Primary gender-affirming inflatable penile prosthesis insertion has a prolonged learning curve

Gender-affirming inflatable penile prosthesis (IPP) insertion in transgender and gender diverse individuals (TGD) is technically complex and associated with high revision rates. This study is the first to evaluate the effect of cumulative institutional surgical experience on 5-year outcomes after primary IPP insertion and construct institutional outcome-based learning curves.

A retrospective analysis was performed using a prospectively maintained institutional database of patients undergoing first-time IPP implantation. The analysis was restricted to patients enrolled until September 2019 to ensure at least 5 years of follow-up. The primary outcomes were 5-year surgery for any cause and 5-year revision surgery for dissatisfaction. Multivariable logistic regression models and risk-adjusted cumulative sum (RA-CUSUM) analysis were used to identify predictors and learning trajectory.

The original cohort included 694 patients. After restricting the analysis to patients with at least 5 years of follow-up, 473 patients were included: 208 (43.9%) received a Boston Scientific device and 265 (56.1%) received a Coloplast device. Overall, 240 patients (50.7%) had no further surgery within 5 years. Five-year device survival was higher after RFFF than with other phalloplasty types, with single-cylinder than with two-cylinder implantation, and with Coloplast than with Boston Scientific devices. On multivariable analysis, cumulative institutional surgical experience, Coloplast device use, and single-cylinder implantation were associated with a lower risk of surgery. The probability of surgery for any cause decreased from 65.6% at case 1 to 32.9% at case 473; RA-CUSUM identified peak proficiency at case 311. Revision for dissatisfaction occurred in 104 patients (21.9%). Its rate was higher with Boston Scientific than Coloplast devices, while flap type and cylinder number were not significant. Cumulative institutional surgical experience was the only independent predictor (OR = 0.997, P = .020). The probability decreased from 33.2% to 12.8%, with peak proficiency at case 261.

Primary IPP insertion shows a prolonged learning curve, with progressive improvement in 5-year overall device survival and revision for dissatisfaction as cumulative institutional surgical experience increases.