Cardiopulmonary bypass technologies - Biomaterials and Devices for the Circulatory System - page 153

6.10 Systemic, cardioplegia leukofi lters and arterial fi lter connected
into extracorporeal circuit.

bypass. 26 I strongly believe that leukocyte depletion technology has a sig-
nifi cant role to play in moderating the infl ammatory injury commonly
associated with open heart surgery. Despite a substantial body of support-
ive evidence, further work is required to determine the most suitable
strategic method of use, and the cohort of patients that will benefi t most
signifi cantly from its application. However, the clinical and laboratory
experience strongly supports a role for leukocyte depletion during open
heart surgery, and I believe that the potential for positive clinical impact
of this relatively simple and uncomplicated technology will be confi rmed
(Fig. 6.10).

6.5.4 Leukocyte deactivation

￿ ￿ ￿ ￿ ￿

Cardiac surgery using CPB is associated with activation of the immune
system elicited by the contact of patient blood with the artifi cial surfaces of
the extracorporeal circuits. Recently there are attempts to develop a medical
device that allows the inhibition of neutrophil activity during CPB without
systemic intervention.
Basically, the idea of leukocyte inhibition module (LIM) arose from
studies involving virus-directed immune responses. The initial approach was
to coat the leukocyte depletion fi lter with a monoclonal IgM antibody
against CD95. The working hypothesis was that neutrophils transiently bind
to the antibody-coated matrix and become rapidly inactivated (no or limited
transmigration). 27 In clinical trials, LIM was introduced into the venous line
of the heart-lung machine. Overall, it was easy to handle and had no toxic