030 Assessment of The Effect of Girth Restriction on Inflatable Penile Implant Length Expansion

IPP placement is gold standard for management of medication-refractory ED. Goals of intraoperative device selection include maximizing length, girth and rigidity. “Right-sizing” or “up-sizing” exist as strategies to maximize these parameters. AMS 700 LGX (Boston Scientific, USA) is the only device known to expand circumferentially and longitudinally. It is unknown whether restricting expansion in one axis (i.e. girth or length) may restrict full expansion in the opposite axis or diminish rigidity. To determine maximal length expansion for both AMS 700 LGX and CX IPPs under conditions of unrestricted and restricted girth expansion across the full spectrum of internal device pressurization. To develop a novel methodology for the reliable measurement of IPP expansion characteristics across a range of penile sizes. Custom IPP cylinder molds were designed using Autodesk Fusion 360 to emulate corpora cavernosa at fixed girth. Molds were 3D printed in polylactic acid (PLA) with variable girth diameters. Unilateral deflated IPPs were inserted into molds using proplyene glycol lubricant to prevent restriction of length expansion via material drag and damage to IPPs (Figure 1). Using an 18mm diameter mold, 21, 18, and 15cm native LGX IPPs and 18 and 15cm native CX IPPs were evaluated. Devices were pressurized from 2 to 18psi in 1psi intervals while measurements were obtained on both the constrained and unconstrained cylinders. Length of the girth constrained cylinder was measured by distal tip displacement. Girth expansion of the unrestrained cylinder was measured using laser micrometry.