurely died of massive bleeding due to inflow port detachment. The pump did not stop due to magnetic-levitation malfunction. Neither pump thrombosis nor major organ infarction was observed at autopsy. In comparison to machined surfaces, the injection-molded pump surfaces were thrombus-free after 60 day implantation. This study demonstrates the feasibility of MedTech Mag-Lev VAD for 60 day circulatory support.
authors: Department of Cardiovascular Surgery, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors: Eiki
authors: E
authors: Nagaoka
authors: Tatsuki
authors: T
authors: Fujiwara
authors: Takashi
authors: T
authors: Kitao
authors: Daisuke
authors: D
authors: Sakota
authors: Tadahiko
authors: T
authors: Shinshi
authors: Hirokuni
authors: H
authors: Arai
authors: Setsuo
authors: S
authors: Takatani
mesh_terms: D000818:Animals; D002417:Cattle; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D006353:Heart-Assist Devices; D060328:Magnetic Phenomena; D008297:Male; D008689:Methacrylates / Q000737:chemistry; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000737:chemistry; D011474:Prosthesis Design; D012770:Shock, Cardiogenic / Q000628:therapy*; D015996:Survival Rate
chemical_list: D020099:Coated Materials, Biocompatible; D008689:Methacrylates; D010767:Phosphorylcholine; C070638:2-methacryloyloxyethyl phosphorylcholine