Abstract
Introduction Vascular surgery affects, among other factors, vessel geometry and might result in
significant flow changes. For this reason a basic understanding of flow behavior at
bifurcations plays an important role for microsurgeons. The aim of the present work
was to establish an experimental model that enables rheological analyses of microvascular
techniques.
Methods Laser Doppler anemometer (LDA) measurements in a total of four cross-sections of
a true-to-scale silicone model were performed. The model was installed in a circulatory
experimental setup that simulates the physiologic human blood flow. The flow velocity
data measured with the LDA system was processed and analyzed with an image-processing
system.
Results The flow curve at each cross-section was recorded for sevem cycles. A physiologic
flow separation at bifurcational level was seen. Maximal and minimal horizontal velocities
of all measurement points were between 0.32 and −0.15 m/s. No signs of turbulentlike
flow were seen in the cross-sections distal to the bifurcation. A total, centrally
located backflow in the diastolic phases in all four cross-sections was registered,
resembling an oscillatorylike flow.
Conclusions The LDA analysis represents a valid experimental method for rheological evaluation
of microvessels. Due to its unique high spatial and temporal resolution, it represents
a worthwhile alternative to other flow investigations.
Keywords
laser Doppler anemometry - rheological analyses - elastic true-to-scale model - microsurgery
