ZEPHYR: A Study Evaluating Surgical Outcome After Implantation of the Zephyr ZSI 475 FTM Inflatable Penile Implant in the Neophallus After Female-to-male Sex Reassignment Surgery

Obtaining erectile function after phalloplasty in female-to-male transsexuals remains a challenging issue and requires the implantation of a device. For biological males, several erectile implants exist and widespread research has demonstrated the successful outcome of these devices. However, substantial differences exist between a native penis and a neophallus and explain the poorer outcome of these devices in female-to-male transsexuals.

In 2018, Falcone et al. published the largest retrospective series on this subject so far and reported that after a mean follow-up of 20 months, only 58% of their patients still had their original implant in place. The main obstacle in these female-to-male transsexuals is represented by the lack of corpora cavernosa in the neophallus which leads to difficult anchorage of the prosthesis, little stability of the prosthesis and a higher risk of cylinder erosion.

Until recently, all penile implants were manufactured for erectile dysfunction in biological males and thus presumed the presence of two corpora cavernosa. In 2016 however, the Swiss company, Zephyr Surgical Implants (ZSI), created a 3-piece inflatable erectile device specifically for female-to-male transsexuals: the Zephyr ZSI 475 FTM. This prosthesis has a realistic gland shape, only one cylinder, and a specific anchorage device made of titanium and silicone to anchor the system to the pubic bone of the patient. These specific features could potentially address the aforementioned issues with implanting erectile devices in the neophallus and hopefully lead to better surgical outcomes in these particular patients.

So far, no literature regarding surgical or functional outcome of the Zephyr ZSI 475 FTM exists. The aim of this study is to prospectively collect data of all female-to-male transsexuals that are treated with the implantation of this device at Ghent University Hospital.

Inclusion criteria

• Voluntarily signed written informed consent according to the rules of Good Clinical Practice (Declaration of Helsinki) and national regulations.
• Age ≥ 18 years.
• Female-to-male transsexual patient.
• Implantation of Zephyr ZSI 475 FTM erectile device.

Exclusion criteria

• Absence of signed written informed consent.
• Age < 18 years.
• Biological males.
• Patients opting for penile implants other than the Zephyr ZSI 475 FTM.