Electrode migration is the most common complication of spinal
cord stimulation (SCS). The problem of longitudinal migration has
already been solved, but lateral migration remains the most
common current complication. The present article describes new
electrodes fixation opportunities for the reduction of lateral
migration in SCS. The pig was chosen as an animal model to
illustrate a new protocol of electrode fixation for the control of
lateral and longitudinal migration. The displacement of the
electrode was measured using two different optical methods: the
digital image stereo-correlation and the digital image processing
methods. Fixation with two anchors has always considerably
reduced electrode displacement and when fixation is done with two
anchors and a loop then lateral migration is reduced by 62.5 %
and longitudinal migration is reduced by 94.1 %. It was shown that
the results are significantly different at the α=0.001 significance
level. Based on a statistical evaluation it is possible to state that the
differences between experimental results obtained for three
different protocols of lead fixation are statistically significant and
we can recommend the new fixation method for common practice.
The geometric shape of the distal anastomosis in an infrainguinal bypass has an influence on its durability. In this article, we compared three different angles of the anastomosis with regard to the hemodynamics. Three experimental models of the distal infrainguinal anastomosis with angles of 25°, 45°, and 60° respectively were constructed according to the similarity theory to assess flow in the anastomoses using particle image velocimetry and computational fluid dynamics. In the toe, heel, and floor of the anastomosis that correspond to the locations worst affected by intimal hyperplasia, adverse blood flow and wall shear stress were observed in the 45° and 60° models. In the 25° model, laminar blood flow was apparent more peripherally from the anastomosis. In conclusions, decreasing the
distal anastomosis angle in a femoropopliteal bypass results in more favorable hemodynamics including the flow pattern and wall shear stress
in locations susceptible to intimal hyperplasia.