A Scanning Electron Microscopy Study of the Attachment of a Thromboresistive Surface Coating to a Membrane Blood Oxygenator

The need for systemic heparin anticoagulation during extended cardiopulmonary bypass (CPB) remains a serious impediment to clinical CPB support of circulatory and respiratory failures, especially in the newborn. Recent development of thromboresistive substrates which can be used to treat extracorporeal surfaces in contact with blood offers the potential for elimination of systemic blood heparinization. The present paper describes a scanning electron microscopy study of the attachment of one such substrate, tridodecyl- methylammonium chloride (TDMAC), to a novel micro-membrane oxygenator.Figure 1 shows a cross-sectional image of the alternating pattern of microchannel conduits for blood flow through the oxygenator. The micro-channels were fabricated on thin metal sheets with an approximate semi-circular shape (150 + 25 microns in radius). The gas exchange to the blood flow in the channels was accomplished through a micro-porous membrane which was placed across the diametric plane of the channels (1).