(228) Penile Prosthesis Sizing Tool (PPST): Toward Standardized Intraoperative Decision-Making

Introduction Proper sizing of penile prosthesis cylinders and rear tip extenders (RTEs) is critical for ensuring both functional outcomes and cosmetic satisfaction in men undergoing inflatable penile prosthesis (IPP) implantation. Currently, intraoperative decisions rely primarily on individual surgeon judgment, with wide variability between operators and institutions. Although device-specific features such as Optimized Tubing Length (OTL) and cut-to-length (CTL) models exist, there has been no standardized algorithm that systematically integrates corporal length, proximal corporal length, scrotal size, and brand-specific tubing parameters into a reproducible framework. Standardization could reduce intraoperative uncertainty, improve reproducibility, and provide valuable guidance in training environments. Objective To develop and validate the Penile Prosthesis Sizing Tool (PPST), a brand-specific calculator designed to generate systematic recommendations for cylinder and RTE selection during IPP implantation, while incorporating device-specific safeguards. Methods Specifications from three major penile prosthesis systems were reviewed, including cylinder sizes, fixed tubing lengths, and OTL and CTL variants. The PPST algorithm was constructed to integrate: (i) total corporal length (T) and proximal corporal length (P), (ii) scrotal size offsets (Small = +2 cm, Medium = +3 cm, Large = +4 cm), (iii) effective tubing length (tubing + RTE), and (iv) a maximum RTE length of 6 cm. A combination was considered valid if cylinder + RTE = T and effective tubing ≥ P. The algorithm prioritized the longest feasible cylinder but considered shorter cylinders with longer RTEs when needed to optimize pump positioning. CTL and OTL models were programmed as fallback solutions when fixed combinations were not feasible. An Excel-based calculator was implemented to produce a Final Recommendation and, when applicable, an Alternative Option. Under the pre-specified grids (T 15–27 cm; P 8–14 cm; scrotum offsets +2/+3/+4 cm; RTE 1–6 cm; CTL excluded), enumeration yielded 928 feasible fixed-SKU combinations in total (Coloplast Titan 217; AMS 700 412; Rigicon 299). Results Simulation testing across a wide range of corporal and scrotal measurements demonstrated that the PPST consistently eliminated infeasible choices and generated clinically intuitive outputs. In most scenarios, the algorithm recommended the longest available cylinder consistent with anatomical and device constraints. When proximal corporal length exceeded tubing capacity, the PPST suggested appropriate adjustments, such as selecting a shorter cylinder with additional RTEs, or advising consideration of proximal shortening. In select cases with large scrotal offsets or T ≥ 24 cm, the calculator triggered device-specific safeguards, including recommendations for CTL or OTL models. CTL or OTL models were only advised as fallback solutions when standard combinations were not viable. Conclusions The Penile Prosthesis Sizing Tool (PPST) is the first scrotum-aware, brand-specific calculator for penile prosthesis sizing. It provides a systematic, reproducible approach to intraoperative decision-making, minimizes uncertainty, and supports consistency in both experienced and trainee surgeons. By explicitly integrating anatomical measurements with device parameters, PPST has the potential to standardize implant sizing and optimize surgical outcomes. Clinical validation is the next step, and future directions include refinement of the algorithm and development of a mobile application for point-of-care use. Disclosure No