197 Decrease in Rigidity Factor Index Results in Greater Cylinder Deflection

To determine whether rear tip extenders affect erectile quality in inflatable penile prosthesis. A penile model simulating two corpora cavernosa in which inflatable cylinders of varying lengths could be inserted was created using a 3D printer. The cylinders were attached to a pressure monitor and inflated to 15 psi (see Figure 1). A 200g weight was then uniformly placed on the tip of the cylinders at the same distance from the pelvic model and the deflection measured using a ruler (see Figures 2 & 3). Cylinders of varying lengths with Rear Tip Extenders (RTE) needed to total 22cm were used. In order to quantify the relative amount of inflatable cylinder to rear tip, the previously described Rigidity Factor (RF) index was used, defined as the live inflatable cylinder length divided by the total prosthesis length (22cm for all measurements in this case). All Titan ® cylinders have a non-inflatable rear of 5cm. Therefore the rigidity factor for each cylinder size is (total cylinder length - 5cm)/22cm.