Methods and Materials
Shunt Creation
Medical grade barium-impregnated silicone catheter tubing with an outer
diameter of 2.8 mm and inner diameter of 1.5 mm (Medtronic, Minneapolis,
MN) were cut into 2-centimeter segments. To mimic the conical shape of
hole in industrial made catheters, eight holes were punched using a 0.5
mm diameter leather punch 1.25 mm apart. Dimension used followed those
seen in Medtronic catheters. The catheter was rotated 90 degrees, two
times, repeating the punching process to create a total of three rows of
eight holes. Excess catheter material left over after punching the holes
was removed using tweezers. The final dimensions of the catheter holes
were 0.5 mm outer diameter with 1 mm edge to edge separation, confirmed
with confocal microscopy (Figure 5). The outer diameter was measured to
ensure this method resulted in accurate dimensions after manually
punching the samples. Sterilization of these samples began with a
one-hour incubation in 10% bleach. Following this, a series of washes
included a 30-minute incubation in ethanol followed by two 10-minute
washes with double distilled cell culture water (Growcells, Irvine, CA).
Phenol red (v/v 1%) (Sigma, St. Louis, MO) was added into the last wash
to observe if a color change occurred, ensuring all ethanol was removed.