Long-term outcomes for mechanical failure and revision following primary gender-affirming penile prosthesis insertion.

[OBJECTIVES] To evaluate revision surgery for mechanical failure and overall revision rates of inflatable penile prostheses (IPPs) in assigned female-at-birth (AFAB) individuals.

[PATIENTS AND METHODS] This was a retrospective cohort study of all AFAB patients who underwent primary IPP implantation between September 2001 and July 2024. Inclusion criteria were first-time insertion of a three-piece IPP in AFAB individuals after phalloplasty for gender incongruence; patients with malleable or two-piece IPPs or previous revisions were excluded. Revision for mechanical failure was assessed using competing risk analysis. Overall revision rates were investigated using survival analysis.

[RESULTS] A total of 694 IPPs were implanted. Most patients had undergone radial forearm free-flap phalloplasty, with staged urethral lengthening performed subsequent to phalloplasty. The time to revision was 3 and 1.4 years for Boston Scientific and Coloplast implants, respectively. Mechanical failure occurred in 29.9% of Boston Scientific and 12% of Coloplast implants. The 15-year cumulative incidence of mechanical failure was 30.6%, while the overall revision incidence reached 65.1%. Competing risk analysis identified the device model as an independent predictor of mechanical failure, with Coloplast implants demonstrating lower risk than Boston Scientific devices (subdistribution hazard ratio [SHR] 0.43, P < 0.001). Cox regression determined the Boston Scientific devices and surgical experience as predictors of revision for any cause (HR 0.75, P < 0.001; HR 0.99, P = 0.027, respectively). The study is limited by the retrospective design and the identification of failure only when patients requested surgery.

[CONCLUSIONS] Mechanical failure and revision rates were substantial. Brand and surgical experience were identified as predictors of outcomes and should be considered during surgical planning. These findings highlight the need for further innovation in device design and studies with improved methodology in this population.