Intravascular Micropump for Augmented Liver Perfusion: First In Vivo Experience

Abstract

The aim of this study was to assess the in vivo performance of a new microaxial rotary blood pump developed for long-term intraportal implantation. The pump, measuring 7 mm in diameter, has a single stage impeller and is powered by a microelectric motor. The pump was implanted into the portal vein in 13 large white pigs under general anesthesia. All animals recovered after the portal pump implantation, and they were observed until the pump failed. The 2 longest running pumps performed for 40 and 36 h, respectively. Either thrombus formation or technical problems, especially in the bearings, were the main causes of pump failure during the experiment. No local or systemic adverse effects were observed during the portal pumping period. Full recovery of the animals following intraportal pump implantation was achieved. However, further technical improvements to the pump are required to maintain a longer performance in vivo.

Fabricated Micro‐Nano Devices for In vivo and In vitro Biomedical Applications

“…Micropumps using blood for long‐term liver perfusion based on rotary actuation have failed due to thrombosis. The pumps were implanted into the portal vein of white pigs, and the implants became inactive after 40 h of operation . In another study, aperistaltic micropump made up of silicon was modified by a self‐assembled monolayer of N‐(triethosilylpropyl)‐O‐polyethylene oxide urethane (PEOU), which prevented the blood from coming in direct contact with the silicon surface.…”

An Integrated Platform for Bio-Analysis and Drug Delivery

“…A stepmotor micropump for the injection of nanoliter volumes of D-amphetamine solution into discrete brain regions of freely moving rats delivered a reliable volume of 50 nl per infusion over an hour at a rate of one infusion per minute [46]. An intravascular micropump for augmented perfusion of blood into the liver was operated in pigs for up to 40 h [47]. A microfabricated implantable micropump with three pumping chambers that are actuated by three piezoelectric lead zirconate titanate disks [48].…”

Investigation of the Washout Effect in a Magnetically Driven Axial Blood Pump

“…This leads to a higher blood traumatization close to the shaft in the axial impeller–motor gap, and potentially to thrombus formation, which should be prevented in any operating case of the pump. This problem can be circumvented by the use of a fixed axle with an axial pivot bearing on top of it inside the impeller body and the impeller being driven magnetically (1,2). In combination with two washout holes in the impeller's hub, thrombus formation can thus be avoided at the nonrotating/rotating interface (3).…”

“…This problem can be circumvented by the use of a fixed axle with an axial pivot bearing on top of it inside the impeller body and the impeller being driven magnetically (1,2). In combination with two washout holes in the impeller's hub, thrombus formation can thus be avoided at the nonrotating/rotating interface (3). This concept is used by CircuLite GmbH (Aachen, Germany) for an implantable long‐term microaxial blood pump that connects the left atrium with the arteria subclavia (Fig.…”