Background: Calcification as a main degenerative mechanism remains a major problem in the long-term
use of (biologic) patch material in pediatric cardiac surgery. To be able to evaluate
the susceptibility of different materials to mineralization processes in vitro, we
developed a standardized perfusion setup.
Methods: A centrifugal pump with its control module, hoses, a PTFE conduit, a heater unit,
pressure lines, and a box were used to establish the perfusion setup. A calcification
solution was chosen for perfusion. Perfused patch material was analyzed histologically
(Alizarin red S staining) and chemically (micro X-ray fluorescence).
Results: The pump perfuses a parallel-connected hose system. In one perfusion line, patch
material is sutured in the PTFE conduit. In the other line, a rubber sheath grounds
the patch. Perfusion takes place at 37°C with 2,000 rpm. This creates a 5 L/min flow,
which is partitioned into the parallel hose system to mimic conditions in pediatric
patients. Perfusion pressure is set at 60 mm Hg. The pilot experiment showed that
clear luminal patch calcification could be detected after 60 days of continuous perfusion.
Conclusion: Our self-made perfusion setup allows testing of different patches on their susceptibility
to mineralization under standardized conditions. With our system, comparative analyses
of different (commercially available) patches can be easily performed under in-vitro
conditions in the future.
