Hydraulic and malleable female-to-male penile implants after phalloplasty in transgender individuals: a retrospective cohort analysis.

Objectives: To provide a comprehensive summary of the surgical outcomes of Zephyr Surgical Implants (ZSI; Geneva, Switzerland) hydraulic and malleable female-to-male (FTM) penile implants (PIs) in transgender patients.

Patients and methods: All transgender patients who underwent hydraulic (ZSI FTM 475) and malleable (ZSI FTM 100) erectile device implantation between January 2017 and March 2024 were retrospectively identified. Demographics, perioperative characteristics, postoperative complications, and re-operations were recorded. Postoperative outcomes of malleable and hydraulic PI implantation were compared and risk factors for early and late complications were identified.

Results: A total of 50 transgender patients underwent 85 PI implantation procedures, including 50 primary and 35 secondary implantations. The postoperative infection rate was 15% for hydraulic PIs and 11% for malleable PIs (P = 0.83). In total, 66 hydraulic PIs and 19 malleable PIs were placed. The late complication rate encompassing dysfunction, malposition and erosion was 56% for the hydraulic PIs and 58% for the malleable PIs (P = 0.68), with a median (interquartile range) postoperative follow-up of 26±12 and 32±22 months (P = 0.22), respectively. The explantation-free survival rate at 3 years after implantation of the device was 39% for the hydraulic PIs compared to 31% for the malleable PIs (P = 0.64). Secondary PI implantations were associated with a significantly higher risk of complications compared to primary procedures (odds ratio 3.5, P = 0.03) regardless of the type of PI. Additionally, urethral lengthening increased the likelihood of late complications with a hazard ratio of 2.6 (95% confidence interval CI 1.3-5.0, P = 0.01).

Conclusion: The ZSI FTM PIs display poor 3-year complication-free survival despite being tailored for implantation after phalloplasty. There were no significant differences in short- and long-term complication rates between malleable and hydraulic PIs. Notably, secondary PI implantation and urethral lengthening were linked to a significantly increased risk of late complications.