(437) Fused Double-Cylinder Penile Prosthesis Placement After Phalloplasty Without Urethral Lengthening: A Novel Technique Using A 2-Piece IPP

Introduction Transgender men (TM) undergoing phalloplasty often desire erectile function, typically achieved via inflatable penile prosthesis (IPP) insertion. All U.S. FDA-approved IPPs are designed for cisgender male anatomy, and there is no standardized technique for IPP placement in TM post-phalloplasty. For patients not prioritizing voiding from the penile tip, phalloplasty without urethral lengthening (P-UL) offers favorable cosmetic and functional results with a lower complication rate. A short distal urethra (1.5 cm) provides a natural appearance. Additionally, testicular prosthesis implantation during Stage 1 phalloplasty creates a capsule-lined pocket ideal for housing the IPP pump later. Without a neourethra in the shaft, space allows for dual-cylinder insertion, improving prosthetic performance. Objective Our specific aims are: 1. Describe a novel technique for two-piece IPP insertion using a fused double-cylinder method in TM post P-UL. 2. Report clinical outcomes over a six-year period. Methods Retrospective chart review of TM undergoing IPP insertion post-phalloplasty at our center over 6-years. Results 28 patients underwent 34 IPP implants between April/2017-Oct/2023 (Mean Age = 40.8 years±13.8(SD). 17/28 (60.7%) patients underwent phalloplasty with urethral lengthening, and 11/28 (39.3%) had P-UL. All had ipsilateral testicle prosthesis implant beforehand. IPP implants were with the AMS 700™ 3-piece (first 5/34=14.7%; all 1 cylinder), or AMS Ambicor™ 2-piece IPP (all subsequent 29/34=85.3%; [22/29 (76%)=1 cylinder & 7/29(24%)=2 cylinders). 2/34 IPP’s required explant (5.9%): for infection, 1/38 (2.9%); and for traumatic-injury wound-dehiscence 3-weeks post-op: 1/38(2.9%). Our technique for 2-piece IPP insertion in TM after P-UL with both cylinders fitted completely into a Dacron vascular graft, which is secured to Obturator ramus with 2-0 Ethibond sutures. The IPP pump fits into the explanted testicle site. Conclusions This method offers multiple advantages: enhanced neoscrotal pocket formation, improved cylinder stability, fuller/symmetric erection (+17% girth), and minimal scarring. It represents a promising approach for optimal functional and aesthetic outcomes in TM post-phalloplasty. Further multi-center studies are recommended. Disclosure No