MedTech Mag-Lev, single-use, extracorporeal magnetically levitated centrifugal blood pump for mid-term circulatory support

ASAIO J. 2013 May-Jun;59(3):246-52. doi: 10.1097/MAT.0b013e31828a75e3.

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.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Coated Materials, Biocompatible / chemistry
  • Heart-Assist Devices*
  • Magnetic Phenomena
  • Male
  • Methacrylates / chemistry
  • Phosphorylcholine / analogs & derivatives
  • Phosphorylcholine / chemistry
  • Prosthesis Design
  • Shock, Cardiogenic / therapy*
  • Survival Rate

Substances

  • Coated Materials, Biocompatible
  • Methacrylates
  • Phosphorylcholine
  • 2-methacryloyloxyethyl phosphorylcholine