Cardiopulmonary bypass technologies - Biomaterials and Devices for the Circulatory System - page 154

side effects. Patients in the LIM group had a shorter mean ICU and hospital
stay. 28 However, these fi ndings have to be confi rmed in a randomized,
blinded study with a suffi ciently high statistical power and cost-
effectiveness should be solved. LIM ought to be regarded as an essential
tool in cardiac surgery to reduce CPB-related immune activation and sub-
sequent pathogenicity. Moreover, patients from other clinical settings, such
as surgical interventions involving ischemia/reperfusion injuries (vascular
surgery, organ transplantation), sepsis, systemic infl ammatory response
syndrome, autoimmune diseases, and polytrauma may benefi t from LIM.

6.5.5 Adsorption technologies

As an extracorporeal technique for blood purifi cation, hemoadsorption was
introduced in the early 1960s along with other physicochemical methods.
The problem of poor biocompatibility of uncoated adsorbents was resolved
by coating adsorbent granules with hemocompatible membranes.
Since the 1990s interest in the use of adsorbents in extracorporeal medical
devices has been rising again. Adsorbents retain the adsorbed molecules by
chemical or physical attraction forces. Physical forces include all types of
van der Waals and hydrophobic interactions, whereas chemical interaction
involves some sort of chemical bond formation between the surface and
the adsorbed species. Some of the devices utilizing adsorptive regeneration
of ultrafi ltrate/dialysate have already been commercialized or have passed
the pilot stage.
One of the most common criticisms of the use of extracorporeal methods,
particularly adsorption, is the lack of selectivity in their action, i.e. in addi-
tion to the target substances removed from the bloodstream, many useful
components can be removed as well. Although this is a legitimate point, so
far no problems or side effects due to the loss of nutrients or other useful
substances were noted. 29
Although use of adsorbent techniques during CPB has passed the experi-
mental stage only recently, results are encouraging. Sandeman et al. 30
reported a prototype in-line fi ltration/adsorption device which has been
developed using novel synthetic pyrolysed carbon monoliths with con-
trolled mesoporous domains of 2-50 nm. Signifi cant removal of the cyto-
kines IL-6, IL-1beta and IL-8 was observed. The coagulation studies
indicated that the carbon device does not exacerbate the propensity of
blood plasma to clot.

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6.5.6 Biosensor technology

Biosensors were introduced in the 1960s to meet the need for fast measure-
ment of glucose for patient monitoring, but it was not until the 1980s that